0 Nature,'^ 1894 J Nature A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE f Supplement to Nature Mny 31, i8g^ :mm. Sii/'plement to Nature,' May 31, 1804 Nature / A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE VOLUME XLIX NOVEMBER 1893 to APRIL 1894 " To the solid ground Of Nature trusts the mind ivhich builds for aye.'' — Wordsworth ^r wi M A C M I L L A N AND CO. Q Richard Clay and Sons, Limited, london and bungay. 'Supplement to Nature, May 31, 1894 Sufiplenteni to Naiure,~\ May 31, 1894 J INDEX Abbe (Prof. C), the Measurement of the Highest Cirrus Clouds, 508 Abbott (W. J. L. ), the Ossiferous Fissures in Shode Valley, near Ighiham, 355 ; the Vertebrate Fauna collected there- from by E. T. Newton, F.R.S., 355 Abnormal Eggs, W. B. Tegetmeier, 366; E. J. Lowe, F. R. S., 366 Abraham (H.), Measurement of Coefficients of Induction, 72 Abrastol in Wines, Discovery of, M. Sangle-Ferriere, 167 Abroad, Voices from. Prof. Henry E. Armstrong, F.R. S., 225 Acari, our Knowledge of the, A. D. Michael, 350 Achromatic Object-Glass, a New, 464 Acoustics ; Application of Sound-Vibrations to Analysis of Mixtures of Gases, E. Hardy, 47 ; Hydrodynamical Acous- tical Investigations, W.Konig, 239 ; Researches in Acoustics. No. 9, A. M. Mayer, 305; the Origin of " Beats," K. L. Schaefer, 370; Relation of Fog Signals to other Sounds, C. A.White, 508; Determination of Pitches of very High Notes, F. Melde, 560 ; an Apparatus to show simultaneously to several hearers the blending of the Sensations of Interrupted Tones, Alfred M. Mayer, 617 Adair (Peter), the disappearance of the Field Vole, 14 Adam (T. H.), Bequest for purposes of Technical Education by, 320 Adams Memorial, the Text of the, 67 Adder's Blood, Poisonous Principles of, MM. Phisalix and Bertrand, 284 Addyman (Frank T. ) Practical Agricultural Chemistry for Elementary Students, 244 Adelberg Grotto, Investigation of, E. A. Martel, 256 Adeney (W. E.), Reduction of Manganese Peroxide in Sewage, 499 Adler, (Dr. G.), Death of, 320 ^^rodynamics ; the Internal Work of the Wind, Prof. S. P. Langley, 273 Afforestation in the British Isles, Prof. W. R. Fisher, 601 Africa : the Natural History of East Equatorial Africa, Dr. J. W. Gregory, 12 ; Dr. J. W. Gregory's Voyage to Mount Kenya, 276, 443 ; Large Supply of Ivory in South Africa, 13 ; Extra-Tropical South African Orchids, Henry Bolus, R. A. Rolfe, 50 ; Georges Muller's Last Explorations in Madagascar, 1 12; Mr. Astor Chanler's East African Ex- pedition, 112; Lieutenant von Hohnel wounded, 112; Mr. Chanler's Expedition, 301 ; Crossing of the Eastern Horn, 163 ; Kling and Biittner's Expedition to Togo, 207 ; Visit of Mr. Crawshay to Nyika Plateau, 210 ; Sir Claude Mac- donald's Journey up the Cross River, 346 ; the Last Great Lakes of Africa, Ludwig von Hohnel, 457 ; Exploration of Lukuga River by M. Delcommune, 559 ; Government Scien- tific Work in the German Protectorates, 581 ; Delimitation of Congo State and Portuguese Frontier, 582 ; the Lubidi River, 582 ; the German Expedition to Delimit Hinterland of Cameroons, 606 ; Intended Expeditions of Dr. Donaldson Smith to Lake Rudolph, and of R. T. Coryndon to Great Congo Forest, 606 Agamennone (Dr. G.), Velocity of Propagation of Earthquakes at Zante in 1893, 439 Agni, the, a Tribe of Fair Negroes, Maurice Delaforce, 263 Agriculture : the Disappearance of the Field Vole, Peter Adair, 14; Wheat-growing in Indiana, 15; Death and Obituary Notice of Prof. E, Lecouteux, 33 ; the Spermophile (Ground Squirrel) Pest in the Mississippi Valley, Vernon Bailey, 36 ; the Nitrification of Prairie Lands, J. Dumont and J. Croche- telle, 96 ; Death of Dr. Webb, 129 ; Practical Agricultural Chemistry for Elementary Students, J. Bernard Coleman and Frank T. Addyman, 244 ; an Elementary Text-Book on Agricultural Botany, M. C. Potter, 290 ; Death of Sir Harry Verney, 368 ; Agricultural Experiment Stations, 373 ; Edu- cational Agricultural Experiments, 568 ; the Cambridge Diploma in Agriculture, 444 ; Analytical Determination of probably "available" Mineral Plant Food in Soils, B. Dyer, 451 ; Agricultural Resources of Canada, Prof. Long, 561 ; Mr. F. L. Scribner appointed United States Agrosto- logist, 605 Ainu, Fresh Light on the, A. H. Savage Landor, 248 Air, Proposed Standard of Normal, A. Leduc, 272 Air-Pump, New Form of Rotatory, Herr F. Schulze-Berge, 65 Aitken (John, F.R.S.): the Origin of Lake Basins, 315 ; the Cloudy Condensation of Steam, 340 ; Number of Dust Particles in Atmosphere of certain Places, 426 ; Dust and Meteorological Phenomena, 544 Alaska, Glacial Erosion in, Prof. G. Frederick Wright, 316 Albatross, the Pterapod Collections of the, 36 Aleutian Islands, the Ptarmigan of, W. B. Everniann, 584 Alford (C. J.), Auriferous Rocks from Mashonaland, 403 Algse, Green, the Alleged Action as Water-Purifiers of, Prof. Schenck, 182 Algje ; the Laminariacese, W. A. Setchell, Z07 Algol, the System of, 349 Allbutt (Prof. T. Clifford), Music, Rhythm and Muscle, 34 Allen (Prof. F. J.), Earthquake at Shepton Mallet, 229 ; t he Mendip Earthquake of December 30-31, 1893, 245 Alloys, the Chemical Composition of, Prof. Behren?, 144 Alsace-Lorraine, Geological Survey Department of, 322 Altazimuths of Pistor and Martin and of Repsold, Accuracy of Divisions of, Prof. J. A. C. Oudemans, 192 Altona, an Incident in the Cholera Epidemic at. Prof. Percy Frankland, F.R.S., 392 Aluminium, Herr van Aubel's Method of Silvering, 356 Amagat (E. H.), Interior Pressure in Gases, 404. ; the Internal Pressure of Fluids and the Form of the Function (p{pvi) — 0, 500 _ Amber in Russia, F. T. Koppen, 181 America : the Shrubs of North-Eastern America, Charles S Newhall, 28 ; American Meteorological Journal, 71, 263, 329, 423; American Journal of Science, 92, 214, 305, 402, 520, 617 ; American Journal of Mathematics, 93, 449 ; Copy of Map by Columbus," 233 ; the True Discovery of America, Captain Gambler, 235 ; American Psychological Associa- tion, 252 ; Recent Publications of the American Geological Survey, Prof. T. G. Bonney, F.R.S., 434; the Pharma- copoeia of the United States of America, 525 Ammen (General J.), Death of, 368 Amoebae, Artificial, and Protoplasm, Dr. G. Quincke, 5 ; Dr. John Berry Haycraft, 79 Amphioxus, the Ventral Nerves of, M. van Wyhe, 24 Amsterdam Academy of Sciences, 24, 141, 192, 38c, 476 Amu-Daria, the old Beds of the, M. Korshin, 515 Anadyr, a new Province in Siberia, 18 Analysers, Harmonic, Prof. O. Henrici, F.R.S., 521 Anatomical Modifications of Plants of the same Species in the Mediterranean Region and in the Region of the Neighbour- hood of Paris, W. Russell, 620 Anatomy, Human and Comparative, at Oxford, Prof. J. Burdon Sanderson, F.R.S., 6; Prof. E. Ray Lankester, F.R.S., 29 Anatomy, Comparative : the Sutura Condylo-Squamosa of Occipital Bone of Man and Mammalia, Prof. Zaaijer, 192 ; Myology of the Hystricomorphine and Sciuromorphine Rodents, F. G. Parsons, 523 ; Death and Obituary Notice of H. C. G. Pouchet, 538 VI Index VSuipleiiient to Nature, L ' May 31, 1894 Ancient Egyptian Pigments, Dr. William J. Russell, F.R. S., 374 Ancients, on the Bugonia Superstition of the. Baron C. R. Osten-Sacken, 198 Anderson (E. W.), the Grafton High Speed Steam Engine, 610 Anderson (Rev. Thomas D. ), New Variable Star in Andro- meda, lOI Anderson's Variable in Andromeda, Prof. E. Pickering, 419 Andes, Eruption of El Calbuco Volcano, A. E. Nogues, 179 Andre (Ch.), Electric Variation of High Regions of Atmo- sphere in Fine Weather, 131 Andre (G.), Formation of Carbon Dioxide and Absorption of Oxygen by Detached Leaves of Plants, 284 Andrev's (E. A.), Asyrnmetron lucayanum, a new Acraniate fount, Barille(M.), Electric Alarm Thermometer for Laboratory Ovens, 355 Barium, the Atomic Weight of, Prof. Richards, 562 Barnard (Prof. E. E.), Brooks's New Comet (18931:), 67 ; Period of Jupiter's Fifth Satellite, 85 ; Photographic Nebu- losities in the Milky Way, 511 Barometer, Bartrum's Open-scale, J. J. Hicks, 48S Barometer, Compensating Open-scale, Mr. Griffiths, 379 Bartrum's Open-scale Barometer, J. J. Hicks, 488 Barus (Dr. Carl), the Cloudy Condensation of Steam, 363 Basaltic Andesite of Glasdrumman Port, co. Down, Derived Crystals in, 499 Base-forming Element, Iodine as a. Prof. Victor Meyer and Dr. Hartmann, A, E. Tutton, 442 Basset (A. B., F.R.S.), A Treatise on Dynamics, W. H, Besant, 146 ; Stability of Deformed Elastic Wire, 215 ; the Foundations of Dynamics, 529 Batacchi Independenti, Fra i, Elio Modigliani, 314 Bath (W. H.), Vertical Distribution of British Lepidoptera, 346 Bather (F. A.), the Zoological Record, 53, 198 Bavaria, Geological Survey Department of, 322 Beadle (C), the Decomposition of Liquids by Contact with Cellulose, 457 Beare (Prof. T. H.), the Research Committee on Marine Engine Trials, 350 " Beats," the Origin of, K. L. Schaefer, 370 Beats in Luminous Vibrations, on the Phenomenon of. Dr. J. Verschaffelt, 617 Beaulard (F. ), Optical Properties of Quartz Plate compressed perpendicularly to Axis, 37 Becher (H. M.), the Death of, 112 Beddard (Frank E., F.R. S.), an Ornithological Retrospect, 31 ; the Fauna of the Victoria Regia Tank in the Botanical Gardens, 247 Bedell, Miller and Wagner (Messrs.), New Form of Contact Maker, 37 Beecher (C. E.), Larval Form of Triarthrus, 92 ; the Thoracic Legs of Triarthrus, 214 ; the Appendages of the Pygidium of Triarthrus, 617 Bees and Dead Carcases, W. F. Kirby, 555 Beetles of New Zealand, W. F. Kirby, 459 Behn (U.), Peculiarities of Electrical Deposit of Silver on Platinum, 321 Behrens (Prof.), (i) the Structure of Native Gold, (2) Chemical Composition of Alloys, 144 Belgique, Bulletin de I'Academie Royale de, 283, 376 Belgium, Neolithic Discoveries in, 227 Beneden (Prof. P. van). Death of, 251 ; Obituary Notice of, 293 Beni Hasan, G. W. Eraser, 169 ; P. E. Newberry, 169, 432 . Bennett (Dr. Geo.), Death of, 63 Bent (J. T.), The Sacred City of the Ethiopians, 314 Bent's (Mr. Theodore), Expedition, Return of, 487 Bentley (Prof. R.), Death of, 228 Benzene Nucleus, Further Light upon the Nature of the, A. E. Tutton, 614 Berlin, the Temperature in and outside, Prof. G. Hellmann, 460 Berlin Geographical Society, the Greenland Expedition of the, 399 Berlin Meteorological Society, 48, 216, 427, 596 Berlin Physical Society, 48, 167, 216, 356, 427, 595 Berlin Physiological Society, 48, 167, 240, 380, 427, 596 Bernard (H. M.), the Stigmata of the Arachnida, as a Clue to their Ancestry, 68 ; the Systematic Position of the Trilobites, 521 Berson (M.), Mutual Action of Bodies Vibrating in Fluid Media, 143 Berthelot (M.), Spontaneous Heating and Ignition of Hay, 240 ; Formation of Carbon Dioxide and Absorption of Oxygen by Detached Leaves of Plants, 284 Bertrand (C. E ), General Characters of Bogheads produced by Algae, 47 Bertrand (G. ), Poisonous Principles of Adder's Blood, 284; Viper Poison, 380 Besant (W. H.) A Treatise on Dynamics, A. B. Basset, F.R.S., 146 Bezold (Prof, von). Wave Clouds, 48 ; Various Modes of Dis- criminating between Clouds, 427 ; Cloud-Formation, 508 Bicalcic Phosphate, Action of Water on, A. Joly and E. Sorel, 572 Bidwell (Shelford, F. R. S. ), the Cloudy Condensation of Steam, 212, 388, 413 Biela Meteors, 67 Bigelow (F. H. ), Recurrence of Hurricanes in Solar Magnetic 26 '68 day period, 330 Bigourdan (M. ), Magnitude and Position of T Aurigse, 85 Bile Ducts, on Absorption by the, Celestin Tobias, 617 Billroth (Prof.), Death of, 345 Biology : Reappearance of the Freshwater Medusa {Liinnoco- diiim Sowerbii), Prof. E. Ray Lankester, F. R. S., 127 ; Text-Book of Biology, H. G. Wells, 148 ; Projected Marine Biological Station at Millport, N.I3., 180; Death of Dr. Chabry, 158 ; Biologie der Pflanzen, 306 ; Forschungsberichte aus der Biologischen Station zu Plon, Dr. O. Zacharias, 385 ; Biology as it is applied against Dogma and Freewill, and for Weismannism, H. Croft-Hiller, 386 ; the Macleay Memorial Volume, 597 ; the Naples Zoological Station, 604 ; Marine Biology, the Pteropod Col- lections of the Albatross, 36 ; Week's W^rk of Plymouth Station, 37, 67, 84, 162, 323, 372, 418 ; Some Laboratories of Marine Biology, 70 ; the Protective Colouration of Vibrius varians, Prof. W. A. Herdman, F.R.S., 417; the Floor of the Ocean at Great Depths, Dr. John Murray, 426 ; Ento- mostraca and Surface-film of Water, D. J. Scourfield, 474 ; the Rovigno Station, 560 ; the Melbourne Exhibition Aqua- rium, 583 Bionomie des Meeres, Johannes Walther, 244 Birch, the Embryonal Development of the, S. Nawaschin, 23 Bird Life in Arctic Norway, Robert Collett, 599 Bird Protection Bill, the New, 54 Birds : Are Birds on the Wing Killed by Lightning ? Skelfo, 577 ; G. W. Murdochs, 601 ; the Early Return of Birds, Robert M. Prideaux, 578 Bjorling Arctic Expedition, the Fate of the, Capt. McKay, 85 ; Proposed Search for the, 606 Black Sea during Pliocence Age, N. Andrusoff, 23 Blackburn's Pendulum for Slow Production of Lissajous's Figures, Improved Form of. Prof. A. Righi, 582 Blakesley (T. H.), a New Electrical Theorem, 450 Bliss (Dr. C. B.), Investigations on Reaction-time and Attention, 439 Snpploncnt to Natitre,~\ May 31, 1894 J Index IX Bloch (Salvador), the use of Collodion Films coloured with Fucbsine in Measurements of Light-absorption, 108 Blondlot's (M.) Experiments on Velocity of Propagation of Electric Disturbance along Wire, 37, '^l ; Experiments on Propagation of Hertzian Waves, M. Mascart, 394 ISlood, the Chemistry of the, and other Scientific Papers, L. C. Wooldridge, 2!; 9 Blood Corpuscles, Determination of Volume of. Dr. Grijns, 476 Boehm (Dr. J.), Death of, 179, 270 Boiler Management and Construction, Marine, C. E. Stromeyer, 410 Boltzmann (Dr. Ludwig), Lectures on Maxwell's Theory of Electricity and Light, 381 Bolus (Henry), Icones Orchidearum Austro-Africanarum Extra- Tropicarum, R. A. Rolfe, 50 Bonaparte's (Prince Louis Lucien) Library, Catalogue of, Victor Collins, 5S4 Bone (W. A.), the Formation of Indoxazen Derivatives, I18 Bonetti (M.), New Form of Electrical Machine, 460 Bonn University, Hygienic Laboratory established at, 345 Bonney (G. E. ), Electrical Experiments, 386 Bonney ((Prof. T. G., F.R.S.), the Erosion of Rock-Basins, 52 ; the Scandinavian Ice-sheet, 38S ; Conversion of Compact Greenstones into Schists, 403 ; Recent Publications of the American Geological Survey, 434 ; the North-East Wind. — Devonian Schists, 577 Bordage (Edmond), Obituary Notice of Paul Henry Fischer, 296 Bordas (M. ), Anatomy of the Trachean System of the Larvae of Hymenoptera, 524 Bornstein (Prof.), Electric Measurements made during Balloon Ascents, 595 Borodin (Alexander), Steam-pumps on Russian Railways, 19 Boron Carbide, Preparation and Properties of, M. Henri Moissan, 500 Bort (L. Teisserenc de), Report on the Present State of our Knowledge respecting the General Circulation of the Atmo- sphere, 217 Botany : The Embryonal Development of the Birch, L. Nawaschin, 23: the Shrubs of North-Eastern America, Charles S. Newhall, 28 ; the Caoutchouc of the Orinoco, Dr. Ernst, 35 ; Botanical Gazette, 46, 306, 424 ; Journal of Botany, 46, 330, 424 ; Localisation of Active Principles in Trnpoeolum, Leon Guignard, 47 ; Icones Orchidearum Austro-Africanarum Extra-Tropicarum, Henry Bolus, R. A. Rolfe, 50; Phanero- gamic Botany of Matto Grosso Expedition, Spencer Moore, 95 ; Morphological and Micro-chemical Investigations on Physodes, E. Crato, 132 ; Memoirs of St. Petersburg Society of Naturalists, 189 ; Origin of Plants and Structures by Self-adaptation to Environment, Rev. G. Henslow, 166 ; Gynodicecism (III), J. C. Willis, 167 ; Death of Dr. G. Boehm, 179, 270 ; British Fungus Flora, a Classified Text- book of Mycology, George Massee, Dr. M. C. Cooke, 195 ; theLaminariacese, W. A. Setchell, 207 ; Handbook of British Hepaticse, M.C. Cooke, 220 ; Death of R. Bentley,228; Death of R. Spruce, 228 ; Index Kewensis plantarum phaneroga- marum nomina et synonyma omnium generum et specierum a Linnaeo usque ad annum mdccclxxxv complectens nomine recepto auctore patria unicuique plantae subjectis, 241 ; the Fauna of the Victoria Regia Tank in the Botanical Gardens, Frank E. Beddard, F.R.S., 247 ; Influence of Artificial Rain on Plants, Prof. J. Wiesner, 253 ; the Edible Lichen of Japan, Dr. M. Miyoshi, 253 ; Death of Baron K. von Kiister, 270; the Internal Temperature of Trees, W. Prinz, 271 ; a Collection presented by Mr. H. Fisher to Nottingham Museum, 271 ; Formation of Carbon Dioxide and Absorption of Oxygen by Detached Leaves of Plants, MM. Berthelot and Andre, 284 ; an Elementary Text-book on Agricultural Botany, M. C. Potter, 290 ; Death of Dr. J. K. Hasskarl, 296 ; Dropsical Disease in Tomatoes, G. F. Atkinson, 298 ; the Original Home of Maize, Dr. Harshberger, 298 ; Cohn's Beitrage zur Biologie der Pflanzen, 306 ; Changes in position of Flower- stalk of Cob.Ta scaiideiis before and after Flowering, Dr. M. Scholtz, 306 ; Embryology of Gnetiim, G. Karsten, 306 ; Origin of Structural Peculiarities of Climbing Stems, Rev. G. Hemslow, 307 ; Sugar Maples, W. Trelease, 323 ; Orchids, W. A. Styles, 352 ; the Solandi Sun-printing Process as applied to Botanical Technique, Prof. Byron Halsted, 370; Botanical Garden established in Mountains near Grenoble, 393 ; Nuovo Giornale Botanico Italiano, 424; Germination of Pollen Grain and Nutrition of Pollen Tube, Prof. J. R. Green, 424 ; the Fertilisation of some Species of Medicago, J. H. Barkill, 426 ; Apogamy in Pteris serrtilata (L. fil.) var. crisiala, A. H. Trow, 434; Measurements of Growth of Trees, J. Heuchler, 439 ; Der Botanische Garten '"s Land's Plantentuin " 2 v. Buitenzorg auf Java, 453 ; Eine Botanische Tropenreise, Indomalayische Vegetationsbilder und Reiseskizzen, Dr. Haberlandt, 453 ; Growth of Mould- Fungi on Solid Compounds of Arsenic, S. Bipodo, 461 ; the Blind Root-suckers of the Sunderbans, 461 ; on the Irrita- bility of Plants, Prof. F. Elfving, 466 ; Root-galls, Dr. M. Masters, 474 ; Origin of Filamentous Thallus of Dutnontia siliformis, George Brebner, 474 ; Illustrated Guide to British Mosses, H. G. Jameson, 479 ; the Flowering Plants of Western India, Rev. A. K. Nairne, 501 ; Remarkable Section of Sequoia gigantea acquired by British Museum, 507 ; Cause of Extinction of Pine in South of England, Clement Reid, 522, Growth of Wellingtonia, Mr. Carruthers, 522 ; Peculiar Method of the Development of the Axillary Buds of Vanda teres, Henry Dixon, 523 ; Deherainea smarag- dina, J. C. Willis, 523 ; Death of Dr. G. A. Weiss, 538 ; Grundziige einer Entwickelungsgeschichte der Pflanzenwelt Mitteleuropas seit dem Ausgang der Tertiarzeit, Dr. August Schulz, 553 ; the Royal Botanic Gardens, Peradeniya, Henry Trimen, F. R.S., 539; Botany of Death Valley, California, F. V. Coville, 583 ; Irritability of Plants, Prof F. Elfving, 466 ; Prof. Pfeffer, 5S6 ; Anatomical Modifications of Plants of the same Species in the Mediterranean Region and in the Region of the Neighbourhood of Paris, W. Russell, 620 Bottone (S. R.), How to manage the Dynamo, i(>'i, Boulenger (Mr.), a Nothosaurian Reptile from the Trias of Lombardy, 95 Bourke(Capt. J. G.), the Medicine-men of the Apache Indians, 439 Bovey, Lignite Age of the, A. R. Hunt, 600 Bowen (Lord), Death of, 558 Boyle (Frederick), the Orchid Seekers, 28 Boys (Prof. C.V., F.R.S.), the Attachment of Quartz Fibres, 45° Boys (Prof), Arithmometers, 618 Bozward (Lloyd), the Earthquake of November 2, 1893, at Worcester, 35 ; Brilliant Daylight Meteor seen near Wor- cester, 368 Branly (Edward), Conductibility of Discontinuous Conducting Substances, 404 Brauns (Dr. D. A.), Death of, 179 Brazil, the supposed Glaciation of, W. T. Thiselton-Dyer, F.R.S.,4 Brebner (George), on the Development of the Mucilage Canals of the Marattiacea, 5 23 Bredikhin (Th.), the Perseids observed in Russia in 1892, 23 Bricout (G. ), Ceric Bichromate and Separation of Cerium from Lanthanum and Didymium, 308 Briggs (William), Mensuration of the Simpler Figures, 28 ; Worked Examples in Co-ordinate Geometry, 52 ; the Geo- metrical Properties of the Sphere, 75 British Forest Trees, J. Nisbet, i British Fungus Flora; a Classified Text-book of Mycology, George Massee, Dr. M. C. Cooke, 195 British Institute of Preventive Medicine, the Directorship of the. Prof. Chas. S. Roy, F.R.S., 269 ; Sir J. Fayrer, F. R.S., 292 ; Prof Victor Horsley, F.R.S., 292 British Isles, Afforestation in the, Prof W. R. Fisher, 601 British Isles, Rainfall Records in, G. \. Symons, 438 British Mosses, Illustrated Guide to, H. G. Jameson, 479 British Museum, Remarkable Section of Sequoia gigantea acquired by, 507 Brodie (F. J.), the Great Drought of 1893, 119 Brogger (Prof W. C), Basic Eruptic Rocks ot Gran, 142 Brooks' Comet (October 16) 18, 39 Brooks, the Tail of Comet {c 1893 ), 210, 233 Brooks' New Comet (c 1893), Prof E. E. Barnard, 67 Brooks (W. R.), a Comet Finder, F. W. Mack, 543 Brough (Bennett H.), Iron Ores of Great Britain and Ireland, J. D. Kendall, 27 Brown (Prof Crum), on the Division of a Parallelepiped into Tetrahedra, 571 Index 'SnJ>file}nent to Nature, May 31, 1894 Brown (E.), a Curiosity in Eggs, 317 Browne (Dr. C. R.) the Ethnography of the Aran Islands, County Gahvay, 468 Browne (Edward G.), a Year amongst the Persians, 528 Brown-Sequard(Dr., F.K.S.), Death of, 538; Obituary Notice of, 556 Brubaker(Dr. A. P.), Radius and Curvature of Cornea, 229 Brucchietli (G.), Effect of Absorption of Hydrogen on Thermo- Electric Power and Electrical Resistance of Palladium, 65 Bruce (A. L.), Death and Obituary Notice of, 134 Brussels, Institutes of Physiology on Electro-Biology estab- lished by M. G. Solvay at, 180 Bryan (G. H.), Worked Examples in Co-ordinate Geometry, 52 ; the Second Law of Thermodynamics, 197 ; a Simple Contrivance for Compounding Elliptic Motions, 498 ; on the Buckling and Wrinkling of Plating supported on a Frame- work under the Influence of Oblique Stresses, 499 Bubbles in Tubes, on the Motion of, 351 Buda-Pesth, Bacteriological Institute established at, 393 ; an Estimate of the Degree of Legitimate Natality, as shown in the Table of Natality compiled from Observations made at, Joseph Korosi, 570 ; Results derived from the Natality Table of Korosi, Francis Galton, F.R.S., 570 Bugonia- Superstition of the Ancients, on the, Baron C. R. Osten-Sacken, 198 Buller (Ernest Wentworth), Navigation by Semi-Azimuths, 223 Bulletin de I'Academie Royal de Belgique, 283, 376, 546, 617 Bulletin de I'Academiedes Sciences de St. Petersburg, 23 Bulletin of New York Mathematical Society, 71, 188, 330,402, 497. 570 Bulletins de la Societe d'Anthropologie de Paris, 306, 330 Bulletin de la Societe des Naturalistes de Moscow, 189 Bullets Infected with Micro Organisms, Herr Messner'sExperi- ments with, 16 Biilow (Baron von), Death of, 106 Burbury (S. H., F.R.S), the Second Law of Thermodynamics, 150, 246; the North-East Wind, 481 Burkill (J. H.), the Fertilisation of some Species of Medicago, 426 Burnside (Prof. W., F.R.S. ), Note on the Theory of Groups of Finite Order, 118; on the Sextic Resolvent of a Sextic Equation, 618 Busquet (J. Rodet et), Les Courants Poly phases. 122 Butler (Edward A.), Our Household Insects, an Account of the Insect Pests found in Dwelling-houses, 147 Butterflies and Moths of Teneriffe, the, A. E. Holt White, W. F. Kirby, 384 Byerly (W. E.), an Elementary Treatise on Fourier's Series, and Spherical, Cylindrical and Ellipsoidal Harmonics with Applications and Mathematical Physics, 598 Cable, Submarine, between Zanzibar, Mauritius, and Sey- chelles, 134 Cacao-Seed, Transportation of, (J. H. Hart), 64 Cain, (Dr. John Cannell), Chemistry in Space, 173 ; Mechanics of Interaction of Ethyl Alcohol and Hydrogen Chloride, 274 Cajal (Prof. Ramon yj, the Minute Structure of the Nerve Centres, 464 Calculating Machines, Mathematical, Prof. O. Henrici, F.R.S., 521 Calderon (Dr. L.), Death of, 507 California, the Earthworms of, Gustav Eisen, 207 California, the Climate of Southern, Dr. C. Theodore Williams, 307 California, Proposed Quarantine Legislation against Insect Pests in, 508 California ; Botany of Death Valley, F. V. Coville, 583 Calmette(A.), Inoculation against Serpent-Poison, 548 Calvert (Albert F.), the Discovery of Australia, 28 Calvert (Philip P.), the Postal Transmission of Natural History Specimens, 314 Cambridge Diploma in Agriculture, 444 Cambridge Philosophical Society, 143, 166, 378, 424, 452, 523 Cameron (Captain Verney Lovett), Obituary Notice of, 537 Cameroons, the German Expedition to Delimit Hinterland of. Dr. Passarge, 606 Campbell (Prof. W, W.), Hydrogen Envelope of the Star D.M. + 30° 3639, 2IO ; the Spectrum of Nova Normje, 586 Campetti (A.), Difference of Potential between Aqueous and Alcoholic Solutions of same Salt, 560 Canada, Agricultural Resources of, Prof. Long, 561 Canada, Discovery of Deposits of Infusorial Earth in, 416 Canadian Geological Survey, the, 438 Canadian Ice Age, the, Sir J. W. Dawson, F.R.S., 552 Canary Islands, Temperature, Rainfall, and Sunshine of Las Palmas, Dr. J. C. Taylor, 425 Cancani (Dr. A.), a New Time-Registering Photographic Seis- mograph, 64 Cancer, Sarcoma, and other Morbid Growths considered in Relation to the Sporozoa, J. Jackson Clarke, 502 Cancer, the C. C. Walker Prize for Investigation of, 508 Caoutchouc of the Orinoco, the, Dr. Ernst, 35 Capus (G.), Ethnical Migrations in Central Asia, from a Geo- graphical Point of View, 593 Carbon, a New Sulphide of, A. E. Tutton, 275 Carcases, Bees and Dead, W. F, Kirby, 555 Cardifi", Roman Villa near, John Storrie, 605 Cardinal Points of the Tusayan Villagers, on the, J. Walter Fewkes, 388 Carlisle Institute of Science, Art and Literature, Opening of, 63 Carr (F. H.), Action of Heat on Aconitine, 377 Carr (Henry), Key to Mr. J. B. Lock's Shilling Arithmetic, 480 Carrington (Mr.), Science at the Free Libraries, 418 Carroll (J.), a Key to Carroll's Geometry, 75 Carruthers (Mr.), Growth of Wellingtonia, 522 Carus (A. des). Tree Pruning, 526 Catalan (Eugene), Death of, 415 ; Obituary Notice of, 437 Catania, Solar Observations at, 67 Cattell (Prof.), Reaction-times and Velocity of Nervous Im- pulse, 462 Caucasus, Geography in, 515 Caucasus, Lake-desiccation on Northern Slopes of, K. N. Rossikoff, 515 Cavallo (W.), Colouring Matter of Tesu, 377 Caves : the Har Dalam Cavern and its Ossiferous Contents, 514 Celebes, Flattening of Chest and Skull in. Baron von Hoevell, 377. Celestial Objects for Common Telescopes, Rev. T. W. Webb, 339 Cellulose, the Decomposition of Liquids by Contact with, C. Beadle, 457 Centipedes and their Young, F. W. Urich, 531 Century Alagazine, Science in the, 352, 543 Cerebellum, Functions of, Dr. J. S. R. Russell, 354 Ceylon, the Royal Botanic Gardens, Peradeniya, Harry Trimen, F.R.S., 539 Chabry (Dr.), Death of, 158 Chamberlin (T. C), Further Studies of the Drainage Features of the Upper Ohio Basin, 617 Chambrelent (M.), the Grape- Vine Harvest of 1893, 47 ; Death of, 81 Chances, a Plausible Paradox in, Francis Galton, F.R.S., 365 ; Lewis R. Shorter, 413 Chandler (A.), the Climate of Torquay, 253 Chandler (Prof. S. C), the Variation of Latitude, 133 Chanler's (Astor), East African Expedition, 112, 301 Chapman (Dr. H. C), Radius of Curvature of Cornea, 229 Charpy (G.), the Transformation of Iron, 192 Charrin (M.), the Action of Sunshine on Microbes, 417 Chassavant (A.), Influence of Metallic Salts on Lactic Fermenta- tation, 96 Chatir (Ad.), a Chemical Study of Green Colouration in Oysters, 263 Chauveau (A. B.), Diurnal Variation of Atmospheric Electri- city, 240 Chemistry : Inorganic Chemistry for Beginners, Sir Henry Roscoe, F.R.S., 3; the Chemistry of Fire, M. M. Pattison Muir, 3 ; on the Latent Heat of Steam, P. J. Hartog and J. A. Harker, 5 ; Carbide of Silicon as Manufactured by Dr. Miihliiuser's Process, 17 ; Analysis of a Vanadiferous Oil, A. Mourlot, 24 ; Chemical Conditions of Activity of Brewer's Yeast, J. Effront, 24; Effect of Electrolytic Dissociation on Magnetic Rotatory Polarisation of Solutions, Herr Humburg, 37 ; Ethyl and Methyl Derivatives of Hydroxylamine, Dr. Kjellin, 38; Death of J. G. Barford, 63 ; Influence of Heat Supplement to Nature,~\ May 31, 1894 J Index XI on Reactions in Aqueous Solutions containing Ferric Chloride and Oxalic Acid, M. Lemoine, 65 ; Compound of Carbon Monoxide with Potassium and Sodium, M. Joannis, 66 ; Determination of True Atomic Weight of Nitrogen, G. Hinrichs, 96; the Nitrification of Prairie Lands, J. Dumont and J. Crochetelle, 96; Influence of Metallic Salts on Lactic Fermentation, A. Chassevant and C. Richet, 96 ; the Pre- paration and Properties of Free Hydroxylamine, A. E. Tutton, 105 ; Isocyanogen Tetrabromide, Dr, Thiele, 1 10 ; Researches on Melting Points of Refractory Inorganic Salts, Prof. Victor Meyer and Dr. Riddle, IIO; Chemical Society, iiS, 142, 239, 306, 377, 425, 450, 523; the Action of Bromine on Azo- benzene, a Correction, H. E. Armstrong, 118; Coloured Hydrocarbons, H. E. Armstrong, 118; the Action of Aluminium Chloride on Heptylic Chloride, 1 18; the Inter- action of Chlorine and Lime, V. H. Veley, 118 ; Note on Hyponitrites, D. H. Jackson, 118 ; the Interaction of Hydrogen Chloride and Potassium Chloride, W. H. Pendle- bury and Mr. McKillop, 118 ; the Formation of Indoxazen Derivatives, W. A. Bone, 118; Synthesis of Piazine Deriva- tives, A. P. Mason and G. Winder, 118 ; Preparation of a-y3- diphenylindoles from Benzoin and Primary Benzenoid Amines, F. R. Japp and T. S. Murray, n8 ; the Freezing- points of Dilute Aqueous Solutions, Harry C. Jones, 132 ; Freezing-points of Alloys in which the Solvent is Thallium, C. T. Heycock and F. H. Neville, 239 ; Freezing-points of Triple Alloys, C. T. Heycock and F. H. Neville, 306 ; Ethereal Salts of Diacetylglyceric Acid in relation to Con- nection between Optical Activity and Chemical Constitution, P. Frankland and J. McGregor, 142 ; Oxidation of Parato- luidine, A. G. Green, 142; Formation of Benzoic Derivatives of Urochrome, [. L. W. Thudichum, 142 ; Combination of Hydrocarbons with Picric Acid, W. A. Tilden and M. O. Forster, 142 ; Conversion of a-hydrindonoxime into Hydro- carbostyril, F. S. Kipping, 142 ; the Temperature of Ignition of Explosive Gaseous Mixtures, A. E. Tutton, 138 ; the New Laboratories of the Institute of Chemistry, 154 ; General Method of Artificially Reproducing Crystallised Anhydrous Silicates, Dr, Hermann Traube, 161 ; Stability and Con- servation of Dilute Solutions of Corrosive Sublimate, Leo Vigron, 167 ; Discovery of Abrastol in Wines, M. Sangle- Ferriere, 167 ; Chemistry in Space, Dr. John Cannell Cain, 173 ; Mr. M. C. Lea's Researches on Transformation of Mechanical Work into Chemical Action, 181 ; a New Process for the Preparation of Ethers, A. E. Tutton, 184 ; Death of Dr. E. Lellmann, 206 ; the Explosive Metallic Derivatives of Acetylene, Dr. Keiser, 209 ; Occluded Gas contained in Oxides of Copper, Zinc, Nickel, and Magnesium prepared by Ignition of Nitrate, Messrs. Richards and Rogers, 209 ; Methods of Coating Aluminium with other Metals, Prof. Neesen, 216; Voices from Abroad, Prof. Henry E. Armstrong, F. R. S., 225 ; Properties of Mirror Silver Chemically Precipi- tated on Glass, Herr H. Liitke, 229 ; Cause of Explosion on Contact of Metallic Sodium with Water, Prof. Rosenfeld, 232 ; Gases Occluded in Coal from Various Durham Collieries, 232 ; Chemical Action of Marine Organisms, Prof. J. W. Judd, 235 ; Magnetic Rotations of Hydrogen and Sodium Chlorides and Chlorine in different Solvents, W. H. Perkin, 239 ; Bromolapachol, S. C. Hooker, 239 ; Nucleic Acid, Prof. A. Kossel, 240 ; Chemical Action in Spontaneous Ignition of Hay, M. Berthelot, 240 ; Practical Agricultural Chemistry for Elementary Students, J. Bernard Coleman and Frank T. Addyman, 244 ; New Compounds of Formaldehyde, M. Henry, 255 ; New Method of Preparing Halogen Sub- stitution Products of Oxides (Ethers) of Alkyl Radicles, M. Henry, 255 ; a New Isomeride of Cinchonine, E. Jung- fleisch and E. Leger, 263 ; Chemical Study of Green Coloura- tion in Oysters, Ad. Chatin and A. Muntz, 263 ; Composi- tion of Waters of Dranse du Chablais and Rhone at Entrance into Lake of Geneva, A. Delebecque, 264 ; Decomposition of Liquids by Contact with Powdered Silica, Dr. G. Gore, 272 ; Proposed Standard of Normal Air, A. Leduc, 272 ; Mechanics of Interaction of Ethyl Alcohol and Hydrogen Chloride, Cannell Cain, 274 ; a New Sul- phide of Carbon, A. E. Tutton, 275 ; on the Chemistry of the Blood, and other Scientific Papers, L. C. Wooldridge, 289 ; a Lecture Experiment, G. S. Newth, 293 ; Isolation of Pure Di-nitro Derivative of Marsh Gas, Dr. Paul Duden, 299 ; New Mode of Preparing Methylamine and Ethylamine, MM. Trillat and Fayollat, 300 ; Synthesis of Lapachol, S. C. Hooker, 306 ; Ceric Bichromate and Separation of Cerium from Lanthanum and Didymium, G. Bricout, 308 ; the Essentials of Chemical Physiology, Prof. W. D. Halliburton, 313 ; New Method of Preparing Phosphorus, Messrs. Rossel and Frank, 323 : Interaction between Oxygen and Phos- phoretted Hydrogen, Dr. van der Stadt, 323 ; Death of Prof. Edmond Fremy, 345 ; Recent Progress in Stereo-Chemistry, Prof. Victor Meyer, 348 ; Extension of Stereo-Chemistry to Inorganic Elements, Dr. Werner, 372 ; Handbuch der Stereochemie, Dr. Paul Walden, 409 ; Thermal Constants of some Polyatomic Bases, MM. Colson and Darzens, 356 ; Adaptation of Alcoholic Ferments to Presence of Hydrofluoric Acid, E. Sorel, 356 ; New Boron Compounds, Prof. Michaelis, 371 ; Preparation and Properties of Boron Carbide, Henri Moissan, 500 ; New Processes for Detection of Vegetable and Mineral Oils, W. de la Royere, 377 ; Mole- cular Formulae of some Liquids as Determined by their Molecular Surface Energy, Miss E. Aston and W.Ramsay, 377 ; Action of Heat of Aconitine, W. R. Dunstan and F. H. Carr, 377 ; Colouring Matter of Tesu, J. J. Hummel and W. Gwallo, 377 ; Interaction of Benzylamine and Ethylic Chlor- acetate, A. T. Mason and G. R. Winder, 377 ; Thermal Value of Replacement of Phenolic Hydrogen in Orcin, M. de Forcrand, 379 ; Campholene, M. Guerbert, 379 ; Two Camphoramic Acids, Messrs. Hoogewerff and van Dorp, 380 ; Comparison of Zinc and Copper Salts of Frankland's Dinitromethylic Acid with those of Methylnitramine, Messrs. Franchimont and H. van Erp, 380 ; Dictionary of the Active Principles of Plants, C. E. Sohn, 385 ; Polymeric Modifications of Acetic Aldehyde, Messrs. AndorfF and White, 396 ; Chemical Composition of Staurolite, S. L. Penfield and J. H. Pratt, 402 ; Celebi-ation of Centenary of Birth of Friedlieb F. Runge, 415 ; the Atomic Weight of Palladium, Prof. Keiser, 418; the Artificial Preparation of the Diamond, M. Moissan, 418 ; the Bakerian Lecture, Prof. T. E. Thorpe, F.R.S., and J. W. Rodger, 419 ; Action of Heat upon Ethylene, Prof. Vivian B. Lewes, 424 ; Liberation of Chlorine during Heating of Mixture of Potassium Chloride and Manganic Peroxide, H. McLeod, 425 ; Salts of Dehydracetic Acid, J. N. Collie and H. R. Le Sueur, 425 ; Iodine as a Base-forming Element, Prof. Victor Meyer and Dr. Hartmann, A. E. Tutton, 442 ; the New Iodine Bases, Prof. Victor Meyer and Dr. Hartmann, A. E, Tutton, 467 ; Analytical Determination of probably available "Mineral" Plant Food in Soils, B. Dyer, 451 ; Stability of Oxides in Relation to Periodic Law, G. H. Bailey, 451 ; Action of Heat on Potassium and Sodium Ruthenium Nitrites, A. A. Joly and E. Leidie, 452; New Ptomaine extracted from Damaged Cheese, Charles Lepierre, 452 ; Crystallised Calcium Carbide prepared by Means of Electric Furnace, Henri Moissan, 475 ; Determination of Specific Gravity of Melted Magnesia, Henri Moissan, 475 ; Exact Atomic Weights, with Silver as Standard, G. Henrichs, 476 ; Alloys of Iron and Nickel, F. Osmond, 476 ; Isomerism of Nitro-benzoic Acids, Oechsner de Coninck, 476 ; Isolation of New Crystallised Compounds of Hydroxyl- amine with Chlorides and Sulphates of Cobalt and Manganese, Dr. Feldt, 489 ; Death of Dr. L. Calderon, 507 ; Death of Dr. Karl Schmidt, 507 ; Compound of Sugars with Mercap- tans, Emil Fischer, 5 lo ; Chloraurate of Silver, Dr. Hermann, 510 ; Amides of Sodium, Potassium, and Lithium, A. W. Titherley, 523 ; Molecular Weight of Ferric Oxide, P. T. Muller, 524 ; Hydrate of Nitrous Oxide, M. Villard, 524 ; on Thallium Hypophosphates, M. A. Joly, 524 ; on yS-dibromo- propionic Acid, Thomas Mamert, 524 ; Prof. Ira Remsen on Chemical Laboratories, 531 ; Death of Dr. W. H. Delff, 538 ; the Gaseous Fluorides of the Simpler Organic Radicles, M. Meslans, 541 ; Fluoroform Prepared in Pure State, M. Meslans, 542 ; Refractometer applied to Study of Chemical Reactions, J. Verschaffelt, 546 ; Study of Crystallised Acetylides of Barium and Strontium, Henri Moissan, 548 ; Two Isomeric Methylcyanocamphors, A. Haller and Minguin, 548 ; Action of Nitrogen, Nitrous Oxide, and Nitric Oxide on Alkaline Ammoniums, A. Joannis, 548 ; Essays in Historical Chemistry, T. E. Thorpe, F.R.S. and M. M, Pattison Muir, 551 ; the Manufacture of Gas, C. Hunt, 561 ; the Atomic Weight of Barium, Prof. Richard, 562 ; Action of Water on Bicalcic phosphates, A. Joly and E. Sorel, 572 ; the Effect of Wave- Length in dealing with Refractive Index in elucidation of Chemical Constitution, MM. Jahn and xn Index [Sicpplevtent to Natinc. May 31, 1894 Moller, 582; Artificial Preparation of Christobalite, Dr. K. von Chrustschoff, 584 ; Lecture Demonstration of Electrolysis of Hydrochloric Acid, Prof. Lolhar Meyer, 584 ; the Pre- paration of Hydrazine Salts from Diazo-derivative of Acetic Acid, Prof. Curtius and Dr. Jay, 585 ; Chemistry in Relation to Pharmaco-Therapeutics and Materia Medica, Prof. B. J. Stokvis, 587 ; on the Fusibility of Mixtures of Salts, M. H. le Chatelier, 595 ; Action of Halogens on Homopyro- catechol, H. Cousin, 595 ; Further Light upon the Nature of the Benzene Nucleus, A. E. Tutton, 614 Chevalier (Rev. S.), the Typhoons of 1892, 560 Chicago, Foundation of International Horticultural Society at, 13 Chicago, the Climate of. Prof. H. A. Hazen, 15 Chicaj^o, Projected Museum at, 64 Chili, Fractures of Coal- Measures of Southern, A. E. Nogues, 47 Chinese Central Asia : a Ride to Little Tibet, Henry Lansdell, W. F. Kirby, 309 Cholera : Virulence of Cholera Bacillus increased by Salt, Dr. Gamaleia, 132 : Sand Filtration as a means of Purifying Water, Mrs. Percy Frankland, 156; Cholera Epidemic: Meteorological Conditions of Hamburg, Captain C. H. Seemann, 180 ; Les Vibrions des Eaux ei I'Etiologie du Cholera, Dr. Sanarelli, 231 ; an Incident in the Cholera Epidemic at Altona, Prof. Percy Frankland, F.R.S., 392; Cholera, Dr. E. Klein, F.R.S., 492 Chorley (Mr.), New High Temperature Thermometer, 538 Christobalite, Artificial Preparation of. Dr. K. von Chrustschoff, 584 Christy (Miller), Scheme for Mapping Geographical Distribution of Vertebrates, 35 Chrono- Photographic Study of the Locomotion of Animals, 41 Chrustachoff (Dr. K. von). Artificial Preparation of Christo- balite, 584 Cider-Apple, Development and Maturation of the, L. Lindet, "9 Cigars, Possible Transmission of Tubercle Bacillus by, Dr. Kerez, 371 City and Guilds of London Institute for 1893, Work of, 607 Civilisation, the Future of, Benjamin Kidd, Dr. Alfred R. Wallace, 549 Clark (Sir Andrew), Death of, 33 ; Obituary Notice of, 6 Clark (W. B. ), the Cretaceous and Tertiary Formations of New Jersey, 347 ; Climatic Features of Maryland, 423 Clarke (J. Jackson), Cancer, Sarcoma, and other Morbid Growths considered in relation to the Sporozoa, 502 Clarke (W. E.), Threatened Extermination of the Great Skua, 253 Claude (G. ), Means of Increasing Security of High Tension Alternate Current Distribution, 119 ; Experiments on Electric Arc in Alternating Circuit, 441 Clavel (G. ), Forest Fires and Drought, 191 Claybury, the Projected Pathological Laboratory at, 129 Clayton (H. Helm), Six- and Seven-Day Weather Periods, 520 Gierke (Agnes M.), a Popular History of Astronomy during the Nineteenth Century, 2 Climate of South Damaraland, Dr. Karl Dove, 14 Climatic and National Economic Influence of Forests, Dr. J. Nisbet, 302 Cloud Formation, Prof. W. von Bezold, 508 Cloud Nomenclature, Luke Howard, 607 Cloud Photography, 267 Clouds, the Measurement of the Highest Cirrus, Prof. C. Abbe, 508 Clouds, the Motion of, M. Pomortseff, 230 Clouds, Various Modes of Discriminating between, Prof, von Bezold, 427 Cloudy Condensation of Steam, the, Shelford Bidwell, F.R.S., 212, 388, 413 ; John Aitken, F.R.S., 340; Dr. Karl Barus, 363 Coal discovered at Port Jackson, 64 Coal from various Durham Collieries, Gases occluded in, W. McConnell, 232 Coal-balls and their Fo.ssil-plant Contents, II. B, Stocks, 14 Coal-gas : the New Process for Enriching with Oxy-oil Gas, Dr. L. T. Thome, 162 Cockerell (T. D. A.), Notes on the Habits of a Jamaican Spider, 412 Cohn's Beitrage zur Biologic der Pflanzen, 306 Cohnstein (Dr.), Influence of Diffusive Processes on Transuda- tion, 48 Cole (F. N.), Simple Groups as far as Order 660, 93 Coleman (J. Bernard), Practical Agricultural Chemistry for Elementary Students, 244 Collector's Handbook, the Outdoor World or Young, W. Furneaux, 52 Collet (Robert), Biid Life in Arctic Norway, 599 Collie (J. N.), Salts of Dehydracetic Acid, 425 Collignon (Dr. R.), Proportion of Trunk among the French, 22 Collins (Victor), Catalogue of Prince Louis Lucien Bonaparte's Library, 584 Cologne, the Largest City (in area) in Germany, 85 Colomb (Vice-Admiral, R.N.), the Manceuvring Powers of Steamships and their Practical Applications, 174 Colour- Aberration of Refracting Telescopes, H. Dennis Taylor, Colour Vision, the Board of Trade and the Railway Companies, Colouring Lantern-slides for Scientific Diagrams, Method for. Dr. J. Alfred Scott, 572 Colours, Painters', Oils and Varnishes, a Practical Manual, Geo. H. Hurst, 194 Colson (Albert), Thermal Constants of some Polyatomic Bases, 356 Columbus, Copy of Map by, 233 Columbus's First Voyage in relation to Development of Ocean- ography, Dr. John Murray, 39 Combustion Motors, Internal, Bryan Donkin, N. J. Lockyer, 430 Comets : Brooks's (October 16), 18, 39 ; Brooks's New Comet (1893.:), Prof, E. E. Barnard, 67 ; the Tail of Comet Brooks (C1893), 210, 233 ; Mechanical Theory of Comets, Prof. J. M. Schaeberle, 84 ; a Remarkable Cometary Collision, 349 ; Halley's Comet, 442 ; Comet-Spectra as affected by Width of Slit, 489; a New Comet, 511, 562; the New Comet W. F. Denning, 531 ; Denning's Comet, 562 ; Ephemeris for Den- ning's Comet (^1894), 586 ; a New Southern Comet, 586 ; Elements and Ephemeris of Gale's Comet, 608 ; a Mistaken Cometary Discovery, Prof. Krueger, 608 Commission, the Report of the Gresham University, 405 Commutator, a Liquid, for Sinusoidal Currents, Prol. J. A. Ewing, F. R.S., 317 Composite Dykes. Henry E. Ede, 77 Concave Gratings, the Astigmatism of Rowlands', 489 Conchology : the Albatross collection of Galapagos Island Shells, Dr. Stearns, 82 ; Death of Paul Fischer, 158 Condensation of Steam, the Cloudy, Shelford Bidwell. F.R. S. , 212, 388, 413 ; John Aitken, F.R.S. , 340; Dr. Carl Barus, 363 Congo State and Portuguese Frontier, Delimitation of, 582 Congress, the Eleventh International Medical, 538, 563 ; Piero Giacosa, 578 Conies, an Elementary Treatise on the Geometry of, A. Muk hopadhyay, 75 Coninck (Oechsner de). Isomerism of Nitrobenzoic Acids, 476 Contetnporaiy Review, Science in the, 32, 155, 444 Cook (Dr. F. A.), Scheme for Antarctic Exploration, 184 Cooke (A. H.), Mimicry in Mollusca, 426 Cooke (Dr. M. C), British Fungus Flora, a Classified Text- book of Mycology, 195 ; Handbook of British Hepaticce, 220 Cooper's Island, U.S., Glacial Potholes of, W. O. Crosby, 160 Copenhagen, Report for 1892 of Magnetic Observatory of, 298 Cornu (A.), Numerical Verifications relating to Focal Proper- ties of Plane Diffraction Gratings, 239 ; a Theorem Connect- ing Theory of Synchronisation with Theory of Resonance, 404 Cornwall, the Charts of, Howard Fox, 82 Correlation of Solar and Magnetic Phenomena, William Ellis, F.R.S., 30, 53, 78, 245 ; A. R. Hinks, 78 ; H. A. Lawrance, loi ; Dr. M. A. Veeder, 245 Coryndon (R.T.), Intended Expedition to Great Congo Forest, 606 Cotes (E.G.), Dried Locusts as Food for Insectivorous Cage- and Game Birds, 253 Cousin (H.), Action of Halogens on Homopyrocatechol, 595 Cousin (Jean), the True Discoverer of America, Capt. Gam- bier, 235 Snjipleinent to Nature, 1 May 31, 1894 J Index Xlll ; Coville (F. v.), Botany of Death Valley, California, 583 j Cozens- Hardy's (W. H.) Journey through Montenegro, 461 ; Craniometry : Description of Sixty-two Crania taken from a Modern Cemetery at Karlsruhe, G. de Lapouge, 520 i'rato (E. ), Morphological and Microchemical Investigations on Physodes, 132 Crawford (J.), Evidence of Existence of Man in Nicaragua in Neolithic Age, 107 rawshay (Mr.), Visit to Nyika Plateau, 210 rayfish, the Blind, W. P. Hay, 133 riminals, Identification of Habitual : Proposed Anthropo- metrical Registry, 437 . Critic Criticised, a. Dr. Alfred R. Wallace, F.R.S., 333 I Crochetelle (J.), the Nitrification of Prairie Lands, 96 ' Croft (W. B.), Lecture-room Experiments on (i) Rings and Brushes in Crystal, and (2) Electric Radiation in Copper Filings, 47 ; some Phenomena of DiiTraction, 354 Crosby (W. O. ), Glacial Potholes of Cooper's Island, U.S., 160 Crustacea : a History of Crustacea, Recent Malacostraca, Rev. Thomas R. R. Stebbing, 74 ; the Blind Crayfish, W. P. Hay, 133 ; Entoniostraca and Surface-film of Water, D. J. Scourfield, 474 Crystalline Schists of Devonian Age, Arthur R. Hunt, 554 Crystallisation in Super-cooled Substances, Velocity of, Mr. Moore, 130 Crystals ; Lecture-room Experiments on Rings and Brushes in Crystals, W. B. Croft, 47 ; the Artificial Colouring of Crystals and Amorphous Bodies, O. Lehmann, 376 ; Instrument for accurately Grinding Section-plates and Prisms of Crystals, A. E. Tutton, 377 ; Derived Crystals in Basaltic Andesite of Glasdrumman Port, co. Down, 499 Csapodi (S.), Growth of Mould-fungi on Solid Compounds of Arsenic, 461 Cunliflfe-Owen (Sir Philip), Death of, 507 Curie (M, P.), Magnetic Properties of Iron at Various Tempera- tures, 595, 620 Currents in the Great Lakes of North America, the, Prof. Mark W. Harrington, 592 Currents, Oceanic, Experiments with Floats on, 301 Curtius (Prof.), the Preparation of Hydrazine Salts from Diazo- Derivatives of Acetic Acid, 585 Curves, Asymmetrical Frequency, Prof. Karl Pearson, 6 Curves, Groups of Points on, F. S. Macauley, 498 Cvijic (Dr. Jovan;, Das Karstphanomen, 197 Cyclones, on Mountain Observatories in connectionVith, M. Faye, 620 Czermak's (Herr P.), Photographs of Ascending Currents in Gases and Liquids, 15 Dall (W. H.), a Sub-Tropical Miocene Fauna in Arctic Siberia, 36 Dana (J. D.), New England, the Upper Mississippi Basin in the Glacial Period, 92 Danckelman (Dr.), Government Scientific Work in the German African Protectorate, 581 Daniel (John), Polarisation Phenomena upon Thin Metal Par- titions, 347 ; Polarisation upon a Thin Metal Partition in a Voltameter, 460 Darboux (M.), French Lady Mathematicians, 205 Darwin (Charles), Proposed Memorial at Shrewsbury to, 320 Darwinianism : Workmen and Work, Dr. James Hutchison Stirling, Dr. Alfred R. Wallace, F.R.S., 333 Darzers (Georges), Thermal Constants of some Polyatomic Bases, 356 Davidson (Prof. George), True Latitude reached by Newport Whaler, 369 Davis (W. G.), a South American Tornado, 263 Davis (W. M.), the Winds of the Indian Ocean, 263 Davison (Charles), the Recent Earthquake, 3f Dawkins(Prof W. Boyd, F.R.S.), Obituary Notice of William Pengelly, 536 Dawson (Charles), Straining of Earth resulting from Secular Cooling, 424 Dawson (Dr. G. M., F.R.S.), Mammoth Remains in Canada and Alaska, 94 Dawson (Sir J. W., F.R.S.), some Salient Points in the Science of the Earth, 196; the Genus "Naiadites" occurring in Nova Scotia Coal Formation, 475 ; the Canadian Ice Age, 552 Day, the Reckoning of the Astronomical, 542 De Morgan Medal, the, A. B. Kempe, F. R.S., 80 Death-rate, Relation between Mean Quarterly Temperature aod, D. H. Dines, 547 Decimal System, Introduction into Russia of, 129 Deeley (R. M.), Sir Henry Howorth and Geology in Nubibus, 122, 173 ; Dr. Alfred Wallace, F.R.S., 173 Deep-sea, the Fauna of the, Sydney J. Hickson, 502 Deherainea smaragdina, J. C. Willis, 523 Delafosse (Maurice), the Agni, a Tribe of Fair Negroes, 263 Delcommune (M.), Exploration of Lukuga River by, 559 Delebecque (A.), Observations on Amount of Solid Matter in Solution in Lake-water, 160 ; Composition of Waters of Dranse du Chablais and Rhone at Entrance into Lake of Geneva, 264 Delffs (Dr. W. H.), Death of, 538 Dembo (Dr.), the Humanest Method of Slaughtering Animals, 427 Demography, Public Health, and, Edward F. Willoughby, M.D., 285 Dendy (Dr. Arthur), Comparative Anatomy of Sponges. V. Calcarca heterocccle, 139 Denison's (Dr. Charles), Climates of United States, 396 Denmark, Central European Time adopted in, 228 Denning (W. F.), Jupiter and his Red Spot, 104; Fireballs, 434 ; the New Comet, 531 ; Denning's Comet, 562 ; Ephemeris for Denning's Comet {a 1894), 586 Denton (J. Bailey), Death of, 81 Deutsche Seeivarte Record of Meteorological Observations taken in North Atlantic, No. xi. , 108 Deutsche Seezvarte Extra-European Meteorological Observations, 540 Devon (North), Earthquake in, 320 Devonian Age, Crystalline Schists of, Arthur R. Hunt, 554 Devonian Schists. — The North-East Wind, Prof. T. G. Bonney, F.R.S., 577 Dewar (T. J.), Spectacles for Double Vision, 433 Diamond, the Artificial Preparation of the, M. Moissan, 418 Diamond, the Thermal Expansion of the. Dr. J. Joly, F. R.S., 480 Diamond, the Artificial Formation of the, J. B. Hannay, Dr. J. Joly, F.R.S., 530 Dickins (F. Victor), the Teaching University, 536 Dielectrine, a New Insulating Material, M. Hurmuzescu, 370 Difiterence Terms, on Regular, A. B. Kempe, F. R.S., 618 Diffraction, some Phenomena of, W. B. Croft, 354 Digits of the Horse, on the Second and Fourth, Prof. Cossar Ewart, 571 Dines, (W. H.), Relation between Mean Quarterly Tempera- ture and Death- Rate, 547 Dinning (William), Death and Obituary Notice of, 81 Diprotodon and its Times, the, C. W. de Vis, 159 Directorship of the British Institute of Preventive Medicine, the. Prof. Chas. S. Roy, F.R.S., 269 ; Sir Joseph Fayrer, F.R.S., 292; Prof. Victor Horsley, F.R.S., 292 Disease, Zymotic, Distribution by Sewer Air of, Mr. Laws, 347 Disease and Race, Jadroo, 575 Ditte (A.), Action of some Metals upon Acid Solutions of their Chlorides, 1 19 Dixon (Edward T.), the Foundations of Dynamics, 578 Dixon (Henry), Peculiar Method of the Development of the Axillary Buds of Vanda teres, 523 Dixon (H. N.), Meteorology, 412 Dobson (B. A.), the Artificial Lighting of Workshops, 18 Dodd (H. W.), Relationship between Epilepsy and Errors of Refraction in Eye, 395 Dog, Prof. Golz's Research on a, which survived for a Long Time Extirpation of the Cerebrum, Prof. H. Munk, 596 Dogma and Freewill, Biology as it is applied against, and for Weismannism, H. Croft Hiller, 386 Dolley (Prof. ), Reaction Times and Velocity of Nervous Impulse, 462 Donkin (Bryan), a Text-book on Gas, Oil, and Air Engines, N. J. Lockyer, 430 Darp (M. van), Two Camphoramic Acids, 380 Double Star Measures, Otto Struve's, iii XIV Index t Supple 111 ent to Nature, May 31, 1894 Dove (Dr. Karl), Climate of South Damaraland, 14 Drainage Features of the Upper Ohio Basin, Further Studies of the, T. C. Chamberlin and Frank Leverett, 617 Dranse du Chablais at Entrance into Lake of Geneva, Compo- sition of Water of, A. Delebecque, 264 Draper (C. H.), Heat, and the Principles of Thermodynamics, 148 Drawing, Machine, Thomas Jones and T. Gilbert Jones, 362 Dredging Expedition at Port Erin, Prof. W. A. Herdman, F.R.S., 503 Drought, Forest fires and, E. Gaget and G. Clavel, 191 Drum Armatures and Commutators, the Construction of, F. M. Weymouth, E. Wilson, 478 Drumlins near Boston, U.S.A., Mr. Warren Upham's Theory of Formation of, 207 Dublin Area, Geology of. Prof. Sollas, 36 Dublin Royal Irish Academy, 523 Dublin Royal Society, 215, 379, 499, 572 Dubois (Marcel), the Classification of Rivers According to Size, 487 Duden (Dr. Paul), Isolation of Pure Di-nitro Derivative of Marsh Gas, 299 Diimichen (Prof. J. von). Death and Obituary Notice of, 393 Dumont (A.), Birth-rate in Canton of Beaumont-Hague, 283 Dumont (J.), the Nitrification of Prairie Lands, 96 Dunstan (W. R.), Action of Heat on Aconitine, 377 Dust and Meteorological Phenomena, John Aitken, F.R.S., 544 Dust-particles in Atmosphere of Certain Places, Number of, John Aitken, 426 Dwarf, Hindoo, Colonel A. T. Fraser, 35, 396 ; Dr. A. E. Grant, 221, 396 Dyer (B.), Analytical Determination of probably available "Mineral" Plant Food in Soils, 451 Dykes, Composite, Henry E. Ede, 77 Dynamics : Solutions of the Examples in the Elements of Statics and Dynamics, S. L. Loney, 122 ; a Treatise on Dynamics, W. H. Besant, A. B. Basset, F.R.S., 146; a Dynamical Theory of the Electric and Luminiferous Medium, Dr. Joseph Larmor, F.R.S., 260, 280 ; the Foundations of Dynamics, Prof. A. Gray, 389 ; Edward T. Dixon, 578 ; A. B. Basset, F.R.S., 529; the Dynamics of the Atmosphere, M. Moiler, 422 Dynamo, How to Manage the, S. R. Boltone, 363 Dynamos, Alternators, and Transformers, Gisbert Kapp, 337 Dynamos, a Text-Book on Electromagnetism and the Construc- tion of, Dugald C. Jackson, Prof. A. Gray, 429 Early Asterisms, J. Norman Lockyer, F.R.S., 199 Earth, the Mass of the, 575 Earth, some Salient Points in the Science of the, Sir J. William Dawson, F.R.S., 196 Earth, Condition of Interior of. Rev. O. Fisher, 379 Earth, Rigidity of. Prof. Bakhuyzen, 476 Earth, the Face of the, Prof. Chas. Lapworth, F.R.S., 614 Earth Currents, W. H. Preece, F. R.S., 554 Earth Movements, Prof. John Milne, F.R.S., 301 Earth Movements and the Question of the Cause of Glacial Conditions, Prof. Hughes, 426 Earthquakes: the Recent Earthquake, Charles Davison, 31 ; Earthquake in Wales and West of England, 34 ; a New Time-Registering Photographic Seismograph, Dr. A. Cancani, 64; Earthquake in Western Asia, 81 ; Earthquakes in Montreal and Peshawur, 106 ; the Earthquake of Novem- ber 5 at Potsdam, 159; in Russian Turkestan, 159; Earth- quake at Shepton Mallet, Prof. F. J. Allen, 229 ; the Mendip Earthquake of December 30-31, 1893, Prof. F. J. Allen, 245 ; Earthquake in North Devon, 320 ; Velocity of Earth- quakes at Zante in 1893, Dr. G. Agamennone, 439 ; Mode of Propagation of Earthquake Shock between Zante and Catania, Prof. Ricco, 606 ; Earthquakes and Method of Measur- ing them, Dr. E. S. Holden, 444; Severe Earthquakes in Greece, 604 Earthworms of California, the, Gustav Eison, 207 Easton (C), La Voie Lactee dans I'Hemisphcre Boreal, 99 Eclipse Meteorology, 349 Eclipse of the Sun, an Annular, 542 Edkins (Dr. J. S.), Human Physiology, John Thornton, 431 Edinburgh, Rainfall Observations in, 520 Edinburgh Royal Society, 331, 426, 571 ; Prize Awards, 581 Edinburgh University, Recent Benefactions, 252 Edmondson (T. W.), Mensuration of the Simpler Figures, 28 ; the Geometrical Properties of the Sphere, 75 Education, the Training of Dull Children and others requiring special care. Sir Douglas Gallon, 461 ; the Secondary Educa- tion Movement, Sir H. E. Roscoe, F.R.S., 203 ; the Pro- gress of Technical Education, R. A. Gregory, 185; Technical Education, Bequest by Mr. T. H. Adam, 320 ; Formation of Association of Technical Institutions, 321 ; some .Simple Methods in Teaching Elementary Physic;, Dr. J. Joly, F. R. S., 379 ; on Preparing the Way for Technical Instruction, Sir Philip Magnus, 400 ; the Work of City and Guilds of London Institute for 1893, 607; Agricultural Education Experiment Stations, 373 ; Educational Agricultural Experiments, 568 Educational Atlas, an, Philip's Systematic Atlas, E. G. Ravenstein, 574 Educator, the New Technical, 148 Edwards (D. T. ), Boring on Booysen Estate, Witwatersrand, 239 Eels in Ice, 271 Effront (T.), Chemical Conditions of Activity of Brewer's Yeast, 24 Egg, Great Auk's, Prof. Alfred Newton, F.R.S., 412, 456; J. E. Harting, 432 Egg, Great Auk's, sold for 300 Guineas, 415 Eggs: a Curiosity in, E. Brown, 317; Abnormal, W. B. Tegetmeier, 366; E. J. Lowe, F. R. S., 366 Egypt, the Projected Irrigation Reservoirs, 129 ; the Tombs of " Beni Hasan," P. E. Newberry, 169, 432 ; G. W. Eraser,. 169 Egypt : Ancient Egyptian Pigments, Dr. William J. Russell, F.R.S., 374 Egyptology : Death and Obituary Notice of Prof. J. van Diimichen, 393 Eiffel Tower, the Diurnal Range in Velocity and Direction of the Wind on the. Prof. Sprung, 596 Eison (Gustav), the Earthworms of California, 207 Elbrus, A. V. PastukhofTs Ascent of the, 515 Electricity : Signor Augusto Righi's Experiments with Electro- Magnetic Waves of Small Length, 15 ; the Various Electric Wave Systems obtained by Lecher's Method, Signor Mazotto, 83 ; English Translation of Prof. Hertz's " Electric Waves," Prof. D. E. Jones, 396 ; M. Blondlot's Experiments on Propagation of Hertzian Wave?, M. Mascart, 394 ; Pro- pagation of Electro-Magnetic Waves, M. Mascart, 379 ; the Reflection of Electrical Waves, Signor Garbasso, 132 ; Dr. Oettel's Researches on Phenomena of Electrolytic Deposition of Metals, 16 ; Personal Recollections of Dr. Werner von Siemens, 25 ; New Form of Contact-Maker, Messrs. Bedell, Miller, and Wagner, 37 ; the Effect on Magnetic Rotatory Polarisation of Solutions of Electrolytic Dissociation, Herr Humburg, 37 ; Blondlot's Experiments on Velocity of Pro- pagation of Electric Disturbance along Wire, 37, 83 ; Behaviour of Air-Core Transformer when frequency below certain critical value, 8; C. Rimington, 46; Electric- Radia- tion in Copper Filings, W. B. Croft, 47 ; Death of A. Reckenzaun, 63 ; Method for Comparing Capacities of Two Condensers of very small capacity, 65 ; Effect of Absorption of Hydrogen on Thermo-electric Power and Electrical Resis- tance of Palladium, Signor G. Brucchietti, 65 ; Measure- ments of Coefficients of Induction, H. Abraham, 72 ; What Electricity is. Prof. Galileo Ferraris, 83 ; the Lausanne Municipal Council and Electrical Transmission of Power, 107; Improved Arrangement for "turning down" Electric Light, F. Moore, xo8 ; Map of Electric Lighting District of London, 298 ; the Kathodic Light, Prof. Goldstein, 427 j Absorption and Branching of Oscillations in Wires, Ignaz Klemencic, 117 ; Simple Method of Testing Conductivity of Dielectric Liquids, K. R. Koch, 118; Means of Increasing Security of High Tension Alternate-current Distribution of Clouds, 119 ; Action of some Metals upon Acid Solutions of their Chlorides, A. Ditte and R. Mentzner, 119 ; Les Courants Polyphases, J. Rodet et Busquet, 122 ; Currents produced by Heating various Metals, W. H. Steele, 13 1 ; Electric Variation of High Regions of Atmosphere in Fine Weather, Ch. Andre, 131 ; Action of Electromagnetic Radiation on Films containing Metallic Powder, Prof. G., M. Minchin, 142; Problemes et Calculs Pratiques d'Electricite, M. Aime Witz, Prof. A. Gray, 145 ; Institute of Electro-Biology established by M. G. Solvay at Supplement to NatitrcC\ May 31, 1894 J Index XV Brussels, 180; Electric Strength of Solid, Liquid, and Gaseous Dielectrics, A. Macfarlane and G. W. Pierce, 181 ; a Modi- fied form of Thomson Quadrant Electrometer, Herr F. Himstedt, 181 ; a very Sensitive Idiostatic Electrometer, Prof. A. Righi, 606 ; the Swiss Experiments upon the use of Electricity gained from Water, 182; Utilisation of Water- power on Seine-Saone Canal, M. Galliot, 272 ; Potentiometer for Alternating Currents, James Swinburne, 190 ; Calculation of Coefficient of Self-induction of Circular Current of given aperture and Cross-section, Prof. G. M. Minchin, 190; Mag- netic Field of Current running in Cylindrical Coil, Prof. G. M. Minchin, 190; Experiments in Devices for Compensating Hysteresis of Iron used for Measuring Instruments, Messrs. Field and Walker, 206 ; Ewart's Investigations on Electric Fishes, Prof. Gustav Fritsch, 222 ; the Effects of Light on the Electrical Discharge, 226 ; Propagation of Electricity, H. Poincare, 239 ; Death of Prof. Hertz, 251 ; Novel Method of obtaining Sinusoidal Alternating Currents of very Low Frequency, Lieut. F. J. Patten, 253 ; Experiments on Elec- trical Convection in Air, M. Hurmuzescu, 254 ; a Dynamical Theory of the Electric and Luminiferous Medium, Dr. Joseph Larmor, F. R. S., 260, 280; Electromotive Force from the Light of the Stars, Prof. Geo. M. Minchin, 269 ; M. Violle on the Electric Arc, 272 ; Experiments on Electric Arc in Alternating Circuit, G. Claude, 441 ; a Liquid Commutator for Sinusoidal Currents, Prof. J. A. Ewing, F.R.S., 317; Peculiarities of Deposit of Silver on Platinum, U. Behn, 321 ; Minimum Electromotive Force necessary for Electrolysis of Dissolved Alkaline Salts, C. Nourrisson, 331 ; Dynamos, Alternators, and Transformers, Gisbert Kapp, 337 ; Polarisa- tion Phenomena upon Thin Metal Partitions, Dr. Arons and John Daniel, 347 ; Polarisation upon a Thin Metal partition as a Voltameter, John Daniel, 460 ; the Thermo-electric Diagram for some Pure Metals, 347 ; Nikola Tesla, T. C. Martin, 352 ; Electric Alarm Thermometer for Laboratory Ovens, M. Barille, 355 ; Notes on Recent Researches in Electricity and Magnetism, J. J. Thomson, F. R. S., Prof. A. Gray, 357 ; Dielectrine, a New Insulating Material, Mr. Hurmuzescu, 370; How to Manage the Dynamo, S. R. Bottone, 363 ; Galvanic Deposits arranged in Streaks, U. Behn, 376 ; Polarisation of Solid Deposits between Electro- lytes, P. Springmann, 376 ; Electricity of Drops, Prof. J. J. Thomson, 378 ; Lectures on Maxwell's Theory of Electricity and Light, Dr. Ludwig Boltzmann, 381 ; Electrical Experi- ments, G. E. Bonney, 386 ; on M. Mercadier's Test of the Relative Validity of the Electrostatic and Electro-magnetic Systems of Dimensions, Prof. Arthur Riicker, F. R. S., 387 ; Dr. G. Johnstone Stoney, F. R. S., 432 ; the Benzeville- Havre Railway Experiments, 395 ; Conductibility of Discon- tinuous Conducting Substances, Edward Branly, 404 ; Chapters on Electricity, Samuel Sheldon, 411 ; Measurement of Capacity of Condensers under Alternating Currents, J- Sahulka, 417; a Text-book on Electromagnetism and the Construction of Dynamos, Dugald C. Jackson, Prof. A. Gray, 429 ; a New Electrical Theorem, T. H. Blakesley, 450; Current-Sheets, R. H. D. Mayall, 452^ New form of Electrical Machine, M. Bonetti, 460; Electrical Sanitation, 469 ; the Construction of Drum Armatures and Commutators, F. M. Weymouth, E. Wilson, 478 ; the Point of Application of Electromagnetic Forces, M. Pellat, 488 ; P. Lenard's Observations on the Cathode Rays in Gases with High Vacua, Prof. Fitzgerald, 509 ; Point of Application of Mechanical Force experienced by Conductor con- veying Current in Magnetic Field, M. Pellat, 560 ; New Method of Studying Discharge, N. Piltchikoff, 540 ; Earth Currents, W. H. Preece, F.R.S., 554; Electric Traction, E. F. Bamber, 567 ; Death of Paul Jablochkoff, 558 ; Difference of Potential between Aqueous and Alcoholic Solutions of same Salt, A. Campetti, 560 ; Communication between Lighthouses and Lightships without Submarine Cable, C. A. Stevenson, 581 ; Improved Form of Blackburn's Pendulum for Slow Production of Lissajous's Figures, Prof. A. Righi, 582 ; Lecture Demonstration and Electrolysis of Hydrochloric Acid, Prof. Lothar Meyer, 584; Transparent Conducting Screens for Electric and other Apparatus, Prof. W. E. Ayrton, F.R.S., and T. Mather, 591 ; Prof, Bornstein on Electric Measurements made during Balloon Ascents, 595 ; the Magnetisation of Iron and Nickel Wires by Rapid Electrical Oscillations, Prof. Klemencic, 607; the Development of Electrical Engineering, Prof. Kennedy, 608 ; on an Electrochemical Method of Observation of Alternating Currents, P. Janet, 620 Elfving (Prof. F.), on the Irritability of Plants, 466 Elgar (Dr. Francis), the Loss of H.M.S. Victoria, 102, 124, 151 Elliptic Functions, the Applications of, Alfred George Green- hill, F.R.S., H. F, Baker, 359 Elliptic Motions, a Simple Contrivance for Compounding, G. H. Bryan, 498 Ellis (William, F. R.S.), Correlation of Solar and Magnetic Phenomena, 30, 53, 78, 245 Emerson (Prof. B. K.), Recovery of, 129 Emin Pasha, Proposed Monument to, 134 Energy, the Nomenclature of Radiant, Prof. Simon Newcomb, F.R.S., 100; Prof. G. F. Fitzgerald, 149; Prof. A. N. Pearson, 389 Engineering : Institution of Mechanical Engineers, 18, 350, 608 ; the Artificial Lighting of Workshops, B. A. Dobson, 18 ; Steam Pumps on Russian Railways, Alexander Borodin, 19 ; Effect of Reversing Screw of Steam- ship on Steering, Captain Bain, 208 ; Marine Engine Trials ; Abstract of Results of Research Committee, Prof. T. H. Beare, 350 ; a Text-book on Gas, Oil, and Air Engines, Bryan Donkin, N. J. Lockyer, 430; the Falls of Niagara and its Water Power, 382 ; the Grafton High Speed Steam-engine, E. W. Anderson, 610 ; the Development of Electrical Engineerine, Prof. Kennedy, 608 England, Earthquake in West of, 34 England and Wales, Geological Survey of, 495 English Spiders, further Notes and Observations upon the Instinct of some Common, R. I. Pocock, 60 Entomology: Collecting in the Transvaal, 12; Entomological Society, 23, 95, 190, 330, 378, 475, 522, 571, 619 ; the Reproduction of Wasps, Paul Marchal, 47 ; Further Notes and Observations upon the Instinct of some Common English Spiders, R. I. Pocock, 60 ; Protective Habit in a Spider, Prof. C. Lloyd Morgan, 102 ; Mimicry by Spider, 207 ; the Silk-Spider of Madagascar, Dr. Karl Miiller, 253 ; Notes on the Habits of a Jamaican Spider, Prof. T. D. A. Cockerell, 412 ; Death of Dr. H. A. Hazen, 63 ; the Sugar-cane Moth, A. S. Skiff, 64 ; Method of Showing Geographical Distribu- tion of Insects in Collections, Prof. E. B. Poulton, F.R. S., 95 ; Dr. Livingstone and the Zambesi Ants, 95 ; the Nematodes of the Pharyngean Glands of Ants, Charles Janet, 119; White Ants, Dr. D. Sharp, F.R.S., 522 ; our Flousehold Insects, an Account of the Insect Pests found in Dwelling-houses, Edward A. Butler, 147 ; the Gipsy Moth Plague in Massachusetts, 231 ; Dried Locusts as Food for Insectivorous Cage and Game Birds, Dr. Giinther, E. C. Cotes, 253 ; Insect Attacks on Crops and Trees, Miss E. A. Ormerod, 253; Report of Observations of Injurious Insects and Common Farm Pests during the Year 1893, Eleanor A. Ormerod, 480 ; Proposed Quarantine Legislation against Insect Pests in California, 508 ; Romance of the Insect World, L. N. Badenoch, 314 ; our Knowledge of the Acari, A. D. Michael, 330 ; Netherlands Entomological Society, 332 ; Vertical Distribution of British Lepidoptera, W. H. Bath, 346 ; Morphology of Pedipalpi, Malcolm Laurie, 378 ; the Beetles of New Zealand, W. F. Kirby, 459 ; Insect Sight and Defin- ing Power of Composite Eyes, A. Mallock, 472 ; Anatomy of the Trachean System of the Larva; of Hymenoptera, M. Bordas, 524 ; Centipedes and their Young, F. W. Urich, 531 ; Death of J. Jenner Weir, 538, 571 ; a Specimen of Gaudaritis flavata (Moore) from the Khari Hills, G. F. Hampson, 571 ; Bees and Dead Carcases, W. F. Kirby, 555 ; Mimicry of Hemiptera by Lepidoptera, G. A. G. Rothney, 619 Entomostraca and Surface-Film of Water, D. G. Scourfield, 474 Eozoonal Structure of the Ejected Blocks of Monte Somma, Dr. J. W. Gregory and Prof. H. J. Johnston -Lavis, 499 Ephemeris for Denning's Comet {a 1894), 586 Epidemic Influenza, Hon. R. Russell, 210 Epilepsy and Errors of Refraction in Eye, Relationship between, H. W. Dodd, 395 Epping Forest Local Museum, Proposed, 393 Epping Forest, the Recent Operations in, 605 Equatorial Africa, the Natural History of East, Dr, J. W. Gregory, 12 XVI Index t Supplement to Nature, May 31, 1894 Equilibrium of Vapour Pressure inside Foam, on the, Prof. G. F. Fitzgerald, F.R.S., 316 Ernst (Dr.), the Caoutchouc of the Orinoco, 35 Erosion of Rock-Basins, the, T. D. La Touche, 39 ; Prof. T. G. Bonney, F.R.S., 52 Erp (H. van), Comparison of Zinc and Copper Salts of Frank- land's Dinitromethjlic Acid with those of Methylnitramine, 380 Eskimo Life, Dr. Fridtjof Nansen, 98 Fspin (Rev. T. E.), a New Variable Star, 67, 1S4 ; Stars with Remarkalle Spectra, 183 Ethers, a New Process for the Preparation of, A. E. Tutton, 184 Ethiopians, the Sacred City of the, J. T. Bent, 314 Ethnical Migrations in Central Asia from a Geographical Point of View, G. Capus, 593 Ethnography : Dr. Modigliani's Sumatra Engano Collections, Prof. Giglioli, 107 ; Internationales Archiv fiir Ethnographic, 377 ; Ethnography of the Aran Islands, County Galway, Prof. A. C. Haddon and Dr. C. R. Browne, 468 Ethnology: Eighth Report of U.S. Bureau, Major J- W. Powell, 132 ; Ethnological Museum at Leyden, Dr. H. ten Kate, 165 ; the Medicine-Men of the Apache Indians, Capt. J. G. Bourke, 439 Etna Eruptions of May and June 1886, Prof. Silvestri's Geody- namic Observations of, 107 Euclid I. to IV., Solutions of the Exeicises in Taylors, W. W. Taylor, 3 Euclid V.-VL, Pitt Press, II. M. Taylor, 52 Euclid's Elements, a Ttxt-Book of, H. S. Hall and F. H. Stevens, 599 Eulerian Movement, the Sense and the Period of the, F. Folic, 617 Europe, Forest Legislation in, B. E. Fernow, £43 Europe, Recent Local Rising of Land in the North-West of of, C. A. Lindvall, 433 Evans (Arthur J.), the Man of Mentone, 42 Evans (Sir John, F.R.S.), the Forgery of Prehistoric Stone Implements, 156 : the Royal Society, 576 Evans (Dr. J. W'.), Geology of Matto Grosso, 94 Evermann (W. B.), the Ptarmigan of Aleutian Inlands, 584 Ewart (Prcf. Cossar), on the Stcond and Fourth Digits of the Horse, 571 Ewart (Prof. J. A., F.R.S.), a Liquid Commutator for Sinu- soidal Currents, 317 Ewart (Prof. J. C), Investigations on Electric Fishes, 222 Exhibition at Hobart, Tasmania, Coming International, 13 Exploration, Antarctic, Dr. John Murray, 112; Scheme for. Dr. F, A. Cook, 1S4 Explosive Gaseous Mixtures, the Temperature of Ignition of, A. E. Tutton, 138 Extra-Tropical Orchids, Harry Bolus, R. A. Rolfe, 50 Face of the Earth, the, Prof. Chas. Lapworth, F.R.S., 614 Falls of Niagara and its "Water-Power, the, 482 Fauna of the Deep Sea, Sydney J. Hickson, 5C2 Fauna of the Victoria Regia Tank in the Botanical Gardens, Frank E. Beddard, F.R.S., 247 Fave (General), Death of, 486, 524 Faye (M. ), on Mountain Observatories in connection with Cyclones, 620 Fayollat (M.), New Mode of Preparing Methylamine and Ethylamine, 300 Fa>rer (Sir Joseph, F.R.S.), the Directorship [of the Institute of Preventive Medicine, 292 Feldt (Dr.), Isolation of New Crystallised Compounds of Hjdroxylamine with Chlorides and Sulphates of Ccbalt and Manganese, 489 Fellenberg (Dr. von). Geology of the Bernese Oberland Alps, 297 Feie (Ch.), Relation of the Length of the Trunk to the Height, 520 Feimentation, Micro-Organisms and, Alfred Jorgensen, Dr. A. A. Kanthack, 527 ; Frank E. Lott, 577 B'ermi (Signor), the Action of Sunshine upon Tetanus Fil- trates, 509 ; Tetanus Poison, 540 Feinow (B. E.), Forest Legislation in Europe, 543 Ferrand (Henri), Mont Iseran, 134 Ferraris (Prof. Galileo), What Electricity is, 83 Fever and Ozone, iSo Fewkes (J. Walter), on the Cardinal Points of the Tusayan Villagers, 388 Fibres, Quartz, the Attachment of. Prof. C. V. Boys, F.R. S., 450 Field (Mr.), Experiments in Devices for Compensating Hyste- resis of Iron used for Measuring Instruments, 206 Figures, Mensuration of the Simpler, William BriggsandT. W. Edmondson, 28 Films of Remarkable Stability, Method of Producing Thin Glass, F. Kohlrausch, 439 Finsterwalder (Prof.), Observations during Nocturnal Balloon Ascents at Munich, 416 Fire, the Chemistry of, M. M. Pattison Muir, 3 Fireball of January 25, the Large, 324 Fireball, Worthington G. Smith, 577 Fireballs, W. F. Denning, 434 Fires, New French Law for the Prevention of Forest, Prof. W. R. Fisher, 233 Fischer (Emii), Compounds of Sugar with Mercaptans, 510 Fischer (Paul), Death of, 158 ; Obituary Notice of, Edmond Bourbage, 296 Fish: the Flying Fish, 13; Ewart's Investigation on Electric Fishes, Prof. Gustav Fntsch, 222 Fisher (H.), Botanical Collection presented to Nottingham Museum by, 271 Fisher (Rev. O.), Condition of Interior of Earth, 379 Fisher (Prof. W. R.), New French Law for the Prevention of Forest Fires, 233 ; Tree Pruning, A. des Cars, 526 ; Prac- tical Forestry, Angus D. Webster, 526 ; AfTorestalion in the British Isles, 601 Fitzgerald (Prof. G. F., F. R.S.), Systematic Nomenclature, 148 ; on the Nomenclature of Radiant Energy. 149 ; on the Change of Superficial Tension of Solid Liquid Surfaces with Temperature, 293 ; on the Equilibrium of Vapour Pressure inside Foam, 316 ; P. Lenard's Observations on the Cathode Rays in Gases with High Vacua, 509 Fixation of Nitrogen by Plants, Recent Investigations and Ideas on the. Prof. H. Marshall Ward, F.R.S., 511 Flame : Prof. Arthur Smithells, 86, 149, 198 ; Prof. Henry E. Armstrong, F. R.S., loo, 171 ; G. S. Newth, 171 Flame, Luminosity of Candle Calculable from Dimensions of, P. Glan, 460 Fleming (Mrs.), a New Southern Star discovered by, 38 ; Four New Variable Stars discovered by, 608 Flint-Saws, the Polado, Dr. R. Munro, 183 Flints, the Formation of, A. J. Jukes-Browne, 160 Flood, on a Possible Cause for the Origin of the Tradition of the. Dr. Prestwich, F.R.S., 594 Flora of Texas, the Trinity (Fossil), W. M. Fontaine, 36 Flounders, a Parasitic Disease in, G. Sandeman, 119 Flowering Plants of Western India, the. Rev. A. K. Nairne, 501 Fluids, the Internal Pressure of, and the Form of the Function

-'s Magazine, Science in, 444 Harrington (Prof M. W.), Unusual Rise of Water character- istic of Atlantic Coast Storms, 297 ; History of Weather Map, 329; the Texan Monsoons, 460 ; the Currents in the Great Lakes of Xorth America, 592 Harris (Walter B.), a Journey through the Yemen, 291 Harshbersfer (Dr.), the Original Home of Maize, 298 Hart (J. H.), Transportation of Cacao-Seed, 64 Harting (J. E.), the Great Auk's Egg, 432 Hartl (Colonel H.), Mercurial Barometers Compared with Boiling-point Thermometers, 424 Hartmann (Dr.), Iodine as a Base-forming Element, 442 ; the New Iodine Bases, 467 Hartog (P. J.), on the Latent Heat of Steam, 5 Hartog (Prof. Marcus), on an Undescribed Rudimentary Organ in Human Attire, 199 Harvard College Meteorological Observatories in Peru, Prof, W. H. Pickering, 180 Harvard College Observatory Report, 256 Harvey (Arthur), the Height of an Aurora, 542 Hassall (Dr. A. H.), Death and Obituary Notice of, 581 Hasskarl (Dr. J. K.), Death of, 296 Hauser (Herr), Method for Making Permanent Microscopic Preparations of Particular Colonies on Gelatine Plate, 273 Haweswater, Bathymetrical Survey of. Mill and Heawood, 540 Hay, Spontaneous Heating and Ignition of, M. Berthelot, 240 Hay (W. P.), the Blind Crayfish, 133 Haycraft (Dr. John Berry), Artificial Amcebce and Protoplasm, 79 Hazen (Prof. H. A.), the Climate of Chicago, 15 ; Errors of the Psychrometer, 263 ; Ten Miles above the Earth, 423 ; Solar Magnetic Influences on Meteorology, 464 Healthy Hospitals: Observations on Hospital Construction, Sir Douglas Galton, K.C.B., F.R.S., 290 Heat : on the Latent Heat of Steam, P. J. Hartog and J, A. Harker, 5 ; Heat, and the Principles of Thermodynamics, Dr. C. H. Draper, 148 ; a Te-e,~\ May 31, 1894 J Index XXlll Krahmer(Dr. L.), Death of, 251 Kreitner (Gustav von), Death of, 184 Krueger (Prof.), a Mistaken Cometary Discovery, 608 Kryloff (Mr.), the Upper Yenisei Region, 230 Kiister (Baron K. von), Death of, 270 Kynaston (Herbert), Gosau Beds of Salzkammergut, 239 La Touche (T. D.), the Erosion of Rock Basins, 39 ; the Origin of Lake Basins, 365 Laboratory at Claybury, the Projected Pathological, 129 Laboratories of the Institute of Chemistry, the New, 154 Laboratories, Prof. Ira Remsen on Chemical, 531 Lafar, (Dr.), Vinegar-producing Yeast, 183 Lake (Harry), Johore, 370 Lake Basins, the Origin of, R. D. Oldham, 197 ; Dr. Alfred R. Wallace, F.R.S., 197, 220 ; Sir Henry H. Howorth, F.R.S., 220 ; John Aitken, F.R.S., 315 ; R. S. Tarr, 315 ; Dr. A. M. Hanson, 364 ; T. D. La Touche, 365 ; Alfred C. R. Selwyn, F.R.S., 412 Lake-water, Observations on Amount of Solid Matter in Solu- tion in, A. Delebecque, 160 Lakes of Africa, the last Great, Ludwig von Hohnel, 457 Lakes, the Finger, in New York State, R. S. Tarr, 606 Lakes of North America, the Currents in the Great, Prof. Mark W. Harrington, 592 Laininariacea , the, W. A. Setchell, 207 Lamp, Improved Lantern Oil-, 1 10 Lancaster (A.), the Commencement and End of Winter, 394 Lancaster (J.); the Continuous Flight of Frigate-Birds, 605 Land, Recent Local Rising of, in the North-west of Europe, C. A. Lindvall, 433 Landor (A. H. Savage), Fresh Light on the Ainu, 248 Landscape Marble, Berry Thompson, 522 Langley (Prof. S. P.), the Internal Work of the Wind, 273 ; the Smithsonian Institution Report, 397 Langmore (Rev. C. W.), a Lunar Rainbow, 321 Lankester (Prof. E. Ray, F.R. S. ), Human and Comparative Anatomy at Oxford, 29 ; Reappearance of the Freshwater Medusa {Liinnocodium soiverbii, 127 ; Collected Essays, Prof. . T. H. Huxley, 310; the Limbs of Lepidosiren paradoxa, 555, 601 Lansdell (Henry), Chinese Central Asia: a Ride to Little Tibet, W. F. Kirby, 309 Lantern Oil Lamp, Improved, no Lantern Slides, Method for Colouring, for Scientific Diagrams, Dr. J. Alfred Scott, 572 Lapouge (G. de). Description of Sixty-two Crania taken from a Modern Cemetery at Karlsruhe, 520 Lapworth (Prof. Chas., F.R.S.), the Face of the Earth, 614 Larmor (Dr. Joseph, F. R. S.), a\ Dynamical Theory of the Electric and Luminiferous Medium, 260, 280 Larsen (Captain), High Southern Latitude reached by Jason Whaler, 559 Latent Heat of Steam, on the, P. G. Hartog and J. A. Harker, 5 Latitude the Variation of. Prof. S. C. Chandler, 133 Latitude, on Variations of, F. Folic, 376 Latitude and Sea Level, the Variation of, Prof. Bakhuyzen, 476 Latitude, the Definition of, F. Folic, 546 Laurie (Malcolm), Morphology of Pedipalpi, 378 Lausanne Municipal Council and Electrical Transmission of . Power, 107 Lavoisier, Proposed Celebration of Centenary of Death of, 603 Lawrance (H. A.), Correlation of Magnetic and Solar Phe- nomena, lOI Laws (Mr.), Distribution of Zymotic Disease by Sewer Air, 347 Lawson (Dr. A. C. ), Anorthosytes of Minnesota Coast of Lake Superior, 131 ; Laccolitic Sills of North- West Coast of Lake Superior, 131 Le Chatelier (H.), General Law of Solubility of Normal Sub- stances, 524 ; on the Fusibility of Mixtures of Salts, 595 Le Sueur (H. R.), Salts of Dehydracetic Acid, 425 Lea (M. C.), Researches on Transformation of Mechanical Work into Chemical Action, 181 Lecher's Method, the Various Electric Wave- Systems obtained by, Signor Mazotto, S3 Lecouteux (Prof. E.), Death and Obituary Notice of, 33 Lecture, the Bakerian, 392 Lecture Experiment, a, J. C. Foye, 531 Leduc (A.), Proposed Standard of Normal Air, 272 Leger(E.), a New Isomeride of Cinchonine, 263 Lehmann(Prof. K. B.), Methods of Practical Hygiene, 285 Lehmann (O.), the Artificial Colouring of Crystals and Amor- phous Bodies, 376 Leidie (E.), Action of Heat on Potassium and Sodium Ruth- enium Nitrites, 452 Leland (G. C), Elementary Metal Work, 554 Lellmann (Dr. E.), Death of, 206 Lemoine (M.), Influence of Heat on Reactions in Aqueous Solutions containing Ferric Chloride and Oxalic Acid, 65 Lenard's (O.) Observations on the Cathode Rays in Gases with High Vacua, 509 Lepidoptera, Vertical Distribution of British, W. H.' Bath, \ 346 Lepidoptera : the Butterflies and Moths of Teneriffe, A. E. Holt White, W. F. Kirby, 384 Lepidosiren paradoxa, the Limbs of, Prof. E. Ray Lankester, F.R.S., 555, 6oi ; Prof. G. B. Howes, 576 Lepierre (Charles), New Ptomaine extracted from Damaged Cheese, 452 Leprosy, the Bacilli of, N. Wnukow, 231 Leslie (George D.), Letters to Marco, 170 Letourneau (Ch.), Stone Cross found at Carnac, 330 Letters to Marco, George D. Leslie, 170 Leucocytosis, Dr. Goldscheider, 167 Leverett (Frank), Further Studies of the Drainage Features of the Upper Ohio Fasin, 617 Lewes (Prof. Vivian B.), Action of Heat upon Ethylene, 424 Lewin (Dr.), Physiology of Ureter, 48 Ley (Rev. W. Clement), Sun-spot Phenomena and Thunder- storms, 531 Leyden, the Ethnological Museum at, Dr. H. ten Kate, 165 Leyden Museum, Notes from the, 161 Libraries, Manchester Free, Forty-first Report of, 133 Libraries, Science at the Free, Mr. Carrington, 418 Lichen, Edible, of Japan, Dr. M. Miyoshi, 253 Life and Rock : a Collection of Zoological and Geological Essays, R. Lydekker, 575 Light, Effects of, on the Electrical Discharge, 226 Light, the Unit of. Dr. Lummer, 356 Light, Lectures on Maxwell's Theory of Electricity and, Dr. Ludwig Boltzmann, 381 Light : an Elementary Text-book, Theoretical and Practical, for Colleges and Schools, R T. Glazebrook, F.R.S., 432 Light, Elliptic Polarisation of. Reflected, K. E. F. Schmidt, 547 Light, Normal and Anomalous Changes of Phase during Reflection by Metals of, W. Wernicke, 547 Light, the Kathodic, Prof. Goldstein, 427 Light- Waves and their Application to Metrology, Prof. A. A. Michelson, 56 Light-sensation, Miss C. L. Franklin's New Theory of, 394 Lighthouses and Light-ships ; Proposed Improved System of Distress Signals, 580 Lighthouses and Lightships without Submarine Cable, Electric communication between, C. A. Stevenson, 581 Lighting, Artificial, of Workshops, B. A. Dobson, 18 Lightning, Method of Photographing Spectrum of, G. Meyer, 417 Lightning? are Birds on the Wing killed by, Skelfo, 577; G, W. Murdoch, 601 Lillienthal's Experiments on Flying, Dr. A. du Bois-Reymond, 355 Limnocodium soiverbii. Reappearance of the Freshwater Medusa, Prof. E. Ray Lankester, F.R.S., 127 Lindet (L. ), Development and Maturation of the Cider Apple, 119 Lindvall (C. A.), Recent Local Rising of Land in the North- west of Europe, 433 Linnean Society, 94, 166, 191, 263, 307, 378, 425, 474, 522, 595 Linnean Society, New South Wales, 119, 168, 264, 424 Liquid Commutator for Sinusoidal Currents, a, Prof. J. A. Ewing, F.R.S., 317 Liquids, Viscosity of, O. G. Jones, 402 Liquids, the Internal Friction of, Prof. T. E. Thorpe, F.R.S., and J. W. Rodger, 419 Liquids, Methods of Determining Refractive Indices of, Mr. Littlewood, 450 XXIV Index V Supplement to Nature, L May 11, 1894 Liquids, the Decomposition of, by contact with Cellulose, C. Beadle, 457 Liquids, the Behaviour of, under High Pressure, J. W. Rodger, 506 Lissajous's Figures, Lnproved Form of Blackburn's Pendulum for Slow Production of, Prof. A. Righi, 582 Literature, the Earliest Mention of the Kangaroo in, Baron C. R. Osten-Sacken, 198 ±-.Utledale (St. George), Across Central Asia, 567 LiUlewood (Mr.), Method of Determining Refractive Indices of Liquids, 450 Liver- Ferment, Note on the. Miss M. C. Tebb, 523 Liversidge (Prof. A..), the Origin of Gold Nuggets, 415 Livingstone (Dr.) and the Zambesi Ants, 95 Lochner (L. J.), the Elongation of Soft Iron by Magnetisation, 160 Lock's (J. B ) Shilling Arithmetic, Key to, Henry Carr, 480 Lockyer (J. Norman, F.R.S.), Early Asterisms, 199 Lockyer (N. J.), Round the Works of our Great Railways, 312 ; a Text-Book on Gas, Oil, and Air Engines, Bryan Donkin, 430 Locomotion of Animals, Chrono-Photographic Study of the, Locusts, Dried, as Food for Insectivorous Cage and Game Birds, Dr. Glinther, E. C. Cotes, 253 Locusts in England, Miss E. A. Ormerod, 253 Lodge (Prof. Oliver J., F.R.S.), Clerk Maxwell's Papers, 366 Lommel (E. von), Objective Representation of Interference Phenomena in Spectium Colours, 46 London Lunatic Asylums, the Projected Pathological Labora- tory in connection with, 129 London, Map of Electric Lighting Districts of, 298 London, University of, the Proposed Reconstruction of the, 558 Loney (S. L.), Solutions of the Examples in the Elements of Statics and Dynamics, 122 ; Plane Trigonometry, 339 Long (Prof.), Agricultural Resources of Canada, 561 Longman! s Magazine, Science in, 156 Loomis (E. H.), a more Exact Method for Determination of Lowering of Freezing-points, 547 Lott (Frank E. ), Micro-organisms and Fermentation, 577 Love (A. E. H.), Stability of Certain Vortex Motions, 118; Motion of Paired Vortices with a Common Axis, 499 Lovett (Edward), Prehistoric Man in Jersey, 487 Low Vapour Pressures, Measurements of, J. W. Rodger, 436 Lowe (E. J., F.R.S.), Abnormal Eggs, 366 Lubudi River, the, 582 Liidtke(Herr H.), Properties of Mirror Silver chemically Pre- cipitated on Glass, 229 Lukuga River explored by M. Delcommune, 559 Luminiferous Medium, a Dynamical Theory of the Electric and. Dr. Joseph Larmor, F. R.S., 260, 280 Luminosity of Candle Calculable from Dimensions of Flame, P. Glan, 460 Lummer (Dr.), the Unit of Light, 356 Lunar Rainbow, a, Rev. C. W. Langmore, 321 Lunatic Asylums, London, the Projected Pathological Labora- tory in connection with, 129 Lydekker (Richard), the Royal Natural History, 220; Life and Rock : a Collection of Zoological and Geological Essays, 575 McAulay (A.), Utility of Quaternions in Physics, Prof. P. G. Tait, 193 Macaulay (F. S.), Groups of Points on Curves, 498 McConnell (W.), Gases occluded in Coal from various Durham Collieries, 232 Macdonald's (Sir Claude) Journey up the Cross River, 346 Macfarlane (A.), Electric Strength of Solid, Liquid, and Gaseous Dielectrics, 181 Macfarlane (Dr. A.), on the Definitions of the Trigonometric Functions, 480 Macgillivray (G. J.), Recognition Marks, 53 McGregor (J. M.), Ethereal Salts of Diacetylglyceric Acid in relation to connection between Optical Activity and Chemical Constitution, 142 Machine Drawing, Thomas Jones and T. Gilbert Jones, 362 Mack (F. W.), a Comet-Finder, W. R, Brooks, 543 McKay (Capt,), the Fate of the Bjorling Arctic Expedition, 85 McKillop (Mr.), the Interaction of Hydrogen Chloride and Potassium Chloride, 118 McLachlan (R., F.R.S.), the Postal Transmission of Natural History Specimens, 172 Maclear (Rear- Admiral, J. P.), Aurora of February 28, 442 Macleay Memorial Volume, the, 597 McLeod (H.), Liberation of Chlorine during Heating of Mix- ture of Potassium Chloride and Manganic Peroxide, 425 McMurtrie's (Mr. James) Collection of Fossil Plants acquired by South Kensington Museum, 415 McNair (Capt. F. V.), U.S. Naval Observatory, 324 Madagascar, the Silk-Spider of. Dr. Karl Midler, 253 Madras, Wrought Iron Making in, 255 Madras Observatory, 511 Magazines, Scienc2 in the, 31, 155, 235, 352,443, 543 Magnetism : Correlation oi Solar and Magnetic Phenomena, William Ellis, F.R.S., 30, 245 ; H. A. Lawrance, loi ; Dr. M. A. Veeder, 245 ; Sun-spots and Magnetic Disturbances, Dr. M. A. Veeder, 503 ; Dr. L. Palazzo, 397 ; Magnetic Susceptibility of Oxygen, K. Hennig, 108; Magnetic Rotary Dispersion of Oxygen, Dr. Siertsema, 607 ; Magnetic Shield- ing of Concentric Spherical Shells, Prof. A. W. Riicker, F. R.S., 141 ; Magnetic Experiments in Senegambia, T. E. Thorpe, F.R.S., and P. L. Gray, 141 ; Elongation of Soft Iron by Magnetisation, S. J. Lochner, 160 ; Law of Mag- netisation ot Soft Iron, P. Joubin, 284, 308 ; Magnetic Field of Current running in Cylindrical Coil, Prof. G. M, Minchin, 190 ; the Hysteresis attending Change in Length produced by Magnetisation in Nickel and Iron, H. Nagaoka, 229 ; Prof. Knott, 230 ; Magnetisation of Iron and Nickel Wires by Rapid Electrical Oscillations, Prof. Klemencic, 607 ; Magnetic-Twist Cycles for Iron and Nickel, Prof. Knott, 230 ; Magnetic Rotation of Hydrogen and Sodium Chlorides and Chlorine in Different Solvents, W. H. Perkin, 239 ; Report for 1892 of Magnetic Observatory of Copenhagen, 298 ; Notes on Recent Researches in Electricity and Magnetism, J. J. Thomson, F.R.S., Prof. A. Gray, 357 ; a TextBpok on Electromagnetism and the Construction of Dynamos, Dugald C. Jackson, Prof. A. Gray, 429 ; Variations of the Pelthier Effect Produced by Magnetisation, L. Houllevigue, 524 ; " Magnetarium," H. Wilde, F.R.S., 521 ; Magnetic Proper- ties of Iron at Various Temperatures, M. P. Currie, 595, 620 ; New Apparatus for Absolute Measurement of the Magnetic Properties of Different Kinds of Iron, Dr. Roepsel, 595 Magnitude and Position of T Aurigae, M. Bigourdan, 85 Magnus (Sir Philip), Elementary Course of Practical Science, Hugh Gordon, 121 ; on Preparing the Way for Technical Instruction, 400 Maize, the Original Home of. Dr. Harshberger, 298 Mallock(A.), Insect Sight and Defining Power of Composite Eyes, 472 Malpighi (Dr. Marcellus), 583 Malta, the Har Dalam Cavern, 514 Mamert (Thomas), on j8-dibromopropionic Acid, 524 Mammalia in North America, the Rise of the. Prof. H. F. Osborn, 235, 257 Man, the Perfect, Dr. Topinard, 520 Man of Mentone, the, Arthur J. Evans, 42 Manchester Free Libraries, Forty first Report of, 133 Manganese Nodules, the Origin of. Prof. J. W. Judd, 235 Manganese Peroxide in Sewage, Reduction of, W. E. Adeney, 499 Manoeuvring Powers of Steamships and their Practical Applica- tions, Vice-Admiral P. H. Colomb, R.N., 174 Maples, Sugar, W. Trelease, 323 AlarattiaccLV, Development of the Mucilage-Canals of the, George Brebner, 523 Marchal (Paul), the Reproduction of Wasps, 47 Margerie (De), Geographical Conditions of Pyrenees, 275 Marine Biology : the Pteropod Collections of the Albatross, 36 ; Week's Work of Plymouth Station, 37, 67, 84, 162, 323, 372, 418; some Laboratories of Marine Biology, 70; Projected Marine Biological Station at Millport, N.B. , 180; the Pro- tective Colouration of Vibriits varians, Prof. W. A. Herd- man, F.R.S., 417 ; the Floor of the Ocean at Great Depths, Dr. John Murray, 426 ; Entomostraca and Surface Film of Water, Dr. J. Scourfield, 474; the Rovigno Station, 560; the Melbourne Exhibition Aquarium, 583 Marine Boiler Management and Construction, C. E. Stromeyer, 410 SicpplcDieiit to Natnrc,~\ Jl/ay 31, 1894 J Index XXV Marine Engine Trials, Abstract of Results of Research Com- mittee, Prof. T. li. Beare, 350 Marine Engineering, Effect of Reversing Screw of Steamship on Steering, Captain Bain, 208 Marine Organisms, the Chemical Action of, Prof. J. W. Judd, 235 Markham (Clements R., F.R.S.), the Present Standpoint of Geography, 69 Marr (John E. ), the Zoological Record, 123 Marrio'tt (W.) : Thunder and- Hailstones of July 8, 1S93, 1 19 ; Comparative Observations with Two Thermometer Screens at Ilfracombe, 426 ; the Koyal Meteorological Society's Ex- hibition, 579 Mars, Melting of the Polar Caps of, Prof. W. H. Pickering, 5S6 Marshall (Prof. Milnes, F.R.S.): Death of, 228; Obituary Notice of, 250 ; Proposed Memorial to, 368 Martel (E. A. 1, Investigation of Adelsberg Grotto, 256 Martin (T. C), Nikola Tesla, 352 Mascart (M.) : Propagation of Electromagnetic Waves. 379 ; M. Blondlot's Experiment on Propagation of Hertzian Waves, 394 Mason (A. T.) : Synthesis of Piazine Derivatives, 118 ; Inter- action of Benzylamine and Ethylic Chloracetate, 377 Mass of the Earth, the, 575 Massachusetts Institute of Technology, 20 Massachusetts Coast Sea- Water and Mud, Russell's Observa- tions on Microbial Condition of, 37 Massachusetts, the Gipsy Moth Plague in, 231 Massee (George), British Fungus Flora, a Classified Text-book of Mycology, 195 Masson (M.), Sterilisation of Bread and Biscuit by Baking, 167 Materia Medica, Chemistry in Relation to Pharmaco-Thera- peutics and, Prof. B. J. Stokvis, 587 Mathematics : Asymmetrical Frequency Curves, Prof. Karl Pearson, 6 ; Mensuration of the Simpler Figures, William Briggs and T. W. Edmondson, 28 ; Bulletin of New York Mathematical Society, 71, 188, 402, 497, 570; American Journal of Mathematics, 93, 449 ; Simple Groups as far as Order 660, F. N. Cole, 93 ; Instruments for Drawing Conic Sections, J. Gillett, 94; Mathematical Society, 118, 215, 284, 425, 498, 61 8 ; Stability of Certain Vortex Motions, A. E. H. Love, 118 ; Note on Theory of Groups of Finite Order, Prof. W. Burnside, F.R.S., 118; Solutions of the Examples in the Elements of Statics and Dynamics, S. L. Loney, 122 ; Formula giving all Values of Integral for Probable Error, Herr Bruno Kampfe, 133 ; Regular Sections and Projections of Ikosatetrahedron, Prof. Schoute, 144 ; a Certain Class of Generating Functions in Theory of Numbers, Major MacMahon, F.R.S., 189; French Lady Mathematicians, M. Darboux, 205 ; Stability of Deformed Elastic Wire, A. B. Basset, F. R.S., 215 ; Quaternionic In- novations, Oliver Heaviside, F.R.S.,246; Modern Mathe- matical Thought, Prof. Simon Newcomb, F. R. S. , 325; the Applications of Elliptic Functions, Alfred George Greenhill, F.R.S., H. F. Baker, 359; Death of General J. Ammen, 368; Death of Eugene Catalan, 415; Lectures on Mathe- matics, Prof. Felix Klein, 456 ; a Treatise on the Theory of Functions, James Harkness and Frank Morley, 477 ; on the Definitions of the Trigonometric Functions, Dr. A. Macfar- lane, 480; on a Spherical Vortex, Dr. J. M. Hill, 498; Groups of Points on Curves, F. S. Macaulay, 498 ; a Simple Contrivance for Compounding Elliptic Motions, G, H. Bryan, 498 ; on the Buckling and Wrinkling of Plating supported on a Framework under the Influence of Oblique Stresses, G. H. Bryan, 499 ; on the Motion of Paired Vor- tices with a Common Axis, A. E. H. Love, 499 ; Mathe- matical Calculating Machines, Prof. O. Henrici, F.R.S., 521 ; Harmonic Analysers, 521 ; Prof. Crum Brown on the Division of a Parallelepiped into Tetrahedra, 571 ; an Ele- mentary Treatise on Fourier's Series, W. E. Byerly, 598 ; a Text-Book of Euclid's Elements, H. S. Hall and F. H. Stevens, 599 ; on Regular Difference Terms, A. B. Kempe, F.R.S., 618 ; on the Sextic Resolvent of a Sextic Equation, Prof. W. Burnside, F.R.S., 618 Mather (T. ), Transparent Conducting Screens for Electric and other Apparatus, 591 Mawer (W. ), Nature Pictures for Little People, 529 Mawley (E.), Phenological Observations for 1893, 426 Maxwell's Theory of Electricity and Light, Lectures on, Dr. Ludwig Boltzmann, 381 Maxwell's (Clerk) Papers, Prof. Oliver J. Lodge, F.R.S., 366 Mayall (R. H. D.), Current-Sheets, 452 Mayer (A. M.), Researches in Acoustics, No. 9, 305 ; an Appa- ratus to show simultaneously to several Ilearer.s the Blend- ing of the Sensations of Interrupted Tones, 617 Mazotto (Signor), the Various Electric Wave Systems obtained by Lecher's Method, 83 Measurements, Physico-Chemical, W, Ostwald, J. W. Rodger, 219 Mechanical Engineers, Institution of, 18, 350, 608 Mechanical Tneory of Comets, Prof. J. M. Schaeberle, 84 Medical Congress, the International, 538, 563 ; the Eleventh International, Piero Giacosa, 578 Medicine : Death of Dr. S. Guttmann, 251 ; Death of Dr. L. Krahmer, 251 Medicine-Men of Apache Indians, Capt. J. G. Bourke, 439 Medusa, Reappearance of the Freshwater {Livinocodium soioerbii), Prof. E. Ray Lankester, F.R.S., 127 Meek (Alexander), the Arbuthnot Museum, Peterhead, 20 Meeres, Bionomie des, Johannes Walther, 244 Melbourne Exhibition Aquarium, the, 583 Melde (S.), Determination of Pitches ol very High Notes, 560 Melius (Dr. E. L.), Experimental Investigation of the Central Nervous System of the Monl.obinson, 444 ; Rugby School Natural History Society, 541 Natural Science: Death of William Dinning, 81 Nature Lovers, a Correspondence, Geo. D. Leslie, 1 o Nature Pictures for Little People, W. Mawer, 529 Naval Architects, the Institution of, 490 Naval Architecture : the Manoeuvring Powers of Steamships and their Practical Applications, Vice- Admiral P. H. Colomb, R.N., 174; Marine I5oiler Management and Construction, C. E. Stromeyer, 410 Naval Observatory, U.S., Captain F. McNair, 324 Navigation : Effect of Reversing Screw of Steamship on Steer- ing, Captain Bain, 208 Navigation by Semi-Azimuths, Ernest Wentworth BuUer, 223 Navigator, Prince Henry the, 443 Nawaschin (S.), the Embryonal Development of the Birch, 23 Nebulae, New, 464 Nebular Lines, the Wave-Lengths of the, Prof. Keeler, 18 Nebulosities in the Milky Way, Photographic, Prof. E. E. Barnard, 511 Neesen (Prof.), Method of Coating Aluminium with other Metals, 216 Neolithic Age in Nicaragua, Evidence of Existence of Man in, J. Crawford, 107 Neolithic Discoveries in Belgium, 227 Neptune, the Satellite of. Prof. Struve, 324 ; IVL Tisserand, 543 Nerve Centres, the Minute Structure of the, Prof. Ramon y Cajal, 464 Netherlands Entomological Society, 332 Netherlands Zoological Society, 24, 264 Neville (F. H.), Freezing points of Alloys in v\hich the Solvent is Thallium, 239 ; Freezing-points of Triple Alloys, 306 New South Wales : Government Report of Meteorological Observations for 1892, H. C. Russell, 252 New South Wales Linnean Society, 119, 168, 264 New York Mathematical Society, Bulletin of, 71, 188, 330, 402, 497.^570 New York State, the Finger Lakes in, R. S. Tarr, 606 New Zealand, Beetles of, W. F. Kirby, 459 Newall (H. F.), Combination of Prisms lor a Stellar Spectro- scope, 379 Newberry (P. E.), Beni Hasan, 169, 432 Newcomb (Prof. Simon, F.R.S.), Suggested Nomenclature of Radiant Energy, 100 ; Modern Mathematical Thought, 325 Newhall (Charles S.), the Shrubs of North-Eastern America, 28 Newman (Mr.), Micro Organisms in Ice, 322 Newth (G. S.), Flame, 171 ; a Lecture Experiment, 293 Newton (Prof. Alfred, F. R.S.), Great Auk's Egg, 412, 456 Newton(E. T., F.R.S.), Two New Reptile Genera from Elgin Sandstone, 189 ; the Vertebrate Fauna collected by Mr. W. J. L. Abbott from Fissure near Ightham, 355 Niagara, the Falls of, and its Water-Power, 482 Niagara District, Inferred Rate of Terrestrial Deformation in the, 520 Nicaragua, Evidences of Existence of Man in Neolithic Age in, J. Crawford, 107 Nichols (Prof. E. L.), Phenomena of the Time-Infinitesimal, "3 Nineteenth Century, a Popular History of Astronomy during the, Agnes M. Gierke, 2 Nisbet (J.), British Forest Trees, i ; the Climatic and National Economic Influence of Forests, 302 Nitrogen, Recent Investigations and Ideas on the Fixation of, by Plants, Prof. H. Marshall Ward, F.R.S., 51 1 Nogucs (A. C.), Fractions of Coal-Measures oif Southern Chili, 47; Glacial and Erratic ^Phenomena in Cachapoal Valley, Chili, 72 : Eruption of El Callmco Volcano (Andes), 179 Nolan (Edw. J.), the Postal Transmission of Natural History Specimens, ico . _ ,„ t Nomenclature of Radiant Energy, on the. Prof. Simon New" comb, F.R.S., 100; Prof. G. F. Fitzgerald, F.R.S., 149; Prof. A. N. Pearson, 389 Nomenclature, Systematic, Prof. G. F. Fitzgerald, F.R.S., 148 ; Fred. T. Trouton, 148 Noorden (Dr. von), the Action of Quinine on Metabolism of Man, 427 Norma, the New Star in, 85 Normte, the Spectrum of Nova, 162, 397 North x^merica, the Rise of the Mammalia in. Prof. H. F. Osborn, 235, 257 North America, the Currents in the Great Lakes of. Prof. Mark W. Harrington, 592 North-East W^ind, the, S. H. Burbury, F.R.S., 481 North-East Wind, the. — Devonian Schists, Prof. T. G. Bonney, F.R.S., 577 Noith Sea, Geographical Evolution of the, A. J. Jukes- Browne, 32 Norway, Bird Life in Arctic, Robert Collet, 599 Norwegian Sealers in Antarctic Waters, 461 Notation, New, for Lines in Spectrum of Hydrogen, 162 Notes from the Leyden Museum, 161 Nottingham Museum, Botanical Collection presented by Mr. H. Fisher to, 271 Nourrisson (C), Minimum Electromotive Force necessary for Electrolysis of Dissolved Alkaline Salts, 331 Nova AurigK, 373 ; Prof. E. S. Holden, 32 Nova Normre, the Spectrum of, 162, 397 ; Prof. W. W. Campbell, 586 Novitates Zoi^logica;, 396 Nuovo Giornale Botanico Italiano, 424, 594 Object-Glass, a New Achromatic, 464 Obrecht (Dr.), Diurnal Ground-Movements at Santiago, 130 Obrucheff's (W. A.) Journey in Ordos Region, 233 Obrucheff (Mr.), the Plateau of Shan-si, 230 Observatories : the Observatory for November, 67 ; the Natfil Observatory, 85, 562 ; Solar Observations at Rome, 163 ; the Vatican Observatory, R. A. Gregory, 341 ; the Com- panion to the Observatory, 163 ; Harvard College Observatory Report, 256 ; Report of the Wolsingham Observatory, 300 ; U.S. Naval Observaiiories, Captain F. McNair, 324 ; Madras Observatory, 511 ; Harvard College Meteorological Observa- tories in Peru, Prof. W. H. Pickering, 180; the Sonnblick Mountain Observatory, 204 ; M. Faye on Mountain Observa- tories in Connection with Cyclones, 620 Occultation of Spica, 464 Ocean at Great Depths, the Floor of the, Dr. John Murray, 426 Oceanic Currents, Experiments with Floats on, 301 Oettel's (Dr.) Researches on Phenomena of Electrolytic Deposition of Metals, 16 Ohio Basin, Upper, Further Studies of the Drainage Features of the, T. C. Chamberlin and Frank Leverett, 617 Oil in Calming Troubled Waters, Best Method of Using, Dr. M. M. Richter. 488 Old (Colonel Walter R.), the Nativity of Rama, 4 Oldenburg (Henry), First Secretary of Royal Society, Herbert Rix, 9 Oldham (R. D.), Rock Basins in the Himalayas, 77 ; Evolution of Geography of India, 163 ; the Origin of Lake Basins, 197 ; the Origin of Rock Basins, 292 Ophthalmology : Radius of Curvature of Cornea, Drs. Chapman and Brubaker, 229 Optics : Optical Properties of Quartz Plate compressed Perpen- dicularly to Axis, F. Beaulard, 37 ; Vision of Opaque Ob- jects by means of Diffracted Lights, M. Gouy, 72 ; some Phenomena of Diffraction, W. B. Croft, 354 ; Numerical Verifications relating to Focal Properties of Plane Diffraction Gra'ings, A. Cornu, 239; the Use of Collodion Films coloured with Fuchsine in Measurement of Light- Absorp- tion, Salvador Bloch, 108 ; Differential Method of determin- ing Refractive Index of Solutions, W. Hallwachs, 206; Change of Intensity of Light Polarised Parallel to Plane of Incidence by Reflection on Glass. Paul Glan, 239 ; a New Mode of making Magic Mirrors, J. W. Kearton, 354 ; New Photometric Method, J. B. Spurge, 355 ; the Unit of Light, Dr. Lummer, 356 ; Magnetic Rotary Dispersion of Carbon Bisulphide in Infra-Red Part of Spectrum, G. Moreau, 370 ; Instrument of Precision for producing Monochromatic Light Supplement to Nature^ May 31, 1894 J Index XXIX of any desired Wave-Length, A. E. Tatton, 377 ; the Effect of Wave-Length in dealing with Refractive Index in elucida- tion of Chemical Constitution, MM. Jahn and MoUer, 582 ; Vision with Compound Eyes, Dr. G. J. Stoney, 379 ; Miss C. L. Franklin's New Theory of Light-Sensation, 394 ; Re- lationship between Epilepsy and Errors of Refraction in Eye, H. W. Dodd, 395 ; the Systematic Aplanatic Objective, C. V. Zenger, 426 ; the Kathodic Light, Prof. Goldstein, 427 ; Luminosity of Candle calculable from Dimensions of Flame, P. Glan, 460 ; Insect Sight and Defining Power of Composite Eyes, A. Mallock, 472; Elliptic Polarisation of Reflected Light, K. E. F. Schmidt. 547 ; Norma! and Anomalous Changes of Phase during Reflection of Light by Metals, W. Wernicke, 547 ; Colour Vision, the Board of Trade and the Railway Companies, 558 ; Kirchhoff's Law connecting Ab- sorptive and Emissive Powers of Substances tested for Glass by G. B. Rizzo, 606 Orchid Seekers, the, Ashmore Russan and Frederick Boyle, 28 Orchids, W. A. Styles, 352 Orchids, Extra-Tropical, Henry Bolus, R. A. Rolfe, 50 Ordos Region, W. A. Obracheff's Journey in, 233 O'Reilly (Dr. M. F.), a Brilliant Meteor, 341 Organic Chemistry, Dictionary of the Active Principles of Plants, C. E. Sohn, 385 Orientation, on the Cardinal Points of the Tumyan Villagers, J. Walter Fewkes, 388 Origin of Lake Basins, the, R. D. Oldham, 197 ; Dr. Alfred R. Wallace, F.R.S., 197 ; John Aitken, F.R.S., 315 ; R. S. Tarr, 315 ; Dr. A. M. Hanson, 364 ; T. D. LaTouche, 365 ; Alfred C. R. Selwyn, F.R.S., 412 Origin of Rock Basins, the, R. D. Oldham, 292 Ormerod (Miss E. A.), Insects' Attacks on Crops and Trees, 253 ; Report of Observations of Injurious Insects and Common Farm Pests during the Year 1893, 480 Orndorff (M.), Polymeric Modifications of Acetic Aldehyde, 396 Ornithology : an Ornithological Retrospect, Dr. R. Bowdler Sharpe, 6; Frank E. Beddard, F.R.S., 31; the Apteryx Genus, Hon. Walter Rothschild, 14 ; the New Bird Protec- tion Bill, 54 ; Death of Dr. A. K. E. Baldamus, 8l ; Threat- ened Extermination of the Great Skua, W. E. Clarke, 253 ; the Great Auk's Egg, 432; Prof. Alfred Newton, F.R.S., 412, 456 ; Great Auk's Egg sold for 300 Guineas, 415 ; the Ptarmigan of Aleutian Islands, W. B. Evermann, 584 ; Bird Life in Arctic Norway, Robert Collet, 599 ; Are Birds on the Wing killed by Lightning? Skelfo, 577; G. W. Mur- dochs, 6oi ; the Continuous Flight of Frigate-Birds, J. Lan- caster, 605 Os Pedis in Ungulates, the, Prof. A. E. Mettam, 341 Osborn (Prof. H. F. ), the Rise of the Mammalia in North America, 235, 257 Osmond (F.), Alloys of Iron and Nickel, 476 Ossiferous Contents, the Har Dalam Cavern and its, 514 Osteology : Zur Kenntniss der Postembryonalen Schiidelmeta- morphosen bei Wiederkauern, H. G. Scehlin, 99 Ostwald (W.), Hand- und Hilfsbuch zur Ausfiihrung physiko- chemischer Messungen, J. W. Rodger, 219 Oudemans (Prof. J. A. C.), Accuracy of Divisions of Altazi- muths of Pistor and Martin and of Repsold, 192 Out-door World, or Young Collector's Handbook, W. Fur- neaux, 52 Oxford, Human and Comparative Anatomy at. Prof. J. Burdon Sanderson, F.R. S., 6: Prof. E. Ray Lankester, F.R.S., 29 Oxygen in Asphyxia, the Physiological Action of, 16 Oxygen, Magnetic Susceptibility of, R. Hennig, 108 Oxygen in the Sun, the Presence of. Dr. Janssen, 585 Ozone, Influenza and Fever, 180 Pacific, North, Ocean, United States Pilot Chart of, 347 Painter's Colours, Oils, and Varnishes, a Practical Manual, Geo. H. Hurst, 194 Palseolithics : the Forgery of Palaeolithic, &c.. Implements, Sir John Evans, 156 ; the Polado Flint Saws, Dr. R. Munro, 183 Palaeontology : Dr. von Zittel's Handbook of, 64 ; Mammoth Remains in Canada and Alaska, Dr. G. M. Dawson, F.R.S., Sir Henry Howorth, 94 ; a Nothosaurian Reptile from the Trias of Lombardy, Mr. Boulenger, 95 ; Congenerousnsss of Pieranodoii, Marsh, with Onilthostoma, Seeley, Prof. Willi- ston, 109 ; the Diprotodon and its Times, C. W. de Vis, 159 ; Two New Reptile Genera from Elgin Sandstone, E. T. Newton, F.R.S., 189 ; the Thoracic Legs of Triarthrus, C. E. Beecher, 214 ; a Thylacine of Earlier Nototherian Period in Queensland, C. W. de Vis, 264 ; Complete Ple- siosaurus found in Wiirtemberg, 271 ; the Alleged Ante- primordial Fauna of Bohemia, Dr. Jahn, 297 ; the Thero- suchia, H. G. Seeley, F.R.S., 450; Diademodon, II. G. Seeley, F.R.S. , 450; the Har Dalam Cavern and its Ossi- ferous Contents, 514 Palazzo (Dr. L.), Sun-spots and Magnetic Disturbances, 397 Pamirs, M. de Poncins' Explorations in the, 18 Pamirs crossed by E. Poncins, 163 Panmixia, George J. Romanes, F.R.S., 599 Parallelepiped into Tetrahedra, Prof. Criim Brown on the Division of a, 571 Paiasitic Theory of the Causation of Malignant Tumours, J. Jackson Clarke, 502 Parenty (H.), Forms of Steam Jets from various Orifices, 347 Paris: Academy of Sciences, 23, 47, 71, 96, 119, 143, 167, 191,215,239,263, 283, 308, 331, 355,379- 404,426,452, 475, 500, 524, 548, 572, 595, 620 ; Prize Awards, 215, 233 ; Prize Subjects of the Paris Academy of Sciences, 234 ; Memoires de la Societe d'Anthropologie de Paris, 283 ; Bulletins de la Societe d'Anthropologie de Paris, 306, 330 ; Pasteur Institute, Statistics for November, 322 ; Streets named after Men of Science, 558 ; Paris Geographical Society Awards, 559 Parsons (F. G. ), Myology of the Hystricomorphine and Sciura- morphine Rodents, 523 Paschen (F. ), Spectra of Hot Gases probably due to Tempera- ture, 82 Passarge (Dr.), the German Expeditton to Delimit Hinterland of Cameroons, 68 Pasteur Institute for India, Proposed, 13, 180 Pasteur Institute, the Proposed Indian, and the Anti-Vivisec- tionists, 130 Pasteur Institutes to be established in Turkey, 437 Pasteur Institute Statistics for November, 322 Pasteur Institute, Report for 1893 of, Henri Poitevin, 581 Pastukoff's (A. v.). Ascent of the Elbrus, 515 Pathology : the Projected Pathological Laboratory at Clay- bury, 129; Death of Dr. E. H. Jacob, 486; the C. C. Walker Prize for Investigation of Cancer, 508 ; Tetanus- Poison, Drs. Fermi and Pernossi, 540 Paton (Dr. Noel), Hepatic Glycogenesis, 141 Patten (Lieut. J.), Novel Method of obtaining Sinusoidal Alternating Currents of very Low Frequency, 253 Pavement, Asphalte, Petroleum in relation to, S. P. Peckham, 306 Pearson (Prof. A. N.), the Nomenclature of Radiant Energy,. 389 Pearson (Prof. Karl), Asymmetrical Frequency Curves, 6 Peckham (S. P.), Petroleum in relation to Asphalte Pave- ment, 306 Peddie (Dr. W.), Torsional Oscillations of Wires, 331 Pedipalpi, Morphology of, Malcolm Laurie, 378 Pellat (M.), the Point of Application of Electro-Magnetic Forces, 488 ; Point of Application of Mechanical Force experienced by Conductor conveying Current in Magnetic Field, 590 Pendlebury (W. H.), the Interaction of Hydrogen Chloride and Potassium Chloride, 118 Penfield (S. L. ), Chemical Composition of Staurolite, 402 PengeIly(W., F.R.S.), Death of, 486; Obituary Notice of, Prof. W Boyd Dawkins, F.R.S., 536; Pengelly (William), J. Starkie Gardner, 554 ; W. Pengelly, F.R.S., and the Age of the Bovey Lignite, A. R. Hunt, 600 Perkin (VV. H.), Magnetic Rotation of Hydrogen and Sodium Chlorides and Chlorine in different Solvents, 239 Pernossi(Signor), the Action of Sunshine upon Tetanus Filtrates, 509 ; Tetanus Poison, 540 Perry (Prof.), Planimeters, 617 Persians, a Year amongst the, Edward G. Browne, 528 Peru, Harvard College Meteorological Observatories in, Prof. W. H. Pickering, 180 Peshawur, Earthquake at, 106 Peterhead, the Arbuthnot Museum, Alexander Meek, 20 Petermann's Mitteilungen, 324 XXX Index tSupj>lement to Nature niay 31, 1894 Petroleum in relation to Asphalte Pavement, S. P. Peckham, 306 Petroleum on the Mendip Hills, Discovery of, 346 Pfeffer (Prof.), Irritability of Plants, 586 Pharmaco-Therapeutics, Chemistry in Relation to, and Materia Medica, Prof B. J. Stokvis, 587 Philip's Systematic Alias, Physical and Political, E. G. Raven- stein, 574 Phiiipp (K.), the Suspension of Foreign Bodies from Spiders' Webs, 481 Philology : Death of Prof. Robertson Smith, 538 ; Catalogue of Prince Louis Lucien Buonaparte's Library, Victor Collins, 584 Philosophical Society, Cambridge, 143, 166, 378, 424, 452 Phisalix (C), Poisonous Principles of Adder's Blood, 284; Viper Poison, 380 Phosphorus, New Method of Preparing, Messrs. Rossel and Frank, 323 Photiniis corriiscus Beetle, Spectroscopic Examination of Light emitted by, A. P. Miller, 540 Photography : Photographs of Ascending Currents in Gases and Liquids, Herr P. Czermak's, 15 ; Chrono-Photographic Study of the Locomotion of Animals, 41 ; Photography of Aerial Vibrations, Dr. Raps, 48 ; Astronomical Photography, H. C. Russell, F.R.S., in ; Photography of Snowflakes, A. Sigson, 131 ; Photography of Rays of very short Wave- Length, Victor Schumann, 254 ; Cloud Photography, 267 ; Geological Photographs, 347 ; Method of Photographing Spectrum of Lightning, G. Meyer, 417 ; Photographic Nebu- losities in the Milky Way, Prof E. E. Barnard, 51 1; the Solandi Sun-printing Process as applied to Botanical Technique, Prof. Byron Halsted, 370 ; Effect of Temperature upon Sensitiveness of Photographic Dry Plate, Dr. J. Joly, F.R S., 379 Photometric Method, New, J. B. Spurge, 355 Physics ; Artificial Amoebse and Protoplasm, Dr. G. Quincke, 5: Herr P. Czermak's Photographs of Ascending Currents in Gases and Liquids, 15 ; Wiedemann's Annalen, 46, 117, 239, 376, 449, 547 ; Air Vibrations, A. Raps, 46 ; Application of Sound- Vibrations to Analysis of Mixtures of Gases, E. Hardy, 47 ; Physical Society, 46, 93, 141, 190, 354, 402, 450, 521, 617; Behaviour of Air-Cone Transformer when Frequency below certain Critical Values, E. C. Rimington, 46 ; Lecture-room Experiments on (i) Rings and Brushes in Crystals, and (2) Electric Radiation in Copper Filings, W. B. Croft, 47 ; Photography of Aerial Vibrations, Dr. Raps, 48 ; Berlin Physical Society, 48, 167, 216, 356, 427, 595 ; Spectra of Hot Gases probably due to Temperature, 82 ; Herr Galitzini's Experiments in Estimation of Critical Temperature, 83; "Flame," Prof Arthur Smithells, 86, 149, 198; Prof Henry E. Armstrong, F.R.S., 100, 171 ; G. S. Newth, 171 ; Separation of Three Liquids by Fractional Distillation, Prof. F. R. Barrell, G. L. Thomas, and Prof. Sydney Young, F. R.S., 93 ; Van der Waal's Generalisations regarding "corresponding" Temperatures, &c., Prof Sydney Young, F. R.S., 93; Phenomena of the Time- Infinitesimal, Prof. E. L. Nichols, 113; Elementary Course of Practical Science, Hugh Gordon, Sir Phillip Magnus, 121 ; Velocity of Crystallisation in Super-cooled Substance, Mr. Moore, 130 ; the Freezing-points of Dilute Aqueous Solutions, Harry C. Jones, 132 ; a more Exact Method for Determina- tion of Lowering of Freezing-points, E. H. Loomis, 547 ; Magnetic Shielding of Concentric Spherical Shells, Prof A. W. Riicker, F. R.S., 141 ; Action of Electro-Magnetic Radiation on Films containing Metallic Powders, Prof. G. M. Minchin, 142 ; Ripples, E. Guyon, 143 ; Mutual Action of Bodies vibrating in Fluid Media, MM. Berson and Juppont, 143; Righi's Experiments on Hertz's Oscillations, Dr. Rubens, 167 ; a Text-Book of Heat, R. Wallace Stewart, 171 ; Heat : an Elementary Text-Book, R. T. Glazebrook, F.R.S., 386 ; the Theory of Heat, Thomas Preston, Prof. G. C. Carey Foster, F.R.S., 573 ; Mr. M. C. Lea's Researches on Trans- formation of Mechanical Work into Chemical Action, 181 ; Utility of Quarternions in Physics, A, McAulay, Prof P. G. Tail, 193 ; Differential Method of determining Refractive Index of Solutions, W. Hallwachs, 206 ; Method of Coating Aluminium with other Metals, Prof. Neesen, 216 ; Physico- Chemical Measurements, W. Ostwald, J. W. Rodger, 219 ; Proposed Standard of Normal Air, A. Leduc, 272 ; Stas's Determination of Atomic Weights, E. Vogel, 283 ; on the Change of Superficial Tension of Solid-liquid Sufaces with Temperature, Prof Geo. Eras. Fitzgerald, F.R.S., 293; on the Equilibrium of Vapour Pressure inside Foam, Prof. G. F. Fitzgerald, F. R.S., 316 ; Torsional Oscillations of Wires, Dr. W. Peddie, 331 ; the Compression of Fluids, Prof Tait, 331 ; the Cloudy Condensation of Steam, John Aitken, F.R.S., 340; Dr. Carl Barus, 363; Shelford Bidwell, 388, 413 ; Forms of Steam Jets from various Orifices, II. Parenty, " 347 ; on the Motion of Bubbles in Tubes, 351 ; Thermal Constants of some Polyatomic Bases, MM. Colson and Darzens, 356 ; Radiation of Gases, F. Paschen, 376 ; the Artificial Colouring of Crystals and Amorphous Bodies, O. Lehmann, 376 ; Condition of Interior of Earth, Rev. O. Fisher, 379 ; some Simple Methods in Teaching Elementary Physics, IDr. J. Joly, F. R. S., 379 ; Experiments in Elemen- tary Physics, W. Rheam, 433 ; Viscosity of Liquids, O. G. Jones, 402 ; a Theorem connecting Theory of Synchronisation with Theory of Resonances, A. Cornu, 404 ; Interior Pressure in Gases, E. H. Amagat, 404 ; Straining of Earth resulting from Secular Cooling, Charles Davison, 424 ; on Homogen- eous Division of Space, Lord Kelvin, P. R. S., 445i 469 ; the Attachment of Quartz Fibres, Prof C. V. Boys, F.R.S., 450 ; Method of determining Refractive Indices of Liquids, Mr. Littlewood, 450 ; Internal Pressure of Fluids, Amagat, 500 ; the Behaviour of Liquids under High Pressure, J. W. Rodger, 506 ; General Law of Solubility of Normal Sub- stances, H. Le Chatelier, 524 ; a Lecture Experiment, J. C. Foye, 531 ; the Magnetic Rotary Dispersion of Oxygen, Dr. Siertsema, 607. Physiology : Physiological Action of Oxygen in Asphyxia, 16 ; Movements of Surface of Heart, M. Potain, 23 ; Berlin Physiological Society, 48, 167, 240, 380, 427, 596 ; Physiology of Ureter, Dr. Lewin, 48 ; Influence of Diffusive Processes on Transudation, Dr. Cohnstein, 48 ; Hepatic Glycogenesis, Dr. Noel Paton, 141 ; Feeding Experiment with Nucleic Acid on Dogs, Dr. Gumlich, 167 ; Leucocytosis, Dr. Goldscheider, 167 ; Experiments on Median Pharyngeal Nerve, Dr. Katzenstein, 168 ; New Method of "Measuring Amount of Circulating Blood, Prof. Zuntz, 168 ; Death of Dr. P. A. Spiro, 179 ; Institute of Physiology established at Brussels, M. G. Solvay, 180 ; Nucleic Acid, Prof. A. Kossel, 240 ; Physiological Psychology and Psycho-Physics, 252 ; Dr. E. B. Titchener, 457 ; Death of M. Quinquand, 270 ; Chronometric Determinations relating to Regeneration of Nerves, C. Vanlair, 283 ; Sugar as Food in Production of Muscular Work, Dr. Vaughan Harley, 283 ; Grundzlige der Physiologischen Psychologie, Wilhelm Wundt, 311 ; the Essentials of Chemical Physiology, Prof W. D. Halliburton, 313 ; the Os Pedis in Ungulates, Prof A. E. Mettan, 341 ; Effects upon Respiration of Faradic Excitation of Cerebrum in Animals, W. G. Spencer, 353 ; Functions of Cerebellum, Dr. J. S. R. Russell, 354; Tactile Areas of Cerebral Cortex, Prof. Munk, 380 ; the Kidney of the Snail, Paul Girod, 380 ; the Humanest Method of Slaughtering Animals, Dr. Dembo, 427 ; the Action of Quinine on Metabolism of Man, Dr. von Noorden, 427 ; Prof Zuntz's Experiments on Respiration by Skin and Intestine of Horse, 427 ; Human Physiology, John Thornton, Dr. J. S. Edkins, 431 ; Re- action Times and Velocity of Nervous Impulse, Profs. Dolley and Cattell, 462 ; the Minute Structure of the Nerve Centres, Prof Ramon y Cajal, 464 ; Determination of Volume of Blood Corpuscles, Dr. Grijns, 476 ; Experimental Investigation of Central Nervous System of Monkey, Dr. E. L. Melius, 498 ; the Scope of Psycho- Physiology, Prof. C. Lloyd Morgan, 504 ; Note on the Liver-ferment, Miss M. C. Tebb, 523 ; Death of Dr. Brown-Sequard, 538; Biographical Sketch of Dr. Marcellus Malpighi, 583 Physodes, Morphological and Micro-chemical Investigations on, E. Crato, 132 Pickering (Prof E.), Anderson's Variable in Andromeda, 419 Pickering (Prof W. H.), Harvard College Meteorological Observatories in Peru, 180 ; South American Meteorology, 263 ; Melting of the Polar Caps of Mars, 586 Pictures, Nature, for Little People, W. Mawer, 529 Pierce (G. VV.), Electric Strength of Solid, Liquid, and Gaseous Dielectrics, 181 Pigments, Ancient Egyptian, Dr. William J. Russell, F.R.S., 374 Piltchikoff (N.), New Method of Studying Electric Discharge, 54° Supplement to Nature, Mav -ii, 1804 Index XXXI Pinkerton (R. H.), Hydrostatics and Pneumatics, 362 Pitt-Press Euclid, v.-vi., H. M. Taylor, 52 Pivot-Testing, Method of, Maurice Hamy, iii Plane Trigonometry, S. L. Loney, 339 Planet Jupiter, the, i8, 67, 85, 104, 300, 323 Planet Venus, the, 233, 413 Planimeters, Prof. Perry, 617 Plant Names, Kew Index of, 241 Plants, Dictionary of the Active Principles of, C. E. Sohn, 385 Plants, Flowering, of Western India, Rev. A. K. Nairne, 501 Plants, on the Irritability of, Prof. F. Elfving, 466 ; Prof. Pfeffer, 5S6 Plants, Recent Investigations and Ideas on the Fixation of Nitrogen by. Prof. H. Marshall Ward, F.R.S., 511 Plating, on the Buckling and Wrinkling of, supported on a Framework under the Influence of Oblique Stresses, G. H. Bryan, 499 PlausiMe Paradox in Chances, a, Francis Galton, F.R.S., 365 ; Lewis R. Shorter, 413 Pleiades, the, 366 Plesiosaurus, Complete, found in Wiirtemburg, 271 Plon, Forschungsberichte aus der Biologischen Station zu. Dr. O. Zacharias, 385 Plumandon (J. R.), Application of Meteorology to the Art of War, 488 Plymouth Marine Biological Station, Week's Work of, 38, 67, 84, 162, 323, 372, 418 Pneumatics, Hydrostatics and, R. H. Pinkerton, 362 Pocock (R. I.), the Zoological Record, 53, 198; further Notes and Observations upon the Instincts of some common English Spiders, 60 ; on the Classification of the Tracheate Arthro- poda, a Correction, 124 Poetry, Astronomy in, 372 ; Rev. Edward Geoghegan, 413 ; G. W. Murdoch, 434 Poincare (H.), Propagation of Electricity, 239 Poison, Serpent, Inoculation against, A. Calmette, 548 Poisonous Principle of Adder's Blood, MM. Phisalix and Bertrand, 284 Poitevin (Henri), Report of Pasteur Institute for 1893, 581 Polado Flint Saws, the, Dr. R. Munro, 183 Polar Caps of Mars, Melting of the. Prof. W. H. Pickering, 586 Polar Exploration, the Proposed Continuous, Robert Stein, i8, 124, 256, 346 Polymorphous Microbe in Syphilis, on the Presence of a, Dr. Golasz, 500 Polyphases. Les Courants, J. Rodet et Busquet, 122 Pomortseff (M.), the Motion of Clouds, 230 Poncins' (M. de) Explorations in the Pamirs, 18 Poncins (E. ), Pamirs Crossed by, 163 Port Erin, Dredging Expedition at. Prof. W. A. Herdman, F.R.S., 503 Port Jackson, Coal Discovered at, 64 Postal Transmission of Natural History Specimens, the, Isaac J. Wistar, Edward J. Nolan, 100; R. McLachlan, F.R.S., 172 ; Philip P. Calvert, 314 Potain (M.), Movements of Surface of Heart, 23 Potholes, Glacial, of Cooper's Island, U.S., W. O. Crosby, 160 Potsdam, the Earthquake of November 5 at, 159 Potter (M. C), an Elementary Text-Book on Agricultural Botany, 290 Pouchet (H. C. G.), Death and Obituary Notice of, 538 Poulton (Prof. E. B., F.R.S.), Method of showing Geographi- cal Distribution of Insects in Collections, 95 Powell (Major J. W.), Eighth Report of U.S. Bureau of Ethnology, 132 Pratt (J. H.), Chemical Composition of Staurolite, 402 Precious Stones, 319 Preece (W. H., F.R.S.), a Manual of Telephony, 454 ; Bril- liant Aurora Borealis of March 30, 1894, 539 ; Earth Currents, 554 Prehistoric Interments of the Balzi Rossi Caves near Mentone, Arthur J. Evans, 42 Prehistoric Man, Evidences of Existence of Man in Nicaragua in Neolithic Age, J. Crawford, 107 Prehistoric Man in Jersey, Edward Lovett, 487 Pressures, Measurements of Low Vapour, J. W. Rodger, 436 Preston (Thomas), the Theory of Heat, Prof. G. C. Carey Foster, F.R.S., 573 Prestwich (Dr., F.R.S.), on a Possible Cause for the Origin of the Tradition of the Flood, 594 Pretoria, establishment of State Museum at, 12 Preventive Medicine, the Directorship of the British Institute of. Prof. Chas S. Roy, F.R.S., 269; Sir Joseph Fayrer, F.R.S., 292 ; Prof. Victor Horsley, F R.S., 292 Prideaux (R. M.), the Early Return of Birds, 578 Prince Henry the Navigator, Quinquecentenary of, 301 Prince (J. J.), Graphic Arithmetic and Statics, 28 Prinz(W.), the Internal Temperature of Trees, 271 Procacci (Dr.), Bactericidal Influence of Sunshine on Drain- water Microbes, 461 Proctotrypidse, the North American, W. H. Ashmead, 182 Protective Habit in a Spider, Prof. C. Lloyd Morgan, 102 Protoplasm, Artificial Amcebje and. Dr. G. Quincke, 5 ; Dr. John Berry Haycraft, 79 Protoplasm, P'oam Theory of, E. A. Minchin, 31 Prudden (Herr), Vitality of Micro-Organisms on Artificial Ice, 395 Prunet (A.), the Propagation of Pourridie by Storage of Graft-Slips in Moist Sand, 24 Pruning, Tree, A. des Cars, Prof. W. R. Fisher, 526 Psychology : American Psychological Association, 252 ; Psychological Review, 297 ; Grundziige der Physiologischen Psychologic, Wilhelm Wundt, 31 1 ; Investigations on Reac- tion Time and Attention, Dr. C. B. Bliss, 439 ; Reaction Times and Velocity of Nervous Impulse, Profs. Dolley and Catteil, 462 ; the Status of the Mind Question, Lester Ward, 510 Psycho Physics, Physiological Psychology and, 252 ; Dr. E. B. Titchener, 457 Psycho-Physiology, the Scope of. Prof. C. Lloyd Morgan, 504 Ptarmigan of Aleutian Islands, the, W. B. Evermann, 584 Pteris serrulata (L. fil.), Var. Cristata, Apogamy in, A. H. Trow, 434 Public, Astronomy for the. Sir Robert S. Ball, F.R.S., R A. Gregory, 243 Public Health : a Treatise on Hygiene and Public Health, T. Stephenson and S. F. Murphy, 285 ; Public Health and Demography, Edward F. Willoughby, 285 Pumpelly (R.), Apparent Time-break between Eocene and Chattahoochee Miocene in S.W. Georgia, 214 Pumps, Steam, on Russian Railways, Alexander Borodin, 19 Puy-de-D6me, Discovery of Ruins of Temple to Mercury on, 14 Pycroft (George), Death of, 538 Pygidium of Triarthrus, the Appendages of the, Charles E. Beecher, 617 Pyrenees : Les Pyrenees, Eugene Trutat, 122 ; Geographical Conditions of the Pyrenees, MM. Schrader and De Margerie, 275 ; Prehistoric History of the Pyrenees, 593 Quarterly Journal of Microscopical Science, 139, 423 Qiia7-terly Review, Science in the, 352 Quartz Fibres, the Attachment of. Prof. C. V. Boys, F. R.S., 450 Quaternionic Innovations, Oliver Heaviside, F.R.S., 246 Quaternions in Physics, Utility of, A. iNIcAulay, Prof. P. G. Tait, 193 Queensland, Progress in 1892 of Geological Survey of, R. L. Jack, 109 Quekett Microscopical Club, 523 Quincke (Dr. G.), Artificial Amoebae and Protoplasm, 5 Quinquand (M.), Death of, 270 Race, Disease and, Jadroo, 575 Radiant Energy, the Nomenclature of, Prof. Simon Newcomb, F.R.S., 100; Prof. G. F. Fitzgerald, F.R.S., 149; Prof. A. N. Pearson, 389 Radloff (W.), the Orkhon River Archseological Expedition, 23 Railways, Round the W'orks of our Great, N. J. Lockyer, 312 Rain, Artificial, Influence on Plants of, Prof. J. Wiesner, 253 Rainbow, a Lunar, Rev. C. W. Langmore, 321 Rainfall : New Form of Rainfall Map, H. L. Russell, 180 ; the Sun-spot Period and the West Indian Rainfall, Maxwell Hall, 399; Rainfall Records in British Isles, G. J. Symons, 438 ; Observations of Rainfall in Edinburgh, 520 Rama, the Nativity of. Col. Walter R. Old, 4 Rambaut (Prof. Arthur A.) on the Great Meteor of February 8,572 xxxu Index [Siipplement to Nature., May 31, 1894 Ramsay (W,), Molecular Formulae of some Liquids as Deter- mined by their Molecular Surface Energy, 377 Raps (A.), Air Vibrations, 46; Pliotography of Aerial Vibra- tions, 48 Rasori (Dr.), the Etiology of Delirium Acutum, 208 Ravenstein (E. G.), Philip's Systematic Atlas, Physical and Political, 574 Kawitz (Dr.), Spermatogenesis in HydromedustC, 240 Ray, a Hermaphrocitical, M. Hoek, 264 Rayet (G.), Forest Fires and Drought, 191 Reaction- Time and Attention, Investigations on, Dr. C. B. Bliss, 439 Reckeu/aun (A.), Death of, 6^ Reclus' (Elisee) Nouvelle Geographie Universelle, Completion of, 256 Recognition Marks, G. J. Macgillivray, Dr. Alfred R. Wal- lace, F.R.S., 53 Records of Geological Survey of India, 109 Red Spot, Jupiter and his, W. F. Denning, 104 Redpath (Peter), Death and Obituary Notice of, 345 Refraction Tables, 134 Refractometer applied to Study of Chemical Reactions, J. Verschaffelt, 546 Reid (Clement), the Dispersal of Shells, Henry Wallis Kew, 361 ; Cause of Extinction of Pine in South of England, 522 Reinach (Saloman), Le Mirage Oriental, 472 Rejected Address, a, 555 Remsen (Prof. Ira), on Chemical Laboratories, 531 Renault (B. ), General Character of Bogheads produced by Algae, 47 . Renk (Herr), Vitality of Micro-organisms on Artificial Ice, 395 Research, Scientific, the Elizabeth Thompson Fund for Ad- vancement of, 539 Respiration, Effect of Faradic Excitation of Cerebrum in Ani- mals upon, W. G. Spencer, 353 Retrospect, an Ornithological, Dr. R. Bowdler Sharpe, 6 Reviews and Our Bookshelf. British Forest Trees, J. Nisbet, i A Popular History of Astronomy during the Nineteenth Cen- tury, Agnes M. Clerke, 2 Inorganic Chemistry for Beginners, Sir Henry Roscoe, F. R.S. , and Joseph Lunt, 3 The Chemistry of Fire, M. M. Pattison Muir, 3 Solutions of the Exercises in Taylor's Euclid I. to IV., \V. W. Taylor, 3 Personal Recollections of Werner von Siemens, 25 The Iron Ores of Great Britain and Ireland, J. D. Kendall, Bennett H. Brough, 27 The Shrubs of North-Eastern America, Charles S. Newhall, 28 Mensuration of the Simpler Figures, William Briggs and T. W. Edmondson, 28 The Discovery of Australia, Albert F. Calvert, 28 Graphic Arithmetic and Statics, J. J. Prince, 28 The Orchid Seekers, Ashmore Russan and Frederick Boy'e, 28 An Examination of Weismannism, G. J. Romanes, F.R.S., 49 Icones Orchidearum Austro-Africanarum Extra-tropicarum ; or, Figures, with Descriptions, of Extra-Tropical South African Orchids, Harry Bolus, R. A. Rolfe, 50 An Astronomical Glossary, J. E. Gore, 51 With the Woodlanders and bv the Tide, a Son of the Marshes, SI Pitt Press Euclid V., VI., H. M. Taylor, 52 The Outdoor World, W. Furneaux, 52 Worked Examples in Co-ordinate Geometry, William Briggs and G. H. Bryan, 52 A Treatise on the Kinetic Theory of Gases, Henry William Watson, F.R.S., Prof. P. G. Tait, 73 A History of Crustacea ; Recent Malacostraca, Rev. Thomas R. R. Stebbing, 74 An Elementary Treatise on the Geometry of.Conics, A. Muk- hopadhyay, 75 The Geometrical Properties of the Sphere, William Briggs and T. W. Edmondson, 75 A Key to Carroll's Geometry, J. Carroll, 75 The Mummy, E. A. Wallis-Budge, F.S.A., 97 Eskimo Life, Fridtjof Nansen, 98 La Voie Lactee dans I'Hemisphere Boreal, C. Easton, 99 An Elementary Treatise on Analytical Geometry, W. J. Johnston, 99 Zur Kenntniss der Postembryonalen Schadelmetamorphosen bei Wiederkauern, H. G. Stehlin, 99 Elementary Course of Practical Science, Hugh Gordon, Sir Philip Magnus, 121 Les Pyrenees, Eugene Trutat, 122 Les Courants Polyphases, J. Rodet et Busquet, 122 Solutions of the Examples in the Elements of Statics and Dynamics, S. L. Loney, 122 Problemes et Calculs Pratiques d'Electricite, M. Aimc Witz, Prof. A. Gray, 145 A Treatise on Dynamics, W. H. Besant, A. B. Basset, F.R.S., 146 Our Household Insects : an Account of the Insect Pests found in Dwelling-houses, E. A. Butler, 147 Text- Book of Biology, H. G. Wells, 148 The New Technical Educator, 148 Heat and the Principles of Thermodynamics, Dr. C. H. Draper, 148 Beni Hasan, P. E. Newberry and G. W. Frazer, 169 Letters to Marco, George D. Leslie, 170 A Text-Book of Heat, R. Wallace Stewart, 171 The Industries of Animals, Frederic Houssay, 171 Utility of Quaternions in Physics, A. McAulay, Prof. P. G. Tait, 193 Painter's Colours, Oils, and Varnishes : a Practical Manual, George H. Hurst, 194 British Fungus Flora, a Classified Text-Book of Mycology, George Massee, Dr. M. C. Cooke, 195 Some Salient Points in the Science of the Earth, Sir J. William Dawson, F. R.S. , 196 Das Karstphanomen, Dr. Jovan Cvijic, 197 Report on the Present State of our Knowledge respecting the General Circulation of the Atmosphere, L. Teisserenc de Bort, 217 On Hail, Hon. Rollo Russell, 217 Weather Lore : a Collection of Proverbs, Sayings, and Rules concerning the Weather, R. Inwards, 217 Hand- und Hilfsbuch ziir AusfUhrung physiko-chemischer Messungen, W. Ostwald, J. W. Rodger, 219 Hand-Book cf British Hepaticae, M. C. Cooke, 220 The Royal Natural History, R. Lydekker, 220 Index Kewensis plantarum phanerogamarum nomina et synomyna omnium generum et specierum a Linnaeo usque ad annum mdccclxxxv complectens nomine recepto auctore patria unicuique plantae subjectis, Sumptibus Caroli Roberti Darwin, ductu et consilio Josephi D. Hooker, con- fecit B. D. Jackson, 241 In the High Heavens, Sir R. S. Ball. F.R.S., R. A. Gregory, 243 Practical Agricultural Chemistry for Elementary Students, J, Bernard Coleman and Frank T. Addyman, 244 Bionomie des Meeres, Johannes Walther 244 The Story of Oar Planet, T. G. Bonney. F.R.S., Supp. iii. The Collected Mathematical Papers of Arthur Cay ley, F. R. S. , Supp. iv. The Pamirs, Earl of Dunmore, Supp. vi. Catalogue of the Madreporarian Corals in the British Museum, George Brook, Prof. Alfred C. Haddon, Supp. ix. Physiological Chemistry of the Animal Body, Arthur Gamgee, F.R.S., Dr. J. S. Edkins, Supp. x. An Essay on Newton's " Principia," W. W. Rouse Ball, Supp. xii. Engineering, Drawing, and Design, Sydney H, Wells, N. J. Lockyer, Supp. xiii. Catalogue of the Egyptian Collection in the Fitzwilliam Museum, E, A. Wallis-Budge, F. S.A., Supp. xiii. Horns and Hoofs, R. Lydekker, Supp. xiv. A Treatise on Hygiene and Public Health, T. Stephenson and Shirley F. Murphy, 285 Public Health and Demography, Edward H. Willoughby, 285 Methods of Practical Hygiene, Prof. K. B. Lehmann, 285 Text-Book of Geology, Sir Archibald Geikie, F.R.S., Prof. A. H. Green, F.R.S., 2S7 On the Chemistry of the Blood, and other Scientific Papers, L. C. Wooldridge, 289 Siipploiicut to Naturc,~\ May ^i, 1894 J Inaex xxxui An Elementary Text-Book on Agricultural Botany, M. C. Potter, 290 Healthy Hospitals : Observations on some Points connected with Hospital Construction, Sir Douglas Gallon, F. R.S., 290 The Vault of Heaven, Richard A. Gregory, 291 A Journey through the Yemen, and some General Remarks upon that Country, Walter B. Harris, 291 Chinese Central Asia : a Ride to Little Tibet, Henry Lans- dell, W. F. Kirby, 309 Collected Essays, T. H. Huxley, F.R.S., Prof. E. Ray Laakester, F.R.S., 310 Gruudziige der PhysiologischenPsychologie,Wilhelm Wundt, 311 Round the Works of our Great Railways, N. J. Lockyer, 312 The Essentials of Chemical Physiology, Prof. W. D. Halli- burton, 313 The Sacred City of the Ethiopians, J. T. Bent, 314 Fra i Batacchi indipendenti, 314 Romance of the Insect World, L. N. Badenoch, 314 Darwinianism : Workmen and Work, James Hutchison Stirling, Dr. Alfred R. Wallace, F.R.S., 333 Dynamos, Alternators, and Transformers, Gisbert Kapp, 337 Golf: a Royal and Ancient Game, Robert Clark, W. Ruther- ford, 338 Celestial Objects for Common Telescopes, Rev. T. W. Webb, 339 Plane Trigonometry, S. L. Loney, 339 Notes on Recent Researches in Electricity and Magnetism, Prof. J. J. Thomson, F.R.S., Prof. A. Gray, 357 The Applications of Elliptic Functions, Alfred George Greenhill, F.R.S., H. F. Baker, 359 The Dispersal of Shells, Harry Wallis Kew, Clement Reid, 361 The Wilder Quarter-Century Book, 362 Machine Drawing, Thomas Jones and T. Gilbert Jones, 362 Hydrostatics and Pneumatics, R. H. Pinkerton, 362 How to Manage the Dynamo, S. R. Bottone, 363 Lectures on Maxwell's Theory of Electricity and Light, Dr. Ludwig Boltzmann, 381 The Story of the Sun, Sir Robert Ball, F.R.S., A. Fowler, 382 The Batterflies and Moths of Teneriffe, A. E. Holt White, W. F. Kirby, 384 Dictionary of the Active Principles of Plants, C. E. Sohn, 3^5 . . , ^ Forschungsberichte aus der Biologischen Station zu Plon, Dr. O. Zacharias, 385 Biology as it is applied against Dogma and Freewill and for Weismannism, H. Croft Hillier, 386 Heat : an Elementary Text-Book, Theoretical and Practical, for Colleges and Schools, R. T. Glazebrook, F. R. S, 386 Electrical Experiments, G. E. Bonney, 386 Handbuch der Stereochemie, Dr. Paul Walden, 409 Marine Boiler Management and Construction, (J. E. Stro- meyer, 410 Chapters on Electricity, Samuel Sheldon, 411 Meteorology, H. N. Dixon, 412 A Text-Book on Electromagnetism and the Construction of Dynamos, Dugald C. Jackson, Prof. A. Gray, 429 A Text Book on Gas, Oil, and Air Engines, Bryan Donkin, N. J. Lockyer, 430 Human Physiology, John Thornton, Dr. J. S. Edkins, 431 Light : an Elementary Text-Book, Theoretical and Practical, for Colleges and Schools, R. T. Glazebrook, F. R. S., 432 Beni Hasan, P. E. Newberry, 432 Der Botanische Garten " 's Lands Plantentuin " 2 v. Buitenzorg auf Java, 453 Eine Botanische Tropenreise, Indomalayische Vegetations- bilder und Reiseskizzen, Prof. Dr. Habe^landt, 453 A Manual of Telephony, W. H. Preece, F.R. S. , and Arthur J. Stubbs, Prof. A. Gray, 454 Einfiihrung in das Studium der Bakteriologie mit besonderer Beriicksichtigung des mikroskopischen Technik fiir Aerzte und Studirende, Dr. Carl Giinther, Mrs. Percy Frankland, 455 Lectures on Mathematics, Felix Klein, 456 Elementary Trigonometry, H. S. Hall and S. R. Knight, 456 A Treatise on the Theory of Functions, James Harkness and Frank Morley, 477 Drum Armatures and Commutators, F. W. Weymouth, E. Wilson, 478 Illustrated Guide to British Mosses, H. G. Jameson, 479 Report of Observations of Injurious Insects and Common Farm Pests during the Year 1893, with Methods of Pre- vention and Remedy, Eleanor A. Ormerod, 480 On the Definitions of the Trigonometric Functions, A. Macfarlane, 480 Key to Mr. J. B. Lock's Shilling Arithmetic, Henry Carr, 480 The Flowering Plants of Western India, Rev. A. K. Nairne, Cancer, Sarcoma, and other Morbid Growths, considered in Relation to the Sporozoa, J. Jackson Clarke, 502 The Fauna of the Deep Seas, Sydney J. Hickson, 502 A Treatise on Elementary Hydrostatics, John Greaves, 503 The Pharmacopasia of the United States of America, 525 Tree Pruning : a Treatise on Pruning Forest and Ornamental Trees, A. des Cars, Prof. W. R. Fisher, 526 Practical Forestry, Angus D. Webster, Prof. W. R. Fisher, 526 Micro-Organisms and Fermentation, Alfred Jorgensen, Dr. A. A. Kanthack, 527 A Year amongst the Persians, Edward G. Brown, 528 Nature Pictures for Little People, W. Mawer, 529 Social Evolution, Benjamin Kidd, Dr. Alfred R. Wallace, F.R.S., 549 Essays in Historical Chemistry, Prof. T. E. Thorpe, F. R.S., M. M. Pattison Muir, 551 The Canadian Ice Age, Sir J. William Dawson, F. R.S., 552 . Grundziige einer Entwickelungsgeschichte der Pflanzenwelt Mitteleuropas seit dem Ausgangder Tertiarzeit, Dr. August Schulz, 553 Elementary Metal Work, G. C. Leland, 554 The Theory of Heat, Thomas Preston, Prof. G. Carey Foster, F.R.S., 573 Philip's Systematic Atlas, E. G. Ravenstein, 574 Life and Rock : a Collection of Zoological and Geological Essays, R. Lyddeker, 575 Disease and Race, Jadroo, 575 The Macleay Memorial Volume, 597 An Elementary Treatise on Fourier's Series and Spherical, Cylindrical, and Ellipsoidal Harmonics, W. E. Byerly, 598 Bird Life in Arctic Norway, Robert Collet, 599 A Text-Book of Euclid's Elements, H. S. Hall and F. H. Stevens, 599 Reymond (Dr. A. du Bois), Lilienthal's Experiments in Flying, 356 Rheam (W.) Experiments in Elementary Physics, 433 Rhinoceros in London, White, Rowland Ward, 584 Rhone at Entrance into Lake of Geneva, Composition of Water of, A. Delebecque, 264 Rhythm, Music, and Muscle, Prof. P. Clifford Allbutt, 340 Ricco (Prof.), Mode of Propagation of Earthquake Shocks between Zante and Catania, 606 ; Speed of Perception of Stars, 608 Richards (Mr.), Occluded Gas contained in Oxides of Copper, Zinc, Nickel, and Magnesium prepared by Ignition of Nitrate, 209 Richards (Prof.) the Atomic Weight of Barium, 562 Richet (C), Influence of Metallic Salts on Lactic Fermenta- tion, 96 Richter (Dr. M. M.), Best Method of using Oil in Calming Troubled Waters, 488 Riddle (Dr. ), Researches on Melting-points of Refractory In- organic Salts, no Righi's (Prof. Augusto), Experiments with Electromagnetic Waves of Small Length, 15 ; Righi's Experiments on Hertz's Oscillations, Dr. Ruhens, 167 ; Improved Form of Black- burn's Pendulum for Slow Production of Lissajous's Figures, 582 ; a very Sensitive Idiostatic Electrometer, 606 Rimington (E. C), Behaviour of Air-Cone Transformer when Frequency below certain Critical Value, 46 Rink (Dr. H.), Death of, 210 XXXIV Inaex [Supplement to Natnre, May 31, 1894 Rio de Janeiro, Annuario do Observatorio do, 299 Ripples, E. Guyon, 143 Rivers according to Size, the Classification of, Marcel Dubois, 487 Rix (Herbert), Henry Oldenburg, First Secretary of the Royal Society, 9 Rizzo (G. B.), Kirchhoff's Law connecting Absorptive and Emissive Powers of Substances tested for Glass by, 606 Robinson (Phil), Shakespeare's Natural History, 444 Rock, on a Method of separating the Mineral Components of a, Prof. W. J. SoUas, F.R.S., 211 Rock, Life and, a Collection of Zoological and Geological Essays, R. Lydekker, 575 Rock- Basins : the Erosion of. Prof. T. G. Bonney, F.R.S,, 52 ; T. D. La Touche, 39 ; in the Himalayas, R. D. Oldham ; 77 Rodet (J.), Les Courants Polyphases, 122 Rodger (J. W.), Hand-und Hilfsbuch ziir Ausfiihrung physiko-chemischer Messungen, W. Ostwald, 219 ; the Bakerian Lecture, 419 ; Measurements of Low Vapour Pressures, 436 ; the Behaviour of Liquids under High Pressure, 506. Roepsel (Dr.), New Apparatus for obtaining Absolute Measurements of Magnetic Properties of different kinds of Iron, 595 Rogers (Mr.), Occluded Gas contained in Oxides of Copper, Zinc, Nickel and Magnesium prepared by Ignition of Nitrate, 209 Rolfe (R. A.), Icones Orchidearum Austro-Africanarum Extra-tropicarum, Henry Bolus, 50 Roman Villa near Cardiff, John Storrie, 605 Romanes (Dr. Geo. F.R.S.) Telegony 6 ; an Examina- tion of Weismannism, 49, 78 ; Experiments in Helio- tropism, 140; Experiments in Germination, 140 ; Panmixia, 599 Rome : Solar Observations at, 67, 163 ; the International Medical Congress at, 538, 563 Roncali (Signor), Virulence of Tetanus Bacillus increased by addition of other Organic Products, 254 Roscoe (Sir Henry, F.R.S.), Inorganic Chemistry for Beginners, 3 ; the Secondary Education Movement, 203 Rosenfeld (Prof.), Cause of Explosion on Contact of Metallic Sodium with Water, 232 Ross (W. J. C), Geology ofBathurst, New South Wales, 94 Rossel (Herr), New Method of preparing Phosphorus, 323 Rossikoff (K. N.), Lake Desiccation on Northern Slopes of Caucasus, 515 Rothney (G. A. G.), Mimicry of Hemiptera by Lepidoptera, 619 Rothschild (Hon. Walter), the Apteryx Genus, 14 Roumania, Glazed Frost of November 11-12, 1893, in, 272 Rovigno Marine Biological Station, the, 560 Rowland's Concave Gratings, the Astigmatism of, 489 Roy (Prof. Charles S., F.R.S.), the Directorship of the British Institute of Preventive Medicine, 269 Royal Astronomical Society, 345 Royal Institution, Resolution of Condolence with Mrs. Tyndall, 179 Royal Meteorological Society, 119, 215, 307, 425, 547, 619 Royal Microscopical Society, 47, 119, 263, 330, 594 Royal Society, 140, 189, 263, 283, 306, 353, 377, 424, 449, 472, 498, 570 ; Henry Oldenburg, First Secretary, Herbert Rix, 9; Medal Awards, 63; Anniversary Meeting, 134; the Royal Society, Sir John Evans, F.R.S. , 576; the Royal Society Club, 79 Royal Society, Sydney, 332 Royere (W. de la), New Processes for Detection of Vegetable and Mineral Oils, 377 Rubens (Dr.), Righi's Experiments on Hertz's Oscillations, 167 Riicker (Prof. Arthur W., F.R.S.), on M. Mercadier's Test of the Relative Validity of the Electrostatic and Electromagnetic Systems of Dimensions, 387 ; Dr. G. Johnstone Stoney, F.R.S., 432 Rudimentary (Vestigial) Organs, 199, 247 ; C. Mostyn, 247 Rugby School Natural History Society, 541 Runge (Prof. C), Experiments on Flying, 157 ; Correction, 183 ; the Spectra of Tin, Lead, Arsenic, Antimony and Bismuth, 509 Runge (Friedlieb F.), Celebration of Centenary of Birth of, 415 Russan (Ashmore), the Orchid Seekers, 28 Russell (H. C, F.R.S.), Astronomical Photography, ill ; New Form of Rainlall Map, 180 ; New South Wales Government Report of Meteorological Observations for 1892, 252 ; on a Meteorite from Gilgoin Station, 325 ; Fine Aurora Australis, 601 Russell (Dr. H. L.), the Bacterial Contents of Sea-water, 559 Russell (Dr. J. S. R.), Functions of Cerebellum, 354 Russell (Hon. R. ), Epidemic Influenza, 210; on "Hail," 217; Brilliant Aurora Borealis of March 30, 1894, 539 ; a Remark- able Meteor, 601 Russell (Dr. William J., F.R.S.), Ancient Egyptian Pigments, 374 Russell (W.), Anatomical Modifications of Plants of the same Species in the Mediterranean Region and in the Region of the Neighbourhood of Paris, 620 Russell's Observations on Microbial Condition of Massachusetts Coast Sea-water and Mud, 37 Russia : Introduction of Decimal System into, 129 ; Amber in, F. T. Koppen, 181 ; Proposed Tea Cultivation in, 393 Russian Geographical Society, Memoirs of, 254 Rutherford (W. ), Golf: a Royal and Ancient Game, 338 Rutley (Frank), the Origin of Certain Novaculites and Quartzites, 547 Ryan (Prof. J.), the Aurora of March 30, 554 Saccharomycetes, Recent Researches on, Alfred Jorgensen, Dr. A. A. Kanthack, 527 Sacken (Baron C. R. Osten), on the Bugonia Superstition of the Ancients, 198 ; the Earliest Mention of the Kangaroo in Literature, 198 Sacred City of the Ethiopians, the, J. T. Bent, 314 St. Petersburg Society of Naturalists, Memoirs of, 189 St. Petersburg, Bulletin de I'Academie des Sciences de, 23 ^ Sakhalin, the Island of, F. Immanuel, 508 Salazan (Seiior), Micro-Organisms in Ice, 322 Salet, (G.), Death of, 604 Salient Points in the Science of the Earth, some. Sir J. W. Dawson, F.R.S., 196 Salt, Virulence of Cholera Bacillus increased by. Dr. Gamaleia, 132 Salts, on the ^Fusibility of Mixtures of, M. H. Le Chatelier, 595 Sanarelli (Dr.), Les Vibrions des Eaux et I'Etiologie du Cholera, 231 Sand-filtration as a Means of Purifying Water, Mrs. Percy . Frankland, 156 Sandeman (G.), a Parasitic Disease in Flounders, 119 - Sanderson (Prof. J. Burdon, F.R.S.), Human and Comparative Anatomy at Oxford, 6 Sangle-Ferriere (M.), Discovery of Abrastol in Wines, 167 Sanitary Conference, the International, 538 Sanitation : Electrical Sanitation, 469 Santiago, Diurnal Ground-Movements at, Dr. Obrecht, 130 Satellite, Anomalous Appearance of Jupiter's First, 300 Satellite, Period of Jupiter's Fifth, Prof. E. E. Barnard, 85 Satellites, Jupiter's, in 1664, 323 Satellite of Neptune, the. Prof. Struve, 324 ; M. Tisserand, 543 Savelief (R.), Sun-spots and Solar Radiation, 274; Solar Spots and Heat received by Earth, 284 Scandinavia, the Slow Ascensional Movement of, A. Badonrean, 159 Scandinavian Ice-Sheet, the. Prof. T. G. Bonney, F.R.S., 388 Schaeberle (Prof. J. M.), Mechanical Theory of Comets, 84 Schaefer (H. L. ), the Origin of Beats, 370 Schardt (Hans), Sur I'Origine des Prealpes Romandes, 322 Scheele (Carl Wilhelm), Prof. T. E. Thorpe on, 32 Schenck (Prof.), the Alleged Action of Green Algae as Water- Purifiers, 182 • Schild (Dr.), Method of Differentiating Typhoid and Colon Bacilli, 298 Schlick (Otto), the Vibrations of Steamers, 491 Schmidt (Dr. Karl), Death of, 507 Schmidt (K. E. F.), Elliptic Polarisation of Reflected Light, 547 Schofer (Dr.), the Bacterial Efficiency of Power Cylinders in Water-Filtration, 180 Supplement to Nat!tre,~\ May 31. 1894 J Index XXXV Scholtz (Dr. M.), Changes in Position of Flower-Stalk of Cobcza scandens, 306 Schoute (Prof.), Regular Sections and Projections of Ikosa- tetrahedron, 144 Schrader (M.), Geographical Conditions of Pyrenees, 275 Schubert (Dr.), Further Observations of the Temperature and Humidity in Woods and in the Open, 596 Schulz (Dr. August), Grundziige einer Entwickelungsgeschichte der Pflanzenwelt Mitteleuropas seit dem Ausgang der Tertiarzeit, 553 Schulze-Berge (Herr F. ), New Form of Rotary Air-Pump, 65 Schumann (Victor), Photography of Rays of very Short Wave- Lengths, 254 Schur (Prof.), a Bright Meteor, ill Science : Science in the Magazines, 31, 155, 235, 352, 443, 543 ; Elementary Course of Practical Science, Hugh Gordon, Sir Philip Magnus, 121 ; some Salient Points in the Science of the Earth, Sir J. W. Dawson, F.R. S., 196 ; American yournal of Science, 214 ; Revival of Science Gossip, 396 ; Science at the Free Libraries, Mr. Carrington, 418 ; Physio- logy for Science Schools, 431 ; Science Progress, 4.4 1 ; the Elizabeth Thompson Fund for Advancement of Scientific Research, 539 ; Prof. Michael Foster on the Organisation of Science, 563 Sclater (Dr. P. L., F.R.S.), the Zoological Record, 123 Scotland : Geological Survey of, 518 ; the Scottish Geographical Society and Antarctic Research, 257 Scott (D. H.), Organisation of Fossil Plants of Coal-Measures, 449 Scott (Dr. J. Alfred), Method for Colouring Lantern-Slides for Scientific Diagrams and other Purposes, 572 Scott (R. H., F.R. S.), Remarkable Sudden Changes of Baro- meter on February 23, 1894, Scourfield (D. J.), Entomostraca and Surface-Film of Water, 474 Screens, Transparent Conducting, for Electric and other Appa- ratus, Prof. W. E. Ayrton, F.R.S. , and T. Mather, 591 Scribner's Magazine, Science in, 352 Sea, the Fauna of the Deep, Sydney J. Hickson, 502 Sea-Level and Latitude, the Variations of. Prof. Bakhuyzen, 476 Sea- Water, the Bacterial Contents of. Dr. H. L. Russell, 559 Secondary Education Movement, the, Sir H. E. Roscoe, F.R.S., 203 Seeley (H. G., F.R.S. ), the Therosuchia, 450 ; Diademodon, 450 Seeman (Captain C. H.), Meteorological Conditions of Ham- burg Cholera Epidemic, 180 Seine-Saone Canal, Utilisation of Water-Power for Electrical Machinery on, M. Galliot, 272 Seismograph, a New Time-registering Photographic, Dr. A. Cancani, 64 Seismology: the Recent Earthquake, Charles Davison, 31; Diurnal Ground-Movements at Santiago, Dr. Obrecht, 130 ; Earth Movements, Prof. John Milne, F.R.S., 301 ; Mode of Propagation of Earthquake Shocks between Zante and Catania, Prof. Ricco, 606 Selwyn (Alfred R. C, F.R.S.), the Origin of Lake Basins, 412 Semi- Azimuths, Navigation by, Ernest Wentworth BuUer, 223 Senegambia, Magnetic Experiments in, T. E. Thorpe, F.R.S., and P. L. Gray, 141 Separating the Mineral Components of a Rock, on a Method of, Prof. W. J. Sollas, F.R.S., 211 Sequoia gigantea acquired by British Museum, Remarkable Section of, 507 Serpent-Poison, Inoculation against, A. Calmette, 548 Setchell (W. A.), the Laminariaceas, 207 Sewage, the Purification of, by Bacteria, Alex. C. Houston, 246 Sewage, Reduction of Manganese Peroxide in, W. E. Adeney, 499 Sewage, M. Hermite's System of Treating Sewage Matter with Electrolysed Sea- Water, Dr. C. Kelly, 539 Sewer Air, Distribution of Zymotic Disease by, Mr. Laws, 347 Sextic Resolvent of a Sextic Equation, on the, Prof. W. Burnside, F.R.S., 618 Shakespeare's Natural History, Phil Robinson, 444 Shan-si, the Plateau of, Mr. Obrucheff, 230 Sharp (Dr. D., F.R.S.,), White Ants, 522 Sharpe (Dr. R. Bowdler), an Ornithological Retrospect, 6 Sheldon (Samuel), Chapters on Electricity, 411 Shells, Magnetic Shielding of Concentric Spherical, Prof. A. W. Rucker, F.R.S., 141 ; Shells, the Dispersal of, Harry Wallis Kew, Clement Reid, 361 Shepton Mallet, Earthquake at, Prof. F. J, Allen, 229 Ships: the Loss of H.M.S. Victoria, Dr. Francis Eigar, 102, 124, 151 ; the Manoeuvring Powers of Steamships and their Practical Applications, Vice-Admiral P. H. Colomb, R.N., 174 Shorter (Lewis R.), a Plausible Paradox in Chances, 413 Shrewsbury, Proposed Memorial to Charles Darwin at, 320 Shrubs of North-Eastern America, Charles S. Newhall, 28 Siam, the Upper Mekong, Warrington Smyth, 416 Siberia, Anadyr, a New Province in, 18 Siberia, a Sub-Tropical Miocene Fauna in Arctic, W. H. Dall, 36 Siemens (Dr. Werner von), Personal Recollections of, 25 Siertsema (D.), the Magnetic Rotary Dispersion of Oxygen, 607 Sigson (A.), Photography of Snowflakes, 131 Silicon, Carbide of, Manufactured by Dr. Miihlhauser's Process, 17 Silk-Spider of Madagascar, the. Dr. Karl Milller, 253 Silver, Mirror, Chemically precipitated on Glass, Properties of, Herr H. Liidtke, 229 Silver on Platinum, Peculiarities of Electrical Deposit of, U. Behn, 321 Silvestri's (Prof.) Geodynamic Observations of Etna Eruptions of May and June, 1886, 107 Simpler Figures, Mensuration of the, William Briggs and T. W. Edmondson, 28 Simpson (C. T.), the Unio Fauna of the Mississippi Valley, 64 Sinuisoidal Currents, a Liquid Commutator for, Prof. J. A. Ewing, F.R.S., 317 Skelfo, Are Birds on the Wing killed by Lightning? 577 Skua, the Great, Threatened Extermination of, W. E. Clarke, 253 Slaughtering Animals, the Humanest Method of, Dr. Dembo, - 427 Smith (Dr. Donaldson), intended Expedition to Lake Rudolph, 606 Smith (Prof. Robertson), Death of, 538 ; Obituary Notice of, 557 Smith (Worthington G.), Fireball, 577 Smithell's (Prof. Arthur) Flame, 86, 149, 198 Smithsonian Institution Report, the. Prof. S. P. Langley, 397 Smyth (Warrington), the Upper Mekong, 416 Snail, the Kidney of the, Paul Girod, 380 Snow-Crystals, Prof. Hellmann, 216, 232 Snowflakes, Photography of, A. Sigson, 131 Social Evolution, Benjamin Kidd, Dr. Alfred R. Wallace, F.R.S., 549 Sohn (C, E. ), Dictionary of the Active Principles of Plants, 385 Sohncke (Prof.), Observations during Nocturnal Balloon Ascents at Munich, 416 Solandi Sun-printing Process as Applied to Botanical Tech- nique, Prof. Byron Halsted, 370 Solar and Magnetic Phenomena, Correlation of, William Ellis, F.R.S., 30, 53, 78, 245; A. R. Hinks, 78; H. A. Lawrance, loi ; Dr. M. A. Veeder, 245 Solar Magnetic Influences on Meteorology, Prof. H. A, Hazen, 464 Solar Observations at Catania, Rome, &c., 67 Solar Observations at Rome, 163 Solar Radiation, Sun-spots and, M. R. Savelief, 274 Solar Spots and Heat received by Earth, M. R. Savelief, 284 Solid Liquid Surfaces with Temperature, on the Change of Superficial Tension of, Prof. Geo. Eras. Fitzgerald, F.R.S., 293 Sollas (Prof.), Geology of Dublin Area, 36 Sollas (Prof. W. J,, F.R.S.), on a Method of separating the Mineral Components of a Rock, 211 Solubility of Normal Substances, General Law of, H, Le Chatelier, 524 Solvay (M. G.), Institutes of Electro-Biology and Physiology established at Brussels, by, 180 Sonnblick Mountain Observatory, 204 Sorel (E. ), Adaptation of Alcoholic Ferments to Presence of XXXVl Index T Supplement to Nature \_ May 31, 1894 Hydrofluoric Acid, 356 ; Action of Water on Bicalcic Phos- phates, 572 South Kensington Museum, Mr. James McMurtrie's Collection of Fossil Plants acquired by, 415 Space, Chemistry in, Dr. John Cannell Cain, 173 Space, on Homogeneous Division of. Lord Kelvin, P. R.S., 445. 469 Spectacles for Double Vision, T. J. Dewar, 433 Spectrum Analysis : Objective Representation of Interference Phenomena in Spectrum Colours, E. von Lommel, 46 ; Spectra of Hot Gases probably due to Temperature, F. Paschen, 82 ; New Notation for Lines in Spectrum of Hydrogen, 162; Spectrum of Nova Normas, 162, 397 ; Prof. W. W. Campbell, 586 ; Stars with Remarkable Spectra, T. E. Espin, 183 ; Photography of Rays of very Short Wave- Lengths, Victor Schumann, 254; Magnetic Rotary Dispersion of Carbon Bisulphide in Infra- Red part of Spec- trum, G. Moreau, 370; Instrument of Precision for Producing Monochromatic Light, A. E. Tutton, 377 ; Radiation of Gases, F. Paschen, 376 ; Combination of Prisms for a Stellar Spectroscope, H. F. Newall, 379 ; Method of Photographing Spectrum of Lightning, G. Meyer, 417 ; Comet-Spectra as affected by Width of Slit, 489 ; the Spectra of Tin, Lead, Arsenic, Antimony and Bismuth, Profs. Kayser and Runge, 509 ; Spectroscopic Examination of Light Emitted by Pho- tinus cor-}-iiscus Beetle, A. F. Miller, 540 Spencer (Herbert), Rejoinder to Prof. Weismann, 155 ; the Spencer- Weismann Controversy, P. Chalmers Mitchell, 373 ; Prof. Tyndall, 352 Spencer ( W. G. ), Effect upon Respiration of Faradic Excitation of Cerebrum in Animals, 353 Spermophiles of the Mississippi Valley, the, Vernon Bailev, 36 Sphere, the Geometrical Properties of the, William Briggs and T. W. Edmondson, 75 Spherical Vortex, on a. Dr. J. M. Hill, 498 Spica, Occultation of, 464 Spiders: Further Notes and Observations upon the Instinct of some Common English, R. I. Pocock, 60 ; Protective Habit in a Spider, Prof. C. Lloyd Morgan, 102 ; Mimicry by a Spider, 207 ; the Silk Spider of Madagascar, Dr. Karl Miiller, 253 ; Notes on the Habits of a Jamaican Spider, Prof. T. D. A. Cockerell, 412 ; the Su-pension of Foreign Bodies from Spiders' Webs, R. Philipp, 481 Spiro (Dr. P. A.), Death of, 179 Sporozoa, Cancer, Sarcoma, and other Morbid Growths con- sidered in Relation to the, J. Jackson Clarke, 502 Sprenger (Prof. A.), Death of, 206 Springmann (P.), Polarisationof Solid Deposits between Electro- lytes, 376 Spruce (Richard), Obituary Notice of, 317 Sprung (Prof. ), the Diurnal Range in Velocity and Direction of the Wind on the Eiffel Tower, 596 Spurge (J. B. ), New Photometric Method, 355 Stadl (Dr. van der), Interaction between Oxygen and Phos- phuretted Hydrogen, 323 Stars : a New Southern Star Discovered by Mrs. Fleming, 38 ; a New Variable Star, Rev. T. E. Espin, 67, 184 ; New Variable Star in Andromeda, Rev. Thomas D. Anderson, loi ; Four New Variable, Discovery of, by Mrs. Fleming, 608 ; the New Star in Norma, 85 ; Otto Struve's Double- Star Measures, III ; Stars with Remarkable Spectra, T. E. Espin, 183 ; Electromotive Force from the Light of the Stars, Prof. Geo. M. Minchin, 269 ; Hydrogen Envelope of the Star D.M. + 30° 3639, Prof. W. W. Campbell, 210; Proper Motions of Stars, 349 ; Speed of Perception of Stars, Prof. Ricco, 608. (See also Astronomy. ) Stas's Determination of Atomic Weights, E. Vogel, 283 Statics, Graphic Arithmetic and, J. J. Prince, 28 Statics and Dynamics, Solutions of the Examples in the Elements of, S. L. Loney, 122 Staurolite, Chemical Composition of, S. L. Penfield and J. H. Pratt, 402 Steam, on the Latent Heat of, P. J. Hartog and J. A. Harker, 5 Steam, the Cloudy Condensation of, Shelford Bidwell, F.R.S., 212, 388, 413 ; Dr. Carl Barus, 363 ; John Aitken, F. R. S., 340 Steam-Engine, the Grafton High-speed, E. W. Anderson, 610 Steam Jets from Various Orifices, Forms of, H. Parcnty, 347 Steam Pumps on Russian Railways, Alexander Borodin, ly Steamers, the Vibration of, Otto Schlick, 491 Steamships, the Manoeuvring Powers of, and their Practical Applications, Vice-Admiral P. H. Colomb, R.N., 174 Steamships, Effects of Reversing Screw on Steering of. Captain Bain, 208 Stearns (Dr.), the Albativss Collection of Galapagos Island Shells, 82 Stebbing (Rev. Thomas R. R.), a History of Crustacea. Recent Malacostraca, 74 Steel Meteorite, a Tempered, 372 Steele (W. H.), Electric Currents produced by heating various Metals, 131 Stthlin (H. G.), Zur Kenntniss der Postembryonalen Scl.adei- metamorphosen bei Wiederkauern, 99 Stein's (Dr.) Arctic Expedition, 256 ; Proposed Station in Ellesmere Land, 18 ; Plan (or Exploration of Ellesmere Land, 346 ; the Proposed Continuous Polar Exploration, 124 Stellar Diameters, the Measurement of, Maurice Hamy, 275 Stephenson (T. ), a Treatise on Hygiene and Public Health, 285 Stereo-Chemistry, Recent Progress in. Prof. Victor Meyer, 348 ; Extension of Inorganic Elements of Stereo-Chemistry, Dr. Werner, 372 ; Handbuch der Stereochemie, Dr. Paul Walden, 409 Stevens (F. H.), H. S. Hall and, a Text- Book of Encliu's Elements, 599 Stevenson (C. A.), Telegraphic Communication by Induction by Means of Coils, 571 : Electric Communication between Lighthouses and Lightships without Submarine Cables, 581 Stevenson (J. J.), Geological use of Name " Catskili," 92 j Origin of Pennsylvania Anthracite, 271 Stewart (R. Wallace), a Text-Book of Heat, 171 Stigmata, the, of the Arachnida as a Clue to their Ancestry, H. M. Bernard, 68 Stirling (Dr. James Hutchison), Darwinianism ; Workmen a'nd Work, 333 Stocks (H. B.), Coal-Balls and their Fossil Plant Contents, 14 Stokvis (Prof. B. J.), Chemistry in Relation to Pharmaco- Therapeutics and Materia Medica, 587 Stones, Precious, 319 Stoney (Dr. G. Johnstone, F. R.S.), Vision with Compound Eyes, 379 ; on M. Mercadier's Test of the Relative Validity ot the Electrostatic and Electromagnetic Systems of Dimen- sions, 432 Storrie (John), Roman Villa, near Cardiff, 505 Streets in Paris named after Men of Science, 558 Stromeyer (C. E ), Marine Boiler Management and Construc- tion, 410 ; Brilliant Aurora Borealis of March 30, 1894, 539 Struve (Prof. Otto), Double-Star Measures, iii ; the Satellite of Neptune, 324 Stuart- Menteath (M. P. W.), Ophites of Western Pyrenees, 264 Stubbs (Arthur J.), a Manual of Telephony, 454 Styles (W. A.), Orchids, 352 Submarine Cable between Zanzibar, Mauritius, and Seychelles, 134 Sugar as Food in Production of Muscular Work, Dr. Vaughan Harley, 283 Sugar-Cane Moth, the, A. S. Oliff, 64 Sugar Maples, W. Trelease, 323 Sulphide of Carbon, a New, A. E. Tutton, 275 Sun, an Annular Eclipse of the, 542 Sun, the Presence of Oxygen in the. Dr. Janssen, 585 Sun, the Story of the. Sir Robert Ball, F.R.S., A. Fowler, 382 Sun-spots : Sun-spots and Solar Radiation, M. R. Savelief, 274 ; Sun-spots and Magnetic Disturbances, Dr. L. Palazzo, 327 ; Dr. M. A. Veeder, 503 ; the Sun-spot Period and the West Indian Rainfall, Maxwell Hall, 399 ; a Large Sun-spot, 419 ; Sun-spot Phenomena and Thunderstorms, Rev. W. Clement Ley, 531 Superstition, on the Bugonia, of the Ancients, Baron C. R. Osten-Sacken, 198 Suspension of Foreign Bodies from Spiders' Webs, the, R. Philipp, 481 Swan (Prof.), Death of, 437 Swedish International Polar Expedition, Results of. Dr. J. Hann, 498 Swift's New Biological Microscope, 523 1 SiiJipUinent to Natun-,~\ May 31, 1894 J Index xxxvii Swinburne (James), Potentiometer for Alternating Currents, 190 Switzerland, Central European Time to be adopted in, 158 Switzerland, the Experiments upon the use of Electricity gained from Water, 182 Sydney Royal Society, 332 Sylvester (Prof. ), 13 Symons (G. J-). Rainfall Records in British Isles, 438 Symons's Monthly Meteorological Magazine, 139, 238, 449, 520 Symons (Mr.), March to October, 1893, 238 Syphilis, on the Presence of a Polymorphous Microbe in. Dr. Golasz, 500 Systematic Nomenclature, Prof G. F. Fitzgerald, F. R. S.. 148 ; Fred. T. Trouton, 148 Tail (Prof P. G.), a Treatise on the Kinetic Theory of Gases, Dr. William Watson, F.R.S., 73 ; Utility of Quaternions in Physics, A. McAuIay, 193 ; the Compression of Fluid, 331 Tarr (R. S.^, the Origin of Lake Basins, 315 ; the Finger Lakes in New York State, 606 Tasmania, the Recent Glaciation of, Dr. Alfred R. Wallace, F.R.S., 3 Tasmania, Coming International Exhibition at Hobart, 13 Taste among (North American) Indians, Sense of, E. H. S. Bailey, 82 Tate (Prof Ralph), the Geology of Australia, 277 laylor (II. Dennis), Colour-i\berration of Refracting Tele- scopes, 183 Taylor (H. M.), Pitt Press Euclid V.-VI., 52 Taylor (Dr. \. C), Temperature, Rainfall, and Sunshine of Las Palmas, Grand Canary, 425 Taylor (W. W.), Solutions of the Exercises in Taylor's Euclid, I. to IV., 3 Tea-Cultivation in Russia, Proposed, 393 Teaching University, the, F. Victor Dickins, 536 Tebb (Miss M. C), Note on the Liver-ferment, 52^ Technical Education : the Progress of, R. A. Gregory, 185 ; Bequest by Mr. T. II. Adam, 320 ; the Work of City and Guild of London Institutes for 1893, 607 ; the New Technical Educator, 148 ; Formation of Association of Technical In- stitutions, 321 ; on Preparing the Way for Technical Instruc- tion, Sir Philip Magnus, 400 Technology, the Massachusetts Institute of, 20 Tegetmeier (W. B.), Abnormal Eggs, 366 Teiegony, Dr. Geo. j. Romanes, F. R.S., 6 Telegraphic Communication by Induction by Means of Coils, C. A. Stevenson, 571 Teleki's (Count Samuel) the Last Great Lakes of Africa, 457 Telephone in India, the, 460 Telephony, a Manual of, W. H. Preece, F.R. S., and Arthur J. Stubbs, Prof. A. Gray, 454 Telescope for Greenwich, a New, 464 Telescopes, Colour-Aberration of Refracting, II. Dennis Taylor, 183 Telescopes, Celestial Objects for Common, Rev. T. \V. Webb, 339 Telescopes, New Form of Equatorial Mounting for Monster Reflecting, Sir Howard Grubb, 499 Teller (F. ), the so-called Granite of Bacher Mountains, 71 Temperature : Ilerr Galitzini's Experiments in Estimation of ^.Critical Temperature, 83; the Temperature of Ignition of Explosive Gaseous Mixtures, A. E. Tutlon, 138 ; on the Change of Superficial Tension of Solid Liquid .Surfaces with Temperature, Prof Geo. Eras. Fitzgerald, F. R. S., 293; Lowest known Temperature, 394 ; Relation between Mean Quarterly and Death-rate Temperature, W. II. Davis, 547 ; Minimum Temperature of Visibility, P. L. Gray, 618; on the Magnetic Properties of Iron at different Temperatures, M.P. Curie, 620 Tempered Steel Meteorite, a, 372 Temple to Mercury on Puy-de-D6me, Discovery of Ruins of, '4 Ten Kate's (Dr. II.) Malaysian and Polynesian (Anthropo- logical) Researches, 23 TenerilTe, the Butterflies and Moths of, A. E. Holt White, W. F. Kirby, 384 Tennant (John), the Viscous Motion of Ice, 173 Terrestrial Deformation in the Niagara District, Inferred Rate of, 520 Terrestrial Refraction in the Western Himalayas, Gen. J. T. Walker, F.R.S., 49S Tesla (Nikola), T. C. Martin, 352 Tesu, Colouring Matter of, J. J. Hummel and W. Cavallo, 377 . Tetanus Bacillus, Virulence of, increased by addition of other Organic Products, Signor Roncali, 254 Tetanus-Poison, Drs. Fermi and Pernossi, 540 Tetrahedra, on the Division of a Parallelepiped into, Prof. Crum Browne, 571 Texas, the Trinity Flora of, W. M. Fontaine, 36 Thermal Expansion of Diamond, the. Dr. J. Joly, F. R..S., 480 Thermodynamics : Heat and the Principles of Thermo- dynamics, C. H. Draper, 148 ; the Second Law of Thermo- dynamics, S. H. Burbury, F.R.S., 150; G. H. Bryan, 197; S. H. Burbury, F.R.S., 246 Thermometer for Laboratory Ov^ens, Electric Alarm, M. Barelle, 355 Thermometer, New High Temperature, Messrs. Baly and Chorley, 538 Thessaly, the Geology of. Prof. V. Hirbel, 36 Thiele (Dr.), Isocyano^en Tetrabromide, iio Thiselton-Dyer (W. T., F.R.S.), the Supposed Glaciation of Brazil, 4 Thomas (G. L.), Separation of Three Liquids by Fractional Distillation, 93 Thompson (Beeby), Landscape Marble, 522 Thompson (Elizabeth) Fund for Advancement of Scientific Research, 539 Thomson (J. J., F. R.S.), Notes on Recent Researches in Elec- tricity and Magnetism, Prof. A. Gray, 357; Electricity of Drops, 378 Thome (Dr. L. T.), the New Process for Enriching Coal-Gas with 0.xy-Oil Gas, 162 Thorneycroft (J. L.), the Circulation of Water in the Thorney- croft Water-tube Boilers, 491 Thornton (John), Human Physiology, Dr. J. S. Edkins, 431 Thorpe (Prof. T. E., F.R.S.): on Carl Wilhelm Scheele, 32 ; Magnetic Experiments in Senegambia, 141 ; the Bakerian Lecture, 419; Essays in Historical Chemistry, M. M. Patti- son Muir, 551 Thudichum (J. L. W.), Formation of Benzoic Derivatives of Uro chrome, 142 Thunderstorms, Sun-spot Phenomena and. Rev. W. Clement Ley, 531 Thwaites (C), Aurora of February 28, 441 Thyroid Gland, the, 270 Tibet, the Chinese Map of. Dr. Wegener, 275 Tidal Phenomena, Grablovitz's Mareographical Observations in Italy, 134 Tietze (Dr. Emil), Geology of Ostrau District, 46 Tilden (W. A.), Combination of Hydrocarbons with Picric Acid, 142 Time, Central European, adopted in Denmark, 228 Time, Central European, adopted in Italy, 81 ; Adoption of Signor G. Jervis's Improved Clock- Dial and Time-Table, 81 Time, Central European, to be adopted in Switzerland, 158 Time-Infinitesima', Phenomena of the. Prof. E. L. Nichols, "3 Tisserand (F.), Motion of Jupiter's Fifth Satellite, 239; the Satellite of Neptune, 543 Titchener (Dr. E. B. ), Physiological Psychology and Psycho- physics, 457 Titherley (A. W. ), Amides of Sodium, Potassium, and Lithium, 523 Tobias (Celeslin), on Absorption by the Bile Ducts, 617 Todd (Sir Charles), Meteorological Work in Australia, 229 Togo, Kling and Buttner's Expedition to, 207 Tomatoes, Dropsical Disease in, G. F. Atkinson, 298 Tombs at Beni Hasan, the, P. E. Newberry and G. W. Eraser, 169 Topinard (Dr. P.), Distiibution of Red Hair in France, 472 ; the Perfect Man, 520 Torquay, the Climate of, A. Chandler, 253 Toxicology : Poisonous Principles of Adder's Blood, MM. Phisalix and Bertrand, 284 ; Viper Poison, C. Phisalix and G, Bertrand, 380 XXXVIU Inde X [SiipJ>lement to Nature-, May 31, 1894 Tracheate Arthropoda, on the Classification of the : a Correction, R. I. Pocock, 124 Transactions of Austrian Geological Survey, 71 Transformers, Dynamos, Alternators, and, Gishert Kapp, 337 Transparent Conductina; Screens for Electric and other Apparatus, Trof. W. E. Ayrton, F.R.S., and T. Mather, 591 Transvaal, Entomological Collecting in the, 12 Traube (Dr. Hermann), General Method of Artificially Repro- ducing Crystallised Anhydrous Silicates, 161 Tree Pruning, A. des Cars, Prof W. R. Fisher, 526 Trees, British Forest, J. Nisbet, i Trees, Measurements of Growth of, J. Keuchler, 439 Trelease (W. ), Sugar Maples, 323 Triarthius, the Appendages of the Pygidium of, Charles E. Beecher, 617 Trigonometry : Accuracy of Divisions of Altazimuths of Pistor and Martin and of Repsold, Prof. J. A. C. Oudeman, 192 ; Plane Trigonometry, S. L. Loney, 339 ; Elementary Trigo- nometry, II. S. Hall and S. R. Knight, 456 ; on the Definitions of the Trigonometric Functions, Dr. A. Mac- farlane, 480 Trillat (M.), New Mode of Preparing Methylamine and Ethy- lamine, 300 Trilobites : Larval Form of Tiiarthrus, C. E. Beecher, 92; the Systematic Position of the Trilobites, II. M. Bernard, 521 Trimen (Henry, F. R.S.), the Royal Botanic Gardens, Peradeniya, 539 Tropical Botanic Gardens and their Uses, 453 Trouton (P>ed. T.), Systematic Nomenclature, 148 Trow (A. H.), Apogamy in Plciis serrulala (L. fil.) Var. Cristata, 434 Trunk, Relation of the Length of the, to the Height, Ch. Fere, 520 Trutat (Eugene), Les Pyrenees, 122 Tubercle Bacillus, Possible Transmission by Cigars of, Dr. Kerez, 371 Tubes, on the Motion of Bubbles in, 351 Tumours, the Parasitic Theory of the Causation of Malignant, J. Jackson Clarke, 502 Tunicate, the, 179 Turkestan, the Earthquake of November 5 in Russian, 159 Turkey, Pasteur Institutes to be established in, 437 Tusayan Villagers, on the Cardinal Points of the, J. Walter Fewkes, 388 Tutton (A. E.), the Preparation and Properties of Free Hydroxylamine, 105 ; the Temperature of Ignition of Explosive Gaseous Mixtures, 13S ; a New Process for the Preparation of Ethers, 184 ; a New Sulphide of Carbon, 275 ; Instrument for Accurately Grinding Section-Plates and Prisms of Crystals, 377 ; Instrument of Precision for Pro- ducing Monochromatic Light of any Desired Wave Length, 377 ; Iodine as a Base-forming Element, 442 ; the New Iodine Bases, 467 ; Further Light upon the Nature of the Benzene Nucleus, 614 Tyndall (Prof.), Death and Obituary Notice of, 128 ; Funeral of Prof Tyndall, 158 ; Resolution of Condolence of Royal Institution with Mrs. Tyndall, 179 ; Herbert Spencer, 352 Typhoons of 1892, the Rev. S. Chevalier, 560 UIrich(Dr. F.), Death of, 538 Ungulates, the, Os Pedis in, Prof. A. E. Mettam, 341 United Kingdom, Geological Survey of the. Sir Archibald Geikie, F.R. S., 495, 518 United States : the Pteropod Collections of the Allxilross, 36 ; Eighth Report of United States P3ureau of Ethnology, 132 ; U.S. Naval Observatory, Capt. F. V. McNair, 324 ; Great Storm in United States, 369; Geologic Atlas of, Sheet i., 369 ; Metrical System adopted by the United States, Henry Gannett, 461 ; the Pharmacopaeia of the United States of America, 525 ; Mr. F. L. Scribner appointed Government Agrostologist, 605 Universities: University Intelligence, 22, 45, 70, 92, 117, 139, 166, 283, 329, 352, 376, 401, 422, 448, 471, 497. 546; University of Edinburgh, Recent Benefactions, 252 ; Report of the Gresham University Commission, 405 ; University College : Physiological Psychology and Psycho-Physics, 252 ; Dr. E. B. Titchener, 457 ; the Teaching University, F. Victor Dickins, 536 ; the Proposed Reconstruction of the University of London, 558 Upham (Warren), Glacial Striae of Somerville, 183 ; Theory of the Formation of Drumlins near Boston, U.S.A., 207; the Fishing Banks between Cape Cod and Newfoundland, 402 Urich (F. W.), Centipedes and their Young, 531 Uropodinrc, Notes on the, A. D. Michael, 594 Uschinsky (Dr.), Cultivation of Pathogenic Bacteria in non- Albuminous Media, 83 ; the Tetanus Bacillus, 84 ; the Fer- . ment Character of Toxic Products of Pathogenic Bacteria, 208 Vallot's 1887 Mont Blanc Meteorological Observations, Alfred Angot, 167 Vanda teres. Peculiar Method of the Development of the Axillary Buds of, Henry Dixon, 523 Vanlair(C.),'Chronometric Determinations relating to Regenera- tion of Nerves, 283 Vapour Pressure inside Foam, on the Equilibrium of, Prof. G. F. Fitzgerald, F.R.S., 316 Vapour Pressures, Measurement of Low, J- W. Rodger, 436 - Variable in Andromeda, Anderson's, Prof. E. Pickering, 419 Variable Star, a New, Rev. T. E. Espin, 67, 184 Variable Stars, Discovery by Mrs. Fleming of Four New, 608 Variation of Latitude, the. Pro"". S. C. Chandler, 133 Vatican Observatory, the, R. A. Gregory, 341 Vault of Heaven, the, Richard A. Gregory, 291 Veeder (Dr. M. A.), Correlation of Solar and Magnetic Pheno- mena, 245 ; Sun-spots and Magnetic Disturbances, 503 Veley (V. H.), the Interaction of Chlorine and Lime, 118 Venus, the Planet, 233, 413 Verney (Sir Harry), Death of, 368 Verschaftelt (J.), Refractometer applied to Study of Chemical Reaction, 546 ; on the Phenomenon of Beats in Luminous Vibrations, 617 Vesuvius, Activity of, 34 Vibrations, on the Phenomenon of Beats in Luminous, Dr. J. Verschaffelt, 617 Vietoria, the Loss of H.M. S., Dr. Francis Elgar, 102, 124, 151 Victoria Institute, 594 Victoria Regia Tank in the Botanical Gardens, Fauna of the, Frank E. Beddard, F. R.S., 247 Vignon (Leo), Stability and Conservation of Dilute Solutions of Corrosive Sublimate, 167 Villard (M.), Hydrate of Nitrous Oxide, 524 Vinegar-producing Yeast, Dr. Lafar, 183 Viper- Poison, C. Phisalix and G. Bertrand, 380 Vis (C. W. de), the Diprotodon and its Times, 159 ; a Thylo- cine of Earlier Nototherian Period in Hueensland, 264 Viscous Motion of Ice, John Tennant, 173 Visibility, on the Minimum Temperature of, P. L. Gray, 61S Vision with Compound Eyes, Dr. G J. Stoney, 379 Vision, Spectacles for Double, T. J. Dewar, 433 Viticulture ; the Propagation of Potirridie by Storage of Graft- Slips in Moist Sand, A. Prunet, 24 ; the Grape-Vine Harvest of 1893, M. Chambrelent, 47 Vivisection ; Prof. Frankland's Our Secret Friends and Foes, 34 Vivisection Bill, the Indian, and the Anti-Vivisectionists, 130 Vogel (E.), Stas's Determination of Atomic Weights, 283 Voices from Abroad, Prof. Plenry E. Armstrong, F.R.S., 225 Voie Lactee dans I'Hemisphere Boreal, La, C. Easton, 99 Volcanoes : Activity of Vesuvius, 34 ; Prof. Silvestri"s Geo- dynamic Observations of Etna Eruptions of May and June, 1886, 107; Volcano Folk-Lore of India, Dr. V. Ball, 109 ; Eruption of El Calbuco (Andes), A. E. Nogues, 179 Vole, Field, the Disappearance of the, Peter Adair, 14 Vortices, Paired Motion of, with a Common Axis, A. E. H. Love, 499 Wagner, Bedell, and Miller (Messrs.), New Form of Contact- Maker, 37 Walden (Dr. Paul), Handbuch der Stereochemie, 409 jl Wales, Earthquake in, 34 Walker (Charles Clement) Prize for Investigation of Cancer, h*^ 508 "' Walker (Gen. J. T., F.R.S.), Terrestrial Refraction in the h|^ Western Himalayan Mountains, 498 Supplement to Natiire,~\ May 31, 1894 J Index xxxix Walker (Mr.), Experiments in Devices for Compensating Hysteresis of Iron used for Measuring InUruments, 2o5 Wallace (Dr. Alfred R., F. R.S.), the Recent Glaciation of Tasmania, 3 ; the Ice Age an 1 its Work, 31, 155 ; Sir Henry H. Howortti on Geology in Nubibus, 52, loi, 173; Recog- nition Marks, 53; the Origin of Lake Bisins, 197, 220; Darwinianism : Workmen and Work, Dr. James Hutchison Stirling, 333 ; Social Evolution, Benjamin I-Cid 1, 549 ; Whit are Zoological Regions? 610 Wallis-Budge(E. A., F.S. A.), the Mummy, 97 Walther (Johannes) Bionomie des Meeres, 244 Ward (Dr. H. M., F.R.S.)i Action of Light on Bacteria, 166, 353 ; Bacterial Photographs of Solar Electric Spectra, 353 ; Recent Investigation and Ideas on the Fi.Kation of Nitrogen by Plants, 511 Ward (Lester), the Status of the Mind Question, 510 Ward (Rowland), White Rhinoceros in London, 584 Ward(R. de C), Thunderstorms, 416 ; the Study of Thunder- storms in Italy, 423 Washington (H. S.), the Basalts of Kula, 402 Wasps, the Reproduction of, Paul Marchal, 47 Water, Sand Filtration as a Means of Purifying, Mrs. Percy Frankland, 156 Water-Filtrr:tion ; the Bacterial Efficiency of Porous Cylinders, Dr. Schafer, 160 W^ater- Power, the Falls of Niagara and its, 482 Water- Purifier, the Alleged Action of Green Algre on. Prof. Schenck, 182 Watson (Dr. William, F.R.S.), a Treatise on the Kinetic Theory of Gases, Prof. P. G. Tait, 73 Watts (W. W'. ), fcrlitic Cracks in Quartz, 547 Wave-Lengths of the Nebular Lines, Prof. Keeler, 18 Waves, Best Method of Using Oil in Calming, Dr. M. M. Richter, 488 W^eather, the Moon and, 275 Weather Lore, Richard Inwards, 217 Webb (Dr.), Death of. 129 Webb (Rev. T. W.), Celestial Objects for Common Telescopes, 339 Webster (Angus D. ), Practical Forestry, 526 Wegener (Dr.), the Chinese Map of Tibet, 275 Weir (J. Jenner), Death of, 538 Weismann (Prof.), Rejoinder to, Herbert Spencer, 155 Weismann, the Spencer-, Controversy, P. Chalmers Mitchell, 373 Weismannism, an Examination of, Dr. G. J. Romanes, F.R. S., 49. 78 .... Weismannism, Biology as it is applied against Dogma and Freewill and for, H. Croft Hiller, 386 Weiss (Dr. G. A.), Death of, 53S Webs, the Suspension of Foreign Bodies from Spiders', R. Philipp, 481 Wells (H. G.), Text-book of Biology, 14S Welsh (F. R.), the Aurora of March 30, 576 Werner, (Dr.), Extension of Stereochemistry to Inorganic Elements, 372 Wernicke (Herr), Vitalitv of Cholera Organisms on Tobacco, 108 Wernicke (W. ), Normal and Anomalous Changes of Phase during Reflection of Light by Metals, 547 Weymouth (F. M.), the Construction of Drum Armatures and Commutators, E. Wilson, 478 Weyr (Prof. E.), Death of, 393 Wheat-growing in Indiana, 15 White (A. E. Holt), the Butterflies and Moths of Teneriffe, W. F. Kirby, 384 White(C. A.), Relation of Fog-Signals to other Sounds, 508 White (W. H.), Recent First-class Battleships, 490 White (Mr.), Polymeric Modifications of Acetic Aldehyde. 396 White Ants, Dr. D. Sharp, F.R.S., 522 Wiazemski's (Prince Constantine) Journey through Asia, 324 Wiedemann's Annalen der Physik und Chemie, 46, 117, 239, 376, 449, 547 Wiesner (Prof. J. ), Influence of Artificial Rain on Plants, 253 Wilde (H., F.R.S.), Magnetarium, 521 Wilder Quarter-Century Book, the, 362 Wilks (Dr. S., F.R.S.), Muscular Action the Origin of Music, 271 Willey (Arthur), Epigonichthys cidtellus, 423 Williams (Dr. C. Theodore), the Climate of Southern California, 307 Williamson (W. C, F.R.S.,), Organisation of Fossil-Plants of Coal-Measures, 449 Willis (f. C), Gynodirecism (HI.), 167'; Deherainea smaragdina, 523 Williston (Prol.), Congenerousness of /"/tv-ti/z/'^/^^w, Marsh, with Oruilhostofiia, SeeUy, IC9 Willoughby (Edward F.), Public Health and Demography, 285 Wdson (E.), the Construction of Drum Armatures and Commu- tators, F. M. VVeymoulh, 478 W^ind, the Internal Work of the, Prof. S. P. Langley, 273. Wind, the No. th- East, S. H. Burbury, F.R.S., 481 ; Prof. T. G. Bonney, F. R.S., 577 Winder (G.), Synthesis of Piazine Derivatives, 118 ; Interaction of Benzjlamine and Eihylic Chloracetate, 377 Wines, Di-covery of .Vbrastol in, M. Sangle-Feriiere, 167 Winograd>ky (M.), a Soil-Microbe assimilative of Atmospheric Nitrogen, 607 Wires, Torsional Oscillations of. Dr. W. Peddie, 331 W'istar (Isaac J.), the Postal Transmission of Natural Histoiy Specimens, 100 Witz (M. Aime), Problcmes et Calculs Pratiques d'Electricile, Prof. A. Gray, 145 Wnukow (N.), the Bacilli of Leprosy, 231 Wohrmann (Baron von). Systematic Position of Trigonidae and Descent of Nayadidae, 46 Wolf (Prof. Rudolf), of Zurich, Death of, 162 ; Obituary Notice of, 266 Wollman (Mr.), Projected Arctic Expedition by, 416 Wolsingham Observatory, Report of the, 300 Wood, from being Worm- Eaten, Means of Preventing, Emile Mer, 119 Woodlanders, with the, and by the Tide, 51 Wooldridge (L. C), on the Chemistry of the Blood, and other Scientific Papers, 2S9 Wright (Prof. G. Frederick), Glacial Erosion in Alaska, 316 ; Continuity of the Glacial Epoch, 520 Wundt (Wilhelm), Grundziige der Physiologischen Psychologie, 3" W iirtemberg. Complete Plesiosaurus found at, 271 \Vyhe (.\I. van), the Ventral Nerves of Amphio\u~, 24 Yeast, Vinegar- Producing, Dr. Lafar, 183 Yemen, a Journey through the, Walter B. Harri.'^, 291 Yenisei Region, the Upper, Mr. Kryloff, 230 Young (Prof. Sydney, F.R.S.), Separation of Three Liquids by Fractional Distillation, 93 ; Van der Waal's Generalisa- tions regarding "corresponding " Temperatures, &c., 93 Zaaijer (Prof), the Sutura Condylo- Squamosa of Occipital Bone of Man and Mammalia, 192 Zacharias (Dr. Q.), Forschungsberichte aus der Biologischen Station zu Plon, 385 Zante, in 1893, Velocity of Earthquakes at. Dr. G. Agamen- none, 439 Zenger (C. V.), the Systematic Aplanatic Objectives, 426 Zittel's (Dr. von) Handbook of Palreontology, 64 Zoology : Zoological Gardens, Additions to, 17, 38, 67, 84, no, 133, 162, 183, 209, 232, 256, 274, 300, 323, 349, 372, 396, 419, 441, 464, 489, 511, 542, 562, 5S5, 608 ; Zoological Society, 95, 166, 190, 306, 378, 425, 475, 523, 594 ; Nether- lands Zoological Society, 24, 264 ; the Ventral Nerves of Amphioxus, M. van Wyhe, 24 ; Scheme for Mapping Geo- graphical Distribution of Vertebrates, Miller Christy, 35 ; the Zoological Record, R. I. Pocock, 53. 198 ; F. A. Bather, 53, 19S ; Dr. P. L. Sclater, F.R.S., John E. Marr, 123; the Rise of the Mammalia in North America, Prof. H. F. Osborn, 235, 257 ; Novitates Zoologicae, 396 ; Myology of the Hystricomorphine and Sciuromorphine Rodents, F. G. Parsons, 523 ; Life and Rock, R. Lydekker, 575 ; the Naples Zoological Station, 604; What are Zoological Regions? Dr. A. R. Wallace, F.R.S., 610 Zuntz (Dr.), New Method of Measuring Amount of Circulating Blood, 168 ; Experiments on kespiration by Skin and In- testine of Horse, 427 Index t Supplement to Nature. May 3C, 1S94 INDEX TO SUPPLEMENT OF JANUARY i8, 1894. Ball (\V. W. Rouse), an Essay on Newton's " Principia," xii. Bonney (Prof. T. G., F.R.S.), the Story of Our Planet, iii. British Museum (Natural History), Catalogue of the Madrepor- arian Corals in the, George Brook, Prof. Alfred C. Haddon, ix. Brook (George), Catalogue of the Madreporarian Corals in the British Museum (Natural History), Prof, Alfred C. Haddon, Cambridge: Catalogue of the Egyptian Collection in the Fitz- william Museum, E. A. Wall is- Budge, xiii. Cayley (Arthur, F.R.S.), the Collected Mathematical Papers of, Major P. A, MacMahon, F. R.S., iv. Chemistry, Physiological, of the Animal Body, Dr. Arthur Gamgee, F.R.S., Or. J. S. Edkins, x. Corals, Catalogue of the Madreporarian, in the Brili>h Museum (Natural History), George Brook, Prof. Alfred C. Haddon, ix. Digestion, Ihe Physiological Chemislryof, Dr. Arthur Gamgee, F.R.S., Dr. T. S. Edkins, x. Dunmore (the Earl of), the Pamirs, vi. Edkins (Dr. J. S.), Physiological Chemistry of the Animal Body, Dr. Arthur Gamgee, F.R.S., x. Egypt : Catalogue of the Egyptian Collection in the Fitz- william Museum, E. A. Wallis- Budge, xiii. Engineering Drawing and Design, Sydney H. Wells, N. J. Lockyer, xiii. Fitzwilliam Museum, Catalogue of the Egyptian CoUecton in the, E. A. Wallis-Budge, xiii. Gamgee (Dr. Arthur, F.R.S.), Physiological Chemistry of the Animal Body, Dr. J. S. Edkins, x. Geography : the Pamiis, the Earl of Dunmore, vi. Geology, the Story of Our Planet, Prof. T. G. Bonney, F.R.S., iii. Haddon (Prof. Alfred C), Catalogue of the Madreporarian Corals in the British Museum (Natural History), George Brook, ix. Hoofs, Horns and, R. Lydekker, xiv. Horns and Hoofs, R. I-ydekker, xiv. Lockyer (N. J.), Engineering Drawing and Design, Sydney H. Wells, xiii. Lydekker (R.), Horns and Hoofs, xiv. MacMahon (Major P. A., F.R.S.), the Collected Mathematical Papers of Arthur Cayley, F.R. S., iv. Madreporarian Corals in the British Museum (Natural History), Catalogue of the, George Brook, Prof. Alfred C. Haddon, ix. Mathematics : the Collected Mathematical Papers of Arthur Cayley, F.R.S., Major P. A. MacMahon, F.R.S., iv. Natural History : the Catalogue of the Madreporarian Corals in the British Museum, George Brook, Prof. Alfred C. Haddon, ix. Newton's " Principia," an Essay on, W. W. Rouse Ball, xii. Pamirs, the, the Earl of Dunmore, vi. Physiological Chemistry of the Animal Body, Dr. Arthur Gamgee, F.R.S., Dr. J. S. Edkins, x. Planet, the Story of Our, Prof. W. G. Bonney, F.R.S., iii. " Principia," an Essay on Newton's, W. W. Rouse Ball, xii. Story of Our Planet, the, Prof. W. G. Bonney, F.R.S., iii. Wallis-Budge (E. A.), Catalogue of the Egyptian Collection in the Fitzwilliam Museum, xiii. Wells (Sydney H.), Engineering Drawing and Design, N.J. Lockyer, xiii. A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. " To the soli a ground Of Nature trusts the mind zuhich builds for aye. -Wordsworth. THURSDAY, NOVEMBER 2, 1S93. BRITISH FOREST TREES. British Forest Trees. By J. Nisbet, D.CEc. (London : .Macmillan and Co., 1893.) WITH the exception of Dr. Schlich's able " Manual of Forestry," of which two volumes are now be- fore the public, the English student of arboriculture has for many years past been almost entirely dependent on French and German works for recent information as regards the progress of that part of the art of forestry which deals with the cultivation of our native and intro- duced trees. The present work is a praiseworthy attempt to remedy this state of dependence, and to provide British foresters with a text-book which shall give the results of modern experience in an English dress. The plan of the work is simple and to the point. After briefly summarising the history of British forests — too briefly, perhaps, will be the opinion of some— the author proceeds to enumerate the chief forest-trees of our country. To those who miss any reference to some of the minor and unimportant woody plants growing in our hedges, it should be pointed out that the principal forms met with as underwood or coppice are treated separ- ately at the end of the book ; while those who feel any surprise at the introduction of several European (but not British) and American trees, especially conifers, should bear in mind that these have been so much planted in England and Scotland of late years, that no work on British forestry can afford to neglect them. Mr. Nisbet seems to have carefully stated what is necessary in this connection. The next sections of the book deal with the important and very interesting subjects of forest growth in rela- tion to soil, the growth of timber in general, and com- parative considerations regarding the growth of forest I trees. It may perhaps be doubted whether the author has j succeeded in stating anything new in this connection, i beyond what has already been put forward in other text- books, and it is admitted that the sources of the informa- NO. 1253, VOL. 49] tion are almost entirely continental, especially German. Perhaps the chief merit of these parts of the book is the author's manner of putting the facts ; for, on the whole, they read well and consecutively, and no student of sylviculture can fail to profit by them. Sylviculture— and the same is true of forestry in general — is a subject about which much can be written and said, and the temptation to be prolix is great, with such materials. The authcrr's conscientious acknowledg- ments of the sources of his quoted tables and experi- mental data may certainly be put to his credit ; and al- though we may doubt whether any practical forester will accept all the statements unreservedly— for foresters, like farmers, are often somewhat apt to generalise too widely from individual experience in one part of a country— few will deny that Mr. Nisbet has succeeded in putting forward very plainly a large amount of in- formation about the sylvicultural aspects of forests in general. The chief fault to be found with this part of the book is, perhaps, that the experience on which the statements are based is almost entirely German, whereas there is really a great deal to be said about the be- haviour and treatment of forests in this climate as well. The principal, and by far the greater part of the book however, is concerned with the treatment of the several species of forest trees in detail. Here, again, the British cultivator will doubtless raise the objection that the author almost entirely confines himself to the experience of foresters in Germany ; but it is more and more borne in upon the reader that there is reason in this, in so far that several really great authorities on the cultivation of trees have arisen in that country, whereas it would be difficult to name any in this country. Be this as it may, there can be no question that Mr. Nisbet has succeeded in collecting a very large amount of valuable information regarding the experience of foresters as to what trees will grow in certain situations, how fast they may be expected to grow there, and how much timber they may be made to yield if properly treated ; as to what trees should preferably be grown to- gether in mixed forests, and why such and such mixtures are undesirable ; and, further, to what dangers given B NATURE [November 2, 189.^ species are exposed when grown in quantity, and so forth. Some of the sections are notably long, and the author gives signs of the discursive habit incidental to those who read and transcribe much from German text-books ; moreover, there are sentences which betray the German method in their construction, and there is a distinctly Teutonic sound about some of the terms and short phrases, such as "soil-improving,"" free enjoyment of light and air," "above-sketched method,'' "equal-aged crops," and so on. With all its faults of diffuse writing, and a certain amount of repetition, the work is likely to bs valuable to students of forestry in this country, as setting forth the experience of German and other continental authorities in the growth and tending of mixed and other forests. One or two misprints have come under our notice, ^,^. an /has dropped on p. i6i ; and should not "prunosa" (p. 328) be pruinosa ? Again, why adopt the antiquated term " Scots Pine ''''i ASTRONOMY OF THE NINETEENTH CENTURY. A Popular History of Astronomy during the. A'ineteenth Ceniitiy. By Agnes M. Gierke. Third Edition. (London : A. and C. Black', 1893.) DURING the six years that have elapsed since the publication of the second edition of Miss Gierke's classical history of astronomy, new light has been thrown upon a number of old ideas, and many important dis- coveries have been made. It became necessary, there- fore, for the authoress to revise her work, to add here, and substitute there, and in all cases to incorporate the recently-acquired facts without breach of continuity. There is no suggestion of interpolation, and nothing but praise can be given for the manner in which the selected material has been assimilated. Attention may be directed with advantage to one or two points. On p. 199 a description is given of the luminous outburst observed upon the sun in September, 1S59. The occurrence is supposed to have been followed immediately by a break in the magnetic records at Kew, and every astronomical text-book instances it in evidence of the sun's ability to disturb terrestrial magnetism. Miss Gierke's words with reference to the matter are as fol- lows, the italicised expression being her own: — "^/ the very instant of the solar outburst witnessed by Carring- ton and Hodgson, the photographic apparatus at Kew registered a marked disturbance of all the three mag- netic elements." Now, at a meeting of the Physical Society in 1S86, the late Mr. Whipple said that from an examination of the magnetic curves, he believed " the very slight notch in the record, many similar to which have occurred since, was of an accidental nature, and a mere coincidence." (Nature, vol. xxxiii. p. 621.) Further, in a letter to the writer of this notice, Mr. Whipple remarked "it was merely an insignificant wriggle of the curves that was recorded at the time of the Carrington and Hodgson observation, and the great NO. 1253, VOL. 49] magnetic storm did not commence for some fifteen hours later." Miss Gierke would do well to mention Mr. Whipple's contention in a future edition, and if she will look at the traces and decide the point— accepting Sabine's interpretation of a magnetic disturbance (Phii. Trans, vol. cliii. p. 274), she would do a good work. Possibly the coincidence will be disproved before the appearance of the next edition. Tenets of belief accepted quite as implicitly have had to be given up in the interim be- tween the publication of the second edition and the one before U5. Thus, in the former edition we read (p. 437) " the conspicuous bright line of the Draco nebula was found to belong very probably to nitrogen"; whereas the present rendering is " the conspicuous bright line of the Draco nebula, although nearly accordant in position with one belonging to nitrogen, has since proved to be distinct from it." But for the suggestion that the chief nebular line had its origin in magnesium, the nitrogen origin would, in all probability, still be accepted. The search for truth initiated by the sugges- tion, has thus borne good fruit in disposing of the nitro- gen-origin " for ever and for aye." One begins to wonder why the idea remained above suspicion for so many years. It is well known that the green line of nitrogen is double, and it now appears that the mag- nesium fluting is really nearer the true position of the chief nebular line than the nitrogen double. What is more, the magnesium origin was indicated by laboratory experiments, whereas nitrogen had nothing but an approximate coincidence to support it. In connection with the spectra of nebulae it may be pointed out that no mention appears to be made of the observation of the discontinuous character of the spec- trum of the Andromeda nebula {Roy. Soc. Proc. vol. xlv. p. 2 16), and of the white nebula in Draco, G.C. 4058 {Ibid. vol. xlviii. p. 219). This is to be regretted, forthe obser- vations are of importance, and, in all probability, many of the spectra now classified as continuous are only irregu- larly so; hence a study of these minute differences of brightness may very considerably add to our knowledge of stellar constitution. We also fail to find a description of Prof Boys' work on the heat of the moon and stars {Roy. Soc. Proc. vol. xlvii. p. 480). There are seventy-two more pages in the third edition than in the previous one, and five plates have been added. An extremely useful set of tables of astronomical data has also been included. The chronological table has, of course, been brought up to date, and it gives an excellent digest of the work that has been done between March 1774 and April 1893. It can hardly be said, ho vv- ever, that the strict impartiality which should characterise a history of astronomy has been exercised when an event of such local interest as a " Lecture by Dr. Huggins, on Nova AurigK, at the Royal Institution," is recorded as having taken place on May 13, 1892, while the announce- ment on February 8, 1892, of the duplex nature of the lines in the spectrum of the same Nova is unmentioned in the table. The merits of the volume are now so well known that it is quite unnecessary to expatiate upon them. It seems to us, however, that if Miss Gierke were more a historian and less a partisan, her work would be of higher value. November 2, 1893] jVA TURE OUR BOOK SHELF. Inorganic Chemistry for Beginners. By Sir Henry Roscoe, F.R.S., assisted by Joseph Lunt. (London : Macmillan and Co., 1893.) Everyone recognises the necessity for having works upon elementary science written by men in thorough touch with their subject. It is with some satisfaction, therefore, that we notice this book, in which Sir Henry Roscoe clearly expounds the elementary principles of chemistry, and describes some of the non-metallic elements and their more important compounds. The book differs froni the author's well-known " Lessons in Chemistry " in arrangement and in style, and is far better suited to the tyro in chemistry. In fact, it is adapted to suit the re- quirements of the syllabus of the Department of Science and Art, and both teachers and students under the Department will benefit by its introduction. There are twenty-one lessons in the book, each complete in itself. At the end of each lesson is a brief summary and a set of questions bearing upon the subjects treated. Believing with all educationalists that principles only become apparent when they are reflected by facts, the author illustrates each step with an experiment. One hundred and eight illustrations elucidate the text, and though many of them are of the ordinary stock character (which is, perhaps, unavoidable in a book of this kind) a fair proportion art from new blocks. In every respect the book is a good one, and contains the kind of knowledge that should be imparted to all beginners of science. The Chemistry of Fire. By M. M. Pattison Muir. (London : Methuen and Co., 1893.) The fact that this book belongs to a University Extension .Series vouches for the popular character of the contents. Extensionists should welcome Mr. Pattison INIuir's con- tribution to their literature, for it represents the work of a practical teacher, and combines accuracy with sim- plicity. It is now generally conceded that the best way to teach chemistry is to deal first with common occur- rences and things, and finally to generalise. Let a student once obtain a correct notion of the changes of composi- tion that happen in the burning of a candle, and he can comprehend all chemical changes. We therefore com- mend the book before us to the notice of committees and organisers of technical education, for it contains just the kind of linowledge that should be imparted to all students under their guidance. Like the majority of the volumes in the series to which this one belongs, >the illustrations are few and very sketchy. On this account it will be difficult for the home-reader to get a clear conception of many of the experiments. Solutions of the Exercises in Taylor's Euclid I. to IV. By W. W. Taylor, M.A. (Cambridge : University Press, 1893.) By the publication of these solutions, Mr. Taylor has furthered very considerably the usefulness of the book written by his brother. In the book he has worked out very fully all the problems, and has arranged the text in such a form as to be thoroughly intelligible to any student. Where several problems were of a similar character, it has been thought expedient to adopt a different mode of solution, while in some cases duplicate solutions have been given. Extension of theorems have here and there been inserted, and a few additional exercises will also be found to have been interpolated. By the adoption of a simple notation, reference can be directly made to the problems in the " Pitt Press Euclid.'' Both teachers and taught will find that they have a very useful companion to the above-mentioned book, while the latter will be very much enlightened in the art of solving many problems. NO, 125 ^, VOL. 49] LETTERS TO THE EDITOR. [The Editor does not hold himsef responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part oj Natukj:. No notice is taken oj anonymous communications. ^^ The Recent Glaciation of Tasmania. In a paper read before the Royal Society of Tasmania in June last, Mr. R. M.Johnston, F.L. S., gives a sketch of wbnt is known of the glaciation of the island, or rail)er of the western portion of it, for no indications of glaciers appear lo have been discovered in the eastern half. This difierence is supposed to be due to the fact that on the western side of the island the rainfall is from 50 to 76 inches annually, wliile in the central valley it is but little over 20 inches. Indications ot placialion among the western mountains were noticed by Mr. Charles Gould, Government geologist, about forty )ears ago, and from information received from him through the late Chief Secretary of Tasmania, the Hon. J. R. Scott, Mr. Johnston took up the inquiry, and for many years has made exploi aliens in the western plateaus and mountains. Mr. C. P. bprenr was anothc;r explorer who published some account of the glacial phenomena in 1886, while more recently Mr. T. B. Moore and Mr. Dunn have recorded similar observations. Mr. A. Mont- gomery, the present Government geologist, has also just pub- Hshed a paper on the same subject. Mr. Johnston tells us that he has personally explored the whole of the western mountains, from the Picton and Craycrolt Rivers, southern branches of the Huon, in the extreme iouih, along the mountain ranges forming the western border of the central plateau, quite through to Emu Bay on the north coast ; and that he has found the clearest evidences of glaciation in almost every valley throughout this great extent of country. From the Arthur Range in the south to Mount Bischoff in the north, are numerous moraines, roches moutonnees, tarns and lakes in great abundance, polished and striated rock-surfaces, and numbers of true erratics. Near the sources of the Franklin River, under Mount Hugel, and only six or seven miles west of Lake St. Clair, are Lakes Dixon and Undine, of which Mr. Johnston writes : — "The valley of Lake Dixon is /«;-tU'a'//c«a', the ideal of a perfect glacier valley. No one, however ignorant of glacial action, could in this neighbourhood gaze upon these beautiful scooped, or rather abraded lakes or tarns, the snow- white, polished, billowy, and cascade-like roches moutcnnces, composed of quartzites, on the upper margin of Lake Dixon, together with the tumbled moraines and large erratics on the lower banks — -at a level of about 2000 feet — without being im- pressed with the idea that its singularly characteristic features must have been produced by the slow rasping flow of an ancient river of ice." Further north, the Murchison, Macintosh and Huskisson rivers, ail branches of the Pieman River, contain similar glacial markings ; and Mr. Dunn has recently described others of the same character about Lake Dora, nearer 10 the wet coast. The latter observer lays special stress on the rounred planed and scored rocks, on hard quartzite and conglomeiate rocks rounded and polished, on numerous tarns in rock-basirs, on moraines covering hundreds of acres, and on numerous huge erratics and perched blocks. (See Annual Report of the Secretaiy for Mines, Victoria, 1893, p. 21.) Mr. T. B. Moore states that he found the rocks polished and striated within 25 feet of the top of Mount Tyndall, or 3S50 feet above the sea, a sufficient indication that the great central plateau at an average elevation of nearly 4000 feet must have been buried in ice or neve to a considerable depth, and have formed the feeding ground for the glaciers, whose effects are so visible in the adjacent western valleys. The Tasmanian geolo- gists are united in the belief that the glaciers never reached the coast or descended much below the 2000 feet level, and that the ice did not extend to the central valley or the eastern side of tl e island. They therefore speak of it as a glacier, not a glacial period, the conditions being somewhat similar to those of the Alps at the present time ; but, owing to the great difference in the rainfall, there was a more marked contrast between the western and eastern districts, while the lofty central plateau afforded a much more extensive snow-field than Switzerland now possesses. The facts here stated on the authority of Mr. Johnston, sup- NA TURE [November 2, 189; ported by those of three other observers, two ol them being the Government geologists, render more singular the statements of Messrs. Officer and Spencer (Nature, June 29, p. 198) as to their not finding any traces of glaciation in the country around Lake St. Clair, which they explored for a month. Lake Dixon, which Mr. Johnston describes as presenting all the evidences of glaciation in their fullest development, appears to be less than ten miles from the lower end of Lake St. Clair, according to the best map I can refer to; while Lake Petrarch, which Mr. Officer describes a'; seeing from the top of Mount Olympus, lies between the two in the Cuvier valley, and is also mentioned by Mr. Johnston as being within the highly-glaciaied region. It IS quite possible that the lakes on the great plateau may be due to da-r.ming up, owing to movements of the superficial gravels and clays by the ice or «/zv' sheet ; but there are evidently an abundance of small valley-lakes and tarns in the we>tern valleys so surrounded by all the marks of extensive glaciation as to render it almost certain that they are true ice-eroded rock basins. It is much to be wished that a more detailed account of this interesting district, with a good map showing all the mountains, lakes, and valleys referred to, would be given us by one of the local geologists, ALFiitD R. Wallace. The Supposed Glaciation of Brazil. Mr. Wallace observes in his letter on this subject, published in Nature (vol. xlviii. p. 589), that "mo authoritative disproof has yet been gi ven of the exceedingly strong and positive statement of Agassiz and Hartt." I confess to my mind the matter had seemed disposed of by the interesting discussion of the subject to be found in the *' Notes of a Naturalist in South America " (1887), by the late Mr. John Ball, F. R. S. This experienced and accurate observer arrived at the conclusion from a study of the phenomena on the spot, that they could be sufficiently accounted for by subaerial denudation (see, in particular, pp. 313-8). In the following passage he rejects the agency of glacial action as definitely as his habitual caution and modesty would allow : — " I was unfortunately not acquainted at that time with the observations made near Tijuca by Prof. Alexander Agassiz, which appear to him to give evidence of glacial action in this part of Brazil. It would be rash, especially for one who has not been able to examine the deposits referred to, to controvert con- clusions resting on such high authority ; but I may remark that the evidence is confessedly very imperfect, and that the characteristic striations, either on the live rock or on the trans- ported blocks, which are commonly seen in the theatre of glacial action, have not been observed. 1 lean to the opinion that the deposits seen near Tijuca are of the same character as those described by M. Liais' as frequent in Brazil. The crystalline rocks are of very unequal hardness, and while some portions are rapidly disintegrated, the harder part resist. The disintegrated matter is washed away, and the result is to leave a pile of blocks of unequal dimensions lying in a confused mass." (P. 342.) VV. T. Thiselton-Dyer. Royal Gardens, Kew, October 23. The Nativity of Rama. I HAVE been much interested in the letter of " Kanhaiyalal," which appears in your issue of August 31. I fully agree with him in the view taken in regard to the verification of dates by astronomical methods, and it really does seem somewhat singular that the example of Sir William Jones, the pioneer of Orientalism in Europe, should have been entirely neglected by his learned colleagues and successors in this department of research. From many considerati )ns ii must be obvious that wherever mention of planetary ' 'yogams" or conjunctions, siderial and lunar positions, &c., are given in the text of .ny classical work, they are to be preferred to any arguments drawn merely from literary style and other empirical data — ^o much relied upon by Orientalists and scholars generally — when the question is one of a calendaric date. I have endeavoured to work out the calculation of Rama's birth figure. In Kamayana is the following slokam, or stanza, referring to Raaaa's birth: — " Chaitre , tiavami/ce tilluiii Nakshatre aditi daivatye seivochha sainsthcsjiu panchasu 1 See his v.-Juable work, '■ Climat?, G^slogie, Faune et Ge'ographie Botaaique de Breiil." Griheshii kjrkatc lagne." From this we learn that Rama was born in the ninth day of the Moon's age, and that five planets were in their exaltation signs, the rising sign {lagnani) beinq; Cancer (of the Hindu Zodiac). The planets' places are given in Section 18 of the English translation of Ramayatia, by Manmatha Nath Dutt, M.A., in the following words :— "And then, when six seasons had rolled away after the com- p'etion of the Sacrifice, in the twelfth month, on the ninth lunar" day, under the influence of the Punarvasu asterism, when the Sun, Moon, Saturn, Jupiter, an i Venus were at Aries, Capricorn,^ Libra, Cancer, and Pisces, and when Jupiter had arisen with the Moon at Cancer, Kaushalya gave birth to that lord of the universe, bowed unto by all thev\orlds, Rama, &c." It may be well to state for the benefit of those not acquainted with the Hindu zodiac, that an asterism includes 13° 20' of the ecliptic circle, and consequently there are twenty-seven asterisms in all. Of these, Punarvasu is the seventh. The zodiac com- mences with the asterism Asiciiii, and the fixed star Revali is the point from which enumeration of longitude begins. This star is said to have been coincident with the equinoctial point To in the year 3600 of the Kali Yuga, i.e. 498 A.D. The last conjunction of Saturn and Jupiter in the sign Libra was in k.v. 4224, and the one previous in k.y. 1344 ; and from this we must subtract three Signs to bring Jupiter into Cancer (its exaltation). This equation referred to the "period" of Jupiter, i.e. twelve years, gives three years to be subtracted. The year k.y. 1 341, therefore, would see Saturn in Libra, and Jupiter in Cancer as required. The Moon being nine days old at the birth of Rama, and its motion in respect to the Sun being 12^ per day, its distance from the place of conjunction must be taken as over 96^. But it is stated in the Slokam that the Moon is in Punarvasu, and as this asterism ends at 93° 20' from the star Revati, it is evident that the conjunction of the luminaries took place in the twenty-sixth degree of Minain or Pisces ; and that on the ninth day the Moon was in the first degrees of Cancer (Hindu Kartaka) and the Sun in the fifth degree of Aries (Hindu Mesham). To determine the date of this planetary epoch we must have recourse to the Ayauamsha, the distance between the fixed star Revati and the Vernal Equinox. The Hindus compute this to be 54" per year, and in accordance therewith their month of Mesham (Aries) begins on April ii. At the present time Revati is behind the Equinox, but in K.Y. 1341 it was in front of it, regarded by the order of the Signs. The calculation for K.\'. 1341, according to Suryasiddhauta, is : — (3600- 1341) X 54" = 33° 53' 6". Referring this to the Equinox, it gives a point corresponding to the twenty-seventh degree of Aquarius in otir zodiac, which was the point at which the Hindu zodiac began in the year k.y. 1 341 ; and from this we must take 4° to bring us to the 26th of Minam, wherein the Sun and Moon were conjoined at the birth of Rama. The result is the twenty-third degree of Aquarius in our zodiac. We have already obtained the year k.y. 1341 from the positions of the planets Jupiter and Saturn, and we may now apply this luni-solar position as a test. On February 11, 18S8, the Sun and Moon were conjoined in the twenty-third degree of Aquarius. This date corresponds to the beginning of the tenth month of the k.y. year 4989. Applying the Metonic cycle, we find that a conjunction ot the luminaries also took place in the twenty-third degree of Aqua- rius (Hindu twenty sixth Minain) in K.Y. 1341, thus : — (4989-1341) -^ 19 = 192 exactly. I have not yet made refer- ence to the position of Venus as given in the above Slokam, but I think there is strong evidence of this being the correct epoch, and I think it not unlikely that Venus had less than 30° west longitude of the Sun, in which case it would be in the Hindu sign Corresponding to our Pisces, i.e. Minam, as required by the Slokam. This epoch corresponds to noon (local time) February 10, 1761 B.C., disregarding the change of Style ; and, if correct, may be the time of the birth of Rama ; but on this point I should not care to judge too hastily, for in view of the recur- rence of these positions at some earlier or later date, we have no evidence which should lead us to select one rather than another epoch. One thing strikes me as sufficiently curious to record in 1 This should be Cancer, not Cnpricorn, as is seen from the f.ict of the Moon's rising with Jupiter. NO. 125 3, VOL. 49] November 2, 1893] NA TURE this connection, viz. that in Saukaravijaya of Vidyaranya, the same positions are given for the planets at the birth of Saukara- chrirya, with the exception of the Moon, which is in Arthra, i.e. Gemini, 6" 40' to 20° o' of the Hindu zodiac. These positions of the Sun, Moon, Jupiter, and Saturn took place on the 1st of Mcsham, Kali Yuga 4221, corresponding to March 30, A.D. 1 1 19, without change of the present style, I am afraid, however, that these dates will hardly suit my Hindu friends, whose devotion to these great personages gives them a sense of "distance" which is best satisfied when ex- pressed in years ! I give these notes, however, for what they may be worth. Adyar, Madras. Walter R. Old. Note. — According to the Suryasiddhanta rules for com- puting the longitudes of the planets, I find thct Mars was in Capricorn, its "exaltation" Sign, in the month o( Mesha/n, K.Y. 1341, as required by the data given for Rama's epoch, its longitude in the Hindu zodiac being Capricornus 13°. — W. R. O. On the Latent Heat of Steam. Since the invention of M. Berthelot's extremely elegant and simple apparatus, described in his " Mecanique Chimique," vol. i. p. 28S, the approximate determination of the latent heat of vaporisation of liquids has become comparatively easy. The exact evaluation of the correction due to the heating of the calorimeter from extraneous sources is, however, a matter of considerable difficulty with the original form of apparatus. The correction is necessarily calculated from data supplied by the thermometric observations made previously to, and after, the actual condensation of the liquid has taken place. For this calculation to be as simple and satisfactory as possible, it is essential that during the whole experiment the temperature of the bodies in the immediate neighbourhood of the calorimeter shall remain approximately constant. In M. Berthelot's method of determination this condition is however not strictly fulfilled. Forduring the "preliminary period-,'' although theflameis lighted over the calorimeter, the liquid in the flask has not yet begun to boil, so that the radiation to the calorimeter varies, and during the "final period" the flame is extinguished and no lurther heat reaches the calorimeter from this source. Also during the beginning of the " middle period," a considerable amount of liquid which has been volatilised from the flask at a temperature below its boiling-point, reaches the worm and is there condensed. We therefore modified the apparatus in such a way that the flame was at a constant height and the liquid was boiling duriii^^ the ivhole time of the experiment, in- cluding both the preliminary and final periods. We found that under these circumstances, with a rise of 3^ or 4° in ten minutes, the Regnault-Pfaundler correction is perfectly accurate. We propose shortly to publish a complete description of our apparatus, and shall not therefore go into details at present. It differs mainly from that of M. Berthelot, by the insertion in the interior of the boiling flask of a glass valve, which is opened when the rise of the thermometer in the calorimeter has become steady, and closed when sufficient liquid has been condensed in the worm. The vapour during both the preliminary and final periods passes into a reversed condenser. Our main reason for this communication is to record the somewhat remarkable results obtained with water, and to ask if any of your readers can give information as to any accurate work upon the latent heat of steam published since that of Regnault {Memoires de V Acadi-mie des Sciences, t. 21) in 1847. We give the results of five experiments (done at pressures differing but little from 760 mm.), which are still subject to cer- tain corrections not exceeding ± i unit. Latent heat of steam (L\ 525-6 5247 5266 525-0 523-9 It will be noticed that in experiment 5, where the amount of water condensed was purposely reduced, so as to increase as far as possible the experimental error, the result obtained differs but slightly [from the mean. This mean, 525-2 (omitting experi- NO. 1253, VOL. 49] \Vt. of water Time of Rise of temp, condensed condensation in calorimeter in grams. in minutes. in deg. C. (I) 10-122 ... Ih .. ■ 3-491 {2) 12-546 ... 15 .. 4-416 (3) 9278 ... 8 .. 3-235 (4) 9-854 ... 7 .. • 3 439 15) 2-742 .. 6 .. -991 T L =i(S ment 5, 525 5) is over 2 per cent, lower than that of Regnault. The thermometer used was one divided into fiftieths of a degree, by Baudin, and was compared with a thermometer calibrated at the International Bureau of Weights and Measures. Every precaution was taken to ensure accuracy of reading. We have sought for confirmation of our results in the indirect determinations of other observers. If we insert the latest values for the specific volume of steam at 99 6 given by Perot {Ann. Chim. et Phys. [6] 13, p. 159) and for the mechanical equivalent of heat by Griffiths ' (Nature, vol. xlvii. p. 476) in the ther- modynamic formula, J dt we find the number 52743 for the value of L at 99-60' C.- The number given by Regnault for lOo' C. is 536-7. We have also selected from the numerous results obtained by Joly {Proc. Per. Soc. vol. xli. p. 358) with his steam calorimeter those relating to silver, which is a substance easy to obtain in a state of purity. If we take the number given by Regnault for the specific heat of silver, we find his own determination of the latent heat of steam confirmed. On the other hand the concordant numbers for the specific heat of silver, given independently by Koppand Bunsen, lead to a result about I A per cent, lower than that of Regnault. The complete discussion of such results, however, is a matter of great difficulty owing to the uncertainty w^hich prevails with regard to the specific heat of water. We have not as yet suc- ceeded in discovering any constant error capable of explaining the discrepancy between our result and that of Regnault, but further experiments are now in progress. The question, as need hardly be pointed out, is of consider- able practical importance in connection with problems relating to the steam engine. P. J. Hartog. J. A. Harker. Physical Laboratory, Owens College, October 19. Artificial Amcebse and Protoplasm. Ln No. 1 25 1 of Nature, Dr. John Berry Haycraft has written a review on Prof. O. Biitsc hii's investigations of microscopic foams and protoplasm. The biological parts of the contribution I may leave my colleague, Prof. Butschli, to answer, but as my investigations are also mentioned, and my name several times quoted, though always mis-spelled as " Nuincke," instead of Quincke, I may perhaps be allowed to call attention to the fact that 1, not Prof. Butschli, as the reviewer asserts, was the first who tried to explain the movements of amoebse and protoplasm by physical laws, by the periodical spreading of a soap solution. In 1879 I explained the voluntary formation of an emulsion ob- served by Prof. Gad, and the amceboid movements of oil- drops by the periodical spreading of a soap solution upon the common surface of oil and water, and I said "that foam is an emulsion of air instead of oil, and that the durability of foam depended on the same conditions as the durability of an oil emulsion." -^ In a continuation of these investigations I explained in the year iSSSthe movements of protoplasm by the same physical principles, making the supposition that it was intermixed with thin oil-films, and in the cells of plants, sur- rounded by an oil-coat. ^ I there fore believe I was the first to point to the foamy structure of protoplasm, which was later on further investigated by Prof. Butschli. Is Dr. John Berry Haycraft acquainted with my investiga- tions, and from whence does he deduce the right of calling them " toys for the physicist " ? They form the conclusion of a series of researches on capillarity which I began 37 years ago, an d by vvhich I, for the first time, showed that surface-tension is con- siderably altered by layers of a foreign substance of far less thickness than i/io of a light-wave ; for the first time, also, the 1 We understand that Mr. Griffiths' number is still subject to a slight cor- rection, but that this does n.,t amount to i part in 1000. - -£ was calculated from Roche's formula quoted by Hirn, Th^orie JMc'canique de la Chaleur, t. J. p. 325. -> G. Quincke, '' Ueber Emulsions bildung und den Einfluss der Galle auf die VerdanuDg" (F/iii^er's .-irc/ik'. 1879, p. 144). ■* G. Quincke." Ueber periodische Ausbreitung an Fliissigkeits oberflachen und dadurch hervorgeru'ene Bewegungserschemungen " (Sitz/ingsber. dey Bcrtiner Akad. 12, 7, 1SS8. \riedeiu. Aiui. 35, p. 580-642, 1S88). " Ueber Protoplasma bewegungen und verwandte Krscheinungen " (^'d^f^/a// der 62 I'ersainmliiHg Deiitscher Naiur/orscher itnd Aerzie, Heidelberg, 1889, p. 204-7). A^A TURE [November 2, 1S93 sphere of molecular action was measured exactly. A number of physical problems were treated, with which in England Lord Kelvin, the late Prof. Clerk Maxwell, Prof. Reinold, Prof. Riicker, Lord Rayleigh, and others have also occupied them- selves. The criticism therefore seems not justified. I know very well that in Germany several representatives of the descriptive natural sciences do not agree with my views pbout the structure and the movement of protoplasm. For instance, Prof. Pfefifer^ reproached me with "'having, without deducing my views from admissible foundation on experience in organism, exclusively constructed them by physical experiments, and thereupon demanded, in an unwarranted manner, a peri- pheric oil-layer for protoplasm." Her*:, too, let me remark, that I concluded the existence of this peripheric oil-layer from the globular form of the surface of pro- toplasm in plasmolysed cells and that I tried for months to find in living cells the characteristic periodic spreading, suspected by me, on the inner side of the hypothetical oil-layer. I have several times observed this spreading and the destruction of the globular form caused thereby. The observations of living cells liave led me to fresh physical experiments, which I published 'in the year lS88, together with my theory nf the siructure and movement of protoplasm. These theories I have always found corroborated in the continuation of my researches since l888. My adversaries, on the csntrary, have as yet not given a satis- factory physical explanation for the above stated phenomena, the globular form of protoplasm surface and the movements in the vicinity thereof. Up to the present day I believe my views to be correct and irrefuted. The facts observed and the physical conclusions inferred by me, may appear extraordinary and not very intelligible to another science, but they are none the less correct and useful. Biological science must, well or ill, take into account the fact that the development of the cell and the life of the organic nature depends on masses and layers which cannot be perceived by the microscope alone. Heidelberg, October 22. Georg Quincke. Human and Comparative Anatomy at Oxford. I\ the article which appeared in your last number under the above heading, expressions occur which may, I think, lead to misconception as to the position of the department of Human Anatomy. It is of such importance in the interest of scientific medical education that the academical teaching of human ana- tomy should «i7^' consist merely in "technical training in an- thropotomy," that I cannot allow the statement that the teach- ing of the subject in Oxford is of this nature to pass without comment. Had the writer of the article in question taken the troulile to inquire of the University lecturer here, or of any of the University professors of human anatomy elseivheie, for instance at Cambridge, Edinburgh or Dublin, or had he con- sulted any of the leading text-books of the subject, he would have found that its scope is much more extended than he sup- pose-. The misstatement having been made, however unin- tentionally, must be corrected. Let me add that the department, which was founded in 1885, was not connected in its oritjin with the department of Com- parative Anatomy, and has had no relation whatever with it •smce. T. BtJRDO.N' Sanderson. Asymmetrical Frequency Curves. Owing to the haste with which I looked through the proof of my letter in last week's Nature (p. 615) two slips escaped me, which 1 hasten now to correct. The ordinates in the dia- c ' I.2.C gram should have been marked ha?iapteryx wa.s pre- viously known only as a former inhabitant of the Island of ' Xorih, A. J. '■ Descriptive Catalogue of the Nests and Eggs found breeding in Australia and Tasmania." (Catalogue No. 12 of the Australian Museum, Sydney, N.S.W.) NO. T253, VOL. 49] Mauritius, and the discovery of identical remains in a locality so far distant as the Chatham Islands, has opened up possibilities of speculation of the most intense interest, and Mr. Forbes' recently exploited theory of the former existence of a great Antarctic continent has changed the ideas of many zoologists with regard to the origin and geographical distribution of many forms of animals and plants. It is decidedly the most interesting episode of the year 1892. Polynesian ornithology has undoubtedly been forcibly brought before our notice by the careful work which has been done by Mr. Wiglesworth, in his " Aves Polynesiae," and a complete list of the species inhabiting the Pacific Islands, with their synonymy and geographical distribu- tion, has been published in the " Abhundlungen" of the Dresden Museum, under Dr. A. B. Meyer's care. Mr. Scott Wilson, with the help of Mr. Evans, has reached the fourth part of the " Aves Hawaienses,'' ^ and with one more part the work will be brought to a conclusion. Mr. Wilson gives some interesting notes on the habits of the species, but it is doubtful whether he has obtained all the material necessary for a monograph of the Hawaian Avifauna, judging by the number of new species which the Hon. Walter Rothschild has been receiving from his collector, Mr. Palmer. These may, of course, be included in the final part of the work, thus bringing it up to date. A visible improvement is to be noticed in the plates of Mr. Frohawk, and the coloured figures of the species look something like the actual birds, instead of being a sort of map, as heretofore. Except forthe splendid paper by Dr. Gadow, before men- tioned, on the classification of birds, very little anatomical work has scarcely been done, in England at least ; and it is to be hoped that Mr. Beddard, who has before now written some useful ornithological papers, and on whom the mantle of Garrod and Forbes is supposed to have fallen, will give us some further results from the splendid opportunities which he enjoys as prosector at the Zoo- logical Gardens. R. BOWDLER SHARPE. HENRY OLDENBURG, FIRST SECRETARY OF THE ROYAL SOCIETY. " C IR, you will please to remember that we have taken "--^ to taske the whole \'niverse, and that we were obliged to doe so by the nature of our Dessein. It will therefore be requisite that we purchase and entertain a commerce in all parts of >* world w*'' the most philo- sophicall and curious persons, to be found everywhere." So writes Henry Oldenburg to Governor Winthrop of Connecticut on October 13, 1667. And in these words he briefly expresses what was the chief aim of the best years of his life. It was mainly by his immense correspondence that Oldenburg forwarded the cause of science, or, as it was then called, ot the " new experimental! learning," by that and by his assiduous discharge of secretarial and editorial work. Without being a man of brilliant genius, he was just such an intelligent, reliable, energetic, and conscientious worker as was needed at that time to form a centre for the new movement. In the history of litera- ture Henry Oldenburg is a familiar figure as the friend and correspondent of Milton ; in the history of philosophy, as the friend and correspondent of Spinoza ; but neither literature nor philosophy is indebted to him to the same extent as science. It is somewhat remarkable that, although the name of Henry Oldenburg is so familiar in the history of the seventeenth century, no complete life of him has ever been written. The only attempt at a con- 1 Scott B. Wilson, .-issisted by A. H. Evans. "Aves Hawaienses: r^h Birds of the Sandwich Islands." Paits iii. iv. 410. (London: R. W Potter, 1892, 1393). lO NA TURE [November 2, 1S93 nected biography is that of Dr. Althaus, of University College, London, who, in iSSS, contributed to the Ai/ge»ieine Zcitung, published in .Munich, a series of very interesting articles upon the hfe and correspondence of this remarkable man. These he supplemented at a later date by many new facts as to Oldenburg's birth, parentage, education, and early life, the results of re- searches undertaken at his instance by Dr. von Bippen, y^ichivist of Bremen. Until these facts were published by Dr. Althaus, we knew nothing whatever of Olden- burg's early life. He appears suddenly upon the scene as the agent for Bremen with the English Commonwealth and a correspondent of Milton's, but who this iriend of Milton's was, and from what pit he was digged, no one seems to have taken much trouble to inquire. We did not, as it now turns out, know so much as the date of his birth, for it is evident from Dr. von Bippen's researches that the date 1626 usually given in biogra- phical dictionaries as the date of Oldenburg's birth is altogether wrong, and that as a matter of fact he must have been born about 161 5, a date which puts the whole of his life and correspondence in an entirely new per- spective. He was, according to this, only seven years Milton's junior, which accords much better with the tone of their correspondence, and he was seventeen years older than Spinoza, which perhaps partly accounts for the somewhat fatherly manner in which he encouraged that philosopher to publish certain of his works. Etjually at sea are the biographical dictionaries (and other works toojras to his descent. The statement copied from book to book that he was descended from the Counts of Oldenburg appears to have been a pure "shot,"' inferred partly from his name, and partly from the fact that in his matriculation entry at Oxford he is called "nobilis Sa.xo,"' which means nothing at all. What we do now know about him is that he was the son of Heinrich Oldenburg (d. 1634), a tutor in the Gymnasium at Bremen, the grandson of another Heinrich Oldenburg (d. 1603)^ Pro- fessor of Mathematics in the same Gymnasium, and great-grandson of Johann Oldenburg, who came from Miinster in 1528 to be the first rector of the Evangelical school at Bremen ; and that he was one of a large lamily who lived in somewhat narrow circumstances. As to Oldenburg's education, we learn that he studied first at the Evangelical school and afterwards at the Gymnasium illustre in Bremen, and that on November 2, 1639, he took there the degree of Master in Theolog)-, the subject of his thesis being " De ministeno ecclesias- tico et magistratu politico. ' Whether, like Gotthold Lessing at a later day, he was intended by his parents for a theologian, we do not know. He did not break with theology so completely as Lessing did, for through- out his life there was a certain theological flavour about him, and, in his interesting " commonplace book " pre- served among the archives of the Royal Society, there is an entry of fifteen pages headed " Sensa Animi mei de Deo et ejus cultu naturali " ; but he revolted from the a priori methods of the current teaching, and in the same iMS. we find accordingly many vigorous passages directed against " the vain shadows of scholastic theology and nominalist philosophy." These outbursts, however, be- long to a later date. It was as a theologian that he graduated at Bremen, and then, for some unknown reason, he went to England. In England he lived for eight years, probably in the capacity of a tutor, probably, too, in royalist families. Some evidence, at any rate, exists in the Bremen archives that during this first English residence he took the king's side against the Parliament. Then comes a gap of four years, during which there are hints that he was travel- ling upon the continent of Europe and cultivating those numerous acquaintances with learned men, which after- wards stood him in such good stead when his life-work NO. 1253, VOL. 49] was to gather scientific information from all parts of the world. From June, 1653, however, his life becomes clear. In that month he was, as I have said, appointed agent for Bremen, in which capacity he had audiences with Crom- well, and made the acquaintance of Crom.weU's Latin secretary, John Milton. The acquaintanceship ripened into friendship, and an elegant but somewhat ponderous Latin correspondence followed. Oldenburg's political mission came to nothing, and then we find him in a country village in Kent waiting in uncertainty as to public events and as to his own future career. That, career was, however, very soon determined, for in 1656 he went to Oxford, and was immediately caught in that current of "experimental learning" which had already begun to flow. Boyle, Wilkins, Wallis, Petty were his constant associates, and his letters at this time show the strong scientific impulse which his mind had received. The passage in Anthony a Wood's " Fasti Oxonienses," which records Oldenburg's Oxford residence, is as fol- lows : — " 1656. In the beginning of this year studied in Ox. in the condition of a sojourner Henry Oldenburg, who wrote himself sometimes Grubendole, and in the month of June he was entred a student by the name and title of iHenricus Oldenburg, Bremensis, noblis Saxo; at which time he was tutor to a young Irish nobleman called Henry 6 Bryen, then'a student. also there. ' Besides Henry O'Brien he had another young nobleman as his pupil during his Oxford residence, namely Richard Jones, son of Catherine Lady Ranelagh and nephew to the Hon. Robert Boyle, and after remaining at Oxford for about eighteen months he accompanied young Rane- lagh upon a journey to the Continent. For a year they remained at Saumur, and while there letters continued to pass between him and Milton. It is rather amusing, to read that Milton had entrusted to Oldenburg a packet of his latest politico-theological writings for distribution to foreign savants, a task which the cautious Oldenburg did not half like, and which he executed, as he informed Milton, by giving copies of the writings " to no one who did not ask for them." How many asked for them he does not say. It was not in truth with the fierce political and theological controversies of the time that Olden-, burg's mind was now engaged. He had gained a new interest and was travelling with a new object. His scientific observations were certainly very mixed, many of them trivial, and some of them superstitious, but they serve to show the direction in which his mind was travel- ling. From Saumur he sends to Boyle " noteworthy observations concerning the existence and the working of-animal poison," and a chemical recipe for an invisible ink, and says that if his travels take him to Italy it will be a satisfaction to give Boyle "news of the industrious Kircher's subterraneous world, his strange Grotta de' Serpi, his story of the growth of pulverised and sowne cockles irrigated by sea-water, his thermometre by a wild-oats- beard, his vegetable phoenix's resurrection out of its owne dust by ye warmth of y« sun, his pretended ocular confu- tation of Kepler's magnetical motions of ye Planets about the Sun, and of Gilbert's magneticall motion of ye Earth and of twenty other remarquable things." At a later date he sends Boyle from Paris the recipe of a wonderful oil which he had picked up in the course of his travels, which was supposed to heal " migraines, palsies, lamenesses, crookednesses, and all ricketing diseases." More wonderful even than this wonderful oil is another of his discoveries, for Samuel Hartlib, in a letter dated April, 1659, informs Boyle that Oldenburg has written to him from Paris that he has in that city discovered a" clever, but very secretly acting" physician, who had spoken to him of a method by means of which one can prepare a drink from sunbeams ! Meanwhile Bovle and the other Oxford worthies con- November 2, 1S93] NA rURE 1 1 i tinued their pursuit of the " new philosophy," meeting generally at that time in " Dr. Wilkins's lodgings in I Wadham College." The London branch of the same movement, too, was now becoming active, meeting usually at Gresham College " at the Wednesday's and Thurs- day's lectures of Dr. Wren and Mr. Rorke." After the ■ Restoration many of the Oxford professors lost their positions and came to London, and on the 28th Novem- ber, 1660, at the close of a lecture of Wren's at Gresham , College, it was resolved to reconstitute the Society, which had hitherto been somewhat amorphous, as a " Society for promoting the physical-mathematical e.xperi- mental sciences." . Oldenburg, who had just returned from abroad, was elected a member of the first Council, and he and Dr. Wilkins were chosen the first secre- taries of the Society. From that moment Oldenburg threw himself heart and soul into the work of the Society. Its interests he regarded as his own, and Prof. Masson gives it as his opinion, and with justice, that without his endeavours and those of Hooke, the Society would scarcely have held together. The great difficulty, of course, was the want of money. Charles II., the so- called " Founder," had promised to endow it, but he broke his promise and only gave it a mace. The Society could not afford to pay its secretary, and yet the secretary must live. In the British Museum is preserved a rough memorandum in Oldenburg's handwriting, quoted, but not very acc'irately, by Weld in his " History of the Royal Society," which gives a very vivid idea of the secretary's labours and poverty. It runs as follows : — The Business of the Secretary of ye R. Soc. He attends constantly the meetings both of ye Society and Councill ; noteth the observables, said and done there ; diges- teth y"^ in private ; takes care to have y™ entered in the Journal and Register-books ; reads over and corrects all cntrys ; sollicites the performances of taskes recommended and undertaken ; writes all Letters abroad and answers the returns made to y'", entertaining a corresp. w''' at least 30 psons ; em- ployes a great deal of time, and takes much pains in satisfying forran demands about philosophicall matters ; disperseth farr and near store of directions and inquiries for the Society's pur- pose, and sees them well recommended, etc. Qy. Whether such a person ought to be left vn-assisted? In connection with this may be mentioned another memorandum of Oldenburg's. It is preserved in the same MSS. (Birch MSS. 4441), and is headed as follows : — Liste oj Members yt are likely to promote ye dessein of ye R. S. Members )* will probably! Such, as will pay, and pro- both pay and give yearly one cure an entertainment to be entertainment to ye Society. | made by others. In the first column occur among others the names of Boyle, Petty, Wren, Evelyn, Wallis, Croon, Grew, Pell, Mercator, Hook, Collins, Newton, and Smethwick. Against the names of Newton, Grew, Pell, Mercator, Hook, Collins, and Smethwick are written the words "no pay." The "no pay " element was one main difficulty of the new Society. Even those who promised to pay, frequently neglected to do so. In 1666 the arrears amounted to ^600 sterling, and in 1673 to ^1957, and this, notwith- standing strenuous efforts on the part of the Secretary to collect the contributions. In fact, at that time, out of 156 Fellows, only 53 paid regularly. At the beginning of 1664 Oldenburg was authorised to make what he could by publishing the Transactions of the Society, but they were printed at his own risk, and seldom brought him in as much as ^40 a year. The very next year the Plague appeared in London and drove away the book-purchasers, and the year after occurred the Great Fire of London, which ruined the booksellers, NO. 1253. VOL. 49 J and made publication still more difficult. Besides all this, the sale of the Latin edition in foreign countries was greatly hindered by the war with Holland. And to crown all, in 1667, the very year after these great dis- asters, Oldenburg himself, who had stuck to his post through Plague and Fire, was imprisoned in the Tower of London. The warrant, which is signed by the Prime Minister, Lord Arlington, charges him with" dangerous plans and practices" ; but the fact appears to be that the immense number of his foreign letters had attracted atten- tion, and since the Government of that time did not under- stand a man who had, as he wrote in the letter quoted above, " taken to taske the whole Vniverse," this voluminous correspondence excited suspicion. He was kept in prison for two months, " during which comitment," as he after- wards wrote to Boyle, he "learned to know his real! friends." Among these friends was Evelyn, who visited him in the Tower on August 8. After his discharge he waited upon Lord Arlington, and then went down into the country to recruit. " I was so stifled by the prison- air," he writes on September 3, " that, as soon as I had my enlargement from the Tower, I widen'd it, and took it from London into the country, tofann myself for some days in the good air of Craford in Kent. Being now re- turned, and having recovered my stomack, which I had in a manner quite lost, I intend, if God will, to fall to my old trade, if I have any support to follow it." He fell to his old trade with his old energy, and how indispensable that energy was to the Royal Society is shown by the fact that during his imprisonment the Society did not meet. Besides his purely official work and his voluminous scientific correspondence, he was ready at all times to do battle for the Society. For in those early days it was far from being plain sailing. The Society had to meet much odium, especially on the score that it was " an enemy of the established religion and destroyer of the ancient well-grounded learning " ; and it is with reference to these charges that Oldenburg breaks out in the fifth volume of the Philosophical Trans- actions : " Let envy snarle, it cannot stop the wheels of Active Philosophy, in no part of the known world. Not in France, either in Paris, or at Caen. Not in Italy, either in Rome, Naples, Milan, Florence, Venice, Bononia, or Padua. In none of the Universities, either in this or that side of the seas. Madrid and Lisbon, all the best spirits in Spain and Portugal, and the spacious and remote dominions to them belonging; the Imperial Court, and the Princes of Germany ; the Northern Kings and their best luminaries ; and even the frozen Muscovite and Russian have all taken the Operative ferment, and it works high, and prevails every way, to the encourage- ment of all sincere Lovers of Knowledg and Virtue." Oldenburg died suddenly in September, 1677, at Charl- ton, in Kent. In the Archives of the Royal Society there are no less than 405 of his autograph letters and drafts, besides ninety-four letters to Robert Boyle in a separate guard-book, and many rough drafts in his own private Liber Epistolaris. One letter in this last-named MS. book, which has not hitherto been published, I cannot forbear to mention in concluding this article, since it shows Oldenburg, even at that early date, as an advocate of the higher education of women. The letter is written to Lady Frances Jones, and is dated August 28, 1660. " I wish heartily," he writes, " that that sexe, which is thus advantaged by Nature with a choyce structure of body, and thereby gives cause to conclude, that the guest thereof must be more than ordinary, would not suffer themselves to be diverted from those nobler improve- ments they are, to speak the truth, as capable of as men ; nor be contented to have their innate capacity in their education stifled or debased to the needle or the making of sweet meats." Many such passages, full of sound sense, might be quoted from his letters did the limits of this article permit, but at present we can only express a 12 Nyl TURE [November 2, 1893 hope that an interesting man who lived in a most interest- ing period may yet find a biographer who will adequately bring him into the light out of the shadow of the giants who were in the earth in those days — Cromwell, Milton, Newton, Spinoza, Boyle — in the midst of whom he moved, and by whose great names his own has hitherto been too much obscured. Herbert Rix. THE NATURAL HISTORY OF EAST EQUATORIAL AFRICA. TR E geology of East Equatorial Africa has been re- corded in a very general way in the maps of the region published by Mr. Jos. Thomson in his " Through Masai Land," and in the more recent one of Prof. Toula ; from these it was known that the area consists of a basal plateau of gneiss and schists, covered by a series of lavas in the interior and marked along the coast by patches of Jurassic rocks. My work therefore lay in the main in the examination of the gneisses and schists with a view to the determination of the method of their formation ; also to the study of the volcanic rocks — which range from basalts to quartz trachytes — and of the relations of the old lava plateaus and sheets to the craters of various ages which play such a striking part in the scenery of the district. The most interesting part of the work consisted in the examination of the great " Graben " or valley of subsidence which runs north and south across the district ; on the floor and on the sides of this are many old lake deposits now buried by lava flows, while the walls are also marked by terraces formed by the existing lakes when at a higher level than at present, or by old ones that have long since disappeared. In some of these terraces are shells with Nilotic affinities, though the localities are now far from the Nile basin. The collections made from the coast Jurassics will al'ow the age of these beds to be definitely settled, and the fossils — Ajninofiitcs, Lytoceras, Bclcjiini/es, &c. — suggest that they are probably Callovian. An interesting addi- tion to the geology of tropical Africa has been the dis- covery of some Palaeozoic shales, more than 130 miles from Mombasa, which have yielded a fairly good fauna, though richer in individuals than species. The evidence collected proves the existence of a former race of men who used obsidian implements, and who lived in a period long prior to any existing tribes ; and also, that the glaciers on Mount Kenia once ex- tended several thousand feet further down the mountain than at piesent; in fact, a regular sheet or cap glaciation preceded the existing valley glaciation. Zoologically the district is somewhat barren, and in many parts only animals with great powers of migration or hybernation are to be seen. In some of the country most famous for its game, none can be found, as it was killed off by last year's drought Cattle disease is respon- sible for the disappearance of many species ; thus, whereas buffalo used to be extremely common, only three were seen ; only one herd of giraffes was met with. Zebra and ostriches are abundant in places, while the commonest antelopes seen were the hartebeest, mpalla, and water buck ; topi are numerous on the Tana. The sparseness of dense forest, except on the higher parts of the district, accounts for the rarity of monkeys. Colobics giierazi was seen at over 9000 feet on Kenia, and some baboons amid the rocks of one of the ridges of the basin of Lake Kibibl. Hyena and a small bush buck range up into the lower Alpine zones on Kenia, while a small rat, Hyrax, and elephants occur in the woods of Sctiecio johnstoni in the upper Alpine zone. Another high record is the occurrence of fresh water crabs (Telephiisd) in some swamps on Leikipia at the height of about 8000 feet. The rarity of limestones doubtless helps to the scarce- NO. 1253. VOL. 49] ness of mollusca. As is well known, most of the species live on trees, whether in river valleys, such as the Sabaki, or among the forests of Kenia, where some small delicate species are common from Sooo to 10,000 feet. Botanically also, the country is somewhat barren and monotonous ; vast areas are covered by nothing but low, umbrella-shaped acacias. The country may be ■ roughly divided into seven zones. The first includes the coastal plain and river valleys, characterised by the abundance of palms, such as the Dum palm {Hyphane ihcbaica) and the Borassus palm {B. flabelliformis) ; the, former is abundant along the coast and fringes the rivers, being found up the Tana as far as south of Kenia, and up the Sabaki to Tzavo. The Screw palm [Fandajius) is rarer, but has a similar range. The salt marshes and lagoons are bordered by the mangrove, while the she-oak, or Casi/an'na, occurs on the ends of exposed promontories on the coast. These have doubtless grown from cones carried by currents from Australia, just as the Krakatab pumice, which now forms banks along the shore, has floated from Malaysia. This zone is succeeded by great sandy steppes covered with mimosa and acacia scrub, with large baobabs, which occur also on the coast. The most typical plants have large and white flowers, a species of Convohndus being the commonest Aloes, and es- pecially the species known to the Suahili as " nkonge," are abundant. The two next zones are the steppes and woods of the high plateaus ; the most striking feature of the former is the high grass, which, when the seeds are ripe and yellow, reminds one of the great cornfields of Dakota. In places the forests of the plateaus pass upward gradually into those of the flanks of the higher mountains, such as Kenia and Settima. The prevalence of lofty junipers which replace the trees of lower horizons, and the dense jungles of bamboos, with a carpet of Selaginclhx characterise the fifth or bamboo zone. Above this are the Alpine pasturages. In the lower part there are numerous orchids. Gladiolus, &c. With the upper zone there appear species of the " everlasting plants" of the Cape, while the only trees are Scnecio joluistoni. Beyond this is the zone above the snow line, where except for a few diminutive yellow composites and lichens, we have passed beyond the realms of plant or animal life. J. W. GREGORY. NOTES. Dr. Potain has been elected a member of the Paris Academy of Sciences (Section of Medicine and Surgery), in the place of the late Prof. Charcot. We are sorry to learn of the death of Dr. H. H. Ashdown, on October 10, at the age of thirty-four. He was a Fellow ot the Royal Society of Edinburgh, and published several memoirs on his physiological investigations. We regret to announce that Mr. T. C. Bain, the Government surveyor and geologist at the Cape, died at Rondebosch, Cape Town, on Ssptember 28. He was born in 1830, and his father was ihe engineer of the well-known Mitchell's Pass Road, at Cape Colony. Mr. Bain was appointed irrigation and geological surveyor in 18S8. The British (Natural History) and Cape Museums contain a number of geological specimens collected by him, among which may be mentioned the collection of reptilian remains from the lacustrine beds of the Karoo. A State Museum is now in course of formation at Pretoria. Mr. P. Krantz has been appointed a curator, and he has, with an entomological assistant, just started on a collecting expedi- tion, which may probably occupy a space of two years. Their mode of transit is in a large wagon drawn by twenty donkeys, these animals having been chosen as best able to withstand the November 2, 1893] NATURE vicissitudes of climate and attacks of " fly " pertaining to some parts of the country proposed to be visited. This wagon has been fitted inside and outside vi'ith shelves and other para- phernalia for holding specimens, cork, medicaments, &c. When not travelling, accommodation is found in a large marquee fixed to the side of the wagon, from which step-ladders, dissecting- table?, &c., may be let down. A lighter and rougher wagon, suited to more inaccessible country, also accompanies the party. Everything has been done to favour the success of this expe- dition, and the Raad has passed a resolution specially exempt- ing those engaged in it from the provisions of the game law. The nucleus of a good general collection should thus surely be obtained, whilst the idea of collecting the Transvaal fauna is highly to be commended. An appeal for subscriptions to found a Pasteur Institute for India is about to be made (says the Allahabad Pioneer). It is proposed to locate the institution in some convenient place near Simla. There the necessary laboratories, fitted with the best scientific appliances, quarters for the officials, and accommo- dation for patients will be provided. The expenses will be I very considerable, but the Government of India, besides giving their cordial approval to the scheme, have contributed notable help by promising the services of a selected medical officer. India has hitherto taken very little interest in bacteriological work, though alniost every European nation, America, and Japan are devoting a large amount of attention to it. It is hoped that in addition to ilsanti-rabic work, the Indian institute may be put on such a footing as to enable it to carry on original research in this and other directions. The institute should also serve as a training school in practical bacteriology for medical men in India. The scheme is full -of promise, and there should be little difficulty in obtaining the funds necessary to carry it out. At the Institution of Electrical Engineers, on Thursday, November 9, Prof. George Forbes, F.R.S., will read a paper on "The Electrical Distribution of Power." According to the Pretoria Press, and from a Blantyre source, a very large supply of ivory has come down from the Lake, in the Lake Company's possession. Huge 6 feet and even 7 feet tusks were to be seen at Mandala, and several thousand pounds must have been paid the Arabi in exchange for this valuable commodity. An International Horticultural Society was founded at the recent congress of horticulturists held at Chicago. The chief object of the^society is to facilitate the exchange of plants, seeds, books, &c. The following officers have been nominated : — President, P.J. Berchmans ; Vice-President, Henry L. de Vil- morin ; Secretary and Treasurer, Mr. George Nicholson, the Curator of Kew Gardens. We are informed, however, that Mr. Nicholson is unable to undertake the work that this office would impose upon him. An International Exhibition of Industry, Science, and Art will be opened at Hobart, Tasmania, on November, 1S94, and will continue open for a period of about six months. The exhibits will be arrangedinto twenty-four classes. Class X. is Chemistry, Apparatus and Processes, Philosophical Instruments; XI. is devoted to Electricity ; Gas and Lighting, other than Elec- tricity, is the subject of Class XII. The following classes are also of scientific interest: XVI.— Machinery, Machine Tools, Hydraulic Machines, and Machines for raisinn; heavy weights. Elements of Machines, Furnaces; XVII.— Prime Movers, and means of distributing their power. Railway plant; XVIII. — Naval Architecture and Engineering ; XLX.— Civil Engineering, Construction, and Architecture, Sanitary Appliances, Aeronau- NO. 1253, VOL. 49] tics, &c. ; XX. — Mining and Metallurgy, Minerals, Quarrying, and Fuel ;«? XXI. — .\gricult>ire, Horticulture, Arboriculture; XXII. — Fisheries. A CORRESPONDENT Writes: "There seems still little re- corded as to the maximum or average size of the Hying fish, Exocxtus sp. On my voyage to the Cape, on board the R. ^LS. DruJiimond Castle, in about the longitude of Greenwich and the latitude 11° S., and on September 9 last, a specimen flew, or was blown, on board, where the bulwarks were 19 feet to 20 feet above the water, which measured iSiJ inches long, with an expanse of izh inches across the wing^;. This was the largest specimen that has ever passed through my hands. It only weighed lib. 6oz. , but a development in weight would clearly be disadvantageous to its power of flight." In the notice of Prof. Sylvester's life which appeared in Nature for January 18S9 (vol. xxxix. p. 217), it is mentioned that after coming out at Cambridge as Second Wrangler, " he was incapacitated by the fact of his Jewish origin from taking his degree," and it is added that in "more enlightened times (1S72) he had the degrees of B. A. and INI. A. by accumulation conferred upon him." The learned librarian of Trinity College, Dublin, Rev. Dr. Abbott, calls our attention to the fact, which should not be overlooked, that though unable to take the degree at Cambridge, he actually passed ad eiindein to Dublin University, and had the degrees ofB.A. and ^LA. conferred upon him there (in virtue of his Cambridge qualification) in 184.1. The honorary degree of LL. D. was also conferred upon him by Dublin in 1865. It may not be without interest to mention that the first Jew to obtain a degree in the United Kingdom was Nathan Lazarus Benmohel, who graduated B. A. at Dublin in 1836, and M.A. in 1846. Six years ago Hofrath Dr. A. B. Meyer, Director of the Natural History Museum at Dresden, published in the Ahhand- luni^en iind Berichte des K. Zool. Museum Zu Dresden, a series of descriptions and drawings of iron-framed cases, and of other museum fittings and apparatus introduced by him in Dresden. Since then a good deal of attention has been directed to the subject of metal instead of wooden framing in museum cases ; and in 1S91 Dr. Meyer gave further details as to his experience in a communication to the Museums Association meeting at Cambridge. In the Abhandlungen of the Dresden Museum for the year 1S92-3, just published. Dr. Meyer returns to the subject of iron-framed cases, on the details of which his recent experi- ence has suggested several improvements. In a series of twenty liihographic and photographic plates, accompanied by elaborate specifications, measurements, &c., he deals with several forms of case, with store cabinets and their fittings, with trays for eggs and nests, sheet iron trays for shells, supports for skeletons and crania, craniometers, and several other varieties of museum appliance and case fittings. In truth Dr. Meyer has, with real German patience and industry, drawn and described in an ex- haustive manner a range of museum cases and appliances which every curator more or less works out (or himself, and of which, having by rule-of-thumb or otherwise attained his object, he thinks no more. But, as Dr. IMeyer points out, museum officials are much given to experimenting at a loss of both time and money, and there is no reason why the results of well-matured experience should not be authoritatively laid down and generally accepted as a basis from which to reach forward to further improvements. The only other means than publication by which museum officials can obtain the results of mutual experi- ments and experiences is by visits to museums, but by that means alone the observer cannot get the precision of information and the working details which are conveyed by Dr. Meyer's mono- graph. The publication indeed confers a signal benefit on all interested in museum work, and it is much to be desired that 14 NA TURE [November 2, 1893 others having like valuable experience should follow Dr. Meyer's example, and put down with precision what they know and have accomplished for the benefit of the ordinary museum officer. Dr. Karl Dove, in a letter addressed to the President of the Berlin Gesellschaft fiir Erdkunde, gives some interesting ])articular3 regarding the climate and vegetation of South Damaraland. The numerous larger rivers, or rather water- cours3S*, of the country contain water almost throughout the year, which in the dry season, however, is found underneath the superficial layer of sand. In August of last year Dr. Dove even found a strongly flowing brook, about ten feet broad, in the hot and dry valley of the lower Swakop. He attributes the per- manence of the rivers to the profusion of strong inclines and the scarcity of purely horizontal plains, which has the effect of diminishing evaporation. The great efficiency of the protection afforded by the soil even in that dry country is shown by the fact that in places where moisture could only be due to rain, traces of it were found in samples a: the depth of three feet after five months of the dry season. The amount of atmospheric precipi- tation was abnormally large during the last rainy season, and the sky was clouded very much like a north European rainy sky. During January over ii S inches were recorded in the vicinity of the higher mountains of Windhoek and the Sheep River. At Windhoek itself the mean rainfall is estimated at 15 "8 inches. The discovery that the rainfall does not show a further increase from lat. S. 22° to 19° is of special importance. At a recent meeting of the British Ornithologists' Club, the Hon. Walter Rothschild read some notes on the genus Apteryx, and exhibited a very extraordinary number of living specimens of these "wingless" birds of New Zealand. He recognises the following as a complete list of the species at present known : — A, australis, Shaw, from the South Island ; A. lawryi* sp. nov. from Stewart Island \ A. maiitehi,* Bartl. from North Island ; A. oweni* Gould, the east coast, South Island ; A. oiueni occidentalis* sub-sp. n., the North Island, and west coast, South Island ; A. haasti,* Potts, central South Island and west of the North Island ;and A. tnaxitiius, Verr. (sp. dub.). South Island. Males and females of those marked with an asterisk were ex- hibited, and also a female specimen of the new sub-species. Mr. Rothschild is engaged on a monograph of these strange birds. During the construction of the Puy-de-Dome Observatory in 1872, the ruins of a large temple were discovered (says M. Plumandon in La Nature). From a tablet bearing a well- preserved inscription it appeared that the temple was conse- crated to Mercury, and, according to historians, it was destroyed towards the end of the third century. Near the middle of the ruins of the temple, in the part that was originally the most highly decorated, there stands a small vertical wall, about one and a half yards high and rather more than two yards long, built of rectangular blocks of stone four inches high and about six inches in length. The blocks are of two different colours, one kind being of light dolomite, while the other is a black lava. The two colours are alternated in each horizontal row, and the rows are arranged so that the vertical joint between any two blocks falls at the middle points of the blocks above and below it. Proceeding, therefore, from the bottom to the top of the wall, or vice versa, the faces of the blocks of each colour form a zigzag pattern of which the lines are inclined about 60" to the horizontal lines separating the successive layers of stone. In fact, the mosaic constitutes a system of parallel lines cut by oblique lines of precisely the same kind as that which is frequently figured in illustration of optical illusions. W'hen the wall is viewed from a short distance the horizontal layers seem to lose their parallelism, and appear to converge towards the interior of the angles formed by two consecutive series of obliques. Zollner first called attention to NO. 1253. VOL. 49] the apparent loss of parallelism which truly parallel lines undergo when they are cut by oblique lines, but it is possible that the mosaic was designedly constructed to deceive the eye, and played an important part in the ceremonial of the temple on the Puy-de-Dome one thousand seven hundred years ago. Nihil novum sub sole. Mr. E. a. AkoREWS describes in the last (October) number of the Studies from the Biological Laboratory of the yohns Hop- j kins University an undescribed Acraniate, Asytnnietron lucay- \ anujii, found in considerable numbers between North and South 1 Bemini, Bahamas, in June and July 1S92. They were taken in the tow-net while swimming at or near the surface, most j abundantly at the early part of the ebb-tide when it had been high tide about nine o'clock in the evening, rarely in the day- time, or late at night, or on the rising tide. They were also obtained buried in the sand flats, but not very abundantly. The specimens taken in June werej larger, often sexually mature, while those taken later were generally immature or larval forms. In captivity their habits were like the European lancelet, the largest was 16 mm. in length and sufficiently translucent to enable one to trace the food or carmine granules to be traced through most of the digestive tracts. The peculiarities of this form, and those which induced the author to venture to refer it to a new genus, are briefly : the gonads being present only on the right, instead of on both sides as in Branchiostoma, the ventral fin having no fin rays, and there being a long caudal process. A PAPER was read lately by Mr. H. B. Stocks to the Edin- burgh Royal Society (Proc. Roy. Soc. Edin. p. 70), " On Certain Concretions from the Lower Coal Measures, and the Fossil Plants which they contain." The interest which attaches to these concretions, or " coal-balls," is the remarkably perfect state of preservation of the fossil contents, in many cases fine plant-cells and fibres being preserved even without complete petrifaction. Chemically analysed, the petrified wood yields mainly carbonate of lime and iron pyrites, each in the proportion of 48 per cent. The late Mr. Binney suggested that the carbonate of lime was dissolved from shells in the marine strata overlying the concre- tionary beds and re deposited on the plants, but, as Mr. Stocks points out, this assumes the lapse of a considerable period of time between the beginning of vegetable decay and the process of petrifaction, a period which would be under ordi- nary conditions fatal to the preservation of the delicate vegetable tissues. Mr. Stocks thinks that decay and petrifaction went on simultaneously, and hopes to prove the following explanation o the mode of petrifaction : by the process of osmosis water con taining the usual quantity of carbon sulphate in solution, passes through the vegetable tissues of the plant, and sets up a series of chemical changes resulting in the formation of carbonate of lime and iron pyrites. The sulphuretted hydrogen combines then with more iron. The spheroidal shape of the nodules is, he believes, merely due to the deposition of calcium carbonate from a solution heavily charged with organic matter. The October number of the Annali of Scottish Natural His- tory contains several interesting articles, amongst them being one by Mr. Peter >Adair, on the disappearance of the short- tailed field vole {Arvicola agrestis), and on some of the effects of the vole plague. This destructive rodent began to be observed in the infested area a few years before 1S90 ; it multiplied with rapidity until the summer of 1892, when the numbers began to decrease, and by the summer of the present year the pest had disappeared. Mr. Adair finds that the disappearance has been general over the whole infested area. On some farms the normal numbers remain, but on others scarcely a vole is to be seen. Various causes have been suggested to account for the disappearance. The drought of last spring and winter may have had some good eftect, for the animal is partial to damp November 2, 1S93] NATURE 15 ground. There is, on the other hand, evidence that an epidemic caused the plague to come to an end. But it is the general opinion of the farmers and shepherds of the district from which Mr. Adair obtained his particulars, that the disappearance is due in a great measure to the work of such natural enemies as the owl, kestrel, rook, blackhead gull, and buzzard, the stoat, and the weasel. The Weather Bureau of Washington has published an elaborate discussion of the climate of Chicago, by Prof. H. A. Hazen, being No. lo of the valuable i)«//^/2/fj now being issued by that department. The city of Chicago is situated at the soath-west of Lake Michigan, whose elevation is about 580 feet above the level of the sea. The earliest observations available were made in 1832, and continued until 1836, after which time they were of a very fragmentary character until November, 1859, since which a continuous series of observations has been maintained, at least as far as regards the temperature. The lake has naturally great influence upon the climate, and this has been investigated in great detail for each separate element. With regard to the winds, the tables show that for the year there is a maximum from the south-west, and- a secondary maximum from the north-east. Daring the cold months there is a marked preponderance of land winds, while in the warm months there is a slight preponderance of lake winds. The mean temperature deduced from twenty years' observations is 48^ '6, and occurs about the third week in April and October. The highest temperature occurs about the middle of July, and the lowest the third week in January; for 174 days the temperature is rising, and during 191 it is falling. The cold spell about the middle of May, which is generally observed in the northern hemisphere, is well marked in the 5 - day means. The highest temperature observed was 99' '6 on July 17, 1S87, and the lowest -23" on December 24, 1872. The maximum tem- piratare was 90' or over on 121 days during 20 years, and a minimum temperature of -15" or below was only reached 16 times. Accurate rainfall observations can scarcely be said to begin at Chicago before 1S67. The annual rainfall from this series is 34*4 inches, and is fairly well spread over each month. A fall of 2 '5 inches in a day only occurred 15 times in 20 years. The work contains an abstract of the observers' jfournal since the occupation of the station by the Weather Service, which includes an interesting account of their experience of the great fire of October 8-9, 1871. We learn from the report on the administration of the ISIeteo- rological Department of the Government of India that the valuable series of meteorological observations which were taken by the late Mr. J. Allan Broun at Trevandrum during the years 1853-64 are being prepared for publication by that department, owing to the action taken by the Royal Societies of London and Edinburgh, and by the Meteorological Council with that view. It is proposed to publish them in three volumes contain- ing (i) hourly observations, (2) comparative observations at various stations on the jTravancore Hills, and (3) discussion of ihe observations. The report shows great activity in the collec- tion of observations from ships entering the Hooghly ; these observations are used in the construction of daily charts of the Indian land and sea area, the publication of which began with January this year. The growing usefulness of ordinary weather forecasts is exemplified by the fact that they have been extended to expeditions in the field, and they have been pronounced by the military authorities to have been very successful. Herr p. Czermak publishes, in Wiedemann^ s Atinahn, some beautiful photographs of ascending currents in gases and liquids. I'or the former a box of rectangular section was used, consisting of plate-glass sides firmly cemented together. At the centre of NO. 1253, VOL. 49] the bottom was placed a flat spiral, the escape spring of a large spindle clock. The spiral could be heated by the passage of an electric current. A glass tube opened into the box at the bottom, directed towards the centre, for the introduction of smoke. A second glass tube led in at the top, for ventilation or the intro- duction of a light gas. Tobacco smoke blown in through the lower tube was seen to spread out on the bottom in a uniform layer, provided all parts of the box were at the same tempera- ture. The touch of the hand on one side was sufficient to produce an ascending current and a motion of the smoke towards the warmer side. It was therefore necessary lo perform the experiments in a room kept at a uniform temperature. On sending a current through the spiral, the mushroom-like figure first described by Vettin was observed to rise in faultless sym- metry. This was photographed by flash-light, and the repro- ductions show the spiral convolutions to great perfection. Since the contours reflected the greatest amount of light, they stand out well from the dark background, and clearly exhibit the in- terior structure of the stream-figure. In order to imitate more closely the actual condition of the atmosphere during the ascent of warm air currents, the upper part of the box was filled with coal-gas. The stream-figure then ascended in the usual manner until its vertex reached the lighter stratum. It then became stationary, expanded in the diffusion stratum, and part of the smoke trickled back to the bottom. Sometimes it was found possible to obtain a cloud-like structure, with a dome in the centre and wavy outlines. The figures were more easily pro- duced and photographed in the case of liquids, but the general type remained the same. Investigations are carried on at the Agricultural Experi- ment Station, Purdue University, Indiana, on much the same lines as at Rothamsted. Bulletin 45 of the Station contains in- formation of interest and importance concerning wheat-growing in Indiana. From field experiments extending over ten years it appears that none of the varieties of wheat tried have any tendency to deteriorate or "run oat," provided proper care is exercised. No wheat proved to be "rust-proof," bat early wheats were generally less injured by rust than later kinds. Eight pecks of seed per acre gave the best returns at the Station, the average yield for nine years being 30-35 bushels per acre. The best results came frooi sowings made not later than Sep- tember 20. The value of crop rotation in maintaining yields of grain has been strongly emphasised, for a comparison of ro- tating crops with constant grain-cropping for seven years showed an average gain of 57 bushels per acre in favour of the former. Another important result obtained was that wheat may be har- vested at any time from the dough stage to the dead-ripe condi- tion, without appreciably affecting the weight or yield of the grain. Finally, a compafison of forms of nitrogen as fertilisers for wheat indicated that sulphate of ammonia is better than nitrate of soda or dried blood. I.\ a former note (June 22, 1893) we have given a sho r account of the means employed by Signor Augusto Righi to obtain electro-magnetic waves of small wave-lengths (about 8 cm.), and also on p. 299, vol. xlviii. we have described some of the experiments he has performed, using waves of this small wave-length. Since then Righi has continued his researches, and has published in the Proceedings of the Royal Academy of Lincei an account of his experiments on the question as to whether the electric force is perpendicular to, or in the plane of polarisation. Trouton, from his experiments on the reflection of electro-magnetic waves from the surface of non-conductors, such as glass and paraffin, has come to the conclusion that the electric force is perpendicular to the plane of polarisation. The reflection of these waves from paraftin.and also from metals,has been studied by Righi, who finds a marked difference in the two cases. In the i6 A' A TURE [November 2, 189; case of paraffin his results agree with those obtained by Trouton ; when, however, a metal is used as the reflector he finds that the plane of polarisation is parallel to the electric force. The author has measured the refractive index, for oscillations having a wave length of 7*5 cm. of the paraffin used in his experiments. He employed for this purpose an equilateral prism, each face being 20 cm. high and 37 cm. broad, and found i '\ for the refrac- tive index. The paraffin employed was not of the highest quality, although it was quite white and homogeneous, and had a melting point of 5o''5 C. Dr. Oettel has continued his researches on the phenomena of the electrolytic deposition of metals (see Nature, July 6, 1893). In the present paper, which is published in the Chemiker Z itung, he gives the results he has obtained in his investigation of the condition of an auxiliary electrode placed between the two principal electrodes in a copper voltameter. For an auxiliary electrode 86 by 131 mm. in size, being a little smaller than the principal electrodes, he finds that copper is deposited on the side next the anode, and dissolved at the side next the cathode ; the quantity dissolved being larger than the quantity deposited in nearly the same proportion as at the principal electrodes. This difference is caused by the electrodes not being composed of pure copper. The deposit on the auxiliary electrode attains as much as 87 p;r cant, of the deposit on the cathode; but depends on the following conditions: — (i) The relative dimensions of the auxiliary electrode and of the chief electrodes. (2) The absolute size of the electrodes ; for, since the copper tends to be deposited chiefly at the edges, the proportion increases when the plates are' small. In order to ascertain if lifle bullets are capable of carrying in- fection, Messner [Minuhenei- med, Wochensdirijt, 1892, No. 23) has been making careful experiments with bullets purposely in- fected with particular micro-organisms. Bullets thustreated were discharged into tin boxes at a distance of from 225 to 250 metres. These boxes were filled with sterile gelatine peptone, and the channel in the latter made by the passage of the bullet was care- fully watched and examined. It was found that in all cases the infected bullets had produced growths of those organisms in the gelatine with which they had originally been brought in contact. In some experiments the boxes, whilst filled with sterile gelatine, were covered over with flannel previously infected with particular bacteria, so that before reaching the gelatine the bullet would first have to pass through the former. Ordinaiy uninfected bullets were used, but in every instance bacterial growths made their appearance in the subjacent gela- tine corresponding to the particular organisms present on the flannel. On the other hand, ordinary bullets, when discharged direct into the gelatine, occasioned only the appearance of moulds and other bacteria usually found in the air. Thus the heat communicated to the bullet during its discharge is not sufficient to destroy any bacteria which may be present upon it ; the temperature produced is also wholly inadequate to sterilise any portions of clothing with which the bullet may come in contact, the latter, on the contrary, carrying with it into the wound those bacteria which may be present on the former. With regard to the physiological action of oxygen in as- phyxia, more especially in coal mines, a committee of the British Association has arrived at the following conclusions : — ^i) In the case of rabbits asphyxiated slowly or rapidly, oxygen is of no greater service than air, whether the recovery be brought about in an atmosphere contaminated by carbonic acid or compleVely free of carbonic acid, and whether artificial respiration be resorted to in addition or not. (2) Pure oxygen, when inhaled by a healthy man for five minutes, produces no appreciable effect on the respiratory rate and volume, nor on the pulse rate or volume. (3) Oxygen, whether pure or somewhat NO. 1253, VOL. 49] diluted, produced no effect on one particular patient, who suf- fered from cardiac dyspnoea of moderately severe type, in the direction of ameliorating the dyspnoea, and, compared with air inhaled under the same conditions, produced no appreciable effect, either on the respiratory rate and volume or on the pulse rate and volume. (4) An animal may be placed in a chamber, the general cavity of which contains about 50 per cent, of car-" bonic acid, and retained there for a long time without super- vention of muscular collapse, provided a gentle stream of a respirable air gas or oxygen, indifferently, be allowed to play upon the nostrils and agitate the surrounding atmosphere. The Quarterly Journal of the Geological Society (No. 196) has been issued. Messrs. Dulau and Co. have issued a catalogue of works on Lepidoptera, Neuroptera, and Orlhoptera. Messrs. Whittaker and Co. have published a pamphlet, by Capt. M. P. Nadieine, on a new system of sanitary drainage and treatment of sewage matter. The Matabele War has induced Mr. E. P. Mathers to issue a "Map of Mashonaland and Matabeleland." A few facts about the Matabeles and their country give the map additional interest. We have received a paper on " Rainmaking," read before the Texas Academy of Science in December 1S92, in which Dr. A. Macfarlane discusses professional rain-makers (not the medicinemen of the Indians, but their civilised prototypes) and disposes of their theories seriatim. Though Mr. A. T. Burgess's "First Stage Agriculture" (Joseph Hughes and Co.) is adapted to the Elementary Syllabus of the Department of Science and Art, it should be valuable to all students of agriculture. The author is concise in his state- ments, so he has been able to give a large amount of informa- tion in a small book. A scarcity of illustrations is the book's only fault. " The Birds of Michigan," by Mr. A. J. Cook, are described in Bulletin No. 94 of the Michigan State Agricultural College. The bulletin is illustrated and contains a bibliography. In the text are recorded the food habits of the birds ; so that the economic importance of the various species can be judged. A section is devoted to a statemeni: of the laws that obtain in Michigan for the protection of game. The list is a useful con- tribution to the ornithology of an interesting region. A USEFUL book on the "Analysis of Milk and Milk Products," by Prof. Henry Leffmann and Dr. William Beam, has been published by Messrs. P. Blakiston, Son and Co., Philadelphia. The book appeals particularly to Ameri- can agriculturists, but it may be introduced with profit into the dairy schools springing up in various parts of the country, and professional chemists will be interested in some of the analytical methods described. Mr. Hugh Gordon's "Elementary Course of Prac.ical Science," part 1, belonging to the series of Science Primers pub- lished by Messrs. Macmillan and Co., is worthy of introduction into all elementary and continuation schools. The experiments described are of a very simple nature, and refer to every-day phenomena. The pupil who conscientiously works through the little book will certainly have impressed upon him the im- portance of exactness, and will thus be given the best foundation of a scientific education. Another book on practical physics is "Lessons and Exercises in Heat," by Mr. A. D. Hall (Rivington, Percivaland Co.) The book contains a series of lessons and exercises, and is November 2, 1S93] NA TURE 17 suitable for use as a supplement to lectures and demonstrations. The experiments described will impress the student with the fact that "science is measurement," hence they are of the right kind, for it is doubtful whether showy experiments are of any educational value. Schools and university classes requiring a good and accurate handbook of heat for the physical laboratory would do well to adopt Mr. Hall's work. Messrs. Longmans and Co. have just published, for Dr. F. Clemow, of the English Hospital, Cronstadt, " The Cholera Epidemic of 1S92 in the Ru.siau Empire." Thfe author states in his preface that to the English medical world Russia is almost a closed book. The reason of this is tha% in consequence of the North- West Greenland studying the phenomena of Arctic glaciers, has returned to Europe, and his report of the work done by his expedition will be expected with much interest. A novelty in political boundary lines is reported in Let Geograpliie, which stales that the frontier between Turkey and Servia is lobe marked throughout its length by a wire fence. The November number of the Geographical Journal is rich in new contributions to geography and exploration. The Earl of J 'unmore's paper on the Pamirs and Central Asia occupies the first place. — The Rev. J. A. Wylie gives an account of a journey through Central Manchuria, with many interesting notes on places and people, and a detailed itinerary which must prove valuable to subsequent travellers. — Lieut. B. L. Sclater writes a detailed report on routes and districts in Southern Nysaland, illustrated by a new map of the district east of the Shire as far as the Milanji Mountains, largely com- piled from his own prismatic compass surveys. — Mr. Theodore Bent communicates a letter from Mr. Swan, who is now ii> Mashonaland, giving an account of fresh ruins recently visited on the Lotsani and Lundi Rivers, the "orientation" of which to the setting solstitial sun he believes he has established. — Mr. W. S. Bruce and Dr. C. W. Donald publish a preliminary re- port of their observations during a voyage toward the Antarctic Sea, and Dr. Schlichter gives his paper on the determination of geographical latitudes by photography. INS TITUTION OF MECHANICAL ENGINEERS C\^ Wednesday and Thursday of last week, October 25 and ^^ 26, a general meeting of the Institution of Mechanical Engineers was held in the theatre of the Institution of Civil Engineers, in Great George-street, Westminster ; the Presi- dent, Dr. William Anderson, occupying the chair. Dr. Anderson retires in- rotation this year, and Prof. Alexander B. W. Kennedy, F.R.S., is proposed as his successor. There were two papers down for reading, as follows : — " On the Arti- ficial Lighting of Workshops," by Mr. Benjamin A. Dobson, of Bolton ; and " On the Working of Steam Pumps on the Russian South-Western Railways," by Mr. Alexander Borodin, Engineer- Director. Mr. Dobson's contribution was an interesting and valuable paper, in which he described the results of inquiries he had made with a view to obtaining the best mode of artificial illumination for the large workshops of his engineering estab- lishment at Bolton. Mr. Dobson's works are engaged in pro- ducing textile machinery, more especially that for cotton- spinning. Many parts of such machinery require to be finished November 2, 1893] NA TURE '9 in the highest manner, and with mathematical accuracy. In order to accomplish this a good light is necessary, but unfortu- nately that is a thing Mr. Dobson can seldom get frooi natural sources at his works. We do not as a rule expect to find engineers and manufacturers exclaiming against the smoke nuisance ; we rather look to hear such things from those who cultivate the gentler arts. It is therefore, perhaps, worth while to quote a few passages from Mr. Dobson's paper, in which he speaks of the state of the atmosphere in Lancashire : — " Although Lancashire coal has a number of excellent quali- ties, yet it is one that makes the most smoke of any. A large portion of the Lancashire manufacturing industries, great and •small, date from a number of years back, when smoke- consuming and smoke-preventing apparatus had not yet been ics ; (9) general studies; (10) chemical engineering; (11) sanitary engineering; {12) geology; (13) naval architecture. Agriculture is not included in this list, on account of its being provided for in a State College at Amberst. In the four years required for graduation, it is sought : — (i) To make the pupil observant, discriminating, and exact. (2) To develop in him a taste for research and experimenta- tion on the one side, and for active exertion on the other. (3) To give him the mastery of the fundamental principles of mathematics, chemistry, and physics, which underlie the prac- tice of all the scientific professions. (4) To equip him with such an amount of practical and technical knowledge, and to make him so familiar with the special problems of the particular scientific profession at which he individually aims, as to qualify him immediately upon graduation to take a place in the industrial order. The chief and dominating feature of the Institute, from the material point of view, consists of its numerous large and well- equipped laboratories. The buildings of the Institute, in addi- tion to drawing, recitation, and lecture rooms and libraries, comprise eight laboratories, or groups of laboratories. The Rogers Laboratory of Physics comprises seventeen separate rooms. It includes a laboratory of general physics devoted to instruction in the principles of physical measurement, a labora- tory of electrical measurements, devoted chiefly to advanced electrical work ; a laboratory of acoustics, one for optical work, and another for photography. In addition to these, there is a dynamo-room and several laboratories of electrical engineering. The dynamo-room (Fig. i) is provided with a Westinghouse engine of 75 horse-power, the sole use of which is to furnish the power to drive the plant of dynamos. This plant, besides a number of smaller machines, comprises a 500 light alternating current Thomson-Houston dynamo, with transformers, a 150 light Edison dynamo, a 200 light Thomson-Houston direct cur- rent dynamo, a 60 light Weston dynamo, a 3 arc-light Brush dynamo, a United .States 300 ampere low voltage dynamo for electrolytic work, and a Siemens' alternating arc-light dynamo. From time to time other large machines are temporarily placed here for purposes of study by the students. The wires from November 2, 1893] NA TURE 21 this room are carried to all parts of the building for experi- mental purposes, as well as for use in illumination. The Kidder Chemical Laboratories are just as well-equipped as the Rogers Laboratory of Physics. They comprise eighteen laboratories, four lecture-rooms, a library and reading-room, balance-rooms, &c. ; in all, thirty rooms. 'There is a laboratory of general che- mistry with 133 working tables, each of which has under it three complete sets of drawers and cupboards ; a laboratory of analytical chemistry, with 108 benches ; an organic laboratory having benches for twenty-six students ; two laboratories of sanitary chemistry, in which, since 18S7, io,oco samples of water have, been analysed for the Massa- chusetts Board of Health ; a laboratory for gas analysis, and three for industrial chemistry, besides a number of smaller ones. The John Cummings Laboratory of Mining Engi- neering and Metallurgy comprises laboratories for milling, for concentrating, and for smelting ores, as well as for testing them by an assay and by the blowpipe, and a library comprising the most im- portant literature of the subject. The engineering laboratories comprise laboratories of steam engineering, of hydraulics, a laboratory for testing the strength of materials, and a room con- taining cotton machinery. The most prominent feature of the steam labora- tory (Fig. 2) is an Allis triple-expansion engine, having a capacity of about 150 horse-power when running triple, with 150 lbs. initial pressure in the high-pressure cylinder. The laboratory also contains a 16 horse-power Harris-Corliss engine, and an 8 horse-power engine used for giving instruction in valve-setting. In addi- tion to these, there is a great variety of apparatus, including condensers, calorimeters, injectors and •ejectors, steam pumps, &c. , directly connected with studies in steam, also apparatus for testing the effi- ciency of transmission of power and for measuring the power transmitted. The hydraulic laboratory (Fig. 3) contains a closed tank, 5 feet in diameter and 27 feet high, extending from the basement under the lower floor to the upper part of the room on the second floor. This is con- nected with a stand-pipe, 10 inches in diameter and over 70 feet high, so arranged that the water may be maintained at any desired point, glass gauges along the stand pipe serving to measure the height. The stand-pipe is con NO. 1253, VOL. 49] nected with a steam pump, with a rotatory pump, and with the ciiy supply. On the sides of the large tank are the connections for the various hydraulic apparaius, in- cluding apparatus for measuring the flow over weirs ; through various sizes and shapes of orifices ; through hose-nozzles ; through different sizes of pipe, with the several varieties of obstructions that occur — namely, diaphragms, couplings, elbows, T's, bends, valves, &c. Also connected with the tank, or wiih a centri- fugal pump, is a Swain turbine, so ar- ranged that measurements can be made of the power transmitted under various heads and with different openings of gate. The most important feature of the biologjtal laboratory of the Institute is the ^portunity of studying ferments, fungi, algae, bacteria, and other low forms of life. Courses are also provided in general biology, microscopy, comparative anatomy and embryology, physiology and histology. The Institute possesses a laboratory of mineralogy, lithology, structural tieology, and economic geology, but it is neither so extensive nor so well equipped as most of the laboratories already named. A praiseworthy feature of the Insti- tute's curriculum is that during the last term of his course every student who is a candidate for a degree spends a large portion of his tim.e in the preparation of a thesis upon some chosen subject. This is alwa\s of the nature of an experimental research, and may be either purely Engiaeenng Laboratory : an Engine Test. scientific or technical in its nature. In many caes the results of this work have been of such a character as to n erit 22 NA TURE [November 2, 1893 publication, and a considerable number of such papers have ap- peared in scientific and technical journals. A high value is attached to the thesis work; and rightly. In it the student is placed in the attitude of an independent investi- gator. He is thrown to a large extent upon his own resources in devising methods of invesiigation and in finding means of overcoming the difficulties that always arise in original work. Such individual aid is given to each student as is necessary to keep him from too great loss of time from using wrong methods ■jf procedure, without, on the other hand, giving him such specific directions as would entirely deprive his work of origin- ality. He thus acquires a knowledge of the patience, care, and .time which it is usually necessary to spend upon the experi- mental solution of any new and untried problem. This early trnining of investigators has produced excellent results. A register of the publications of the Institute and of its officers, students, and alumni, between 1862 and 1S82, was compiled by Prof. W. R. Nichols, and has been brought up to date by the late Prof. L. M. Norton and Prof. A. H. Gill. The list in- cludes books, pamphlets, reports, contributions to periodicals — everything, in fact, except contributions to daily newspapers^ — made by the the teaching staffduring their connection with the school, and by students during their connection with the school and in after life. As Prof. Gill remarks, no truer index of the value of an educational institution can be found than the work which its alumni have done and are doing, and when we say that the total number of titles of communications given in the list is nearly 2,900, thirteen hundred of which have been added since 1SS8, it will be agreed that the system of training at the Massachu-etts Institute of Technology is one that gives a love of investigation to the students ; and lo the man of science this desire to extend natural knowledge should be the end and aim of all scientific education. UNIVERSITY AND EDUCATIONAL INTELLIGENCE. OxFOKD.— At a meeting of the Junior Scientific Club, on Friday, October 27, Mr. M. D. Hill, of New College, was NO. 1 25.:;, VOL. 49] elected President for the current term. Mr. E. S. Goodrich exhibited some recent additions to the University Museum, including a specimen of Palseospondylus, a specimen of Indris- brevicandatus, and the brain of "Sally," the chimpanzee, who was so well known at the Zoological Gardens. Mr. Wynne- Unch, of New College, read a paper on mining ; and Mr. Gordon, of Keble College, read a paper on the effects of tem- perature on the incubation of eggs. The Ashmolean Society held a meeting on Monday, October 30, when Mr. A. G. Vernon Harcourt read a paper on the properties of ferrous chloride, and Dr. W. B. Benham one on the effects of sedentary life on certain annelids. The Junior Scientific Club seems to have ousted the older and more senior Ashmolean Society almost completely. At the meetings of the latter, which offers communications of at least equal, perhaps of greater, interest than the Junior Society, the attendance seldom reaches a dozen, and of these a large propor- tion consists of ladies who are more or less directly interested in the lecturer. The attendance at the Junior Scientific Club, on the other hand, is always large, and frequently exceeds fift). The reason of this disparity is not easily found. Some people attribute it to the lesser formality of the proceedings of the younger society, and to the fact that smoking is permitted during the meetings. The Sherardian Professor of Botany announces a course of six lectures on forestry, to be given by Dr. J. Nisbet, at the Botanic Garden, daily from Monday, November 6, to Saturday, Novem- ber II, inclusive. Cambridge. — The Engineering Laboratory Syndicate ask for a grant of ;^iooo to enable them to complete the buildings lequired for the accommodation of the department. From private sources nearly _^5O0o have been subscribed lor the pur- pose, but this is insufficient for the whole of the work in contemplation. Prof. Ewing reports that no less than seventy- four students have entered for courses in engineering during the present term ; and it is very desirable that their work should not be hampered by delay in providing the necessary rooms for their accommodation. It had been hoped that subscriptions towards so valuable an extension of the scientific equipment of the University would flow in liberally, but the stream of bene- faction seems for the present to have dried up. The scheme for examinations in agricultural science will come before the Senate for decision on November 9. Already a note of dissent has been sounded by a well-known theological graduate. Mr. R. A. Sampson, Fellow of St. John's, has been ap- pointed Professor ot Mathematics at the Newcastle College of Science. SCIENTIFIC SERIALS. U Antliropologie, tome iv. No. 3. —The current number contains four papers of much interest. Dr. R. Collignon con- tributes an article on the proportions of the trunk among the French, whom he divides into three classes : (i) the Celts, in the sense in which Broca used that term, that is to say, a short, dark, brachycephalic and mesorhine people, such as those found in Auvergne, Limosin, and the centre ot France generally ; (2) the tall, lair, dolichocephalic Kymris, found in the north-eastern or Belgic departments of France ; and (3) those who are really cross-breeds. The measures of the trunk are five in number : — (i) The total height, in the sitting position, from the inter- clavicular notch to the seat ; (2) the maximum bi-acromial diameter ; (3) the maximum bi-humeral diameter ; (4) the maximum bi-iliac diameter ; (5) the maximum bi-trochanteric diameter. The following measures of the thorax are also taken : (l) the distance from the superior border of the clavicle to the inferior border of the false ribs, measured on a perpen- dicular line passing over the nipple; (2) the transverse width, and (3) the antero-posterior width, at the height of the nipples ; (4) the circumference just below the nipples ; (5) the circum- ference about 3 cm. below the nipples. Observations were made on sixty Celts, seventy Kymris, and eighty Celto-Kymris. It appears that there is a regular gradation between the three classes. Among the brachycephalic Celts, the trunk and thorax are shorter than amongst the dolichocephalic Kymri, whereas in all other respects the measurements of the Celt exceed those of the Kymri. The people cf mixed blood occupy an inter- mediate position. When the total height or the length of the NOVKMDER 2, 1S93] '.VA TURE Irunk is taken as a standard, the same general result? are obtained, but the lenirth of the thorax as compired with that of the trunk is greater in the Celts than in the Kymri. A com- ]iarison with similar measurements of various races of Tunis, negroes of the Soudan, and a single bushman, leads the author to the conclusion that in any given race all the measures of the body increase in absolute length and diminish in relative length as the stature increases, and vice vcisA. — In a piper on the IMatriarchate in the Caucasus, Maxime Kovalevsky adduces facts which tend to prove that the ancestors of the mountaineers who live in the high valleys of the Caucasus at the present time practised what Morgan and Fison have called '•'Troup marriage."- — Dr, H. Ten Kate gives an account of his re-searches in Malaysia and Polynesia during a scientific mission promoted by the Royal Geographical Society of the Nether- lands, in the course of which he examined 999 Malaysians of possessing clear scientific views of natural forces and phenomena, and an inventive mind ; the other, Mr. Halske, a man thoroughly acquainted with mechanics, the use of machines and tools, and possessing the skill to make, and to teach others how to make, delicate mechanism. There was a demand in Germany, in Russia, in England, and elsewhere, for what they could make ; their work was thoroughly to be relied upon, and orders streamed in on them. Dr. Siemens says somewhere in this volume that every- thing he has done for natural science has been due to a claim made upon him by applied science. It was the ab- solute necessity under which he was to make accurate measurements that set him to work to invent an exact standard of resistance, possessing which he was after- wards able to elaborate a rational method for testing the electrical condition of submarine cables. Previously to this, Jacobi's standard, which was a determined length of copper wire of a determined section, was used at the Berlin factory, but copies of these standards were found to dift'er so much that Dr. von Siemens set to work to in- troduce a standard of his own. In revolving this matter in his mind he came to the conclusion that " it was both desirable and convenient to be able to combine a definite geometrical notion with the unit of resistance." He there- fore used mercury,the only metal fluid at ordinarytempera- tures, whose resistance cannot be affected by molecular variations, made a series of important experiments, and finally having defined his unit as a metre length of mer- cury of a square millimetre section at o' C, he sent copies of his standard to physicists and telegraph engineers suggesting their use in determinations of resistance. We refrain from entering into a discussion as to the relative values of units, whether Weber's absolute unit, the B.A. c.g.s. unit, the ohm, or others ; the main point is that Dr. von Siemens wanted a clearly defined unit, he had found the absolute necessity for it in his electrical work, and now possessing it he was able to press forv/ard to other achievements. Here was a decided step in advance. Measurements which had previously been variable were now uniform, tests which formerly could not have been made could now be applied, and work which was formerly •carried on more or less by rule-of-thumb, could new be done with a certainty of result. We have referred to submarine telegraphy as one of the great achievements of this century, and the brothers Sie- mens, Werner, William and Carl, have taken a share in it. Almost every submarine cable of importance has been shipped from the Thames. The first tentative efforts were made in England, and the final successful results have been achieved here. Cable-laying is now one of the NO. 1254, VOL. 49] scientific arts, and our author has had a large share in making it so. We are here brought face to face with the two sides of the question, the scientific and the technical, and at the same time with two national characteristics, the com- bination of which has produced these results : English enterprise, German investigation. And there is yet another link in this chain of events, which it is difficult to see how we could have done without, the finally unsuc- cessful but at the time needful and useful practical ex- periment of underground cables in Prussia. " My friend Halske " . . , " was the first to encounter these pheno- mena."' " Halske found, first of all, that with shorter lines our self-interrupting indicator telegraphs acted with much greater speed than corresponded to the resistance of the line. When communication between Berlin and Cothen had been established, a distance of about 95 English miles, the giving apparatus ran with double velocity, whilst the receiving apparatus stopped altogether. This at the time inexplicable phenomenon occurred the earlier the better the lines were insulated, which induced Halske purposely to impair the insulation of the line by the addition of artificial watery by-passes." " When the underground line had been extended to Erfurt, Halske's watery by-passes were no longer sufficient. But mean- while I had become convinced that the peculiar behaviour of the underground wires could only be ascribed to the electrostatic charge already observed at the testings in the factory, the wire namely forming the inner, the damp soil the outer coating of a Leyden jar." " The very sur- prising and disturbing phenomena of electrical charges in underground conductors required thorough study. Further, it was necessary to establish a system for the determination of the situation of faults in the conduction and insulation of underground wires by measuring cur- rents at the end of the wires. The uncertainty of the measurements of currents led to the necessity of replac- ing them by resistance measurements, and thereby to the setting up of fixed reproducible standards of resistance and scales of resistance. For this purpose the methods and instruments for current and resistance measurements had also to be improved and adapted for technical use ; in short, a whole series of scientific problems had cropped up, the solution of which was called for by technical needs." And so later on, when the actual problems of submarine telegraphy had to be solved. Dr. Werner took his share in their solution all the more ably because of the ex- perience he had already gained, and of his system of studying the science on which the art was founded. His narrative, especially in this connection, is full of adventures, not unaccompanied with danger, the descrip- tion of which is always interesting and often graphic. The lesson of the life, of which a few personal recol- lections are given in this volume, appears to be this : Find out the work you were sent here to do, and do it with your might. All the work that has to be done is not great work, but may be good work for all that ; it may not lead to honour and fortune ; but it has to be done, and if you are the one who has to do it, do it well. Dr. von Siemens had a work to do ; it matters little, it seems to us, whether others were engaged on the same work or not ; he did his share. As to who the person is November 9, 1893] NA TURE 27 that first made a particular discovery is often a difficult question to settle ; it is, after all, perhaps a matter of ac- cident, or shall we say rather a matter of gift. But the man who follows his guiding star, and is led by it to honour, and success, and fortune, is one whose example others may well follow, even though it may not lead those others there. A great work or a very little work has to be done ; set to work and do it. There is your guiding star shining clear and bright ; follow it. There may be bright scintil- lations to the right and left ; they may be merely igncs faint, or they may be other men's guiding stars ; they have nothing to do with you. You may have to work hard, but any way try to work wisely ! IRON ORES. The Iro7t Ores of Great Britain and Ireland. By J, D. Kendall, F.G.S. With numerous illustrations. (London : Crosby Lockwood and Son, 1893.) ALTHOUGH numerous works relating to mineral deposits of particular districts have appeared at different times, besides larger treatises dealing with the subject generally, such as the late John Arthur Phillips' •• Ore Deposits," the want of a systematic account of our present knowledge of the origin and occurrence of British iron ores, and of the means of working these ores, has long been noticed. This want will.be supplied by the volume under consideration. The author is a mining engineer of thirty years' experience, and he has been able to supplement a careful study of the available litera- ture by unpublished information derived from his own observations. The result is a volume that will prove of substantial value as a work of reference to all interested in the iron industry of this country, more especially as the published information can only be found by a la- borious search through the volumes of the Journal of the Iron and Steel Institute, and of the Transactions of other societies, Mr. Kendall has broken up his volume, ^ which covers 430 pages, into four parts. In the first, he gives some interesting information regarding the early working of iron ores, of which there is indirect evidence in nearly all the valleys of the Lake district. The presence of Roman coins, some of them as early as Trajan, found in heaps of iron cinder in Sussex and near Monmouth, proves that iron was made at a very early period from the red and brown oxides. Indeed, it is possible that these beds were worked at an even earlier period, for flint flakes and rough unturned pottery were found by Boyd Dawkins on the surface of a slag heap near Battle. In the second part, the author discusses the geological position and mineralogical characteristics of iron ore deposits. The third section deals with the age and origin of the deposits, and the last describes the method of searching for and working iron ores, with useful in- formation on working costs, selling prices, and conditions of leases. The author's task is not a light one. Within the limits of 430 pages to describe even the main features of the long list of mines which give the United Kingdom (1891) its 12,777,689 tons of iron ore, valued at ;^3,355,86o at the pit's mouth, is by no means easy. With the aid of NO. 1254, VOL. 49] forty-one illustrations and five folding plates, he has, however, been enabled to compress a large amount of information within a comparatively small compass, the value of the descriptions being increased by the insertion of bibliographies for each district. As would naturally be expected, all the ores noticed in the volume are not treated with equal fulness, preference having been given to those of the greatest commercial or scientific importance. It is to be regretted that the great lode of Perran, near Truro, should have been dis- missed in a single line. The late Sir Warington Smyth made many attempts to introduce this curious deposit to the notice of ironmasters, and it has formed the subject of numerous important memoirs. The most interesting descriptions given by Mr. Kendall are perhaps those re- lating to the district with which he is specially acquainted — the hematite district of West Cumberland and Fur- ness, a district which has received less attention from geologists than any other of equal importance in the British Isles. The ores are of special value for the part which they play in admixture with the poorer qualities of ironstone, as well as for the production of Bessemer pig- iron. So irregular, however, are these deposits that the boring-tool may easily pass within a few inches of amass worth thousands of pounds without discovering a trace of it. There can be no doubt that the acquirement of an accurate practical knowledge of these irregular de- posits, of which the surface tells no tale, is the most difficult subject with which the mining engineer has to deal, and yet in many cases the difficulty is entirely ignored, with the result that the cost of exploration is enormously increased. The chapter on the ironstones of the carboniferous rocks contains little that is new, the bulk of the informa- tion being contained in the " Memoirs of the Geological Survey." The analyses given relate to the iron ores collected by S. H. Blackwell, and the author might with advantage have mentioned the fact. The formation of this collection marked an epoch in the history of metal- lurgy, for, notwithstanding the magnitude of the interests involved in the iron and steel industries, no systematic collection representing the workable ores of the kingdom had been made until the Great Exhibition of 1851. The want was then supplied by the liberal exertions of Mr, S. H, Blackwell, a Dudley ironmaster, who, after the ex- hibition, presented this extensive and interesting series to the Museum of Practical Geology, munificently placing a sum of £soo at the disposal of Dr. Percy towards defray- ing the cost of their analysis. The results were subse- quently published at Government expense in the " Memoirs of the Geological Survey." The perplexing and fascinating subject of the genesis of iron ore deposits is treated by the author with great fulness, and his conclusions deserve attentive considera- tion. He brings forward a large amount of evidence in support of the views propounded by Sorby and by Huddleston that the ores of Cleveland and Northamp- tonshire were produced by the replacement of an ordinary limestone, and extends the theory to all deposits occurring in the secondary rocks. The source of the iron, he believes, may have been in the clays, with which all these deposits are closely connected. In the case of the red heematites, he is of opinion that the most likely 28 NA TURE [November 9, 189; source of the iron is to be found in volcanic emanations of ferric chloride, a theory that appears more ingenious than sound. The author does not appear to have con- sulted the writings of recent foreign workers in this field. A study of the memoirs of R. D. Irving, Kimball, Van Hise, and H. V. Winchell, on the genesis of American iron ores, might have induced him to modify some of his views. The author's remarks on the value of geology to the mining engineer deserve attention. It is undoubtedly of urgent importance for the economical utilisation of the iron ore resources of the kingdom, that those entrusted with the management of mines should have a more ex- tended knowledge of the nature of irregular deposits than is too often the case. In these days of technical education, it is surprising to see money wasted in search- ing for these deposits in situations where some know- ledge of stratigraphy would have shown that there was no chance of finding them. It is surely not too much to ask that mineral explorers should understand the elements of their work. Bennett H. Brough. OUR BOOK SHELF. The Shrubs of North-Eastern America. By Charles S. Newhall. 8vo, pp. 249, with 116 woodcut figures. (London : G. P. Putnam's Sons, 1893.) The author of the present volume had previously written a similar book on the trees of the same region, which he defines as " Canada and the United States east of the ]Mississippi and north of the latitude of Southern Penn- sylvania.'' This region is peculiarly rich in both trees and shrubs, most of which are hardy and will flourish in this country ; and, as a matter of fact, many are familiar here in cultivation. Therefore a work of this kind appeals to amateurs on this side of the Atlantic as well as the other, and, although an unpretentious produc- tion, we can recommend it as a useful aid to those interested in the subject, especially to such as already possess some general knowledge of shrubs. The de- scriptive part is as free from technicalities as it could well be, and intelligible to any person whose knowledge of botany does not go beyond the veriest rudiments. The figures are for the greater part merely outlines, and so far accurate ; yet hardly sufficiently detailed for use in our gardens, where American plants are associated with those of all other temperate climes. In the fields and forests of America they would be more serviceable. Botanical and popular names are given, and the deriva- tion of the former, at least as to genera. The descriptive matter is here and there enlivened by appropriate poetical quotations ; and the properties and uses of the more important plants are given. The Ericaceae are perhaps the most numerous and attractive among the shrubs of Eastern America. No fewer than ten genera of this family are enumerated. Missing the Rose Acacia, Rohinia hispida, we had almost convicted the author of omitting a favourite shrub ; but we find it does not reach quite so high a latitude as 40^ in America, though it is quite hardy in most parts of the British Islands. We also missed \^& Menispcrniuin, Wistaria, and other climbers ; but we suppose they will be included in the " Vines" of North America, to be dealt with in a third volume, announced by the author. W. B. H. • Meitsiiratioti of the Simpler Figures. (Univ. Corr. Tutorial Series.) By William Briggs and T. W. Edmondson. (London: Clive Univ. Coll. Press, 1893.) Those students who have acquired a fair knowledge of algebra, trigonometry, and Euclid, will find in this NO. 1254, VOL. 49] book a most excellent guide to the mensuration of most of the more simple figures generally met with. Instead of presenting the reader with the stereotyped " rule and example " system, the authors have treated them as just a series of problems giving proofs of the formulae used and numerous examples. That the book throughout is clearly and yet not too fully written speaks well for the student, and its scope is intended to meet the requirements of candidates for such examinations as. the Intermediate B.A. and B.Sc. of the University of London. The measurement of rectilinear figures and the circle are first treated, followed by chapters on the geometry of the rectilinear solids and their surface- areas. This is succeeded by the methods of measuring the volumes of the rectilinear solids, and the last two chapters deal conclusively with the cylinder and cone and the sphere. The definitions throughout are well expressed, and the problems neatly worked out, while the figures could hardly be improved. We may mention that in the chapters relating to the rectilinear solids all figures have been drawn in perspective and shaded, giving the student a clearer idea of the forms of the various figures. The Discovery of Australia. By Albert F. Calvert (London : George Philip and Son, 1893.) Mr. Calvert describes his book as " a simple state- ment of such historical facts as I could collect ; and a reproduction of certain maps which more or less illus- trate the gradual progress of knowledge regarding the great island continent, now called Australia." From this it will be inferred that there is nothing strikingly novel in the production. Mr. Calvert has found many tracings on old charts indicating a knowledge of the existence of a great southern continent, and he thinks that probably some individual navigator landed on the western coast of Australia in the fifteenth or sixteenth century, after- wards bringing the news of his discovery to Europe. A large portion of the book is devoted to the voyages of Capt. Cook, the reason being that " he was really the discoverer of Australia in its present geographical con- figuration." The volume is well printed, and the maps are finely reproduced. It is doubtful, however, whether the author has added much to elucidate the subject which he treats. Graphic Arithmetic and Statics. By J, J. Prince. (London: Thomas Murby, 1893.) In addition to questions in Practical Geometry, the Science and Art Department has given notice that in the future questions in Graphic Arithmetic and Statics will be included. The issue of this small book is intended to supply students with information on these two subjects, sufficient for both the elementary and advanced stages. In forty-eight pages the author has brought together all the important problems, working them out clearly for beginners with the help of diagrams. In addition to those of the more elementary kind, a graphical determination of the square roots of numbers, the resolution of forces, resultant of parallel forces, iS:c., are also dealt with. Nothing that the reader will find in this book will be found superfluous, though it could with advantage be slightly extended. The Crchid Seekers. By Ashmore Russan and Frederick Boyle. (London: Chapman and Hall, 1893.) Up the Sarawak river to Kuching, and thence to Siram- bau, went a small party in search of a blue orchid re- ported to exist in that region, and supposed to he Vanda ccerulea or V. carulescetis. The leader of the party was a German botanist well versed in orchidology, who iden- tified each plant as it was found, and delivered botanical discourses whenever an opportunity occurred. The story November 9, 1893] jVA TURE 29 is mainly one of adventure ; nevertheless, much of scientific interest is weaved into it, and the boy who reads it without skipping the closely-printed portions will obtain some useful knowledge of the natural history of Borneo. LETTERS TO THE EDITOR. [The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond 'vith the writers of, rejected viantiscripts intended for this or any other part q/" NATURE. No notice is taken of anonyvioiis communications. '\ Human and Comparative Anatomy at Oxford. I AM sorry that Prof. Burdon Sanderson should state that a " misstatement " occurs in the article written by me in your issue of October 26, and still more so that whilst makine; such a charge he altogether omits to cite the " misstatement " which he sets out to correct. My knowledge both of the University of Oxford and of the teaching of anatomy is, as a mere result of individual history, far more intimate than is that of my colleague, Prof. Sanderson, a fact which may account for some difference in our opinions on these topics. When in 1885 the Convocation of the University was asked to sanction the payment of a small salary for a limited period to a lecturer in Human Anatomy — out of University funds already taxed to an inconvenient extent — there existed four ancient foundations in Oxford assigned to the support of teachers of "Anatomy," viz. : the Linacre Professorship of Human and Comparative Anatomy, the Tomlinsian Lectureship of Anatomy, the Aldrichian Professorship of Anatomy, and the Lee's Readership in Anatomy. The small Tomlinsian and Aldrichian endowments had been united in 1S03 by Parliamentary autho- rity, and the salary arising from them was in 1858 assigned to the payment of a demonstrator or demonstrators nominated by the Linacre Professor. There were thus, as teachers of anatomy in the University, the Linacre Professor and his Aldrichian demon- strator, and the Lee's Reader. Whatever may have been the conceptions of the ancient founders as to the nature of that study which they designated ." Anatomia," or the intentions of University Commissioners who gave the title of " Professorship of Human and Comparative Anatomy " to Linacre's revived readership in medicine, or by whatever conditions the result may have been determined, it is certain that in 1885 the holders of the Linacre, Aldrichian, and Lee's teacherships were not giving that "technical training in anthropotomy," that "topo- graphical knowledge of the human body," which forms a part of medical professional education, and is administered in every hos- pital-medical school throughout the country. What these Oxford teachers were doing was to teach anatomy in its broad academi- cal sense. They taught the anatomy of man and of animals as a branch of biological science, and f venture to assert that they taught the anatomy of man and of vertebrate animals with as ample material illustration, and in as complete and detailed a way, as is desirable for the training of University students in- tending to pursue the study of any one of the great branches of biology as a science. What they did not do was to furnish the professional medical student with that special acquaintance with the arrangements of tendons, nerves, and blood-vessels in each little tract of the human body which might be the seat of a surgical operation or a medical exploration. Both the teaching and the acquirement of these details is tedious and uninteresting, although necessary for the surgeon. The subject-matter is called "human anatomy," or the "anatomy of man" — as distinguished from "anatomy" in its wider sense, and more especially as distinguished from com- parative anatomy. Human anatomy is not a branch of science ; it is topographical information. In order to render it less un- interesting than it would be (and under some teachers is) when strictly taught, it is customary for the teacher of human anatomy to introduce scraps of the various branches of science which bear upon the significance of animal structure into his text-books and lectures. He thus imports a little physiology and mechanics, a little comparative anatomy or animal morphology and embry- ology into his teaching. The real significance, however, of the facts learnt by the medical student in his course of "human NO. 1254, VOL. 49] anatomy " is in their application to surgical and medical prac tice, and it is in referring to these applications that the teacher of human anatomy finds the legitimate and most successful leaven, for his dead weight of detail. Such being the somewhat repellent character of the pursuit of human anatomy considered apart from the science of morph- ology or comparative anatomy, it is not surprising that the Oxford teachers of "anatomy " in 1885 had all devoted them- selves to the latter study, and left the technical topographical human anatomy uncared for. But unattractive and uninteresting as it is, this human anat- omy has to be " gone through "' by the medical student. Oxford had been roused to a sense of her obligations to medical study by a movement, in which I took a somewhat prominent part,, and accordingly when in 1885 it was represented to Convocation that although the University had three teacherships of anatomy and splendid collections illustrating the structure of animals (including man), yet there was no provision for carrying on the instruction in anthropotomy necessary for technical students of medicine, that body generously and deliberately consented to provide a new teachership for the specific purpose of filling this gap in the machinery of the Oxford Medical School. I should be very sorry to see any tendency to frustrate the excellent purpose of Convocation, and I feel confident that the renewal of the periodic grant made by that body to pay the salary of a lecturer in human anatomy must depend on the lec- tureship being strictly restrained within its original boundaries. We do not want at Oxford a fifth teachership of anatomy added to the four which have somehow slipped away from "anthro- potomy " into pleasanter and more philosophic regions. The University ought not to be asked for more money with the object of effecting once more such a transformation. But this- will certainly be the case if vague theories about "the academical teaching of human anatomy " are allowed to pass without protest. Oxford, November 4. E. Ray Lankester, P.S. It is strange that Prof. Sanderson (himself an Edin- burgh man) speaks in his letter of the University professor of Human Anatomy in Edinburgh. There is no such professorship in Edinburgh. Sir William Turner is professor oi Anatomy in Edinburgh, as is the eminent comparative anatomist Gegenbaur in Heidelberg. The separation of human anatomy from com- parative anatomy has not been carried out in these Universities- as it has been deliberately in Oxford. Anthropotomy is taught in the former by demonstrators and assistants acting under the direction of the professor of anatomy. That was the intention of the late University Commissioners with regard to Oxford when they constituted the Linacre Professorship of Human and Comparative Anatomy. Some persons, however, thought it best (I am not now discussing the merits of the arrangement)- that the example of Edinburgh, Heidelberg, and other European Universities, should be departed from in Oxford, and that the functions of the Edinburgh Professor of Anatomy and his staff should in Oxford be divided between the Linacre Professor of Comparative Anatomy and an independent lecturer in Human Anatomy. The Monros, Goodsir, Allen Thomson, and other distin- guished Scotch teachers were, like Gegenbaur, KiJlliker, and others in German Universities, professors of "Anatomy," not exclusively of "Human Anatomy." The Oxford plan of relieving the titular Professor of Humaiv and Comparative Anatomy of an important but technical branch of his teaching, by the appointment of a lecturer ad hocy has not a precise parallel in other Universities. Moreover, in Germany the subject of microscopic anatomy or histology is very usually undertaken by the Profesfor of Anatomy (e.g. Kolliker, Waldeyer, His), although in Oxford the Professor of Physiology is by statute called upon to give instruction in his- tology. It would probably not meet with unanimous approval were the present Oxford lectureship in Pluman Anatomy — in- imitation of "academical teaching" elsewhere — to be diverted wholly or partly to the subject of histology. — E. R. L, " Geology in Nubibus." An Appeal to Dr, Wallace and others. In his timely and important letter to you. Dr. Wallace con- gratulated us all on having got rid of a 7t'3/ glacial nightmare by sweeping away the tropical glaciation which has been favoured NA TURE [November 9, 1893 by some high authorities, including himself, Mr. Darwin, and Air. James Geikie. While we may all share in this congratula- tion, it must be remembered what it involves. It has been the fashion with an extreme and aggressive school of glacialists to postulate an excavating tendency in ice to which the formation of lake basins and valleys-without-outlets in mountain districts has been attributed. They will not allow that rock basins are due to any other cause than "omnipotent ice." They scoft' at explorers of the mechanics of ice in Alpine countries, like Prof. Bonney and Mr. E. Hill. They jeer at those who have devoted much patience to unravelling the mysteries of Plutonic action, like Prof. Judd and others, who attribute a large number of lakes to dislocations and to foldings of the sub- jacent rocks. It is no use, in arguing with them, to refer to mechanical difiiculties like those involved in conveying thrust of more than a certain amount through a substance like ice, which is known to crush under a moderate pressure, nor to pro- duce any number of mechanical arguments against the capacity of ice to erode lake basins such as those in question ; nor is it any use appealing to the stupendous geological difficulties against their conclusions which have been accumulated by quite a number of skilled geologists at home and abroad. All these •efforts are futile, for we are told that the ice to which appeals must be made is quite a different thing to any ice we can ex- periment upon or examine, and that it must not therefore be measured by the ordinary laws that govern ice such as we know it, and this appeal to transcendental ice is considered to be orthodox science in the nineteenth century, an age when induction is supposed to have become a supreme law to us all, and when rt/rzwi postulates are generally discarded from the realm of physical research. Let this pass, however, and let us test the •question in another way. Let us test it, in fact, by this very case of Brazil, There has never been a glacial period in, nor are there traces of glacial action in the highlands of, Brazil, we are told by Dr. Wallace. Granted. How then can Dr. Wallace, ar.d those who agree with him in this matter, explain the existence on the plateau of Bahia of perhaps the largest and most remark- able collection of rock basins in the world, rock basins exist- ing, too, in close juxtaposition with most i^erfect examples of giants' cauldrons on the largest scale. This is assuredly a dilemma for the transcendental school of geologists. Let me quote from Mr. Allen's graphic descriptions of these rock basins. Speaking of the plateau of Bahia, he says : "Over this whole region there is an almost entire absence of loose materials on the surface . . . slight knolls and shallow basins alternate which rarely difter more than 20 or 30 feet in eleva- tion, fn the rainy season many of these basins become filled with water, forming shallow lagoas varying in area from less than one to more than 50 acres, from most of which the water evaporates in the dry .--eason .... So numerous were these lagoas for more than 50 miles that it seemed natural to speak of this region in my notes as the "Lake Plain." Almost everywhere the elevations are evenly rounded, indicating that the rocky crust has been exposed to rain and probably long continued abrasion. But the absence of abraded materials seemed most remarkable ; very rarely were even loose boulders observed, though a few such were repeatedly noticed. At fre- quent intervals there were irregular holes in the rocks, usually nearly filled with water, to which the inhabitants give the name of 'caldeiraos.' These caldeiraos are of frequent occur- rence Nearly all of the considerable number examined proved to be genuine pot-holes, and some of them were of great size. The largest one I measured was elliptical in outline, 18 feet long, 9 or 10 in width, and 27 deep, with smoothly worn sides. . . . These pot-holes often occur out on the plain, far away from any high land, and they are sometimes found exca- vated on the summits of slight bulgings in the plain, or even on the top of a hill." I would ask, in all seriousness, whether, if phenomena like these had been described from the Alps or from Nova Scotia, they would not assuredly have been pointed to by extreme glacialists as the unerring footprints of great ice-sheets, and yet Dr. Wallace, who is a champion of the school, repudiates the former glaciation of Brazil altogether. What is to be said in regard to this dilemma then ? It is quite clear that either the facts must be disputed (and who is to dispute them ?), or else the champions of ice at-all-hazards must concede that rock basins and giants' cauldrons can be made by other agencies than ice. If so, they can be made as well in one place as in another. If they could be made by other causes on the plateau of Bahia, vvhy not in the highlands of Tasmania? I am bound to say I was taken aback by Dr. Wallace's com- ments on a letterfrom one of your correspondents, whichappeared in Nature a short time ago. That gentleman professed to make an exploration of certain parts of Tasmania with another ex- perienced geologist. They were both champions of the glacial theory. They both went prepared to find traces of glacial action there, and certainly in our latitudes no evidence seems more easily discriminated, and they came back convinced that in the districts where the rock basins of Tasmania abound, there are no traces of glacial action to be seen. They could find none. Mr. Johnstone, who has written an elaborate and detailed geological memoir on the island, and who has explored it in many directions, could find none either, save on the western flanks and in the valleys of the Tasmanian Alps in the western part of the island, where it has been long known that traces of former local glaciers exist. There is absolute unanimity among the native geologists that nothing in the shape of ice-sheets existed there, and there is no ice-spoor in the central districts where the great Tasmanian lakes occur. Dr. Wallace's answer to all this was certainly unexpected. He has not himself visited the island, and yet he disputed not only the inferences but the facts and the observations. Why should the voice of Esau be listened to and approved in Brazil, and that of Jacob be repudiated in Tasmania ? Mr. Johnstone and the other observers in Tasmania are assuredly to be trusted in such an issue quite as much as Prof. Branner. I cannot see on what ground the discrimination is made, except the desperate inconvenience of postulating a glacial nightmare in the tropics. Assuredly the whole difficulty lies in championing a theory of the origin of lakes, unknown in geology until introduced by Ramsay, whose extravagance at times may be measured by some of his phrases addressed to the British Association when he pre- sided over the geological section. From all sides there comes a revolt against this theory, which is based on no empirical evi- dence, and is at issue with the mechanical properties of ice so far as we know them, and with the observations of practised observers of the first rank. I am bound to say that those geologists who habitually make appeals to forces in Nature, and to properties of matter which are purely hypothetical and unwarranted by experience, are leading us back to times when Aristotle and deductive reasoning dominated European thought, and when Bacon had not yet taught us better things. My attention has been called to an oversight in my previous letter. Among those who many years ago did good work in dissipating the particular glacial monster that was generated in the valley of the Amazons, was my old friend Dr. Woodward, whose papers on the subject in the volume of the Anit. and Mag. of Nat. Hist, for 1871, pp. 59 and loi, I had overlooked. IlEMiY H. HOWORTH. 30 CoUingham Place, Cromwell Road, October 27. Correlation of Solar and Magnetic Phenomena. I WAS glad to see (Nature, vol. xlix. p. 2) in the notice of Miss Gierke's "Popular History of Astronomy," that at- tention was drawn (l) to the correspondence in time between a certain luminous outburst seen on the sun on September i, 1859, by Carrington and Hodgson, and a disturbance of the magnets at the Kew Observatory : and (2) to the statement of the late Mr. Whipple that the magnetic movement was really a small one, and that in his opinion the observed correspondence was a mere accidental coincidence. Those who have read Carrington's original account (Monthly Notices of the Royal Astronomical Society, vol. xx. p. 13) will remember that at the time he him- self did not lean towards hastily connecting the phenomena, remarking that " one swallow does not make a summer." But authors of text-books on astronomy, who may be only to a partial extent observers, are too apt to state the matter in such a way as to give an impression that we have here an undoubted instance of direct connection, instead of a case of apparent con- nection, to be taken merely for what it is worth, seeing that the occurrence has remained to the present time without corrobora- tion. I should like to take the opportunity to support, in the fullest manner, the opinion of Mr. Whipple, which acquain- tance with the Greenwich magnetic registers tells me to be a true one. The magnetic movement in question, as recorded at Greenwich, was similarly small. But the erroneous impression lives long. May I therefore be NO. T254. VOL. 49] November 9, 1893] Nu4 rURE further allowed to give some reasons for the opinion expressed. That there exists a relation between sun-spots and mat^neti'^m is undoubted. And although those who are able to study the variations of sun-spots side by side with the variations of map;- netism can very well see to what extent the relation definitely holds, it is difficult adequately to convey to others a due im- pression of all the circumstances of the case. Periods of maxi- mum sun-spots are periods of great magnetic activity and energy, whilst periods of minimum sun-spots are periods of magneiic quiet. But it has not yet been found possil)ieto trace direct correspondence in details. Thus, when a large spot is present there may occur one or more considerable magnetic dis- turbances or storms, some enduring it may be for a i&w hours only, others it may be for several days, but, assuming direct solar influence, what it is that precisely determines when such disturbances shall arise is unknown. Further, at times of sun- spots being numerous, there is also considerable general magnetic irregularity. Now, in these magnetic disturbances and irregu- . larities there will be innumerable individual motions far I exceeding in magnitude that accompanying the Carrington sun I outbuist, and yet during all the many years that have elapsed since 1859, through which period the solar surface has been continuously scrutinised by hundreds of observers in different ; lands, no second occurrence similar to that of 1S59 has come to 1 light. But if there be so close a connection between solar and ' magnetic phenomena as the occurrence in question would seem to indicate, the fact that we have no corroboration of the solitary observation of 1S59 is surely remarkable, considering j that, of late years, it is very much to correspondence in details I that attention has been to a great extent directed. If irregular magnetic movements were comparatively few, the observation y Green, Sir yohn Kirk, K.C.B. , Prof. Oliver Joseph Lodge, Sir John Lubbock, Bart., William Davidson Niven, Dr. William Henry Perkin, The Marquis of Salisbury, K.G., Prof. J. S. Burdon Sander- son, Adam Sedgwick, Prof. Thomas Edward Thorpe, Prof. William Augustus Tilden, Prof. IV. Cazvthorne Unwin. It is with deep regret that we announce the death of Sir Andiew Clark, Bart., on November 6, at the age of sixty- seven. By the death of Prof. E. Lecouteux, France has lost one of its foremost agriculturists. Lecouteux was born at Creteil (Seine) in 1819. He was one of the founders, and afterwards a vice- president, of the Societe des Agriculteurs de France. He was also at one time president of the Societe Nationale d'Agricul- ture. Many important additions to agricultural literature were made by Lecouteux, and the effects of his beneficial influence will be apparent in France for many years to come. The Municipal Council of Paris has had an elegant album designed for M. Pasteur, containing the address presented to him in the name of the city of Paris at the celebration of his seventieth birthday in December of last year. Brussels University will shortly have a laboratory of Psychological Physics, endowed by private munificence. The Rector, Prof. M. H. Denis, has nominated Drs. G. Dv/elshauvers and P. Stroobant to take charge of the researches and practical work. Dr. John Andersox, F. R.S. , who for the past two years has been collecting materials in Egypt for a work on the mam- mals and reptiles of that country, is, we understand, again re. turning to Egypt to continue his researches, proceeding in the first instance to Suakin. jVA ture [November 9, 189; Prof. Guido Cora, of Turin, in iS86 a gold medallist of the R.G.S., has received this year a special gold medal from the Imperial Russian Geographical Society of St. Petersburg. Mr. Charles Stewart has been elected Fa ilerian Professor of Physiology to the Royal Institution of Great Britain, the ap- pointment to date from January 13, 1S94. Dk. von jHERiNGhas been appointed Director of the Natural History Museum, Sao Paulo, Brazil. Dr. Woldrich, Vienna, has been nominated Professor of Geology in the Bohemian University of Prague. Dn. T. Plesice hai been elected to the Directorship of the Zoological Museum of the St. Petersburg Acadeuiy of Sciences, in the place of the late Prof. A. Strauch. Dr. Carl Berg has been reappointed Professor of Zoology at the University of Buenos Ayre.=, a chair he occupied between 1875 and 1890, and which remained vacant after he went to Monte Video. Prof. G. E. Hale is expected to be present at the meeiing of the Royal Astronomical Society to-morrow, and to give an address on the suljject of his solar researches. In Nature of July 20 (vol. xlviii. p. 268) we published a communication fro.ai Prof. P. F. Frankland, calling attention to certain oVijections which had been raised by some membtrs of the Society for Promoting Christian Knowledge against the pub- lication of his little book, " Our Secret Friends and Foes," in the Romance of Science Seiies. The objections were stated formally by the Secretary of the Victoria-street Anti- Vivisection Society, and endorsed in most forcible terms by Lord Coleridge, as set forth in the correspondence published in our issue referred to. The protest calling upon the S.P.C.K. to withdraw the book from circulation, on the ground that it favoured "experi- ments upon living animals," was handed in last July with some fifty signatures attached, and in accordance with a rule of the Society was submitted to the Standing Committee, whose judg- ment in matters of this kind is considered final. This Com- mittee has just passed the following resolution : — " The Standing Committee having taken into consideration the statement of ob- jections, made under Rule xxxvi., against the book entitled " Our Secret Friends and Foes," by Prof. P. F. Frankland, and the remarks thereon submitted respectively by the author and the General Literature Committee, are unable to see suffi- cient reason for withdrawing the book from the Society's list." The decision arrived at will give general satisfaction to English men of science, and forms a fitting sequel to the correspondence forwarded to us by the author of the book. At last there is a possibility that a scientific method of identification will become part of our prison system. The Home Secretary has appointed a committee to consider the means at present available in this country for the identificalion of habitual criminals, and to report to him whether they could be improved by the adoption either of the Bertillon method of identification in use in France, or of Mr. Galton's finger-print method, or in any other way. The report will be awaited with interest. The Exhibition of the Photographic Society of Great Britain will close on Wednesday, November 15. An International Congress of Applied Chemistry will be held at Brussels on August 4, 1S94. The Russian Chemical Society will celebrate its twenty-fifth year of existence by a special meeting at St. Petersburg on November 18. NO. 1254, VOL. 40] The Newcastle-on-Tyne and Northern Counties Photo- graphic Association propose to hold an international photo- graphic exhibition next April. An "Exposition Universellc" will be opened at Lyon on April 26, 1894, ^I'l will remain open until the following November. Sections will \>z devoted to electricity, hygiene, and agriculture. At the meeting of the Museunis" Association, held in July last, under the presidency of Sir W. II. Flower, K.C.B., F.R.S., the following officers were elected by the Council : — Dr. V. Ball, C.B., F.R.S., to be president. Prof. D. J. Cunningham, F. R. S., and Mr. Walter Armstrong vice-pre- sidents. The Association will meet in Dublin next year, about the end of June or the beginning of July. The new session of the Royal Geographical Society will conmence on November 13, when the president, Mr. Clements R. Markham, C. B., F.R.S., will discourse on "Geographical Desiderata, or Exploring Work to be done and Geographical Problems to be solved." On November 27, Dr. John Murray will read a paper on " The Antarctic Region and the Scientific and Commercial Results of its Exploration." The seventy-fifth session of the Institution of Civil Engineers will be commenced on November 14, and the meetings before Christmas are likely to be occupied, in addition to an address from Mr. Giles, president, with the design and construction of impounding reservoirs for water-works at Tansa (Bombay), Baroda, and Jeypore, with machinery for the manufacture of casks, and with the development of hydraulic power-supply in London. The first meeting of the 140th session of the Society of Arts will be held on Wednesday, November 15, when the opening address will be delivered by Sir Richard E. Webster, M.P. A course of Cantor lectures will be given by Prof. Frank Clowes in January and February next, his subject being "The Detec- tion and Measurement of Inflammable Gas and Vapour in the Air." Captain Abney will deliver three Cantor lectures on " Photometry " in April. The following are among the papers down for reading after Christmas : — " London Coal Gas and its Enrichment," by Prof. Vivian Lewes ; "Experiments in Aero- nautics," by Mr. Hiram S. Maxim ; "Pewter," by Mr. J. S:arkie Gardner ; " Electric Signalling without Wires," by Mr. W. H. Preece, F.R. S. Two juvenile lectures on " Plants : their Foes and Defences," will be delivered by Mr. W. Gardiner, F. R.S., in January. It is reported that Vesuvius is in a state of activity, and streams of lava are distinctly visible at night. An earthquake was distinctly felt in various parts of Wales and the West of England' on Thursday, November 2, about 5.45 p.m. From reports of the occurrence we gather that at Milford Haven the tremor lasted about twelve seconds, and ap- peared to travel from north to south. In the St. Helens district of Swansea the shock lasted about five seconds. A distinct upheaval of the earth is reported from Carmarthen, where the shock is said to have listed thirty seconds. Two successive shocks were felt at Cardigan, accompanied by a rumbling noise travelling from the sea in a south-easterly direction. In Pem- broke there was a heavy rumbling sound, and the earth was felt to tremble for about seven seconds. The wave appeared to be travelling from south-east to north-west. Very faint shocks were felt at Cardiff and along the Rhondda Valley. In North Wales, however, the tremor was of a very pronounced character. Both shores of the Mersey seem to have been affected. From correspondents of the Times it appears that at Aigburth, just south of Liverpool, the vibration was felt at 5.44. At Wood- side, on the Cheshire side of the Mersey, the time was "November 9, 1893] jVA TURR .^^5 5h. 45ui. 30s. ; at Crosby, about five miles to the north of Liverpool, 5.47 ; at Shrewsbury 5.48, the duration in this case being estimated as three seconds. In Bristol it is reported that the tremor was distinctly felt along a course from north- west to south-east for forty seconds. Mr. H. Courtenay, writing to us from Waterford, says that the disturbance was experienced thereat 5.25. Mr. Lloyd Bozward, of Worcester, describes the occurrence as follows: — "On Thursday last, at 5.45, a smart shock of earthquake was experienced. At this house the shock was vertical ; no noise was heard, but in a second or two after the first shock a feeble one followed. Persons on the ground-floor observed nothing. The shock was felt at Boughton Park, southwards a mile hence, and there also the servants on the ground-floor felt nothing. These places are on the west side of the Severn. It is somewhat rare for the same shock to be felt on both sides of the Severn, but on this occasion it was some- what severely felt at some large ironworks on the eastern side of the river. There the motion is described as a swaying one, and a rumbling like the passing of a heavy wa;4gon was heard. At Boughton and the ironworks the time given is 5.4S p.m. I took the hour at the time of the shock from a clock, a good time- keeper, in the room with me. At Callow End, Dermstone, a farmstead ten miles north-east of Worcester, no shock was felt, but a loud noise was heard." Dr. N. M. Glatfelter reprints from the fifth annual report of the Missouri Botanic Garden " A Study of the Vena- tion of ^a/Zx." Photographic reproductions are given of the leaves of twenty-four American species of willow, and an attempt is made to classify them according to their venation. The Deby collection of diatoms now in possession of the British Museum, and open for reference by students in the Cryptogamic Herbarium, is the finest in existence, both as regards the number of species, the authority of the nomenclature, and the beauty of their preparation and preservation. Besides those collected by M. Deby himself, it includes a large number of type-slides prepared by other eminent diatomists. The collection of diatoms in the British Museum is now estimated to amount to about 50,000 slides. Dr, H. Wild, Director of the Central Physical Observatory at St. Petersburg, has published in German a summary of the deci- sions of the various international meteorological conferences, from that held at Leipzig in 1872 until that held in Munich in 1891. The arrangement is first under subjects, and secondly according to chronological order, and the svork will be found very useful for reference by persons who may be seeking for information upon any particular subject, instead of having to consult some thirteen different volumes. We have received the report on the operations of the German Meteorological Office for the year 1892, which closes an impor- tant period in the history of that institution, owing to the completion of the organisation of the rainfall stations which began with the year 18S5, and the establishment of a first-class me- teorological and magnetical observatory at Potsdam. The rainfall stations now number nearly ipoo, and the stations which send special reports of thunderstorms exceed 14CO. The report con- tains not only a list of the official publications for the year, but also a list of the contributions of the officials to both German and foreign periodicals. We also note that, in order to keep up an interest in the work, the office issues no less.than 200 copies of the popular meteorological journal Das Wetter to its observers. The report of the Director of the Royal Alfred Observatory, Mauritius, for the year 1S91 has just reached this country. The maximum shade temperature during the year was 95''4 on December 8, and the minimum 5i''o on August 3. The highest temperature in the sun was i62^'7, and the lowest on NO. 1254, VOL. 49] the grass 46''o. The rainfall amounted^to 44'63 inches, being 3 "15 inches below the average, but at some other stations in the island the rainfall was much greater than at the Observatory. Dr. Meldrum collects 'observations from ships visiting the island, for the preparation of meteorological charts of the Indian Ocean ; the number of days' observations tabulated during the year amounted to 9,600, taken between 23^ N. and 46' S. latitude. Colonel A. T. Eraser has sent us an interesting note from Beliary with regard to two Hindoo dwarfs which he photo- graphed in the Kurnoul district of the Madras Presidency, not far south of the river Kistna. In speech and intelligence the dwarfs were indistinguishable from ordinary natives of India. From an interrogation of one of them, it appeared that he be- longed to a family all the male members of which have been dwarfs for several generations. They marry ordinary native girls, and the female children grow up like those of other people. The males, however, though they develop at the normal rate until they reach the age of six, then cease to grow, and become dwarfs. These stunted specimens of humanity are almost help- less, and are quite unable to walk more than a few yards. Mr. Miller Christy outlines a scheme for mapping the geographical distribution of vertebrate animals in the Zoologist for November. He proposes to construct a map showing, by means of different colours, the following points for each species : — (i) Its present (indigenous) area of permanent residence throughout the world ; (2) its summer and winter ranges throughout the world (if migratory) ; (3) its relative abundance in different parts of its area ; (4) its lines of migration (if any) ; (5) the additional area (if any) over which any species, now partly or wholly extinct, can be traced within historic times ; (6) the additional area (if any) over which it has been naturalised by human agency ; and (7) other points of interest, such as iso- lated occurrences, erratic movements, areas of hybridization, &c. Though it may be some years before a scheme of this kind is well under weigh, authorsof monographs of genera or families would do well to systematise their works, so that they could easily be used in the compilation of a topographical catalogue or bibliography. The extensive and increasing demand for india-rubber renders it possible that the supply will eventually become exhausted, so attempts at artificial cultivation of rubber trees are being made in various rubber-producing countries. Mr. Hart remarks, in the June Bttlletln of the Royal Botanic Gardens, Trinidad, that rubber has been procured in the Gardens from Castilloa elastica, and that trees of a mature size will produce it in paying quantities. It has also been proved that Ihveas of several species will thrive well in Trinidad. In this connection a paper by Dr. Ernst, on the caoutchouc of the Orinoco, published in the first number of the Kevista Nacional de Agricidture, and included in the Bulletin, is of interest. Dr. Ernst says that the rubber of the Orinoco is extracted from the juice of the Hdvea brazilietisis, Miill, a tree belonging to the family Euphor- biacea. and not to that of the Hevea Guayamnsis. The milky juice obtained from the trees, through incisions made in the bark, has the consistency of cream, and the rubber existing in it in minute globules constitutes from thirty to thirty-three per cent, of the weight. The rubber collectors of the Amazons employ the slow, primitive, and contaminating process of evaporating the juice in the dense smoke of a wood fire, in order to separate the rubber from it. A far better method of ob- taining coagulation is to add a six per cent, solution of alum to the juice, and then submit the coagulated rubber to pressure in order to extract the water it contains. Dr. Ernst thinks that every effort should be made to extend and conserve the forests, thickets, or groves of rubber trees, suggesting, among other things, that 36 NATURE [NoVEiMBER 9, 189; ! when the collectors work a grove they should ba made to plant a certain number of tree?. Only by such means, and by adopting a chemical mode of coagulation, can the rubber production of the Amazon territory bi increased in quantity and improved in quality. Mr. Vernon Bailey has prepared a report, for the U.S. Department of Agriculture, on the haunts and habits of the soermophiles, known in America as gophers or ground squirrels, inhaUting the Mississippi Valley region. Five distinct species of the gsiius Spennophllus inhabit this region, and four are re- stricted to it. On account of the immense damage done to crops by these mammals, several States have endeavoured to exterminate them, and they have formed the subject of in- vestigation at a number of agricultural colleges and experi- mental stations. The increase of the pest is probably due to the thoughtless destruction of its natural enemies. We learn that no less than sixteen of the seventy-three species and sub-species of hawks and owls found in the United States are known to prey on the various members of the genus Spermophilus. Among mammals, the spermophile's enemies include the badger, fox, coyot, wild cat, and weasel, all of which are hunted and killed for sport or because of poultry-yard depredations. In several States immense amounts of money have been paid as bounties for the destruction of the pest, but the results are far from satisfactory ; and it is evident that a bounty is only a temporary expedient for the extermination of these or any other animals. Mr. Bailey says that in many ways spermophiles render valuable service to the farmer, so he does not recommend a complete destruction of them. The evil which they do to crops, however, is very considerable over more than two-thirds of the United States ; hence there is a general demand for some economical means of destroying them. The animals can, of course, be shot, and in this way limited areas may be freed from their ravages. Fumigation and trapping have also been em- ployed with more or less success ; but the most effective and quickest results have been obtained by placing in the bur- rows a bunch of rags or waste saturated with carbon bisulphide, and closing up the hole. The information on this point given by Mr. Bailey should be of use to agriculturists ; indeed, the whole of the bulletin is of high importance. At the request of the Royal Academy of Science in Vienna, Prof. V. Hirbel undertook a geological tour this season in Thessaly. One or two short reports from him are published in the journal of i\\Q .Mathematics natur^idssensch. C/asse {No. 20, October 12). Respecting the geology of Northern Greece, he writes that calcareous formations of the Flysch have the most extensive outcrop on the three parallel chains of the Pindus range. Dykes of serpentine intrude through the Flysch, and occur as flows interbedded with the overlying Cretaceous lime- stones. The age of the much larger intrusive masses of ser- pentine in the sandstone zone of the upper Peneus has not yet been definitely ascertained. In the "Proceedings of the U.S. National Museum" (vol. xvi. pp. 471-478, pi. 56), Mr. William Healey Dall de- scribes a "Sub-tropical Miocene Fauna in Arctic Siberia." This fauna consists of a few well-preserved specimens of mol- luscan genera, Ostrea, Siphonaria, Cerithium, &c., which were found in 1855 by a member of the "Ringgold and Rodgers Exploring Expedition in the North Pacific." The fossils occur in Miocene sandstones of the Sea of Okhotsk, which are exactly like those of the Alaskan coast, and they are of interest chiefly because ihey prove beyond doubt strong affinities of the M'.ccene mollusca of these northern seas with species now living in the warm seas of Japan and China. According to Mr. Dall, the annual mean temperature of the waters in the Okhotsk area liar, diminished by at least 30° to 40° F. since Miocene time. NO. 1254, VOL. 49] The U.S. National Museum has also published a report by Mr. James [. Peck, on the pteropods and heteropods collected by the U. S. Fish Commission steamer, Allmtross, during the voyage from Norfolk, Va., to San Francisco in 1877-8. The pteropod collections of this voyage are, for the most part, from the Cari- bean and Panamaic provinces, and the material belongs almost exclusively to the family Cavoliniidse. From none of the deeper dredgings in the Pacific were pteropod deposit shells reported, though at times the surface collections in the same regions showed an abundance of the live animals. Mr. Peck agrees with Agassiz that bottom distribution is largely deter- mined by the course of the ocean currents, so that by means of pelagic fauna and their bottom distribution, light maybe thrown upon the course of the currents. To this cause Agassiz ascribed the presence of Arctic pteropods along the New England coast, from the course of the Labrador currents, and Mr. Peck believes that the differences between the bottom and surface collections of the Albatross on the voyage in the Gulf of Panama and at the Galapagos Islands may be similarly explained. Some years ago, a discovery of fossil plants was made for the first time in the Trinity Division of the Comanche series of Texas. These have now been worked out in detail by Mr. Wm. Morris Fontaine, who has published his results, together with aseriesof illustrative plates, in the " Proceedings of the U.S. National Museum" (vol. xvi. pp. 261-282, pi. 36-43). There are twenty-three species described ; by far the greater number are conifers belonging to the genera Abietites, Laricopsis, Pinus, Frenelopsis, Sequoia, &c., a few Cycad genera, and a new species of Equisetum are also present ; ferns are of exceed- ingly rare occurrence, and angiosperms entirely wanting. Seven of the species have been identified with forms from the Lower Potomac deposits (Lower Cretaceous) of Virginia, and several others show striking points of similarity with the same flora ; four species agree with Wealden types. The whole character of the " Trinity " flora, more especially the absence,, so far as known, of angiosperms, seems in favour of Jurassic as well as Cretaceous affinities. It certainly does not bear the dis- tinct Cretaceous impress of the flora in the Potomac or Wealden formations. Mr. Fontaine refers the "Trinity" flora, therefore, to the base of the Cretaceous deposits in Texas, occupying a slightly lower horizon than the very similar flora in the Potomac deposits of Virginia. The recent geological history of the Arctic lands is discussed by Sir Henry Howorth in the Geological Magazine. The general conclusions to which he arrives are as follows : — (i) During the Pleistocene period the Arctic lands, instead of being overwhelmed by a glacial climate, were under compara- tively mild conditions, and were the home of a widely-spread and homogeneous fauna and flora, constituting, perhaps, the best defined life-province in the world. (2) Since Pleistocene times the climate of these Arctic lands has been growing more and more severe, resulting in the extinction of a portion of their vegetable and animal inhabitants. (3) While one portion of this Pan-Arctic fauna and flora still remains largely homo- geneous, another portion has become differentiated by evolution in Northern America and Northern Europasia, into the Nearctic and Palrearctic regions respectively. (4) The true and the only glacial climate which we know to have prevailed in the Arctic lands was not during the so-called glacial age of geolo- gists, that is during"the Pleistocene period, but in that which is now current, and which is the product largely, if not entirely, of changes of level in the earth's crust which have occurred since Pleistocene times. The " Geology of Dublin and its Neighbourhood" has found a clear interpretation at the hand of Prof. Sollas, of Dublin Uni- versity [vide Proceedings of the Geologists' Association, August, November 9, 1S93] A' A rURE pp. 91-121). Prof. Sollas discusses the origin of the ancient quartzites, grauwackes, and slates in that district, and gives drawings from microscopic sections to ilkistrate the evidence in favour of their originally sedimentary nature. Paireontological evidence is present in the form of numerous worm-tubes and the doubtful organic remains known as Oldhamia radiata and antiqua. The whole group is regarded as a deposit in the tranquil sea of a period, probably Cambrian or pre-Cam- brian, which he rather happily characterises as the " Age of Worms." Just as in the Highlands of Scotland, this Irish area has been subjected to great earth-movements, not only once, but several times. First, in later Cambrian age, the sedimen- tary rocks were rolled up into a series of anticlinal and synclinal folds. Ordovician time saw the rocks once more lielow sea level, and a second elevatory movement set in with extreme slowness in Upper Ordovician time. The third period of move- ment is of post-Carboniferous date, and of simpler character than the two preceding, the flexures having in the main followed those of the Ordovician movements. In his concluding pages Prof. Sollas briefly refers to the absence of mesozoic and tertiary deposits, the general characters of the glacial period, and the distribution of the boulder-clay over the Dublin area. Sketch maps and diagrams illustrate the paper. The effect upon the optical properties of a plate of quartz of compressing it in a direction perpendicular to its axis has been investigated by M. F. Beaulard, who publishes his results in I he Joicr7ial dc Physique. A quartz plate was cut normally to the axis and compressed laterally, thus superimposing a double refraction, varying with the pressure, upon the rotatory power. Allowing a beam of plane-polarised light to fall normally on to the plate, he obtained inside the crystal two elliptic vibrations propagated with different velociti'es and exhibiting after emer- gence a certain difference of phase. These two vibrations in- terfered and gave an ellipse whose elements could be experi- mentally determined. The pressures were obtained by means of a Perreaux dynamometer, varying from o to 530 kgr. per square cm. The quartz was placed between two jaws which could be made to approach each other by turning a screw. One of the jaws was fixed firmly in a frame, the other moved on guides which communicated the pressure to an elliptical pair of springs, the amount being indicated on a dial through a rack and pinion arrangement. The dynamometer was mounted on two wooden platforms allowing of the orientation of the quartz plate normally to the incident ray. The rest of the apparatus consisted of a polariser, a quarter-wave mica plate, a pair of quartzes with two different rotations, an analyser, and a spec- troscope with eye-piece slit. It was found that the rotatory power remains constant ; that the difference of phase due to double refraction alone is proportional to the pressure, and that the.angle between the major axis of the emergent ellipse and the original incident vibration increases at first with the pres- sure (for plates of given thickness), then oscillates, and at par- ticular pressures the two directions are the same, so that at some points the major axis turns in a direction contrary to the natural rotation of the quartz plate. At a recent meeting of the Academie des Sciences (Paris), M. Poincarc communicated an account of the experiments on the velocity of propagation of an electric disturbance along a wire, which have been carried on by M. Blondlot at Nancy. The wires used were of "high conductivity " copper, 3 mm. in diameter, and were fixed to the telegraph posts between the Prefecture and the Maxeville Asylum, a distance of aboat one kilometre. The method employed was very like that used by Wheatstone in his attempt to measure the velocity of the pas- sage of an electric discharge, only instead of a rotating mirror M. Blondlot uses a rotating photographic plate. Matters NO. 1254. VOL. 49] are so arranged that twosparks pass between two knobs, one direct and the other after travellin:; round the 2 kilometre circuit. The mean of five experiments gives a velocity of 296 kilometres per second, the retardation being ^\^, of a second. On a line 2 kilometres long, that is, one where the electricity has to travel over 4 kilometres, the velocity obtained was slightly greater, namely 29S kilometres per second. In a paper read before the American Institute of Electrical Engineers, Messrs. Bedell, Miller, and Wagner give an account of a new form of contact-maker which they have employed in their experiments on transformers. The contact-maker was required to connect for an instant a voltameter with the circuit of the transformer at any required part of the cycle. The in- strument consists of discs carried by a spindle which was con- nected to the shaft of the dynamo. A needle projects from the face of this disc and forms one of the electrodes for making contact, the other being formed by a fine water-jet issuing from a nozzle which is insulated from the rest of the instrument. The water-jet is supplied by a jar of water, several feet above, the connection being through a rubber tube. The nozzle of the water-jet is carried by a disc which is capable of being rotated, and has its edge graduated in degrees. The needle cuts the water-jet near the nozzle before ihs continuous column has had time to break up into drops. It was found necessary to put a little salt in the water, as pure water does not work, while acidulated water corroded the nozzle. This form of contact- maker the authors find far superior to any of the usual mechani- cal devices, the contact being perfectly constant and reliable. In the Zeitschrift fiir physikalische Chemie, vol. xii. No. 4, Ilerr Humburg gives an account of a significant piece of work which was undertaken for the purpose of obtaining additional evidence as to whether the magnetic rotatory polarisation of solutions gave any support to the hypothesis of electrolytic dissociation. Measurements were made on solutions of the lower fatty acids in water, benzene, and toluene. The mole- cular rotation of the dissolved substance was calculated on the supposition that the value found for the solution was the sum of those given by the amounts of solvent and dissolved substance which it contained. The numbers thus obtained were found to be practically independent of the concentration and of the chemical nature of the solvent, and were identical with the values given by the free acids. Not only was this the case with acids such as acetic, proponic, and butyric, which are held to be but feebly dissociated in aqueous solution, but also of the chlor-acetic acids, which are supposed to be much more strongly dissociated. Similar results were -obtained from observations on solutions of various inorganic; salts, such a^ potassium iodide, sodium bromide, ammonium nitrate, and barium bromide in water, and in methyl alcohol. Although the molecular conductivity of the aqueous solution of any of the salts was invariably much greater than that of the alcoholic solution, nevertheless the molecular rotation of the salt was the same in both cases. In con- junction with the work of Schonrock on this subject (see Notes, vol. xlviii. p. 230), the above results indicate that the effect of electrolytic dissociation on the magnetic rotatory polarisation of solutions (if such an effect really exists) is too small to be detected by ordinary methods of measurement. Although such a large number of investigations have been made on the bacterial contents of waters derived from such different sources as lakes, rivers, springs, and wells, only a few observations have been made on the microbial C(ondition of sea- water. Giaxa's are the earliest recorded examinations, and exhibit the poverty in this respect of sea-water. Thus, in the Bay of Naples, at about a mile and a half from the shore, only ten organisms were found in I c.c. Russell, also working in this bay at distances of 2\ to 9 miles from the coast, obtained NA TURE [November 9, 1S9; from 64 to 6 n I c.c. respectively. Very different is, however, til ; bacterial condition of sea-mad, a> many as 245,000 microbes being fojnd in i c.c. of sliiis at a dapth of 164 feet, and 12,500 at 1,640 feet, whilst sea-water exaiiined at such depths con- tained 121 and 22 respectively. Russell has been recently ex- tending his observations {Bjtanical Gxzette, vol. xvii. 1892) to the sea-water and mid on the Missachusetts coist. The num- ber of bacteria, both in the water and slime, was very much less in these more northern and cooler waters than in the Mediter- ranean at Naples. The microbes present in the mud from Buzzard's Biy average from 10,000 to 30,000 per c c, being but a very sncil! fraction of the number found in Meiiterranean mud at equal depths. Simples of mad were also obtained about 100 miles from the shore at a depth of 100 fathoms, on the edge of the great continental platform skirted by the Gulf Stream. These samples are the farthest from land that have ever been bacteriologically examined, and bacteria were found in large numbers ; moreover, the two prevailing varieties present were identical with those obtained near the Massachusetts coast. As in his earlier researches, Russell also here found but few varieties of bacteria in the mud, mostly two or three, and curiously one form, Cladothrix intn'cata, isolated from Mediterranean mud and frequently met with, was only rarely found in this Atlantic slime. Ethyl and methyl derivatives of hydroxylamine, in which the alkyl radicles replace an atom of the hydrogen in the amido group, and are therefore directly linked to nitrogen, have been isolated by Dr. Kjellin, of Heidelberg, and their mode of pre- paration and properties are described in the current number of the Bericlite. They have been obtained by the decomposition with hydrochloric acid of the esters of meta-nitro-benzaldoxim, which oxim was merely 'selected on account of its ready pre- paration in a state of purity. The process consisted in boiling the ester with seven limes its volume of concentrated hydro- chloric acid in a flask to which a reflux condenser was attached, subsequently cooling, saturating the liquid with hydrjchlorio acid gas, and again boiling for a few minutes. A large quantity of meta-nitro-benzaldehyde is deposited and removed by filtration, after which the hydrochloride of the substituted hydroxylamine is obtained by evaporation, first over a water bath, and finally over sulphuric acid. In order to isolate the free bases from the hydrochlorides, the same method was adopted as proved so efficacious in the isolation of hydroxylamine itself, namely, decomposition with sodium alcoholate, and subsequent fractional distillation of the resulting liquid in vacuo. The hydrochloride was dissolved in the minimum quantity of methyl alcohol, and a little less than the calculated quantity of sodium iv.ethylate added, the large evolution of heat being controlled by extraneous cooling. The deposited sodium chloride was removed by filtration through asbestos ; filter paper cannot be employed on account of the strongly corrosive properties of these methyl and ethyl derivatives of hydroxylamine. Upon distillation in vacuo in the case of the methyl compound, after the greater portion of the methyl alcohol has passed over and at a temperature of 35-40"', an alcoholic solution of the base distils, then finally the free base admixed with a small propor- tion of alcohol. Upon submitting this last fraction to redis- tillation, at a temperature of 62° and a pressure of 15 m.m., the pure )3-methyl hydroxylamine, CH3NH.OII, distils as a colourless liquid, which solidifies' to a solid composed of colour- less and odourless prisms upon cooling with ice or agitation of the receiver. The crystals melt sharply at 42°, but do not resolidify until the mach lower temperature of 20° is reached. Upon distillation in vacuo in the case of the ethyl compound, after the methyl alcohol has largely passed over an alcoholic solution of the base distils for a short time, then lastly the ethyl compound itself commences to sublime and condenses in the receiver in the form of large leafy crystals, filling the whole receiver. After pressing the crystals on porous plates to remove any superficial oil, pure yS-ethyl hydroxylamine C.,H-NH.OH is obtained ; the crystals are quite colourless and odourless, and exhibit a mother-of-pearl lustre. They melt sharply at 59-60° without decomposition. The /3-methyl and /3-ethyl derivatives of hydroxylamine are substances which are readily soluble in water and lower alcohols, but only very slightly in ethe pnd benzene. The crystals of both deliquesce in moist aii. In the case of the methyl compound the deliquesced substance rapidly volatilises ; but in the case of the ethyl compound the deliquescence can only be observed in badly-stoppered bottles, for in the open air the spontaneous volatilisation is so rapid that the substance has not time to deliquesce before it entirely disappears. Both com- pounds react strongly basic, and reduce alkaline copper and silver solutions as energetically as hydroxylamine itself in the cold. They strongly attack organic substances, but do not etch glass, nor do they appear to be explosive substances like free hydroxylamine. Both compounds are rapidly destroyed by halogens with production of halogen acids ; concentrated hydriodic acid converts them to amines. When heated for some time in a sealed tube with concentrated hydrochloric acid, the methyl compound suffers an interesting change, being converted into ammonia and formaldehyde — CH3NH.OH = NH3 -F HCOH. Notes from the Marine Biological Station, Plymouth. — Last week's captures include another living specimen of Lima Loscomhii, the Holothurian Tliyone fusus, and the rare Nemer- tines Cai-inella polyinorpha (second specimen), Cei ebratiilus juarginatus (first record), and a large Lineus bilincatus (16 cm. long). The tow-nettings have been of a uniform character. The diatom Coscinodiscus has been present in remarkable pro- fusion for several weeks past. Medusae have been scarce. The most plentiful larva; are those of Polychaetes, of Cirrhipedes, the Mysis stages of several Decapods, and Scyphonaiites. Veligers are present in small numbers ; and isolated specimens o{\\\&\2^cs'stoiCephalothrix, Porcellana and Carcintis {Megaljps) have also been observed. Very few individuals of Crangoti vulgaris are now to be found bearing ova. The additions to the Zoological Society's Gardens during the past week include a Black handed Spider Monkey [Ateles geoffroyi) from Nicaragua, presented by Mr. T. E. M. Rymer- Jones ; a Rhesus Monkey {Macacus rhesus, 9 ) from India, presented by Miss G. A. Gollock ; two Macaque Monkeys (Afacacus cynoinolgus, i i ) from India, presented respectively by Mr. W. Wylde and the Hon. Mrs. E. Yorke ; a Philippine Deer {Cervus philippinus, 9 ) from Manila, presented by Capt. T. E. Saunders ; seven Common Quails {Coturnix coiiununis), two Common Terns {Sterna hirundo), two Common Toads (Bufo vu/garis) European, two Bull Frogs [Kana catesbiana) from North America, a Grey-headed Porphyrio {PorpJiyrio poliocephala) from India, presented by Mrs. Rickards ; a Smooth Snake {Coronella hvvis) British, presented by Mr. A. Green ; a Bay Wood Owl {Phodilus bodius) fron Java, deposited; two Rose-Hill Parrakeets {Platycercus eximius) from Tasmania, a Purple Sandpiper ( Triiiga striata) British, purchased. OUR ASTRONOMICAL COLUMN. A New Southern Star. — Prof. Krueger has received a telegram from Prof. E. C. Pickeiing to the effect that a new- star was discovered by Mrs. Fleming on October 26. Its Right Ascension is given as 230° 34', and its North Polar Distance = 140° 14'. The magnitude on July 10 =:7'o. No further details have been received, but from the date for which the magnitude is given it is probable that the star was detected by NO. 1254, VOL. 49] November 9, 1893] NA JURE Mrs. Fleming upon a photographic plate taken in July. The telegram has been communicated to the observatories in the southern hemisphere. "Astronomical Journal " Prize. — Owing to the fact that during the past six months only one comethasbeen discovered, and that its period of visibility was unusually short, and also to the probable prevalence of a bad time of observini; weather daring the winter, the period specified in the ofTer of this prize for observation of comets has been extended by six months. Tiie closing time for this prize will now take place September 30, 1894. Comet Brooks (October 16). — Last week we gave Bid- schof's elements and ephemeris for this comet. This week, for the sake of comparison {Aitroiioijiischen Nachriclilcn, No. 3194), we give the elements of the comet as obtained from the observations made at Hamburg, October 17 ; Greenwich, October iS ; Pola, October 19; .Strassburg, October 23, and Vienna, October 24. They are as follows : — Elements, T = 1893 September 19-209 M.T. Be/lin. w = 34^7 20-50 ) 45 = 174 53"20 iS93'o i = 129 4577 ) log q = 9 '9099 2 The current ephemeris is for I2h. Berliri mean time. Nov. •3 a App. 1. m. s. 2 58 50 o 53 2 59 5 9 7 22 9 39 12 o 14 25 S App. + 30 27-2 31 20'6 32 14-8 33 9 9 34 5-8 35 2-6 36 0-4 36 59'i Br. O 82 o So Unit of brightness occurred on October 17. Moon Pictures. — In an article on the " Origin of the Lunar Craters," which has appeared in the last two numbers of Proinctheiis (Nos. 212, 213), the writer has been able to secure some excellent illustrations. These pictures are copies from photographs taken at Paris by the lirothers Paul and Prosper Ilenr)-, and diustrate regions near the South Pole. The current number of Knowledge also contains two fine re- productions of lunar photographs obtained by MM. Henry, illustrating an article by Mr. A. C. Ranyard, on the tints of the lunar plains. Mete<:>r Showers during November. — During this month, in addition 10 some minor shower-, Mr. Denning's table informs us that there are two which are above the usual brilliancy. The positions of the radiant points are as follows, the two most brilliant being printed in heavier type : — Date. Radiant, ct 5 Meteors. Nov. 13 . 150 +22 . Swift ; streaks 16 154 + 41 . Swift ; streaks 17 53+71 . .Slowish 20 62+23 .Slow ; blight 27 25 ^44 . Very slow ; trains 30 190 + 58 Swift ; streaks GEOGRAPHICAL NOTES. Some anxiety may have been caused amongst Dr. Nansen's friends by reports published in an evening paper from the slender testimony of some Samoyedes, that the Kara Sea was unusually hampered by ice this season. The Nouvellcs Geographiqttes, it is satisfactory to see, reports on the authority of the captains of the Russian vessels carrying railway material to the Yenesei, and of Captain Wiggins, that the navigation of the Kara Sea was particularly easy this summer, the ice being thin and not compact. The Hammerfest whalers also reported that never within human memory has the sea been so free from ice. At the end of December one vessel saw not a single ice- NO. 1254, VOL. 40] berg between Nova Zemlya and Franz Josef Land. In the Kara Sea the cuirent, which is usually westerly at that season, was this jear running norih-norlh-west, at the rate of a mile an hour. '1 he note indicates that Captain Wiggins enlertaired no doubt of Dr. Narsen having easily reached the New Siberian Islands, which were to be his real starting-point. In continuation of the soundings of the English lakes recorded in this column from time to time during the summer, Mr. E. Ileawood, assisted by Mr. Shields, has last week made bathy- metrical surveys of Ennerdale, Buttermere, and Crummock Waters. The annual report of the Tyneside Geographical Society shows that there is now a memberthip of loii, and the society generally in a flourishing state. From its headquarters in Newcastle the Tyneside Society extends its operations over a coniiderable area, and has established a regular branch in the city of Durham. Dr. John Murray, of the Challenge?-, has written an elaborate paper on the first voyage of Columbus in relation to the development of oceanography. It is published in the current number of the Seotlish Geooraphical Magazine, illus- trated by reproductions of a number of ancient maps. Dr. Murray deals incidentally w iih the origin of the name America, rejecting Horsford's fantastic guess that it came from the name of the Norse explorer Erik the Red, and inclining towards Marcou's theory of its native origin from the Amerrique tribe of Indians in South America. As to Amerigo Vespucci's con- nection with the rame, the author views it .as a playful nick- name given to him on account of the similarity of his Christian name, which was superseded hy A ifierira, just as he himself is frequently called "Challenger Muiray" for the sake of distinction. THE EROSION OF ROCK-BASINS. T Na recent letter to Nature (vol. xlviii. p. 247, July 13, 1S93), ■^ Sir H. Howcrlh attacks the ^iews of those extreme glacial- ists who hold that a glacier is able, by means of the fragments of rock frozen into its under surface, to excavate rock basins : and with justice, so far as the larger fasins, such as tho-e of the great .Swiss and Italian lakes are concerned, for it has beeii frequently shown, especially by Prof. Bonney, that such a cause is quite inadequate to account for the excavation of those basins. It seems inconceivable that a glacier which is barely able to move the \ooit debris lying in its path, should be able to plough out hard rocks to any dei th whatever below the general valley level. On the other hand, the frequent occurrence of rock basins in regions which are now, or were in former times, subjected to glaciation, is so remarkable, that it appears as though there must be some connection between the two sets of phenomena. Sir II. Howorth says that, "so far as we know, the mecha- nical work done by ice is limited to one proces*^. The ice of which glaciers are formed is shod with boulders and widi pieces of rock which have fal'en down their crevasses. These pieces of rock abrade and polish and scratch the rocky bed in which they lie when they are dragged over it liy the moving ice. Without this motion they can of cour.'e effect nothing either as burnishers or excavators." But there is another agent of erosion which is only called into play under the peculiar circumstances afforded by glaciers, and one which, I venture to think, is suffi- cient to account for the formation of these hollows. This is, briefly, the action of the water, derived from the melting of the surface of the glacier. It is now some five years since 1 had the good fortune to be able to explore some of the large glaciers in the higher regions of the Himal.iyas, and formed the conclu- sions which I am now about to put forward ; but it seemed to me so likely that they had occurred to others, and probably been dismissed .as unsatisfactorj- — though of this I could not assure myself, as it is long since I have had access to any library in which pipers relating to such questions might be found— that I hesitated to publish them. It seems, however, from the remark in Sir II. Iloworth's letter, quoted above, that no weight has hitherto been attached to this cause oferosion, how- ever slight it may be, and therefore my observations inay pos- sibly be of some value. Before going into details, I wish to draw attention to one or two facts which have been overlooked by Sir H. Howorth, and which have an important bearing on the discussion. In the first place, whatever be the cause of motion, it is an undoubted 40 A^A TURE [November 9, 189; f ict that the lower portions of large glaciers do move over level or nearly level ground, and that for considerable distances. Whether the bottom layers of the glacier move at all under such circumstances does not matter much, but that the surface layers move is proved by the manner in which stones are carried down nnd deposited in a moraine often several miles distant from the foot of the steep slopes at the head of the valley. I am inclined to think that the amount of plasticity attributed to ice, founded on laboratory experiments, has been considerably underrated, and that under the conditions in which it exists in a large glaci'^r it does actually flow, though very slowly, like a viscous boiy. Why gravity shAuld cease to do any work on the ice. when it rests on a level surface, as Sir H. Ho worth states, I cannot see, and when we consider the enormous thickness and weight of ics in a large glacier, there seems nothing strange in its spreading out or flowing In the only direction in which motion posits, the stream which rushes out from beneath the glacier is unable to cut down into the solid rock. Therefore, supposing the erd of the glacier to remain at or about the same position for a long period, and allowing for a moment that there is any erosion whatever going on beneath the glacier higher up, there is undoubtedly a tendency towards the formation of a hollow, closed at its lower end by a rock barrier. Having clambered over the masses of moraine matter which conceal the lower end of the glacier, we enter upon a broad expanse of ice comparatively free from boulders. Here the surface of the ice usually lies at a very gentle inclination, and may continue in this manner for several miles, until the foot of the steep snow-covered slopes, riddled with crevasses, forming the third stage alluded to above, is reached. It is to this middle, gently sloping portion of the glacier that I wish especially to draw attention, as it is here that the agent of Glacier at head of Bhutra Va'.ley Zanskar Rang , Kashmir, a Old INIora'ne ; /■, present termination cf glacier. is possible, if we allow any degree of plasticity whatever. In the second place, that erosion of some kind, and that to a large amount, does go on beneath a glacier is proved by the turbid state of the water which issues from the end of it, and it must be remembered that this turbidity of the water is not occasional like that of a river \\\ flood, but is continuous, or at least is re- current every twenty-four hours, throughout a great portion of the year. In ascending one of the larger Himalayan glaciers we notice at least three well-defined stages. First, at the foot of the glacier, and for a considerable distance up, perhaps a mile or more, the ice is almost completely concealed by the burden of moraine stuff brought down from above, which, as the ice melts away, is continually being deposited on the floor of the valley. As a result of the continued renewal of these loose de- NO. 1254, VOL. 49] erosion, to which I refer the digging out of the hollows, is alone efl'ective. And it is in such positions — that is, imme- diately below a point where the inclination of the valley de- creases more or less abruptly — that in a formerly glaciated region rock-basins are most commonly found. The ice in this portion of the glacier is traversed by occa- sional narrow crevasses, into which the streams, often of con- siderable size, arising from the melting of the surface ice under a hot Indian sun, plunge sooner or later, carrying down numerous pieces of rock with them. Even if the crevasse does not originally extend to the bottom of the glacier, a shaft must quickly be worn out, so that the falling water is enabled to exert the whole of its force directly on the solid floor of rock. These waterfalls are, of course, well known under the name of " moulin," but I do not think that sufficient weight has been November 9, 1893] NA TURE 41 attached to them as an agent of erosion. They must act like so many gigantic drills upon the rock surface, and dig out hollows similar to those found at the foot of an ordinary water- fall. It may be objected that, when the glacier has retreated, we ought to find, instead of one large hollow, a series of pits corresponding to the position of each moulin ; but here the peculiar conditions afforded by the presence of the ice come into play. Any particular moulin never keeps the same posi- tion for any length of time, not only because a new crevasse may open at any point in the course of the stream, but also because the water is continually cutting back the edge of the fall, as in an ordinary waterfall, but much more quickly. Thus the drills, in course of time, work backwards and forwards over the whole of the area occupied by this portion of the glacier. Indeed, their action may be compared to that of a rapidly revolving drill moved slowly over the surface of a piece of wood, which would ultimately be cut out to any desired depth, •or to the action of a sand-blast directed on a piece of plate-glass. It may be noted that none of the streams find their way dov/n the glacier as far as the mass of moraine matter near its lower end, so that they can have no effect on the rock barrier, which, as I have pointed out, has a tendency to form beneath that por- tion of the glacier. Moreover, the majority are swallowed up before they reach the lower third or so of this middle portion ■of the glacier, and thus the well-known section of the bed of those rock basins which have been attributed to glacial action, •deepest near their upper ends, and gradually shallowing lower down, is simply and easily accounted for. It is a curious fact that, in the Himalayas, true rock basins are of very rare occurrence, although the conditions for their for- mation on the above hypothesis are conspicuously present. It is not, however, difficult to account for their absence if we con- sider the enormous amount of debris carried down by the Hima- layan glaciers as compared with that borne by most European glaciers, to judge from pictures and photographs of the latter, it is only the lower portion of the Himalayan glaciers that is so entirely covered by debris, and the difference may be partly due to the fact that the hill-sides above this portion of the glacier are much less protected by ice and snow than in the case of the northern glaciers. On the retreat of the glacier this burden of moraine stuff would be quite sufficient to fill up any hollow ■that may have been formed beneath it. This is well shown in the accompanying illustration, where there is a well-defined old moraine at a, the present termination of the glacier being at b. Between these two points stretches an almost level plain, some four or five miles long, in which we should have expected to find a lake, supposing a hollow had been worked out beneath the glacier ; but in place of it we find this broad stony plain -covered with debris, evidently derived from the main glacier and from the side valleys. But suppose the glacier were to advance again, all this loose material would in course of time become frozen into the bottom of it, and carried out. Then if a rapid retreat of the glacier were to occur, leaving no time for the hollow — if any exists — to be filled up again, we might have a lake where the plain now is. Or, the contrast may perhaps be accounted for by a difference in the rate of change of climate since the glacial period, which may have been more slow in these southern latitudes than further north, so that the northern glaciers had not sufficient time during their retreat to fill up the hollows formed beneath them. If, as has been supposed, the extension of the European glaciers was partly due to a diversion of the Gulf Stream, might not the rapid breaking down of the barrier which caused that diversion have given rise to the rapid amelioration of climate required? It would not, I think, be difficult to carry out a few measure- ments of the erosion that goes on beneath a glacier, which might throw much light on the question. If one visits the mouth of one of these glaciers early in the morning, the stream which issues from it is seen to be nearly, but never quite, free from sediment. This amount of sediment might, I think, be taken as that due to the rasping action of the ice itself, aided by the rocks frozen into its under surface. As the day proceeds, and the surface of the glacier begins to melt, the volume of water issuing at its foot quickly increases, and at the same time it becomes thick with mud. It would be easy to measure the velocity of the stream, and the amount of sediment at intervals during the day, and from this, knowing the area of the glacier, we could estimate the erosion due respectively to the rasping action of the ice and to the drilling action of the moulins. That the latter would be enormously in excess of the former I have NO. 1254, VOL. 49] no doubt whatever, and I think that it is worth considering whether this may not be an adequate cause of those hollows which do undoubtedly occur in positions that seem to connect them with a former extension of glaciers. T. D. LaTouche, CHRONO-PHO TOGRAPHIC S TUB V OF THE LOCOMOTION OF ANIMALS} 'X'HE chief interest in the study of organised beings is to look ■*■ for the similarity which exists between the special con- formation of each species, and the particular characters of the functions in this species. The union of comparative anatomy and physiology is becom- ing more and more close, and will, without doubt, lead to the discovery of the fundamental laws of morphology — laws by means of which the inspection of an organ will permit us to foresee the particularity of its function. These relations begin to be comprehensible in the case of the organs of locomotion of vertebrates. The size and length of the muscles, the relative dimensions and forai of the bony supports of the members, the extent and the form of the articulating sur- faces enable us to infer the character of the movements of mam- mals ; and, on the other hand, the accuracy of these deductions can be proved by controlling them by chrono-photography, which gives the geometrical character of these movements. Attempts have been made to extend this method of analysing the moveoients of a number of difi'erent animal species by chrono-photography, and they have been successful not only with mammals, but also with birds, . reptiles, fishes, molluscs, and arthropods. It will no doubt be a lengthy enterprise to collect the numerous series of pictures necessary for this comparison, but we have been able to assure ourselves that it is nearly always possible to obtain such pictures by varying the conditions according to the kind of animal studied. Reptiles, for example, must be put in a kind of circular canal, where they can run at their ease ; the chrono-photo- graphic apparatus is placed above the path in which the animal runs, and thus photographs the successive attitudes during the course. The fish swim in similar troughs filled with clear water, and illuminated underneath, in order that their silhouettes should appear on a clear background. At other times the animal is lighted from above, and thus appears light on a dark back- ground. Similar arrangements are employed for insects. _ It is not necessary to have here the dark background which served for the study of mammals and birds. The principal difficulty is to ascertain whether the animal under experiment is moving in its normal fashion. Wilh the domestic and tame kinds this is not considerable, but with wild species it requires much patience and many attempts to secure the natural movement. On comparing some of the types of which chrono-photo- graphic images have been obtained, very interesting analogies are found. Thus, for locomotion on land, as well as in water, it is possible to follow the gradual transitions between simple reptation and the more complicated kinds of locomotion. An eel and an adder put in water, progress in the same way ; a wave of lateral inflexion runs continually from the head to the tail of the animal, and the velocity of the retrograde progression of this wave is slightly greater than the rate of movement of the animal itself If an eel and an adder are placed on the ground, the manner of reptation is modified in the same way with both species. The undulatory movement has here and there a greater ampli- tude, and this amplitude increases with the smoothness of the surface on which the animal moves. With fish, provided they have fins, and with reptiles which have feet, there remains, in general, a more or less pronounced indication of the undulating movements of reptation. With the dog-fish, for instance, the retrograde wave which goes the length of the body is very pronounced ; it is much less with salmon, and exists hardly at all, except at the end of the tail, with fish with thicker bodies. The retrograde wave during the terrestrial movements of the Gecko is plainly visible, but is less pronounced with the grey lizard and green lizard. The batrachians present, during the successive phases of 1 Translation of a communic.-ition oy M. Marey to tlie Paris Academy of Sciences. 42 jVA TURE [November 9, 189^ \ their evolution, varied types of locomotion, familiar to every one, of which the chrono-photographic analysis is very in- teresting. The tadpole of the toad, for example, exhibits progression in the first stage by the undulation of the fin, when the feet appear there is a mixed type of locomotion ; the tail undulates, and on both sides the posterior members execute the movements of swimming which is usual to them. 'Ihese movements of the posterior limbs alone remain some time after the tail has disappeared. Of these movements, which resemble so niuch those of human swimi-ing, one is especially notice- Did they belong to the same age as those of the Reindeer Period of the Dordogne ? Or should-they, on the other hand, be referred to some still living race of men already settled on that Ligurian coast in the "Polished Stone Period"? Other in- quirers, again, have sought a third alternative, and referred them to an intermediate period, to which the name " Miolithic," or,, better, " Mesolithic," has been speculatively given. In view of these differences of opinion, the discovery in Feb- ruary of last year of fresh human remains in one of these grottoes associated with relics that throw a clearer light on the Fig. I. — Movements of the Scorpion. able ; in this the anterior limbs do not take any part, and the posterior, after having formed a right angle with the axis of the body, approach each other till they become parallel, then bend and stretch themselves again to begin anew. The movements of the lizard's limbs escape direct observation on account of their rapidity, but on the chrono-photographic images, taken at ihe rate of forty to fifty a second, one can easily follow the suc- cessive movements of the limbs in front and behind. With the ^rey lizard, as well as the Gecko, the normal pace is that of a trot, that is to say, the limbs move diagonally. The great Fig. 2. — Movements of the Gecko. amplitude of the movements of the limbs, combined with the undulation of the axis of the body, causes the limbs to approach one another very much on one side, and the next instant to separate. The Gecko carries its hind foot nearly under the arm- pit on the side where the body becomes concave ; the instant afterwards, this side becomes convex, the anterior limb advances very much, and the two limbs (the body presenting on this :-idea convex arc) will be wide apart. \ Many other very interesting observations can be made relating to the movements of insects and arachnids. THE MAN OF MEN TONE} 17 EW groups of prehistoric finds have provoked a more per- sistent controversy as to their date and character than those of the Mentone Caves. Were they Palceolithic or Neolithic? ' " On the Prehistoric Interments of the Balzi Rossi Caves near Mentone, .ind their Relation to the Neolithic Cave-Burials of the Finalese." Liy Arthur J. Evans. A rcsimu' of a paper communicated to the Anthropo- logical Institute. (The cuts are kindly lent by the Institute.) culture and surroundings of those deposited with them than any hitherto discovered there, has naturally created considerable interest. Thecavesin which thesediscoverieshave been made are formetf in the sea-face of the promontory of lower cretaceous limestone that rises just across the Italian frontier on the Ventimiglia side of Mentone, and which, from its red bastions, is locally known as Baousse Rousje, or, in its Tuscan shape, Balzi Rossi. As- early as 1S58 the Swiss geologist, M. Forel, had obtained from a superficial layer of one of these caves various animal bones- associated with implements. Subsequently Mr. ]\Ioggridgedug a section in the grotto known as the Barma dou Cavillou, re- vealing five floors "formed in the eartli by long-continued trampling," with traces of a hearth in the centre of each, andi around flmt flakes, axes, hammer-stones, and bones of animals. The animal bones were, however, of existing species, and this- evidence clearly pointed to Neolithic habitation. But later, M. Riviere, whose patient exploration of these caverns deserves our warm recognition, whatever may be thought of the conclusions- drawn by him, unearthed in the same cave, only a foot or two- from the point where Mr. Moggridge's excavations had ceased, the perfect skeleton of a man. The skeleton lay on its left side in the attitude of sleep. A stone lay beneath its head and another behind the loins. An ornament composed of bored shells — which may recall the trochus-studded nets still worn by \'enetiaii peasants — was found adhering to the skull, their adherence being due to a ferruginous substance, fragments of which lay near, and which gave a ruddy colour to the whole. Evidently this ochreous substance had been used by the departed in his- life-time to paint his face and body, and the whole character of' the deposit clearly points to careful interment. From the dis- covery of bones of extinct animals mixed with the ashes in the overlying stratum, M. Riviere concluded nevertheless that the skeleton was palaeolithic. The fact that the skeleton of the Barma dou Cavillou was- undoubtedly embedded amongst Quaternary remains lent some weight to M. Riviere's opinion, and his view of the matter found' acceptance from such competent judges as Mr. Pengelly and others. But the presence of the Neolithic hearths, noted by Mr. Moggridge, in an adjacent part of the cave, combined with other circumstances, led M. De Moitillet and Prof. Boyd Dawkins from the first to take a different view. They saw only the evidence of a Neolithic interment in a Palaeolithic stratum. The annexed diagram (Fig. i) will give an idea of the general conformation of the cave or cleft known as the Barma Grande, NO. 1254, VOL. 49] November 9, 1893] NA TURE in which the most recent discoveries have been made. From the dat?. that I was able to gather on the spot from quarrymen who at one time or another had taken part in its excavation, the original floor of the cave, at its mouth, over the spot— that is where the skeletons were found— was 7-50 metres above the stratum in which they lie. But this depth only includes what has been artificially removed from the cave. There are reasons for believing that the deposit had originally been somewhat higher, but that the original level of the floor had been previously lowered by natural agencies. In 1884 a discovery of a human skeleton had already been made in this cave by Louis Julien, the foreman of the men ern- ^)loyed in quarrying the cliff ; and so far as the details of this Fig. I. ■find have been preserved, they answer very closely to that of the Barma dou Cavillou. The discovery of 1892 was made •close to the spot where the skeleton ol 1884 had been un- earthed. Unfortunately, as in the former case, it was not made by a ■scientific excavator, but by men engaged in quarrying the lime- stone cliff. I visited the spot shortly afterwards on more than •one occasion, but the ornaments and implements had been re- moved by the owner of the quarry to his house, and there was ■some difficulty in ascertaining the exact position in which the ■Several relics were discovered. The subjoined sketch (Fig. 2) will give a fair notion of the position in which the bodies were found. They lay across the present mouth of the cave, with their heads to the east. The many nassa ncritea, and''on the legs a little below the top of the tibias were two Cyprccas. Immediately behind this lay a skeleton, recognised by Dr. Verneau as that of a woman. It rested on the left side with the knees slightly drawn up, and its right hand almost resting (^:0 & e^ni on the giant's shoulder. It is said to have held another flint knife. This female skeleton was not so richly decked with ornaments as the other two, the bone and tooth pendants being absent in this case. The third skeleton, of a youth, lay in much i£ection at A. A. F:g. 3 — Flint knife found with first skeleton, i linear (23 :■: s cm.). ■outermost skeleton was that of a man apparently well on in life. Unfortunately the skull was broken with a blow of a pick at the moment of discovery, and the length of the skeleton can therefore be only approximately given. From his heel to his ■shoulder he measured i "85 metres, so that he was probably at least as tall as the taller of the three adult "-keletons found in '1872-1873, which reached the length, according to M. Riviere, of 2 metres. This gigantic frame was somewhat turned to the •left, but it lay more on its back than the other two. By his left hand, laid close to his femur, lay a long flint knife (Fig. 3). About the neck and on the skull were remains of ornaments of teeth and bone, fish vertebrae and pierced shells, among them NO. 1254, VOL. 49] the same attitude as the second, with its right hand raised asif to be laid on the shoulder of the individual in front of it. Under or near its head a third flint knife was discovered. Both the two inner skeletons, though of tall stature, were distinctly smaller than the first discovered. From the position in which the bodies lay it seems natural to conclude that the two smaller individuals here interred were in a position of dependence on the old giant. Amongst the ob- jects found, chiefly, as far as I could gather, about the heads and necks of the skeletons, were remains of necklaces or head ornaments of shell and bone, amongst which may be mentioned bored shells, fish vertebrae, and teeth— apparently canines of 44 NATURE [November 9, 1893 deer — which had been much rubbed down and in some cases adorned with incised lines and nicks (Fig. 4). Of the bone ornaments discovered, the most remarkable were some curious objects like double eggs or acorns connected by a common stem (Fig. 6). These, too, were incised in a similar manner. Amongst the bored shells found I was shown specimens of small Cyprasa (millepunctata), Cerithium, and a kind of Trochus, and a quantity of Nassa neritea — the same shell that formed the head ornament of the skeleton excavated by ivi. Riviere in the Barma dou Cavillou. Another interesting correspondence between the present dis- covery and that of the Barma dou Cavillou was the presence, in the earth about the skeletons, of lumps of a ferruginous sub- stance, which in this, as in the other cave, had partly stained the bones. There can be no doubt that this had been placed with tht departed that he might have the wherewithal to paint his face and body for entry into the Spirit World. On the osteological characteristics of the skeletons I cannot speak as an expert. They have, however, been examined by competent authorities, whose accounts in the main agree. The skulls were decidedly dolichocephalic. The large skull has prominent supra-orbital ridges, the smaller skull has these pro- minences less marked and is narrower across the frontal bones, but, still, stronger, thicker, and more definitely ridged than the Neolithic skulls of the Fiiialese. Professor Issel, M. Riviere, Mr. A. V. Jennings, and more recently Dr. Verneau have been independently led to compare the Cro-Magnoa skulls— M. Riviere especially laying stress on the curious rectangular orbits. Prof. Issel, in a communication read before the Natural History of Genoa, although himself in favour of the Palao- lithic date of the interments, was yet led to the conclusion that the crania and skeletons presented on the whole the same racial Laugerie Haute and Basse, but there were included quartzite and other forms peculiar to the still earlier art of Le Moustier. In the same way the bones of extinct animals found lead us on this- showing to the conclusion that the " Man of Mentone " dated back to the days of the earliest group of Pleistocene mammals. But as a matter of fact among several cases of bones of animals found in the immediate neighbourhood of the skeletons that have been recently examined all are of recent species, and not a single characteristic Quaternary form occurred. It is to be observed, moreover, that the mere fact that these were inter- ments, implying as it does previous excavation, makes the appearance of Pleistocene remains, and even Paloeolithic imple- ments at higher levels in the cave-earth, of no value for determining the age of the skeletons. The careful laying out of the dead in the attitude of sleep with his flint knife in his hand, his necklace and head ornaments, and the ochre beside him wherewith to paint his face and body in the other world — all this shows a development in religious custom which has hitherto in no single well-authenticated in- stance been carried back to Palaeolithic times. It is character- istically "Neolithic." We may go further and say that the special forms of sepulture discovered here fit on in a suggestive way to the burial rites still practised at a later date on this same coast by the Neolithic people of the Finalese. There too we find the body laid out in the same attitude of sleep, with the legs partially drawn up, an attitude which, as distinguished from the still more contracted posture of the Northern races in. primaeval times, we may perhaps venture to regard as character- istic of a less severe climate, and the less habitual necessity for drawing up the legs under the shelter of whatever served them, as a mantle. There too we find the same bored shells and teeth hung round the neck, and the same ferruginous substance laid Fig. 4. — Deer'i-:oo:h psndants. .haracteristics as the undoubtedly Neolithic skeletons of the caves of the Finalese further along the same Ligurian coast. The great depth at which these skeletons occurred, and the absence, in this whole group of finds, of pottery, polished stone implements, and the bones of domestic animals, must be cer- tainly taken to show that they date from a considerably earlier period than the Neolithic interments of the Finalese caves — in which all these elements of more developed culture are abundantly represented. But are we therefore to conclude that the Balzi Rossi remains are of Paleolithic date? It seems to me that there are other circumstances to be con- sidered in connection with these latter finds, which do not admit of such a conclusion — unless, indeed, the word " Palseo- lithic " is to be given a sense different from its usual accepta- tion. When we come to examine the views as to the extreme antiquity of the instruments, such as M. Riviere has not hesi- tated to put forward in the most unqualified manner, we find, in fact, a curious illustration of the danger of proving too much. The skeletons lie in all cases beneath a vast mass of cave-earth in which the remains of extinct animals are undoubtedly associated with implements of flint and bone that may justly be regarded as the work of Palceolithic man. Therefore we are told the interments themselves must belong to the same age. Long flint knives such as those discovered, may, it is true, find parallels in some of the later Palseolithic caves such as that of La Madeleine, though like implements were also in common use in Neolithic times. But the argument invoked by M. Riviere leads us to consequences far beyond this. In the cave- earth of the overlying stratum implements occurred not only of types characteristic of the Magdalenian group, of .Solutre, and of NO. 1254, VOL. 49] Fig. 5 — Bone arrow-head. beside the departed to deck his person in the Spirit World ; there too flint and bone objects (some of these latter of very similar forms) were placed ready to his hand. In the caves of Balzi Rossi, however, the skeletons were at most propped up oj pillowed by large stones : in the Finale interments, such as those of the grotto of the Arene Candide, we find, in the case of the adults, stones placed round and over the skeletons so as to form a rude cist, though the children were still simply buried in the cave-earth. In these later interments, moreover, the polished axes and pottery placed beside the dead as well as the remains of domesticated animals attest the higher stage of culture amidst which they had lived. Still the points of similarity in the sepul- chral rites practised in both groups are unmistakable. And in view of these points of resemblance the conclusion arrived at by Prof. Issel, that the Balzi Rossi skeletons, in spite of some more primitive characteristics, belong essentially to the same race as the skeletons of Finalmarina, gains additional force. The bone implements supply us with some fresh points of relationship. The bored pendants, formed of canines of deer much worn down, found with the skeletons both in the Barma Grande and the Barma dou Cavillou are identical even to their notched decorations with ornaments of the same kind found by Prof. Issel in the Caverna delle Arene Candide near Final- marina associated with undoubtedly Neolithic remains. Iden- tical pendants have also been found in the Neolithic deposit of the Grotta di Sant' Elia in Sardinia. It is to be observed that very similar deer's tooth ornaments, though without the notches, were found in the caves of La Madeleine, Laugerie Basse and Les Eyzies, where they are ascribed to the Reindeer Period. A stumpy bone punch also found near the Barma Grande skeletons, in the possession of Mr. A. V. Jennings, is of the same type as a bone implement from the excavations ofc he Neolithic deposit November 9, 1893] NATURE in the grotto of the Arena CandLde. Another very close parallel is afforded by the cusped bone instrument represented (Fig. 5), which the Rev. J. E. Somerville, of Mentone, obtained from the neighbourhood of one of the last discovered skeletons of the Barma Grande. Though blunter and thicker, it greatly resembles some of the bone arrow-heads from the Neolithic burial-place in the Arene Candide cave. Of all the bone objects, however, discovered with the present interments the most interesting are those already referred to as Fig. 6. — Bone ornaments, {a) with fish-vertebrae adhering. resembling two small eggs, or acorns, with their big ends united with a connecting stem. The bossy part of these ornaments was decorated with rows of parallel lines running up the sides like the rungs of so many ladders. Seven or eight of these are said to have occurred in all, but, like other relics found, most of them have since disappeared. The shape of different specimens varied slightly, some being more elongated than others. Fig. 7. — Scandinavian amber beads. But what at once struck me on seeing these objects was the great resemblance they presented to certain amber ornaments discovered with early Neolithic skeletons in the galleried tombs of Scandinavia and North Germany. The objects in question are certain double-bossed ornaments of amber, in Scandinavia generally known as "hammer-shaped" beads, and which, from their supposed resemblance to the stone-hammers of the same period, have been by many supposed to have been worn as amulets. (Fig. 7.) NO. 1254, VOL. 49] The geometrical system of ornamentation/ ments from the Mentone Cave seems to be f/ on bone and horn relics of the " Reindee other hand, like the bone ornaments thems occurs, it presents the closest analogy to a style or >w very characteristic of the Later Stone Age in Northern Eufoj.^ The conclusion, then, to which we are led by these converg^~~ ing lines of evidence is that the interments of the Barma Grande and the other caves of the Balzi Rossi cliffs, though embedded in a Palaeolithic stratum, are themselves of Neolithic date. On the other hand, however, the entire absence of pottery, of polished implements, of remains of domestic animals, as compared with the abundance of all these features in the Neolithic interments of the Finale Caves further up the same Ligurian coast, is on any showing a most remarkable phenomenon. A greater degree of petrification is also ob- servable in the bone and other objects discovered. In allproba- bility, therefore, tve Jiave here to deal with an earlier Neolithic stratum than any of which we have hitherto possessed authentic records. If the evidence of these Balzi Rossi interments is to count for anything, it must henceforth be recognised that a race representing the essential features of the later population of the polished Stone Age was already settled on the Ligurian shores of the Mediterranean at a time when many of the civilised arts, which have hitherto been considered as the original possession of Neolithic Man on his first appearance in Europe, were un- known. It will no longer be allowable to say that these sup- posed immigrants from Asia brought with them at their first coming certain domestic animals, and had already attained a knowledge of the potter's art, and of the polishing of stone weapons. And, if this is the case, something at least will have been done towards bridging the gap between the earlier and later Stone Age in Europe. Till such time, however, as remains of extinct animals are found in such association with human in- terments as to prove their contemporaneity we must still allow for a vast interval of years between the latest remains of the " Reindeer Period " and interinents, such as those of the Men- tone Caves. The racial characteristics of the skeletons of the Balzi Rossi, while linking them at one end with the later Neolithic occu- pants of the Finalese, show that they had essentially the same physical type as the early skeletons found in Cro-Magnon Cave with very similar ornaments of bored shells and teeth. The same features occur again in the skeletons from the Neolithic grotto of the Homme Mort, in Lozere, and in some of the French dolmens, as that of Vignettes. The type recurs East of the Apennines and in Central Italy, Sicily, and Sardinia ; and the field of comparison extends to Southern Spain and the Canaries. The physical connection with the Dolmen people derives ad- ditional interest from the comparisons established between the bone ornaments found with the Barma Grande skeletons and the amber hammer-beads of the Scandinavian Gallery Graves, and the decorative system of the pottery found in the same. It looks as if in the polished Stone Age the Neolithic settlers in the North of Europe had transferred to the new materials, such as amber and earthenware, forms and ornamentation which had already been an ancient possession of a race settled on European soil in still more primitive times. Two shells found with the Balzi Rossi interments, Pecten maximus and Cypma viillepnnctata, seem to point to Atlantic connexions. In the later Neolithic interments of the Finalese, on the other hand, which may represent the same race in a more advanced stage of development, we see new influences coming in from a very different direction. Some of the shells found with these seem to have been derived from the Southern Mediterranean, and one, the Mitra oleacea, found by Prof. Issel in Caverna della Arene Candide, must have made its way by some primitive line of intertribal barter from the Indian Ocean. UNIVERSITY AND EDUCATIONAL INTELLIGENCE. Oxford.— Mr. Theodore J Pocock, of Corpus Christi College, has been elected to the Burdett-Coutts Scholarship in Geology. For the Merton Biological Fellowship a strong list of candidates is reported, including among others Messrs. F. E. Beddard, M. S. Pembrey, E. A. Minchin, P. C. Mitchell, and R. T. Gunther. 45 jVA TURE [November 9, 1893 As the result of a memorial addressed to them by the demonstrators in the various departments of Natural Science, the Hebdomedal Council have appointed a committee, consisting of Mr. T. Raleigh, of All Souls, and Mr, T. H. Grose, of Queen's College, to inquire into the position and status of the demon- strators at the museum. Cambridge, — Dr. Forsyth has been appointed chairman of the Examiners for the Mathematical Tripos, Part II., and Mr. Welsh, of Jesus College, for Part I. Pro.f. Ramsay, of University College, London, has been elected Examiner in Chemistry for the Natural Sciences Tripos. At St. John's College, Mr. E. W. Macbride, Hutchinson Research Student, and University Demonstrator in Animal Morphology, has been elected to a Fellowship. Mr. MacBride took a Mi:.t class in both parts of the Natural Sciences Tripos (zoology and botany) in 1890-91, and is the author of various morphological papers based on researches conducted in Cam- bridge and at the Zoological Station at Naples. He has been President of the Union Society, and is well known as a vigorous debater. At the competition for Fellowships on this occasion there were no less than seven candidates in Natural Science, v^ho had all taken first class honours in the Tripos as students of St. John's. SCIENTIFIC SERIALS. Wiedemann's Annalen dcr Fhysik'icnd Chemie, No. 10. — On air vibrations, by A. Raps. The changes of density at the nodes of open and closed organ pipes were recorded by allowing a beam of strong white light to fall upon the mirror of a Jamin interference refractor. One of the reflected beams was sent through a pipe at the node, the other through a box containing undisturbed air. After reunion by the second mirror, these two beams gave rise to interference fringes, which were displaced during the changes of density accompanying the sound of the pipe. A section across these fringes, consisting of bright and dark points, was received upon a revolving drum carrying sensi- tive paper, and the oscillation of the points gave rise to a series of curves representing the sound vibrations with very fair accu- racy. A series of eighty-eight photographs are reproduced, which give valuable hints concerning the structure of the various notes, and also some vowels and consonants produced in the open air.— Luminous phenomena in electrode-less vacuum tubes under the influence of rapidly alternating electric fields, by H. Ebert and E. Wiedemann. This paper, a sequel to the general investigation published in No, 9, deals with the details of the phenomena observed between the condenser plates of a Lecher wire system in the case of spheres, cylinders of various lengths, conaxial double cylinders, and glass parallelepipeds with plane ends. — Heat of dissociation in electro-chemical theory, by H. Ebert. Calculations based upon heat of dissociation and electro- lytic work show that the forces of chemical affinity are chiefly of an electric nature, that the forces due to "valency- charges" are the most powerful of any atomic forces, and that any additional chemical forces are, in comparison, infinitesimal. — Equipotential lines and magnetic lines of force, by E. von Lommel. Some further photographic tracings of these lines are given, and their bearing upon the Hall effect is discussed. — Objective representa- tion of interference phenomena in spectrum colours, by the same author. Simple arrangements are described for exhibiting Newton's rings, gypsum fringes, convergent polarised light phenomena, and fringes produced by the rotation of the plane of polarisation in quartz prisms, upon a screen. For Newton's rings the light from the heliostat is reflected by a colour plate, and falls upon a lens which produces an image of the sun at its focus. By placing a slit at this focus and a prism between slit and lens, the rings in all the spectrum colours may be thrown upon the screen by shifting the slit. — Papers by Kayser and Runge, P, Czermak, and R. J. Holland have already been mentioned. The pages of the Botanical Gazette for September contain but little except reports of the proceedings of the Botanical Section of the Madison meeting of the American Association for the Advancement of Science, of the Madison meeting of the Botanical Club, and of the Madison Botanical Congress, That for October contains several important papers : — On the fructi- fication of Junipcnts, by Mr. J. C. Jack, who states that in America the fruit of the English species of juniper does not NO. 1254, VOL. 49] mature until the autumn of the third year after blossoming p on the development of the embryo-sac of Acer 7-ndnitn, by Mr, D, E, Mottier ; on the achenial hairs of Composilce, by Miss 1 M. A, Nichols ; and on the bacterial flora of the Atlantic Ocean in the vicinity of Woods Holl, Mass., by Mr. H. L. Russell. The results obtained by the author accord in a general way with those previously made in the Mediterranean. While the water and underlying sea-flow are filled with bacterial life, they are by no means in an entirely quiescent condition. Both water and mud are peopled with micro-organisms which are undergoing their cycle of development here as elsewhere. The Nos. of \heJoiirnalo/ Botany for October and November are almost entirely occupied by papers on local and descriptive botany, including the completion of Mr. E. G. Baker's synopsis of Geneva and species of Malvece, and a sketch of the botany of Ireland, by Mr. A. G, More. The summer number of the yaJu-biich (Austrian Geological Survey) contains contributions by Drs. Emil Tietze, von Wohr- mann, Bittner, Skuphos, and others. Dr. Emil Tietze writes on the " Geology of the Ostrau District." Great hopes were raised in this neighbourhood by the discovery of coal near Wagstadt, in the Upper Oder valley, but Dr. Tietze informs us that the coal occurs only locally and in mere fragments. With regard to the age of the Ostrau beds, he argues that they should be grouped with the upper and not with the loiver carboniferous series. They rest unconformably on the Culm grits and shales and are conformably succeeded by the Schatzlar beds, a deposit closely resembling the Ostrau beds in general character. Another paper by Dr. Tietze aiscusses the prospects of the salt 1 industry in East Galicia. — Baron v. Wohrmann contributes an article on the " Systematic Position of the Trigonida; and the Descent of the Nayadidre." He shows that both the Trigonidje and the Nayadidae have true heterodont hinges, and that there- fore the classification into schizodont and heterodont bivalves suggested by Neumayr cannot be carried out. Taking the fresh-water bivalve Unio as type-form of the Nayadidse, v. Wohrmann traces the phylogenetic relationship of this family with the genus Trigonodus (Up. Triassic shore deposits), and through Trigonodus with the ancient ancestral type, Myophoria> (Devonian to Rha;tic). — Dr. Theodor Skuphos completes his survey of the Partnach beds in the Northern x\lps. He found in the Vorarlberg deposits of this age a new fossil Saurian, which he names Partanosattrus Zitteli. Dr. Skuphos thinks it probable that this Saurian is identical with certain remains found in extra-alpine deposits of Upper Muschelkalk age in Wiirtemberg. SOCIETIES AND ACADEMIES. London. Physical Society, October 27. — Prof, J. Perry, F.R.S., vice-president, in the chair. — Mr. E. C. Rimmgton read a paper " On the Behaviour of an Air-Core Transformer when the Frequency is Below a certain Critical Value." Taking the ordi - nary differential equations for two circuits having self and mutual induction, and assuming sinusoidal E.M.F.'s and con- stant coefficients, the author shows that although the difference of phase between the primary P.D. and primary current is- always diminished on closing the secondary circuit, yet under certain circumstances this closing increases the impedance of the primary. With constant P.D. this means that closing the secondary decreases the primary current, a phenomenon not usually observed. The critical conditions necessary for in- creased impedance are fully worked out in the paper, as well as those under which this increase becomes a maximum. In the case of two identical coils with no magnetic leakage, the critical value of o (a =- where/ — 2ir times the frequency, L the inductance of the primary, and r^ its resistance) is ^/2, whilst that to give maximum impedance is . The maximum in- crease possible is 15^ per cent. The corresponding values are given for various amounts of magnetic leakage in tabular form, and curves were exhibited at the meeting showing how the im- pedance, current, power, and magnetising effect vary for different values of a. To test his conclusions the author made experi- ments on two coils close together, the observed increase in im- pedance amounting to 3 '2 per cent. In addition to the analytical November 9, 1893] jVA TURE 47 investigation, the subject is treated geometrically at considerable length. Prof. Minchin showed that the impedances might be represented by two hyperbolas, having /- as abcis^oe and the squares of (he impedances as ordinal^. These could be readily constructed from the data given. A line representing the primary inductance drawn on the same diagram intersects one hyperbola, showing that the impedance has always a maximum value. By a simple construction the phase angle between the I primary and secondary currents could be determined for any | given conditions. Dr. Sum[)ner observed that increased iai- ! pedance on closing the secondary necessarily meant a decrease | in the lag of the primary current behind the primary P.D. Mr. j Blakesley was pleased to see the geometrical method of such service, and thought it much simpler than the analytical one. The reason why increased impedance on closing the secondary of ordinary transformers had not been noticed was because their lag angles were very large. In a figure published some 3-ears ago to represent the actions of transformers, the angles he had chosen were such as would make the primary impedance increase on closing the secondary. Giving , an expression connecting the primary currents on open and closed secondary respectively, he now showed that to get increased impedance, the sum of the lag angles in primary and secondary must exceed 90°. To get large power in the secondary the primary lag should be nearly 90°, and the secondary about 45'. He also pointed out that some of the figures in thp paper might be simplified considerably. Prof. Perry said he had long had the impression that if a suffi- ciently small current were taken from the secondary, increased impedance would be observable in all cases, and he quoted some numbers he had given in the Phil. Mag. for 1891, show- ing a decided increase. Mr. Rimington, in reply, said he was not aware that the effect he had now brought forward had been observed previously. The result was completely worked out analytically before using geometrical methods. — Mr. \V. B. Croft showed "Two lecture-room experiments.' One, on " The Rings and Brushes in Crystals," was performed by very simple apparatus in two ways. In the first, a bundle of glass plates was used as a polariser, and a Nicol prism as analyser. When a Nicol could not be conveniently obtained, a glass plate •could be used as a reflecting analyser. For a convergent system two gla'ss card-counters were used, the crystal being placed be- tween them. Very good results were produced by this simple apparatus. In the second arrangement the crystal was placed on the eye-piece of a microscope 'whose objective was removed), and covered by a tourmaline. On reflecting light up the tube by means of a piece of glass held at the proper angle excellent results were obtained. Another experiment, on " Electric Radia- tion in Copper Filings," was similar to those described by Dr. Dawson Turner at the Edinburgh meeting of the British Asso- ciation. A battery, galvanometer, and glass tube containing copper filings were joined in series. Under ordinary circum- stances no current passed, but immediately an electric spark was produced by an electric machine many feet away, the galvano- meter was violently deflected, and remained so until the tube was tapped. On trying different materials, aluminium and copper seemed about equal, but iron not so good ; carbon allowed the current to pass always. Prof. Minchin said the phenomena were strikingly like those exhibited by his " impul- sion cells," for the moment a spark passed, even at a distance of 130 feet, they became sensitive to light. Very minute sparks were capable of producing the change, but by adding capacity to the sparking circuit the effect could be greatly modified. Replying to a question from Mr. Rimington, he said the change was due to electromagnetic vibrations, and not to light emitted by the sparks. jNIr. Blakesley inquired if lengthening the sparks produced greater effect on the copper filings. Mr. Lucas asked if the resistance of a tube ever became infinite again if left for a long time. In reply, Mr. Croft said the current sometimes passed before the spark actually occurred between the knobs. He had not left tubes for very long, and had not found the resistance reappear without tapping. Royal Microscopical Society, October iS. — A. D. Michael, President, in the chair. — Mr. J. G. Grenfell described some marine diatoms, recently found at Plymouth, belonging to the genera Mdonra and Surirella, which were of interest owing to the presence of pseudopodia. Mr. A. W. Bennett objected to the term pseudopodia being applied to these pro- cesses unless it could be shown that they were actual prolonga- tions of the internal protoplasm. Mr. T. Comber said that KO. 1254, VOL. 49] Prof. Grunow was of the opinion that the processes were spines. — Mr. E. M. Nelson exhibited and described a new model of a microscope by Messrs. Watson. — Mr. F, Chapman read Part V. of his paper "On the Foraminifera of the Gault of Folkestone.' — Prof. Bell gave a resume of a paper by Dr. R. L. Maddox, " On Progressive Phases of 3'//ri7/«;« tWw/awi." The author had traced the development of this organism, and had discovered some points which appeared to be entirely new in the history of bacteria. Paris. Academy of Sciences, October 30. — M. de Lacaze-Duthiers in the chair. — The grape vine harvest of 1893 ^""l ^^^ produce of the Camargue, by M. Chambrelent. In spite of the severe drought the vineyard-; of the Gironde have given the richest yield in the century. Tliis has been due to a unique combination of favourable circumstances during their development. The facility with which they withstood the drought may be attri- buted to the fact that vine-leaves have a peculiar power of absorb- ing dew, which has been very abundant. This year has also witnessed the earliest date of harvest known in the century. In 1822 it took place on August 31, whilst this year it was eight days earlier. The quality of the harvest, which improves with the quantity, may he expected to prove very good. — On the application of sound vibrations to the analysis of mixtures of two gases of different densities, by M. E. Hardy. The apparatus, called the formenephone, consists of two organ pipes, one of which is filled with pure air, the other contain- ing themixture of gases to be analysed. The pipes are of the same dimensions, and give the same note when blown under the same circumstances. If one of them is filled with air contain- ing I per cent, of formene, the unison is disturbed and one beat is heard every three seconds. With 2 per cent, there are three beats in two seconds, with 3 per cent, two beats per second, and so on. Similar results may be obtained with car- bonic acid as an impurity. The figures given apply to pipes sounding C4. For mixtures whose density closely approaches that of air Cg is more suitable. Each determination is finished in a few seconds. The apparatus is well suited to the determi- nation of the amount of fire-damp in mines. — Observations of Comet Brooks ( 1S93, Oct. 16) made at the Algiers Observatory by MM. Rambaud and Sy. — Observations of the sun made at the Lyon Observatory ^Brunner equatorial) during the first half of 1893, by M. T. Guiilaume. This is a summary of the obser- vations made of sunspots and faculi^, with particulars of their positions and areas. — On a new theorem of mechanic-, by M. N. Seiliger. — On carboxyl derivatives of dimethylaniline (dimethylamidobenzoic acid) by M. Charles Lautb. — On the baking temperature of bread, by M. Aime Girard. Numerous experiments have proved that 101° C. is the normal temperature in the interior of bread and biscuit during baking if the product is to be satisfactory. — Study of the reproduction of wasps, by M. Paul Marchal. Careful observations of the physiological function of the workers, miscalled neuters, of a common wasps' nest have proved parthenogenetric reproduction by the workers, withou: the cooperation of the males, and the exclusively male sex of the individuals thus produced. It appears that there is a division of labour between the queen, who produces mainly females and workers, and the workers themselves, which are only capable of producing males. — On the localisation of the active principles in Trotuohim, by M. Leon Guignard, In the Tropxolum family, all the organs enclose myrosine, localised in cells distinct from those which contain the glucoside, whicli it decomposes to produce the essence. The latter does not pre- exist in the tissues and cannot be formed without the interven- tion of the ferment. The family shows in this respect a complete analogy with the Crucifers and Capparideas. — On the existence of gismondine in the geodes of a basalt of the environs of Saint-Agreve (Ardeche), by M. Fer- dinand Gonnard. — Fractures of the coal measures of southern Chili, by M. A. E. Nogucs. In the lignite region extending from the' Bay of Talcahuano to Lebu, there is found a large fault running from east to west, which it is proposed to call the Lebu-fault. To the north of this fault the strata incline towards the west ; to the south, they incline towards the east. Between San Rosendo and Lebu may be traced a system of parallel north - to-soulh faults which have affected the older strata; a system o parallel east-to-west faults, which have dislocated the arenaceous lignite territory ; and a system of secondary faults, which have brought about changes of level in this same formation. — General 48 NA TURE [November 9, 1893 characters of the bogheads produced by Algae, by MM. C. E. Bertrand and B. Renault. A study of the boghead oi Autun, the kerosene shale of Australia, and the brown torbanite of Scotland show that these deposits are due to the thalli of a single species of alga, that of Autun containing Pila bibracteiisis, the kerosene shale Reinschia australis, and the Torbanite an- other Pila, Berlix. Meteorological Society, October lO. — Prof, von Bezold, President, in the chair. — Prof Hellmann spoke on the frequency of hal'j phenomena, after having first described their typical features and their causation by reflection and refraction from hexagonal ice-prisms. From observations at Upsala extending over seven years he had ascertained that the 22° halo is most frequently observed, then mock suns and moons, then the 46° halo, and least frequently the vertical pillars of light. On the whole the phenomena are five times more frequent in connection with the sun than with the moon. During the course of a year the phenomena follow a regular course ; solar-halos are at a maximum in May and a minimum in December, whereas lunar- halos are at a maximum in December and a minimum in May. If snow-crystals were equally plentiful in the air at all periods of the year, then solar-halos would be most frequently seen in June, at the time when the sun is above the horizon for the longest period on each day. But inasmuch as there are fewer snow-crystals in the air in the summer, the maximum is put back to May. The maximum for lunar-halos occurs when the nights are longest and there are most snow-crystals in the air. Statistics from the polar stations for 1882-83 show that only solar pheno- mena occur during the period of midnight sun, and only lunar phenomena during the polar night, their frequency being solely dependent on the occurrence of clouds. An account was given of a stroke of lightning in Heligoland which had smitten two persons near the railroad, killing one and stunning the other. Photographs were exhibited of the latter as showing the characteristic marks on the arm, chest, abdomen, and legs. After a member of the Society had suggested a new method of estimating clouds — which, however, requires further working out and testing — the President drew attention to wave-clouds as described by Von Helmholtz in his most recent theoretical work on the dynamics of the atmosphere. They occur when two layers of air travelling with diflTerent velocities pass one over the other, in which case waves are formed and clouds at the junction of the layers. These clouds are then drawn out into long strips, formerly called polar-bands. They occur not only in the layers of cirrus clouds, but also at lower levels. A wish was expressed that these clouds might be photographed. Physical Society, October 20. — Prof Knndt, President, in the chair. — Dr. Raps gave an account of his work on the photography of atrial vibrations. The method is based on the use of a Jamin's refractometer, which produces interference phenomena by means of reflection and refraction of a ray of light at the surfaces of two parallel glass plates. When the air between the two plates is transmitting waves of condensation and rarefaction, the interference bands are displaced, and if they fall on a slit behind which a sensitized paper is kept in motion on a drum, the waves of aerial vibration may be recorded. The experiments were first made on a closed organ-pipe, near whose upper end were two openings facing each other but closed with glass. Through these the two rays of light passed before they were made to interfere. When the pipe was gently blown, sine curves alone were'obtained, corresponding to the funda- mental note of the pipe. As the pressure was increased, the overtones became more and more prominent, until at last they alone determined the shape of the curve. Further experiments were made with closed reed pipes, after it had been ascertained that the tongue of the reed vibrates like a pendulum. The phenomena were the same as in the first case. Experiments with open pipes were found to be much more difficult, but even in this case good photographs of the vibrations were obtained. D.-. Raps had also been able, by the same method, to photograph the vibrations resulting from the singing of vowels, and to show that definite harmonic overtones are characteristic of each vowel. Similarly photographs had been taken of the vibrations due to a hunting-horn. Dr. Raps further exhibited an Ampere apparatus for lecture purposes, in which the current was supplied by means of metallic instead of mercury contacts. Physiological Society, October 27.— Prof, du Bois Reymond, President, in the chair. — Dr. Lewin gave an account NO. 1254, VOL. 49] of researches on the physiology of the ureter, carried out in con- junction with Dr. Goldschmidt. These had shown thati the entry of urine into the upper end of the ureter is due to pres- sure exerted by the kidneys that the peristaltic waves of con- traction of the ureter either pass right down to the bladder, or occasionally stop short in their course along the ureter ; that the point of entry of the ixreter into the bladder is possessed of a sphincter, but that notwithstanding this it is occasionally possible for fluid to be driven back out cf the bladder into the ureter. — Prof Senator spoke briefly about the experiments he made some seventeen years ago, on the results of varnishing the skin in men, defending their validity, and the conclusion that varnishing does not affect the health, against objections which had recently been brought forward. — Dr. Cohnstein described experiments on the influence of diff"usive processes on transu- dation. When salt solutions were allowed to flow under a- constant pressure through a ureter or jugular vein surrounded by fluid, it was found that the amount of salt passing through into the outer fluid increased with the pressure on the latter. Similarly a solution of egg-albumen diff"used more copiously into an external fluid than could be observed when it was forced by filtration into a space filled with air ; but the amount of albumen which passed through was independent of the external pressure. This diffusion must play a very important part in the transudation of fluid fro n the blood-vessels, and in the tissue- cells of the living organism, and may suffice to explain many as yet incomprehe nsible phenomena. CONTENTS. PAGE Dr. Werner von Siemens 25 Iron Ores, By Bennett H. Brough 27 Our Bookshelf:— Newhall : " The Shrubs of North- Eastern America. " — W. B. H 28 Briggs and Edmondson : " Mensuration of the Simpler Figures " 28 Calvert: " The Discovery of Australia " 28' Prince : " Graphic Arithmetic and Statics " 28 Russan and Boyle : "The Orchid Seekers " 28 Letters to the Editor : — Human and Comparative Anatomy at Oxford. — Prof. E. Ray Lankester, F.R.S 29 " Geology in Nubibus." An Appeal to Dr. Wallace and others. — Sir Henry H. Howorth, M.P., F.R.S • 29 Correlation of Solar and Magnetic Phenomena.^ William Ellis, F.R.S 30 The Recent Earthquake. — Charles Davison. ... 31 An Ornithological Retrospect. — Frank E. Beddard, F.R.S 31 The Foam Theory of Protoplasm. — E. A.Minchin . 31 Science in the Magazines 31 On a Meteorite which fell near Jafferabad in India on April 28, 1893. By Prof. John W. Judd, F.R.S. 32 Notes 33 Our Astronomical Column : — A New Southern Star 38 " Astronomical Journal " Prize 39 Comet Brooks (October 16) 39 Moon Pictures 39 Meteor Showers during November 39 Geographical Notes 39 The Erosion of Rock Basins. {Illustrated.) By ^T. D. LaTouche 39 Chrono-Photographic Study of the Locomotion of Animals. {Illustrated.) 41 The Man of Mentone. {Illustrated.) By Arthur J. Evans 42 University and Educational Intelligence 45 Scientific Serials 46 Societies and Academies 4^ NA TURE 49 D' ROMANES ON WEISMAXN. An Examinatio7t of Weismannism. By G. J. Romanes, M.A., LL.D., F.R.S. (London : Longmans, Green. and Co., 1893.) R. ROMANES is a most competent hurler of hard words, and in this volume is concerned at least as ' much to convince the reader that Weismann is an un- certain guide as to be to him himself a certain guide. In the preface he states his intention to publish his criticisms "in separate form and in comparatively small editions, so that further chapters may be added with as much celerity as Prof. Weismann may hereafter produce his successive works." In the text, writing of the relations between the views of Galton and Weismann, he talks of those immense reaches of deductive speculation, which, in his opinion, merely " disfigure the republication of stirp under the name of germ-plasm " (1) The mention of certain occurrences which are believed in by Dr. Romanes, but the admission of which he considers illogical on the part of Weismann, "seemed attributable to mere care- lessness on the part of their author." Another consider- ation is "made by Weismann for the sole purpose of saving as much as he can of his previous theory of variation." Another is " an obvious equivoque." The mechanism of heredity is planned out (in Weismann's latest volume) " in such minuteness of detail and assur- ance of accuracy that one is reminded of that which is given by Dante of the topography of the Inferno." Of the actual criticism the last chapter and the two appendices alone require special treatment, as they alone were written after the publication of " Amphimixis" and. " The Germ-plasm." It does not seem useful to insist with Dr. Romanes that the continuity of the germ-plasm is the inverse of the basis of the theory of pangenesis. The most im- portant part of the continuity theory has no parallel in Darwin's provisional hypothesis. It is the attractive suggestion of a material basis of heredity which can be identified with structures visible under the microscope ; which can be seen, in some cases, to separate immedi- ately from the fertilised ovum to form the foundation of the germ-cells of the new individual, or, in other cases, to move along "germ-tracts " to the foundation of the germ-cells of the new individual. What is directly com- parable in the two theories is the picture each gives of the phenomena of inheritance viewed in pangenesis as a roll- ing up of gemmules from an existing body to form germ- cells ; in the germ-plasm as the unrolling of germ- plasm to form a developing body. In this, as Dr. Romanes points out, the one theory is the inverse of the other, and very naturally similar groups of facts may appear in the one as stages of rolling up, in the other as stages of disintegration. But here again Weis- mann, aided no doubt by the vast advance in micro- scopical science, constantly is more in touch with observed facts of microscopical detail than was Darwin. Dr. Romanes uses a good deal of space for a minute and interesting comparison of Weismann's germ-plasm with the "stirp" of Galton. He urges that natural NO. 1255, VOL. 49] selection, so potent in the organic world, probably does not cease in the separate parts of a body during develop- ment, and therefore supports Galton's view of a competi- tion among many gemmules of the same order as to which shall actually cause development. But natural selection is not a force : it is merely an aspect of certain occur- rences, and while there may be many (as Galton thinks) or few (as Weismann thinks) units of germ-plasm each capable of causing development, and only one of which does cause development, the aspect of the occurrences on which Weismann wishes to direct attention is that the process of development goes on by an orderly dis- integration of the germ-plasm through various stages of units, and that the order is determined by the " historic architecture " of the germ-plasm. This "historic archi- tecture" is the material representation (on Weismann's theory) of the observed fact that ontogeny does to some extent repeat phylogeny. A continual struggle among innumerable units would account for too much variation, and would leave unrepresented the habitual fixedness of heredity. In his criticism of Weismann's view of evolution Dr. Romanes first states how recent further investigations (those of Maupas and others) into the conjugation of Pro- tozoa have led to an identification of conj ugation with sexual reproduction, so far as they both result in a mingling of germ-plasm, but he quarrels with Weismann for not abandoning the potential immortality of the Protozoa. But whether Protozoa conjugate or not, on the broad average they divide by fission. That means that Protozoa alive to-day have come down in a con- tinuous chain of cell-life from primeval Protozoa, unless indeed there have been continual re-creations of Protozoa. Even if it were proved that spore-formation invariably interrupted at long or short intervals chains of simple fission, still practical immortality may be held by regard- ing spore-formation as merely multiple fission. In a more important criticism Dr. Romanes seems to me to misinterpret Weismann's position. When the continuity of germ-plasm first presented itself to Weis- mann's mind, and brought with it the idea that the somas of each generation were mere pendants of the chain of germ-plasm, it became difficult to see how the impression of outside nature on the soma could be impressed in turn on the germ-plasm. This led to an examination of a new kind into acquired characters, and the result of that examination satisfied Weismann and many others that there was no sufficient reason for supposing that charac- ters acquired by the individual were transmitted to the progeny. Of course this is still a matter of argument, and as Dr. Romanes in this book refers to a full treatment of the question, the publication of which has been delayed by his regrettable illness, it may well be that he will ad- duce fresh and important considerations. But the fact remains that Weismann, driven back from acquired characters as a cause of phylogenetic variation, came to regard the mingling of germ-characters in amphimixis (traceable back to the direct influence of the environment upon organisms antecedent to amphimixis) as the source of all variation. The germ-plasm lived as a parasite within the soma, and was related to it only by the fact that it got food from the soma. In the more developed doctrine D jVA ture [November i6. 189; Weismann retains the original conception. But the germ-plasm is now a particulate substance, and inequalities of nutritioti affecting the separate elements cause variations in it. The original conception has now become more definite, and this increase in definition has effected a reconciliation with some strong objections to the generalised idea. It seems to me extraordinary that a critic so acute as Dr. Romanes, not in the heat ^^ controversy but in a deliberate book, should call this "reuioving stone by stone, his doctrine of descent," and " turning upside down the fundamental postulate." In order to reach such a view he has had to be much more certain than Weismann, about what Weismann meant, and to attribute to "mere carelessness" the inclusion in Weismann's earlier writings of indications pointing in this direction. In Appendix I. the germ-plasm is discussed specially in so far as Weismann considers pangenesis a less con- ceivable and a more formal explanation. I think the key to the criticism is again to be found in a misconcep- tion by Dr. Romanes. He quotes from Weismann : — " How can such a process {i.e. the passage of gem- mules into growing germ-cells) be conceivable when the colony becomes more complex, when the number of somatic cells becomes so large that they surround the reproductive cells with many layers, and when, at the same time, by an increasing division of labour, a great number of different tissues and cells are produced, all of which must originate de ftovo from a single reproductive cell.?" He goes on : — "Here again the obvious answer is that no one has ever propounded such a statement. Far from supposing that ' all the different cells and tissues of a complex organism must originate de novo from a single repro- ductive cell,' the theory of pangenesis supposes the very contrary — viz. that somatic changes in the past history of the phyla had not thus originated in any reproductive cell. The idea of somatic changes originating in repro- ductive cells belongs to the theory of genn-plasm; but even this theory does not suppose all the great number of different cells and tissues which compose a complex organism to have ever originated de novo from a single reproductive cell.'' What Weismann means seems clear enough, although it is dark to Dr. Romanes. The whole of a complex organism grows out from an ovum, and this origin occurs de novo in each generation. Pangenesis supposes that gemmules from each cell in the body somehow come together to form the ovum, and they come together so that they unroll in proper order. For this process there is no trace or shadow of evidence : to many it seems a priori inconceivable. According to Weismann's theory the germ-plasm has been slowly built up in phylogeny, and slowly unrolls in the individual development. On any supposition the process is wonderful : on Weismann's hypothesis the evolution of germ-plasm has actually followed the evo- lucion of living things from simple to complex, and there is no new wonder in its complexity, nor is the unrolling of the historically elaborated germ-plasm more wonderful than the actual development of the historically elaborated soma. The hypothesis of pangenesis supposes that in each living organism there is a new wonder, the giving oft" of gemmules, and their building up into an ovum NO. T255, VOL. 49] which reproduces not only the structures which gave oft" gemmules, but many an embryonic structure dating far back in phylogenetic history. Appendix II. deals with Telegony, and practically con- sists of Dr. Romanes' recent controversy with Herbert 'Spencer. In the mass of confused data about this sub- ject it seems fairly established that at least it is very rare. The influence of a first sire does not as a rule affect children to a second sire. Herbert Spencer thinks that the established cases are fatal to Weismann's theory, inasmuch as they prove that influences impressed on the soma can be transferred to the offspring. Romanes thinks that they are not fatal, inasmuch as germ-plasm from spermatozoa of the first sire coming in contact with the ovary when a spermatozoon caused impregnation, might, as they disintegrate, allow some of their germ- plasm to penetrate the ovary and reach other ova. The actual explanation seems, to the present writer, a much simpler one, but as he is collecting facts he will only mention it. In the best established cases, as for in- stance Lord Morton's mare, and the sow quoted by Mr, Spencer, the first sire was of a more ancestral type than the second sire, and the characters in the progeny attri- buted to the influence of the first sire were atavistic, and in ordinary cases would have been simply referred to as throw-bapks. But as at present Dr. Romanes' criticism of Weismann is the matter in hand, it is enough simply to point out that in this most difficult case for followers of Weismann, Saul also is among the prophets — Dr. Romanes agrees with Weismann ! P. C. M. EXTRA-TROPICAL ORCHIDS. Icones Orchideariuji Anstro-Africanaruni Extra-tropi- cnrtivi ; or Figures, ivith Descriptions of extra-tropical SoutJi African Orchids. By Harry Bolus, F.L.S. Vol. i. Part i. (London : William Wesley and Son.) 'T^'HIS is an excellent work, devoted to the orchids -L of extra-tropical South Africa, and arranged on the lines of the " Refugium Botanicum" of Mr. Wil- son Saunders. The first part includes fifty plates, containing figures and dissections (partly coloured) of fifty-one species. The text comprises descrip- tions in Latin and English, references to original descriptions, synonymy, geographical distributicn, with critical and explanatory notes. The author's many years of careful study of South African orchids, as well as his previous writings on the subject, are sufficient guarantee of the quality of the work ; and as regards the plates, a decided improvement is noticeable, both in the drawings and lithography, as compared with his previous " Orchids of the Cape Peninsula" (reviewed in Nature, vol. xxxix. p. 222). The work will be of great use to the systematic botanist, for, as Mr. Bolus has well pointed out, i^w orders of plants stand more in need of illustra- tion from living specimens than orchids, because of the high degree of specialisation of many of the parts, some of which are very fleshy, and seldom recover their shape after soaking or boiling. Nine new species are described in the present part, Angrcecuni caffrum, A. Maudce, Habenaria Galpini, Satyriiiin Guthriei, S. ocellatiiin, PacJiites Bodkini, Disa sabulosa, D. cotiferta, and Bro'iun November i6, 1893] NA TURE Icca Galpini. There are strong grounds, however, for suspecting that Satyrium Ctithriei is not a true species, but a nati'ral hybrid. It was described from a single hving specimen found growing with S. candidiim, Lindl., in burnt-ott' places on the Cape Flats, Tokai, near Cape Town, by Mr. F. Guthrie. Mr. Bolus remarks that the column "resembles in some degree that of Satyrium bicallosum, Thunb., while both are in this respect very different from that of any other Satyrium known. In every other character this differs greatly from S. bical- losiim, and I very much doubt if it is a natural hybrid." This remark shows that Mr. Bolus had suspicions about the matter. It is a remarkable fact, however, that in every character in which S. Giithriei differs from 5. bicallosuin it approaches S. ca7ididw)i ; in fact, with the exception of the column, it bears a much closer resem- blance to the last-named species, and as the organs generally are intermediate in character between those of the two species, there seems little doubt that it is a natural hvbrid between them. Many such organisms are now- known, and as both the species grow in the district, there is nothing improbable about the matter. There are several points of interest about the work, one or two of which may be mentioned here. The discovery of a new species of Pachites is very interesting, as the original one has only been met with on four occasions. Burchell found a single specimen in 1S15 ; Krausse met with another twenty-four years later ; and now, after a lapse of fifty years, Mr. Schlechter has discovered two more specimens. Mr. Bolus hopes to publish a figure in the next part of his work. It is a curious coincidence that the new species is only'known from a single speci- men. An interesting note is given as to the affinities of Schizochilus. Sonder had indicated it as a member of the Habenariea?, but Bentham transferred it to Disea;. Mr. Bolus again places it near to Habenaria, and his drawings unmistakably show that this is its real posi- tion. Mr. Bolus calls attention to a very curious character found in Satyrium pumiltan, Thunb., which Lindley referred to a separate genus. The flowers are transversely striped with brown, like a Stapelia, and to make the resemblance more complete, they also have a heavy odour of putrid flesh. As it differs so markedly from its allies in these characters, it is evident that we have here an adaptation to secure the visits of the insects which fertilise the Stapelias of the same region. And this reminds us that scarcely anything is known of the fertilisation of South African orchids. ^Ir. Bolus figures a beetle on the plate of Disa elegans (t. 35), which he found upon one of its flowers, with a pollinium attached to its thorax. It is said to be a species of Peri- trichia, belonging to a group of well-known fertilisers. " This being only the second instance," remarks the author, "of an insect actually carrying orchid pollen which I have seen during many years' study of Cape orchids, I have thought it desirable to figure it with the plant." Among the undoubtedly handsome species may be noted Disaferrugi7iea, Swartz, and D. graminifolia, Ker. The former is noted as " abundant on Table Mountain," and its dark orange-vermilion flowers are " largely sold in bouquets in the streets." The latter was c?L\\&&Hersciiclia graininifoUa by Lindley, though Mr. Bolus considers Herschelia as only a section of Disa. We are told that NO. 1255, VOL. 49] '' it is one of the commonest species within our limits, has a rather long flowering period, and attracts universal observation by its beauty and brilliancy ; so much so, that Lindley, in dedicating it to the great astronomer Herschel (who also was a great orchid-lover and culti- vator), felicitously speaks of it as " species hsc pulcher- rima colore cosli attstralis intense caeruleo superbiens ! " Future parts of this useful work will be awaited with interest. R. A. Rolfe. OUR BOOK SHELF. An Astronomical Glossary. By J. E. Gore. (London : Crosby Lockwood and Son, 1893.) Fifty years ago it was the fashion to insert a glossary or dictionary of astronomical terms in every work on astronomy, but few of the books published in late years include these helpful explanations. Mr. Gore endeavours to supply the need in the volume before us. And if the science of astronomy had made no advances during the last half-century, we should have been able to give the highest commendation to his compilation. But since celestial science has had its limits considerably extended, and the old astronomy is giving place to the new, we naturally expect to find the new terms defined in a glossary whicn pretends to contain " an explanation of all the terms and names generally used in books on astronomy." We were greatly surprised therefore, upon looking through the book, to notice the omission of many common and im- portant words to be found in almost every work on astronomy. Among other omissions are the words corona, prominences, chromosphere, photospliere, spectroscope, and prism. Zones are correctly described, and are exemplified by " torrid zone," " frigid zone," and " temperate zone," but the term "sun-spot zone" is un- explamed. No mention is made of spectroscopic binaries, or of motion in the line of sight, or of zodiacal constella- tions. Stereograms are defined, but not spectrograms — that useful word coined for spectroscopic negatives. Neither meridian instrument, nor meridian circle are indexed. In fact, so many words constantly employed in astronomy at the present time are omitted, that we have come to the conclusion that Mr. Gore has only attempted to include in his glossary words used when he was a schoolboy. The tables of data merely refer to members of the solar system, and their value would be increased if the solar parallax were given which formed the basis of their computation. Lists of remarkable red stars, variable stars, and stars for which orbits have been computed, conclude the book — a book that might have been very handy to latter-day astronomers, but which in its present form is of no use whatever. With the Woodlanders attd By the Tide. By " A Son of the Marshes." Edited by J. A. Owen. (Edinburgh and London : William Blackwood and Sons, 1893.) The author of this book is well known as a close ob- server of nature ; and a more enthusiastic lover of natural creatures and things for their own sake it would be difficult to find. To look at flocks of bramble finches feed in some particular old beech-woods at sunrise, he trudged for five miles through snow-covered woodlands ; and the book is filled with accounts of similar sights observed at all times of the day and seasons of the year. In fact, "A Son of the Marshes " is imbued with the true spirit of a naturalist — the spirit that leads men to sacrifice everything in order to obtain a clearer insight intc nature. An interesting instance of protective colouration is given on p. 163. Some broken egg-shells of the fern-owl having caught the author's eye, he looked closer into thi fragments, and saw what appeared to be a short, crooked 52 NATURE [November i6, 189; bit of dead furze stem. As he was bending over it, the supposed withered stem moved slightly, and gave him the impression that he was looking at the back of a large viper that had half buried itself in the furze. A still closer scrutiny showed that the semblance of a crooked piece of furze was two fern-owls about three days old. We have read the book from cover to cover, and have been interested throughout. The author has looked to animate nature for his facts ; hence his work possesses the sterling ring which every student of science delights to hear. Pitt Press Euclid, V.-VI. By H. M. Taylor, M.A. (Cambridge: Univ. Press, 1893.) We h?ve previously had occasion to refer to the earlier issues of this series of books on the elements of Euclidian geometry. The present publication is quite up to the standard of the former ones, and contains some impor- tant variations from the usual mode of treatment. In dealing with the fifth Book, Mr. Taylor rejects altogether the use of figures, since, as he rightly says, the book is not essentially geometrical. With a general knowledge of proportion as derived from treatises on algebra, a student is sufficiently equipped to follow its applications in Book vi. The numbering of the propositions is somewhat altered owing to the omission of some of the propositions in the Greek te.xt. With regard to Book vi. Mr. Taylor has made some modifications in the treat- ment of similar figures, and many theorems are more briefly proved by adopting the definition of similar polygons there enumerated. The additional theorems which are inserted have been arranged in series — one, for instance, giving the student a sketch of the theory of transversals, harmonic and anharmonic ranges and pencils, leading up to Pascal's theorem ; another of nine propositions, concluding with Gergonne's neat solu- tion of the problem to describe a circle to touch three given circles. The method of inversion, Casey's exten- sion of Ptolemy's theorem, properties of coaxial circles, and some porismatic problems follow next in order, the book concluding with a capital set of exercises and an index for the first six books. The Out -door World, or Young Collector's Handbook. Bv W. Furneaux, F.R.G.S. (London : Longmans, 1893-) A GREAT deal of information useful to the young col- lector, for whom Mr. Furneaux has prepared this hand- book, is to be found in its four hundred pages. There are sixteen coloured plates, some of which are excellent and none bad, and more than five hundred illustrations in the text. Those of birds are somewhat unequal ; some indication of relative size would have been helpful. The linnet and the cuckoo are placed side by side, and the former is apparently the larger of the two, while on the opposite page the great tit is considerably bigger than the lark, and rivals the cuckoo in apparent propor- tions. If the length of the bird had been given in brackets after the name under each figure, it would have prevented misapprehension. We have dipped here and there into the letterpress, and found the information accurate and clearly put. IVorked Examples in Co-ordinate Geometry. (Univ. Corn Coll. Tutorial Series.) By William Briggs and G. H. Bryan. (London : W. B. Clive and Co., 1S93.) The examples which are here brought together are intended to serve as a graduated course on the right line and circle, forming thus a useful companion to the book on Co ordinate Geometry already published by the same authors. The work line is specially designed for the private student, and this is why the problems have been dealt with in such detail, everv step in their solution NO. 1255, VOL. 49] being clearly explained. The examination papers may fairly be taken as good test papers, for the questions seem to have been carefully selected, and the more im- portant ones on book work are not lacking. For those teaching themselves this subject by working out the problems given, a good insight should be obtained, while the references to the author's work on co-ordinate geometry, above referred to, will be found very useful to those possessing that book. LETTERS TO THE EDITOR. [ The Editor does not hold himself responsible for opinions ex- pressed by /lis correspondents. Neitlier can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part ^"Naturk. No notice is taken of anonymous communications. \ Sir Henry H. Howorth on "Geology in Nubibus.'' Having given my views on glacial geology in the current issue of the Fortnightly Review, to be followed by one dealing at some length with the ice-origin of lake-basins, I should not have thought any reply to Sir Henry Howorth's "Appeal" necessary except for the consideration that my articles may not be seen by many readers of Nature. And first, I would remark, that the mental attitude which Sir H. Howorth imputes to extreme glacialists I have myself been unable to detect in their writings. In fact, I was under the impression that the "scoffing " and "jeering" was chiefly from the other side ; but it seems I was mistaken, and I must apologise for my ignorance. Those who read my articles will see that I make no appeal to "transcendental ice," but judge of its powers and properties by its admitted effects. Sir H. Howorth says .that " ice is known to crash under moderate pressure," implying that a glacier a mile or perhaps half a mile thick is impossible. But will he or anyone else tell us what happens to the ice after it is crushed, and the pressure that crushed it is continued and slowly increased ? Will it not suffer re-gelation and become denser ice; and if by sudden increase of pressure it is again crushed, will it not by still further pressure again suffer re-gela- tion ? He stops at the first " crushing," as if that were the end of all things so far as a glacier is concerned. All this, however, is beside the question from my point of view. The work of ice on the rocks is as clear as that of palaeolithic man on the flints ; all the difficulties that may be suggested as to how he lived, or how he shaped the flints do not in the slightest degree affect our conclusion that the palaeolithic flint implements are the work of 7nan ; and there is equally clear evidence that ice did march a hundred miles, mostly uphill, from the head of Lake Geneva to Soleure, whatever transcendental qualities it must have possessed to do so. As to "perhaps the largest and most remarkable collection of rock-basins in the world" — the largest being of 50 acres and the deepest 30 feet deep — I must really decline to occupy your space in showing how simply these may have been produced by ordinary denuding agencies, or in denying that any glacialist, even of " the most extreme and aggressive school," would claim them as proofs of glaciation. As regards the question of Tas- manian glaciation, my last communication to Nature (Nov. 2) seems to me to render any further observations unnecessary. No doubt the conclusions of the various writers will be fully har- monised by a more complete study of the whole region. The last point touched on by Sir \\. Howorth — whether the advocates of the ice-origin of certain groups of lakes are " extravagant" in their views, following the methods of Aristotle rather than those of Bacon, and founding their be iefs on "purely hypothetical properties of matter and forces of nature" — I will leave to the judgment of those who do me the honour of reading my forthcoming article in the Fortnightly Review. Alfred R, Wallace. The Erosion of Rock-Basins. Mr. T. D. LaTouche's letter (page 39) is very interesting as a more than usually independent contribution (for the reason given therein) to the interesting question of glacial November i6, 1893] NATURE d5 erosion, and as showing how similar (allowing for the differ- ence in size) are the phenomena of the Himalayan and the Alpine glaciers. But I think that moulins, as a rule, are not likely to be very important agents in the formation of the rock-basins in which lakelets and tarns are often lodged. So far as my ex- perience goes, the range over which the moulin-torrents can act is very restricted ; for the crevasse, which gives the opportunity to the water, is generally formed very nearly at the same part of the glacier. Thus after the moulin has travelled for a very short distance down the glacier, a new crevasse opens out behind it and cuts off the torrent. I have frequently seen four or five dry shafts in advance of the working moulin. The lateral range also of the moulin must be small. Hence I think that the giant's-kettle (as is usually supposed) more accurately repre- sents the ordinary product of a moulin. An excellent illustra- tion is afforded by the well-known ' ' glacier-garden " at Lucerne. I think, also, that the rock-basins, of which we speak, are more commonly found in|situations where moulins would not be numer- ous or large, viz. in cwms and corries. It is, however, true that in certain undulating rock districts, as parts of Scandinavia and the Scotch Highlands, lakelets are common. The form of these, however, does not appear to bear much relation to the hollow produced by a moulin. So that I doubt whether we can regard a moulin as an agent of primary importance in the production of an ordinary rock-basin, though it may sometimes be a minor contributory. As I have more than once discussed the question of the probable cause of the formation of tarns as well as of large lake-basins, it is needless to repeat what has appeared in print. T. G. Bonney. 23 Denning Road, N.W., November 13. "The Zoological Record." Ix your Notes for October 26, on p. 621, you follow the Editor of the Zoological Record in suggesting that, under the present financial conditions, palaeontology should be removed from the volume issued by the Zoological Society, and provided for by the paleontologists themselves. Against such retrogres- sion we desire to protest. " Everyone knows," as you say, "that an incomplete record is of very little use"; and how absurdly incomplete a recotd would be that took no account of palaeontology ! The objectors probably spring mostly from the ranks of systematic zoologists. We will deal with them on their own ground. The systematic position of I.imuliis has long been a vexed question, which no one can attempt to solve without consulting the work of Malcolm Laurie on the fossil Eurypterids. The classification of the Crinoids has troubled zoologists since the days of Johannes Midler ; but neither he nor anyone ever dreamed of settling it without reference to paleontology. Students of recent Bryozoa will not be grateful to those who keep them in ignorance of J- W. Gregory's lately published work on the Bryozoa of the early Tertiary rocks. And so we might go on ad infinitiivi. Another argument that may affect the systematists is that if they reject all names of fossil genera and species from the record, they will have no means of knowing whether the new names they may wish to propose have been used before or not. It is even possible that some of them may unwittingly describe as new forms already described by some unknown palaeontologist. It is hardly neces- sary to remind the morphologists, embryologists, and zoij- geographers of the help that they constantly receive from the palaeontologists ; they, at least, will not wish to have the record made incomplete. It is suggested that every branch of science should have a record, and that paleontologists should undertake the compila- tion of a separate one. This would as good as double the work, both for recorders and students. What we have said above shows that palaeontology is not a separate science. Zoologists and palaeontologists ought to be the same people, and when they have strength enough they are so, as the names of Cuvier, Owen, and Huxley sufficiently testify. The paleontological recorder would still have to work through the writings of the zoologists, while even the pure neontologists would have per- petually to refer to the palaeontological record. What is really wanted is to complete the Zoological Record, not to make it incomplete — to go forward, not backward. It is admitted that some of the recorders do tackle the palaeonto- logical literature. Why should not all? If a group is too large for one man, then give it to two, and if a second man cannot be got to work on half-pay, then double the pay. NO. 1255, VOL. 49] To prevent the record becoming too big, make it merely an index, and cut out the abstracts, which are rarely correct. If more money is wanted, appeal to other societies which might naturally be supposed interested in the work. It is unfair that a single society should bear the burden of a work that is of value to all, and one can hardly suppose that it would refuse kindly offers of help. We believe, indeed, that the only reason why some of the recorders abstain for the present from the palaeontological work is because they feel that part, at least, of the expense ought to be borne by the society more directly in- terested. R. I. POCOCK, F. A. Bather, B. B. Woodward. British Museum (Nat. Hist.), October 30. Recognition Marks. A QUESTION in natural history has occurred to me, which, I think, might with advantage be discussed in your columns. It is usual to account for the white tail of the rabbit {Lefiis cittiicttlus) by saying that it is useful as a danger signal to others of the species. Wallace, in his "Darwinism," speaking of rabbits, says that " the white upturned tails of those in front serve as guides and signals to those more remote from, home." Now, there appear to me to be two objections to this theory. The first is that the tail of the hare {Lepus limidns) is also white, and is turned up in precisely the same manner when running ; but it is obvious, from the habits of this animal, that in its case it would be quite unnecessaary for such a purpose. And in the second place, if this were so, how could it have been produced by evolution ? The object of the white tail is said to be to assist other rabbits to escape, not the possessor of the white tail itself. But the principle of evolution is the survival of the animal fittest to preserve its own life, not of the fittest to preserve the lives of others of the same species. G. J. Macgii.livray. 3 Belford Park, Edinburgh, November 6. Mr. Macgillivray has failed to grasp the principle of natural selection when he thinks that it cannot produce a character useful to other animals of the same species. The action of natural selection is to preserve the species, as well as each individual separately ; and, consequently, every character useful to the species as a whole would be preserved. This is obvious when we consider such characters as nest- build- ing in birds, and milk-secretion in mammals, which do not benefit the individual possessors, but their offspring ; and the same principle applies to every character which is mutually useful to individuals of the same species, as are what I have termed "recognition characters." Neither can I admit that the habits of the hare render the white upturned tail "quite unnecessary." The hare is a nocturnal feeder, and a mark which readily distinguishes a friend from an enemy, and enables the young during their short period of infancy to keep within sight of the mother, must be of considerable importance. Alfred R. Wallace. Correlation of Solar and Magnetic Phenomena. In writing on this subject (Nature, vol. xlix. p. 30), to save space I omitted to refer to one other case of 1 resumed connection. But as such omission might be misunderstood, may I here briefly allude to it? M. Trouvelot, on June 17, 1891, observed changes going on in connection with a luminous ap- pearance near the western limb of the sun, such as he had not before seen. But the magnetic movement was in this case insignificant (see The Observatory, vol. xiv. pp. 326-32S;. The same reasoning as before may be applied. If the smaller mag- netic motions do really directly depend on solar changes of so marked a character, how does it happen that many greater re- corded magnetic movements remain without corresponding solar change having been seen ? It is a very interesting, indeed critical point, but much more information is necessary to prove that such close connection really exists. The appearance was seen by Trouvelot near the sun's limb. There is a significant sentence ending a letter from the Rev. Walter Sidgreaves, of Stonyhurst {The Observatory, vol. xiv. page 326), as follows : — " But there are no indications of mag- netic disturbance accompanying the folar eruptions seen through the spectroscope. Even the brilliant display on the western limb, of the loth [September 10, 1891], has left nothing that 54 NA TV RE [November i6, 189; can be considered a record of itself on the maf^netograph curves." William Ellis. Greenwicli, November 9. [With regard to the case cited by Mr. Ellis, it is worth re- mark that at the time of Trouvelot's observation, the writer of our "Astronomical Notes" asked Mr. Whipple whether the eruption was accompanied by any anomalous magnetic move- ments. Mr. Whipple replied : " There was not the slightest magnetic disturbance on June 17, 1891, at the hour you men- tion, or for days before or since." The point was again raised at th? beginning of last year, and to make assurance doubly sure, Mr. Whipple a&ain referred to the Kew curves, but failed to find any trace of what could be termed a magnetic disturbance at ihe hour inquestion. (See Nature, February 25, 1892.) — Ed.] THE NEW BIRD-PROTECTION BILL. SENTIMENT is a beautiful thing in its way, and when that way happens to coincide with the way of common sense, the man must be a brute who defies it. But unluckily that does not always happen, as is testified by several instances that could but here shall not be cited, for they will come uncalled to the recollection of many of our readers, and indeed to some they are ever present. These need not to have the difference between a sound and an unsound sentiment pointed out. But there is also a sentiment that is perfectly sound at the start, and yet, chiefly through want of knowledge — we hesitate to call it ignorance, because that might imply blame — sooner or later begins to betray symptoms of running on the wrong track, when, if the brakes cannot be applied, it comes into violent collision with common sense. As the latter is the weightier mass the harm it gets from the impact is not often very serious, and the injuries received seldom cause more than delay, however annoying that may be ; but the effect on the lighter body is apt to be destructive, and though in some cases it may be only repelled with slight damage, in others it may be shattered. In either event, seeing that it set out with good intentions, the result is to be regretted. Of this kind of sentiment is that which actuates the extreme advocates of Bird Protection. Time was when the sickening slaughter of sea-fowl at their breeding- stations around our coast appealed alike to sentiment and to common sense — to say nothing of science — to in- terfere. First carried on for what was called " sport," but soon for the sake of mere lucre, the feathered denizens of our cliffs and beaches were shot down by the thousand, to do nobody any good but the " plume-trader." The Act of Parliament which received the Royal Assent in June 1S69, and is always to be remembered in connection with the name of Mr. Christopher Sykes, was just in time to save from extinction the population of many a thronged resort which has always presented, and we trust always will present, a spectacle of delight to the large and in- creasing class of our fellow-countrymen who appreciate the harmonies of nature, even if the resorts on the English coast cannot compare with those where the Northern Ocean in vast whirls Boils round the naked melancholy isles Of sea-girt Thule, or the Atlantic surge Pours in among the stormy Hebrides. That Act may have had its shortcomings : few Acts are without them ; but nobody can doubt it was effective to do good, and it was followed by other Acts, based on the same principle, and tending to relieve persecuted beings from persecution. An exception indeed must be made as regards one of them, but that one (which was com- mented upon at the time in these columns ') only serves to support the allegation in our introductory paragraph. In 1S72 some enthusiasts followed the line of sentiment regardless of common sense, and succeeded in converting a well-considered and practical measure into one that 1 Nature, viii., p. i, (May i, 1S73). NO. T255, VOL. 49] was specious and useless. They had their reward, for in the next session their parliamentary leader obtained a Select Committee of the House of Commons to enquire into the subject, and the result of the investigation showed every reasonable person the baselessness of the points for which the extreme party had contended, while three years later the very Bill which they had mutilated and mauled passed through Parliament almost exactly in the form in which it had been originally introduced. The enthusiasts, however, had the satisfaction of stopping useful and much wanted legislation for four years in order to gratify their own gushing and unintelligent sentiment, while their Act, always a dead letter, was superseded by the Act of 1880 which consolidated all previous legisla- tion. Still the spirit that moved the enthusiasts is not dead. In one way or another it shows itself every year — sometimes, though not often, it confines itself within the bounds of common sense, but of late it has become we may say rampant. None of the former Acts had done anything to stay the taking of birds' eggs. Indeed, birds' eggs had been, and that purposely, wholly left out of consideration, and this in the eyes of many excellent people has seemed to be a glaring defect — even a crime. Let us stop birdsnesting, say they, and the number of our birds will be indefinitely increased. Nightingales will mul- tiply, Goldfinches will be as plentiful as Sparrows, and Skylarks will swarm. Little do these good people realise the state of things. Let us grant that in the immediate neighbourhood of towns and. large villages, where birds are already at a disadvantage, boys will emerge, and successively rob nest after nest as it is built with an eftect that may be called devastating. The case, how- ever, is very different in the country at large. There the first species of those we have just named already enjoys a protection incidentally yet almost invariably conferred upon it by the law of trespass. We can believe almost any act of folly or stupidity on the part of some game- keepers, and the widely-told story that one of that profession once declared that he destroyed Nightin- gales because their singing disturbed the nights' rest of his pheasants may have some foundation ; but nearly all observers who have informed themselves by experi- ence will agree that the part of England which Nightin- gales choose to occupy is generally as fully stocked with them as the place will hold. It is certain to those who watch that the number of Nightingales which return to this country with each returning spring is greater than that which can find room. Hence those ever-recurring contests of melody that we hear from rival cock birds on their first coming, to say nothing of the actual conflicts, often ending in the death of one of the combatants, that take place between the competitors. And it is only natural that it should be so. That if a Nightingale's nest be taken the same birds immediately build a second, and if need be a third, is a perfectly well-known fact, and it would be a very unlucky pair of Nightingales to have their nest robbed thrice in a season. At a very moderate computation the number of young Nightingales that must annually attain their full growth in this country doubles that of their parents, since from five to six are commonly reared in each nest ; and, with a large allow- ance for casualties in youth, it is safe to calculate upon four of each brood having reached maturity when the time of emigration arrives. What happens during their absence from this country is of course beyond our ken, but the certainty with which migratory birds return to their home is now well-recognised ; and it is not less certain that of this species more return to England in spring than are able to find accommodation in our woods, coppices, and shrubberies, as the conflicts just mentioned testify. Hence it would follow that were the taking of a Nightingale's egg made a capital offence, we should not have, one year with another, more Nightin- gales, though, to retain the number we have, it is impera- November i6, 1893] NATURE 55 tive that the old birds should have protection at the breeding season. To take the second case we have cited, that of the Goldfinch, the details are not the same, though the final result be so. Until some fifteen or twenty years ago the diminution in the numbers of this species was notorious ; but the reasons of that diminution are easily revealed to any enquirer, though it may be hard to say which of them be the stronger. The practice of netting in spring time, now illegal though probably still used in some places, was carried on to an extent that if it were not supported by the clearest evidence people would hardly believe. Combined with this disastrous practice was the fact that so much heath and common land had been brought under the plough, and the mode of agricul- ture so much improved, as sensibly to affect the Goldfinch's supply of food, for its fare was truthfully termed by the poet " the thistle's downy seed,' combined however with that of other weeds hated by good farmers. But no doubt, at the hands of the bird-catchers, the Goldfinch. being so great a favourite for the cage, still suffers severely, and it may be true that enough do not leave this country at close of summer to satisfy the waste of life that occurs during its migration and in its winter-quarters ; though as to any considerable diminution in its numbers being caused by birdsnesting, the notion of such a thing will be scouted by all who have had opportunities of observing its breeding-habits. Our third instance, the Skylark, is without doubt one of those birds that needs protection least. Nobody persecutes him so soon as he ceases to fiock and settles with his mate in their chosen spot. Their nest in the growing corn, or the wide pasture, is safe from even the predatory rat, and the open country they haunt is no place for the Sparrow-hawk, that deadly foe to so many small birds. There, in the course of the season, they make their three or four nests, and rear in each as many young, so that the annual increase of the species may be safely computed as five-fold, and when we also consider that thousands if not tens of thousands arrive every autumn on our shores and spread over the whole country, with a safe conscience the most devoted lover of birds may, if he has a mind to it, eat lark- pudding in winter without compunction. We have cited these three cases — the Skylark, the Goldfinch, and the Nightingale, because we have them so frequently put forward by sentimentalists as birds that all right-minded people would wish to see more numerous. We should like to count ourselves among the right-minded, but the sentimentalists must forgive us for refusing to believe that the number can be increased in the way they advocate — visiting with punishment the schoolboys who would take the nests of any one of them. Far otherwise, however, is it with many birds of which the enthusiasts never think. Those, for instance, that habitually breed in places open to all comers, and especially on islands near our coast, on the sea shore, and by the side of inland but navigable waters. In such places there is no law of trespass ; and, as all who have been at the pains to inform themselves know, these birds suffer from the way their exposed nests are ravaged, and are surely decreasing in number. Yet by the general public they are little heeded, chiefly because the general public knows nothing about them — not even their names — and moreover encourages the ravages by blindly buying the booty of the ravagers. Thus it is that many a beach, and many a heath, and many a marsh and mere, is made desolate, for the ravage is continued throughout the whole of the breeding-season, with the result that scarcely an egg is left from which a young bird — be it Duck or Gull, Tern or Plover can be hatched. Yet it is obvious that it would not be so very difficult to stop this destruction, and that without interfering with the long-established practice, which we hold to be no more detrimental to their species than it is illegitimate, of taking toll of their NO. 1255. VOL. 49] eggs. Pick out the places at which the practice is carried on, and limit the time during which the eggs may there be lawfully gathered, so as to give each pair of birds the opportunity of bringing off their brood. Early in the present Session a " Bill to amend the Wild Birds' Protection Act, 1880,'' was brought into the House of Commons by Sir Herbert Maxwell, which Bill, owing to the well-deserved popularity of its introducer, ran its course unchallenged, and achieved the almost unexampled success of being read a third time and passed with scarcely an alteration of importance. The scope of the Bill was to enable any County Council to prohibit "the taking or destroying of any species of wild bird or the eggs of any species of wild bird." This Bill, of course, attracted the attention of the Committee which had been appointed the year before by the British Association " to consider proposals for the Legislative Protection of Wild Birds' Eggs," and in the opinion of that Committee, as subsequently reported at the late meeting of the Associa- tion at Nottingham, the Bill was declared to have been framed on a mistaken principle " in that it sought to effect the desired object by empowering local authorities to name the species,' the eggs of which were to be protected, thus requiring in every case of prosecution proof of identity, which in the majority of cases would be difficult, if not impossible to supply." The House of Lords at first took almost precisely the same view as the British Association Committee ; and, chiefly at the instance of Lord Walsingham, than whom there could scarcely be a more competent peer, amended the Bill accordingly, producing what would, in the opinion of many experts, be a very workable measure. But unhappily in the subsequent process of passing the Standing Committee of the Upper House, their lordships were induced, by those who were not experts, to go a great deal further, and nobody acquainted with the facts of the questions involved, can doubt that on this occasion the efficacy of the Bill was not a little damaged in various ways. ' In this condition it in due course returned to the House of Commons, where the British Association Com- mittee, as stated in their report, hoped it would, in spite of its transformation, still find favour; but its original parent, Sir Herbert Maxwell, would have none of it, and consideration of the Lords' Amendments having been adjourned on August 21 for three months, it stands by the accidental prolongation of the Session, for further discussion in a few days. In the meanwhile the British Association Committee has been reconstituted and strengthened by the substitution of several ornithologists of repute in place of some naturalists who had never paid any special attention to the matter, while Sir John Lubbock has accepted the post of chairman, and Mr. Dresser, who was for many years Secretary to the Old "Close-Time" Committee of the Association that effected so much good, undertakes the same duty in the new body, the other members of which are Mr. Cordeaux, Mr. W\ H. Hudson, Prof. Newton, Mr. Howard Saunders, Mr. T. H. Thomas, Canon Tristram, and Dr. V'achell. With a chairman at once so conciliatory and so influential, and a secretary of so much experience, it may be hoped that the difficulties, great as they are— for they involve a contest between the two Houses of Parliament — will not prove insuperable, and that some way may be found of saving this Bill, for all will admit that if it be not passed this Session a long while may elapse ere a House of Commons is good-humoured enough to let a measure of the kind slip through its entanglements, as did that of Sir Herbert Maxwell at the beginning of this year. This is surely a case where sentiment should yield to common sense. 1 It may be remarked that the Bill was so carelessly worded as to leave it open to duubt, though this was certainly not the intention of its supporters, whether a Couniy Council could by one act make it apply to all Wild Birds, or only to some that should be named. 56 NATURE [November i6, 1893 LIGHT-WAVES AND THEIR APPLICATION TO METROLOGY. ■pX'ERY accurate measurement of a physical quantity -*^^ depends ultimately upon a measurement of length or of angle : and it will readily be admitted that no effort should be spared to make it possible to attain the utmost limit of precision in these fundamental quantities. At present, lengths are measured by the microscope, and angles by the telescope ; and the extraordinary degree of accuracy already attained by the use of these instru- ments depends entirely on the properties of their optical parts in their relation to light-waves ; so that, in fact, light-v.-aves are now the most convenient and universally employed means we possess for making accurate measure- ments. It can readily be shown that this high degree of accuracy is especially due to the extreme minuteness of these waves. Fig. 1. Thus it is well known that the image of a luminous point consists of a series of concentric coloured rings surrounding a bright central disc which is smaller the smaller the ratio of the wave-length of the light to the diameter of the objective employed. In fact, it can be shown that the radius of the bright central disc contains as many wave-lengths as the distance of the image from the objective contains the diameter of the objective. Thus in a telescope twenty diameters long, the dia- meter of the bright disc is forty wave-lengths or 002 mm. If the image be magnified "by increasing its distance from the objective, or otherwise, these diffraction rings are magnified in the same proportion ; so that nothing is gained thereby in distinctness, beyond the point where the rings are just large enough to be visible. But, were it not for the inevitable loss of light, it would be advan- vibration ; but to determine the position of 0 with respect to a b, this is not at all necessary ; and in fact, if we dis- regard the possible inconvenience due to the dissimilarity between the phenomenon observed and the object whose • position is to be measured, it v/ould be as well to entirely annul the central portions of the lens, leaving only an external annular ring, or better still, only two small por- tions at opposite ends of a diameter. This involves no sacrifice of accuracy, but on the contrary a very considerable gain ; for it is now possible to increase the size of the interference fringes up to any desired limit without diminishing the intensity of the light, the result being the same as could be obtained with a perfect microscope of unlimited magnifying power with a source of unlimited intensity. For this purpose the two small portions to which the lens is reduced are replaced by plane mirrors or prisms, whose office is simply to bring the two interfering pencils into coincidence. Further, the pencils, in- stead of starting from a point or a line, may be separated by a plane transparent surface ; and a second similar surface may be used to reunite the pencils after reflection. Thus the telescope or microscope will have been con- verted into a refractometer. The exact nature of the analogy will be apparent by a com- parison of Figs. I and 2. It may be assumed that under the most favourable circum.stances the utmost attain- able limit of accuracy of a setting of the cross-hair of a microscope on a fine ruled line is about „^,7 of a micron. Now, it is usually admitted that the middle point of an interference fringe, if it be sufficiently broad and clear, can be determined within about ^^ of the width of a fringe. In the refractometer this would mean only ,,Vi of a light-wave, or about o'oi^, from which it would follow that the refractometer is about five times as accurate as the microscope. But a number of trials with the form of refractometer shown in Fig. 8 gave as the mean error of a series of ten observations : Fr. Fr. Fr. Morley 00056 ... Nicholson 0*0059 ... Xooiio The third observer had no previous practice in this kind of measurement. tageous for measurements of position to increase the magnification much further. This can be accomplished by an extremely useful instrument which has been misnamed the " interferential refractometer.' It will be interesting to note that not- withstanding the apparent difference in form, this apparatus, when used as a measuring instrument, differs in no essential particular from the microscope or the telescope, or (what is perhaps a trifle unexpected) the spectroscope ; and it is possible to change any one of these instruments into the other by unimportant modifi- cations. Thus, let 0, Fig. i, be a source of light, ab ?l lens which forms an image of 0 at o'. The operation of the lens, when used to distinguish minute objects, depends upon the accuracy with which all its parts contribute to make the elementary waves reach the focus in the same phase of NO. 1255, VOL. 49] It is evident from these results that ;j'y of a fringe is too large an estimate of the average error of a setting, and that it is, in fact, less than 001 of a fringe, corresponding to an error in distance of about 0.003/x. For angular measurements the microscope is replaced by the telescope. Fig. 3 represents a disposition sometimes adopted for observing minute angular displacements of the mirror d c; the light starts from o, is reflected by the plane parallel glass plate/ to the objective a b oi 2l telescope, whence the now parallel rays proceed to the mirror c d. Thence they retrace their path to the plate /, through which they are transmitted, forming an image of the source at o\ which is viewed through the eyepiece. Fig. 4 is the exact analogue in the form of a refracto- meter ; and Fig. 5, though slightly different in aspect, is still essentially the same instrument. The path of the November i6, 1893] NA TURE 57 rays \so p a c a po' for one of the pencils, and opbdbpo' for the other. From considerations quite analogous to those em- ployed in the former case, it can be shown that the ,M#?#MM#«] limit of accuracy attainable in the estimations of angles involves an error of about one-fifth of the angle subtended by a light wave at a distance equal to the diameter of the objective. This is halved by the fact that the angular motion of the beam is twice that of the mirror ; so that with a telescope of locm. aperture the limit of accuracy may be estimated at ogfjj-ff.jjj, or say o.\". But taking o.oi fr. as the smallest perceptible displacement of the mirrors c d, the corresponding angle of rotation of the NO. T255, VOT.. 49] line c d (lo cm. long) would be only ougJouoij, or say 0.0 1 ".^ It is not at first evident that there is any relation be- tween the refractometer and the spectroscope. A com- parison of Fig. 6 and Fig. 7 shows, however, that there is a strict analogy. Fig. 6 represents a disposition some- times adopted to observe the spectrum by means of a concave grating, and Fig. 7, with unimportant modifica- tions, is the arrangement actually employed in the analysis of radiations by means of their " visibility curves," as will be explained below. Exactly as in the case of mirrors and lenses, we may here, too, sacrifice "resolution" and "definition" by using only the extreme portions of the surface, with an actual gain in "accuracy." To compare numbers, it appears that the average error in the comparison of Fig. 6. wave-lengths by a gratine with 250,000 lines is about one part in half-a-million. With this number of waves in the difference of path of two interfering pencils, the corre- sponding error in the refractometer observations are of the order of one twenty-millionth. The name "interferential refractometer" seems rather inappropriate to an instrument which has so many im- portant applications beside the measurement of indices of refraction ; but as it has been sanctioned by long usage it will be retained. Among the many forms of the apparatus which have been rendered classic by the works of Arago, Fresnel, Fizeau, Jamin, and Mascait, and which are so admirably adapted to the work for which they were designed, there are none which aie not open to serious objections when applied to the solution of such problems as the measure- FiG. 7- ment of lengths and angles, for the analysis of the con- stitution of the light of spectral lines, and especially for the determination of wave-lengths in absolute measure. For these, the form of instrument shown in Fig. 8 has many important advantages, among which the following may be mentioned : — It is simple in construction, and is easily adjusted ; it may be used with a broad luminous 1 In the use of the revolving mirroras in galvanometers, gravity and torsion balances, &c., the accuracy can be increased by enlarging the surface of the mirror ; but the moment of inertia is thereby increased, and in greater pro- pirtion. But in the refractometer the mirrors c d may be made insig- nificantly fmall, and yet, with the same distance between the outer edges, the accuracy may be increased at least tenfold. It is important tonoie that any linear motion of the line joining the mirrors, or even a rotation about ihislme, has no effect on the fringes. It seems probable that this form of instrument may be of service in such problems as the measurement of the mjon's attraction, constant of gravitation, variations of the vertical, &c. 58 jVA TURE [November i6, 1893 surface as source of light ; the pencils may be separated as far as desired ; its range of difference of path between the interfering pencils is unlimited ; and when properly adjusted the position of the interference fringes is per- fectly definite, so that there is no uncertainty on account of parallax, and no difficulty in counting the number of fringes passing a given point. Finally, it may be added, that this is probably the only form of instrument which permits the use of white light (and consequently of the identification of the fringes) in the determination of the position or inclination of a surface without risk of distur- bance due to contact or close approximation. As shown in Fig. 8, the refractometer consists essentially of a plane parallel plate of optical glass Gj and two plane mirrors M^ Mj. The beam of light to be examined falls on the plate Gj at an angle, usually 45°, part being re- flected and part transmitted.^ The reflected portion is returned by ihe mirror M.,, and passes back through the in- clined plate. The transmitted portion is returned hy the mirror .M[,and is reflected by the inclined plate, and from Fic. 8. this point it coincides with the other beam, so that the two are in condition to produce interference fringes.- A little consideration will show that this arrangement is in all respects equivalent to an air-film or plate between two plane surfaces. If the virtual distance between these surfaces is small, white light may be employed, and inter- ference fringes may be observed similar in all respects to those between two plates of glass pressed nearly into contact.^ ' The front surface of the plate Gj is lightly coated with silver. The light which leaves the refractometer is a maximum where the thickness of liie silver film is such that the intensities of the transmitted and reflected portions are equal. The silvering has another impjrtant advantage in diminishing the relative intensity of the light reflected from the other sur- face ; and lorlhis reason the thickness ol the film may be advantageously increased, which permits also a more uniform surface. The ultimate ratioof intensities of the two pencils is not afTeeted, for what is lost by transmission on entering the plate is made up by reflection on leaving it. ■-' One of the beams has to pass twice through the thickness of the glass plate Gi, and in order to equalise the two paths, a similar plate G; is intro- duced in the path of the other beam. 1 If the plate Gi be not silvered, the colours follow the same order as those of Newton's rings, but if the silvering be sufficiently heavy, the colours are complementary ; this, if the plates Gi and Go are exactly equal and parallel. Otherwise, the excess of path in-glass of one of the pencils disturbs the order of colours by the effect of achromatism due to the dispersion of the glass, as was first pointed out by Cornu. If, however, the distance exceeds a few wave-lengths, monochromatic light must be employed. In this case the fringes are in general invisible, unless they be viewed through a small aperture. If, however, the two surfaces are very accurately parallel, the fringes are always dis- tinct, and it follows from the symmetry of the conditions that they are concentric rings. Their diameters increase as the square root of the order of the ring. These rings are not formed at the surface of the mirrors" (as is the case when the distance between them is small), but are perfectly distinct when the eye or the observing telescope is focussed for parallel rays. In the preceding comparison between the refractometer and the telescope, microscope, or spectroscope, the "ac- curacy" has been increased at the expense of '"defini- tion.'' When, however, the object viewed is beyond the "limit of resolution ' of the instrument, its form and distribution of light can no longer be inferred from that of the image. Thus, if the object be a disc, a triangle, or a double star, the appearance in the telescope is the same. Similarly in the spectroscope, a source of great complexity cannot be distinguished from one which pro- duces a single spectral line. So that for such objects, even in the ordinary sense of the word "definition," the more familiar optical instruments cannot claim any ad- vantage over the refractometer ; but if by "definition" is meant not the actual resemblance of the image to the object, but the accuracy with which the form or the dis- tribution of light in a minute source may be inferred, then it can be shown that all the advantage rests with the refractometer. As an illustration of such an application of inter- ference methods, let us consider the celebrated experi- ment of Fizeau, in which Newton's rings are observed with a sodium flame as source. The light, consisting of two separate systems of radiations differing by about one-thousandth in wave-length, each system produces its own series of interference fringes. When the surfaces are nearly in contact, the difference of path is very nearly the same for both systems, and the fringes coincide, and the clearness is a maximum. When, however, the difference of path reaches about 500 waves for one of the systems, it is a half wave more for the other; and the maxima of intensity of the one coincide with the minima of the other; hence at this point the fringes are faintest. But ^^-^ when the difference of path of the first system ^-Va is about 1000 waves, it is a whole wave more V ^ for the second, and the fringes coinciding, there is again a maximum of distinctness. M . Fizeau has counted 52 such periods, corresponding roughly to a difference of path of 50,000 wave=. Suppose, now, that this double line were so close that it could not be resolved by the spectroscope ; then from the evidence furnished by the variations in distinctness of the interference fringes as the difference of path in- creases, the duplicity of the line could be readily detected. But beside this, it can be shown that the relative inten- sities of the components, their distance apart, and even the distribution of intensities within the component lines can be inferred. Thus it has been shown {Philosophical Magaziiie for September, 1892) that among some twenty radiations wnich were examined (though all give simple lines in the spectrum) the great majority are shown to be highly complex. Thus, the red hydrogen line is a double whose components have the intensity ratio 7 : 10, and whose distance is about a fiftieth of the interval between the sodium lines. Each component of the yellow sodium lines is itself a double whose components are in the ratio 7 : 10, and whose distance is about one-hundredth of that between the principal components. Thallium gives a double line whose components are in the ratio i : 2, at a distance of about a fiftieth of that of the sodium lines, NO. 1255, VOL. 49] November i6, 1893] NATURE 59 while each component has a small companion whose intensity is about a fifth of that of the principal lines, at a distance of about one three-hundredth of that of the sodium lines. The green mercury line is made up of a QTOup of five or six lines, the strongest of which is itself double (or perhaps triple) the distance of the compo- nents, being less than a five-hundredth part of that between the sodium lines. These distances, small as they are, can be measured within about a twentieth part, so that by this means it is possible to detect a change of wave-length correspond- ing to the ten-thousandth part of that between the two sodium lines. The red line of cadmium is the simplest of all the radi- ations thus far examined, consisting of a single narrow line whose intensity falls off symmetrically according to an exponential law, its width (at the points where its intensitv is reduced to half its maximum value) being only 0002 (D^-D.,). The green and the blue cadmium lines are also comparatively simple, and all three of these lines give interference fringes clearly visible at a differ- ence of path of 100 mm., and under appropriate condi- tions they all satisfy the requisites for a definite and inalterable standard of length. The most important of these conditions is that the radiating vapour be so rare that the molecules may vibrate freely ; in other words, that the time occupied in the col- tisions between the molecules be so short relativelv tc the very large number of waves which pass as the refer- ence plane is moved from one surface to the other. This problem has been solved in the following manner. Nine standards were constructed similar in all respects to that of ten centimetres, save that each succeeding one was half as long as the preceding. The last of the series is thus approximately o"39 mm. long, corresponding to a difference of path of 078 mm. The number of waves in this distance in red cadmium light is 1212 plus a fraction, which is corrected by direct observation of the difference of phase of the circular fringes on the upper and the lower (front and rear) surfaces of the standard. This verifica- tion is also made with the green and the blue radiations. It is important to note that the measurement of these fractions alone is sufficient to fix the whole number, even if there be an uncertainty of several waves. Thus, the relative wave-length of the three radiations being known, the number of green and of blue waves corresponding to the observed number of red waves can be readily calcu- lated, as is shown in the following table : — Number of Waves. Wave-length. Observed. Calculated. Fig. 9. that of the free path, that its influence in disturbing the Iree vibration may be neglected. Experience shows that in general this limit corresponds to a pressure of one or two thousandths of an atmosphere. It may be noted that at atmospheric pressure — even when the radiating substance is introduced in quantity barely sufficient to colour a Bunsen flame — the greatest difference of path attainable is only one or two centi- metres, whereas with mercury vapour in a vacuum tube interference fringes have been observed with a difference of path of 47 centimetres, or about 850,000 waves. In order to make any practical use of these minute quantities for standards of length, it is necessary to em- ploy an intermediate standard, such as that shown in Fig. 9, consisting of a bronze bar carrying two plane-parallel glasses, silvered in front, the distance between which can be compared on the one hand with the fundamental standard in actual use— the metre or the yard — and on the other with the length of a light-wave. The former process is accomplished by moving the standard (whose length it is convenient to take at 10 centimetres) ten times through its own length, the coin- cidence and the parallelism of the. surfaces being con- trolled at every step by the interference fringes in white light formed between these surfaces and that of the re/if c?ice plane (the virtual image of the mirror M.\l in G,, Fig. 8). The position of a fiducial mark on this standard is compared by means of two micrometer micro- scopes with the lines defining the standard metre at the first and last steps. In the second process the only difficulty encountered is due to the very great disproportion between the length of a wave and that of the 10 centimetre standard, and the consequent difficulty in keeping the correct count of NO. 1255, VOL. 49] 0-64389 1212-34 I2I2'34 0-50863 153476 153476 0-48000 1626-16 1626-13 If the whole number assumed as the basis of this cal- lation were in error by one or more waves, there would be no correspondence between the observed and the calculated fractions. The length of this standard and the succeeding one are now compared as follows: — The two standards being placed side by side in the refractometer il on a fixed support, and i on a movable carriage, the reference plane (r. Fig. 10) is moved until it coincides with A, the lower (or front) surface of 11, and the interference fringes in white light are adjusted to the proper distance and in- clination by adjusting the inclination of the reference plane. Next, c, the lower surface of i is brought to coincidence with the reference plane, and similarly adjusted, and then all the adjusting pieces are released from the carriages, so that these rest undisturbed on the ways. This completes ihejirst stage of the com- parison. Second Stage.— Th^ reference plane R' is now moved back till it coincides with D, the upper surface of 1 and B II D ---R' I C ' A t; D B I C II A R" -R' Fig. 10. Fig. II. the adjustment of the interference fringes carried out as before. Third Stage.— Tht standard, I, is moved back till its lower surface (C, Fig. 11) once more coincides with the reference plane, r', and its inclination is again adjusted by the interference fringes. Fourth Stage. — The reference plane is finally moved back till it comcides with D, the upper surface of i, and its inclination is again adjusted. If now the standard ll 6o NA TURE [November i6, 189; is just twice as long as l, the fringes will appear simul- taneously on both upper surfaces, D and B. The adjustment of the length of the standards is usually made to within a few waves, and the outstanding differ- ence is measured by a compensating device. This is furnished by the rotation of the compensating plate, Go, Fig. 8. The plate is held in a metal frame which is supported at one end by a short thick rod firmly fixed to the bed. At the other end a delicate spiral spring is attached ; the tension of the spring tiuists the rod through a minute angle, and thus alters the thickness of glass traversed by one of the interfering pencils. The other end of the spring is attached to a flexible cord pass- ing over a pulley which is connected with a graduated circle. The angular motion is thus reduced about 100,000 times, and yet the proportionality is preserved. Suppose the outstanding .difference is f a fraction of a wave-length known to within one or two tenths, then II = 21 + e and consequently the number of red waves should be 2 X I2i2'34 + f. This fraction is corrected by direct observation, as in the case of standard I, and the same control is furnished by the concordance of the results for the three colours ; so that an error in the whole number of waves is well-nigh impossible. The process of comparison and correction is repeated in the same way with the other standards, until we finally arrive at the whole number of waves and approximate fraction in the 10 centimetre standard. Up to this point the question of temperature and pressure is of minor importance, for the comparisons and corrections are made while both standards are under the same con- ditions ; and being all made of the same material, it is sufficient to know that the temperature is the same for both. In the measurement of the fractions on the 10 centimetre standard, however, it is necessary to know the temperature and pressure with all possible accuracy, and it is also important that the comparison of this standard with the metre should be made, as nearly as may be, under the same conditions as that of the deter- mination of the standard in light-waves. The author having been honoured by an invitation from the International Bureau of Weights and Measures to undertake a series of experiments upon the lines here briefly indicated, the necessary apparatus was constructed in America, and shortly afterward installed in the Bureau International des Poids et Mesures at Sevres. Two complete and entirely independent determinations were made. These have not yet been completely re- duced, but an approximate calculation gives for the number of waves of red light in one metre of air at 15' C. and 76 mm. 1st series ... ... ... ... I553i63'6 2nd series I553i64'6 The difference from the mean is half a wave, or about one fourth of a micron.^ From these results it follows that we have at hand a means of comparing the fundamental standard of length with a natural unit — the length of a light-wave — with about the same order of accuracy as is at present possible in the comparison of two metre bars. This unit depends only on the properties of the vibrating atoms of the radiating substance, and of the luminiferous ether, and is probably one of the least changeable quantities in the material universe. If, therefore, the metre and all its copies were lost or destroyed, they could be replaced by new ones, which would not differ from the originals more than do these among themselves. While such a simultaneous destruc- tion is practically impossible, it is by no means sure that, 1 The error in the determination of the relafi'z'e wave-lengths of the three radiations is very much smaller, probably less than one twenty-millionth. NO. 1255. VOL. 49] notwithstanding all the elaborate precautions which have been taken to insure permanency, there may not be slow molecular changes going on in all the standards ; changes which it would be impossible to detect except by some such method as that which is here presented A. A. MiCHELSON. FURTHER XOTES AXD OBSERVATIONS UPON THE INSTINCTS OF SOME COMMON ENGLISH SPIDERS. ly/r ANY of what would otherwise be most interesting ^*- anecdotes respecting the habits of spiders have been related by persons who, being unacquainted with the immense number of " kinds" of this group that there are in England, not to mention the rest of the worlds have apparently considered that all needful information in the way of the animal's identity has been supplied by the simple statement that it is a spider. Such anecdotes have of course a certain value, inas- much as they furnish some general information respecting the instincts of the class as a whole. But to those who are anxious to compare together the instincts of indi- viduals of the same or different species, genera, and families, who are anxious to acquire in short some little knowledge of the comparative psychology of the group, they are distressingly incomplete. To remedy in part these deficiencies, to verify the experiments of others, and to make fresh observations upon some points that are open to dispute, I took the opportunity, during a recent visit to North Cornwall, of compiling a set of notes upon the habits of some of the commonest spiders in the neighbourhood. In the following paper, which is based upon these notes, I have added some brief accounts of the webs, habitats, or general appearance of the spiders, so that those persons who are not acquainted with the animal by name, may yet, with but little trouble, ascertain what the species are that are under discussion. Agalcna labyrijithica. — This spider may be looked upon as the country cousin of the common house spider, Tegcjian'a atrica, which being essentially a lover of bricks and mortar, is found in lofts, disused rooms, &c., where it spins in corners and other angles a horizontal, triangular sheet of web, a familiar structure which must be associated in all minds with the word cobweb. The snares of Agalena are essentially like those of Tegenarid, consisting of a short silken tube or funnel, one end of which is buried in the bush that the spider has chosen to build in, while the other opens upon, and is continuous with, a widely extended horizontal sheet composed of fine closely woven silken threads. During the daytime the spider, if cautiously approached, may usually be seen squatting at the entrance of her funnel. She is, however, remarkably wary, and this, coupled with her equally remarkable agility, makes the task of capturing her by no means an easy one. For, by means of the further open e.xtremity of the tube, she can make her escape into the bush beyond. Wherever I have had an opportunity of observing this spider, I have noticed that it appears to have a special liking for furze bushes ; and it seems reasonable to suppose that this selection of so prickly a site for the building saves the young and also the nest from destruction at the hands, or rather the noses and legs, of cattle. Upon examining the debris of prey, with which the orifice of the funnel was usually strewn, I was surprised to find that it consisted more often of the remains of bees than of flies — generally, indeed, the limbs, wings, C.>04 = sFeClj H- 2HCI 4- 2C0._,. At any temperature the rate at which decomposition takes place is found to follow the well-known law of mass action, which states that the amount of substance which is being decomposed at any instant is proportional to the amount of unchanged substance contained in unit volume of solution. The rate of change, concentration remaining the same, is found to vary to a most marked extent with variation in temperature. Thus at IOO^ in one hour "lo of the original amount of substance was decomposed, whereas at ordinary temperatures after six years only '019 equivalents had reacted. The presence of water accelerates the velocity of change according to a law which varies slightly wuih the temperature, a slight excess of oxalic acid accelerates the rate, a large excess of oxalic acid or of ferric chloride retards it. Excess of concentrated hydrochloric acid almost completely arrests the reaction. The efi'ects whicli these and other materials exert upon the course of the simple reaction, the author studies both by chemical and thermochemi. cal methods, and shows that they may be explained by the occurrence of secondary reactions. The communication, which extends over more than 100 pages, serves to give some idea of the patient labour involved in elucidating the mechanics of what appears at first sight to be a comparatively simple case of chemical decomposition. NO. 1255, VOL. 49] 65 NATURE [November i6, 189; The Calendar of the University College of Xottingham for the thirteenth session, 1893-94, has just been issued. A " Bibliography of the Chinookan Languages " (including the Chinook jargon) has been prepared for the Bureau of Ethnology, Washington, by Mr. J- C. Pilling. Messrs. Perken, Son, and Rayment have published the eighteenth edition of a little book on "Intensity Coils," and the second edition of "The Magic Lantern: its Construction and Use." Both books are suited to the wants of the scientific amateur, Mr. Albert F. Calvert presents, in his "Mineral Re- sources of Western Australia" (George Philip and Son), an array of facts of particular interest to the capitalist and emi- grant. Beneath the surface of that country lie belts and reefs of gold-bearing rocks sufficient to satisfy the most avaricious, and Mr. Calvert is desirous that the profuseness of these and like mineral deposits should convince people that the country offers " mighty possibilities" to enterprise. Dr. 1\L C. Cooke's " Romance of Low Life among Plants," published by the Society for Promoting Christian Knowledge, is an interesting and very readable book on cryptogamic vege- tation. Though written in language " understanded of the people," and full of romantic beliefs connected with plants in a bygone age, scientific accuracy is not sacrificed, and scientific words are not strictly tabooed, as they usually are in the diffuse books designed for the popular palate. A larger number of illustrations would render the book still more interesting and valuable. Dr. a. R. C. Selwyn, C.M.G., F.R.S., the Director of the Geological Survey of Canada, has had a catalogue prepared of the fine stratigraphical collection of Canadian rocks exhibited by the Survey Department at the Columbian Exposition. The collection comprised 1500 specimens, illustrating all the forma- tions known to occur in the Dominion of Canada, from the Laurentian to the Pleistocene. Mr. W, F. Ferrier gives a few explanatory notes with regard to the rocks represented in the collection. If the number of books published on a particular subject can be regarded as an indication of the interest taken in that subject, we are led to the gratifying conclusion that physical laboratories are rapidly increasing. Books dealing with practical physics are constantly being published, and the last received by us — " Practical Work in Heat," by Mr. W. G. Woollcombe (Clar- endon Press) — shares the generally excellent character of works of its kind. It is now believed by all men of science that physics cannot be properly taught by lectures alone, any more than chemistry, and the belief is slowly but surely causing our schools and colleges to give facilities for such necessary prac- tical work. ]Mr. Woollcombe's book includes sections on ther- mometry, expansion, calorimetry, evaporation, and radiation. Excellent experiments are described in each section, and their performance does not necessitate the use of expensive apparatus. In fact, the book contains a practical course in heat that we should like to see introduced into every school which includes physical science in its curriculum. Compounds of carbon monoxide with potassium and sodium respectively have been obtained by M. Joannis, by the action of gaseous carbon monoxide upon solutions in excess of liquefied ammonia of the peculiar compounds which potassium and sodium form with ammonia. M. Joannis has for several years been investigating the nature and reactions of these latter compounds, potassammonium and sodammonium, and the results of his researches have been referred to in previous notes (see Nature, vol. xliii. p. 399, and vol. xlv. p. 158). The reactions which NO. 1255. VOL. 49] occur between these substances and carbon monoxide are of a most interesting character, throwing light as they do upon the nature of the dangerously explosive compound of potassium and carbon monoxide which formerly produced such deplorable accidents during the commercial pioduction of metallic potas- sium by the method of Brunner. A considerable number of investigations have been carried out with the object of obtaining a complete knowledge of this explosive substance, but the re- sults arrived at can scarcely be termed concordant. Most of the \ investigators agree in assigning to it the simple formula KCO, but the descriptions of its properties are very diverse. Liebig and likewise Lerch describe it as a black powder, while Brodie endows it with a red colour. The latter chemist found it to react in a most violent manner with water, while Liebig's sub- stance was much more gentle in its demeanour towards that solvent, and actually permitted of the application of a moderate heat with no more serious result than quiet inflammation. More recently Nietzki and Beuckiser have described it as not only ex- plosive but as detonating, when exposed to the moist atmosphere, under the influence of the least concussion in its neighbourhood. The potassium compound now described bears most resemblance to the unstable substance of Brodie and of Nietzki and Beuckiser, although differing in several particulars. The analogous sodium compound does not appear to have been pre- viously obtained. When dry carbon monoxide is allowed to bubble through a solution in liquefied ammonia of potassammonium, the blue sub- stance of the probable composition (KNH3) n produced by dis- solving metallic potassium in liquefied ammonia, the containing vessel being cooled to - 50°, the deep blue colour gradually diminishes in intensity, and is eventually supplanted by a pale rose tint, the attainment of which signifies the completion of the interaction. Upon removal from the cooling mixture the lique- fied ammonia gradually vaporises, depositing as it does so a rose- coloured powder which upon analysis proves to be pure potassium carbonyl KCO. When left undisturbed in a sealed tube for some time this pink powder darkens in colour, then answering very closely to the description of Brodie's substance. It cannot be heated to the temperature of boiling water, explo- sion ensuing considerably below that temperature. Detonation likewise occurs if the merest trace of air is admitted, and instantly when touched with a drop of water. Air and water both appear to act by causing such an elevation of temperature by their reaction with a small portion as to bring about sudden decomposition of the whole. It is, however, possible to study the reaction with water by admitting a drop of that liquid into an exhausted tube containing potassium carbonyl in such a manner as not to come into direct contact with the substance ; the aqueous vapour then slowly reacts with the apparent pro- duction of deliquescence and the eventual formation of a yellow viscous liquid. The nature of this liquid is reserved for a future communication. Sodium does not resemble potassium in directly uniting with carbon monoxide. Sodammonium (NaNHj);/, is, however, readily decomposed by carbon monoxide with formation of sodium carbonyl, NaCO, a substance which may be isolated in a manner similar to that employed for the isolation of the potassium compound. It is a pale lilac-coloured substance which is powerfully explosive like its potassium analogue. Detonation ensues under the influence of small quantities of either air or water. Under the influence of heat its colour darkens, no gas is evolved, but about 90° sudden explosion occurs, and with such force that no glass has yet been found to withstand it. It also explodes like the potassium compound under the influence of percussion, although not quite so readily as the latter substance. Tiie nature of the changes occurring in November i6, 1893] NA TURE 67 the explosion by percussion were ascertained by performing the reaction in a sealed tube of strong glass, also containing a few i^'lass beads. The rattling of the beads was sufficient to induce explosion, and in one experiment out of a large number the tube remained intact. It was found that the products were all solid substances. The main reaction proceeds in accordance with the equation 4NaCO = NaoCOj -f NaoO + 3C. A small quantity of sodium cyanide was also produced. When a drop of water i^ introduced into a similar tube detonation immediately occurs, and the whole tube is filled with a red flame, the colour of which may perhaps be accounted for by the fact that a considerable quantity of hydrogen gas is liberated. The other products of the reaction are sodium carbonate, free carbon, and a small proportion of carbon monoxide. Water vapour, however, reacts in a quiet manner, as in the case of potassium carbonyl, the substance successively changing colour to iTick-red, reddish- hrown, and dark violet, until at length a viscous liquid of a deep red colour is produced, whose nature, together with that of the liquid derived from the potassium compound, M. Joannis is now investigating. Notes from the Marine Biological Station, Plymouth. — Last week's captures include a specimen of the fine Nemertine Cerebratulns i-oseia:, now first recorded for the British Isles. There are clearly hosts of interesting forms in the deeper water off the Devon and Cornish coasts, if only we had a stout ■steamboat from which to dredge this rich locality. The float- ing fauna has not been rich, owing to the prevalence of northerly and easterly winds. The presence of Radiolaria, in spite of this, has been an interesting feature. Terebellid and Polynoid larvK, Sa^itta, and a few Ophiuroid Phitei have also been observed. The additions to the Zoological Society's Gardens during the past week include a Bonnet Monkey (Ulacacus siniciis, ? ) from India, presented by Mr. James Kendal ; a Hairy-nosed Wombat {Phalascovtys latifrotis, 6 ) from South Australia, two Marabou Storks {Lcptoptilus criemeiiijertis), a White-necked Stork ' Disstira episcopiis) from West Africa, a Javan Adjutant (.LeptoptiUis javanicus) from Java, presented by Mr. E. W. Marshall, F.Z.S. ; a Macaque Monkey Macacus cynomolgiis, 9) I from India, presented by Mrs. B. E. F. Stevens ; two and three ' Hedgehogs {Erinaceits ettroficus) British, presented respectively by Mr. W. Chatterton and Mr. A. S. Bird ; two Herring Gulls {Lams a>-gen'alii:) British, presented by Mr. B. Tremble ; a ; Blossom-headed Parrakeet {Palaornis cyanocephahts, i ) from • India, presented by Mrs. Osmond Barnes ; a White-handed Gibbon {Hylobates lar., 9) from the Malay Peninsula, de- posited; a Mona Monkey {Cercopithectis mona,S )Iiom West Africa, two Lapwings ( Vaitelhcs vti/§aris), a Common Curlew {Xumenius ar juata) British, purchased ; three Dingoes (Caiiis diii^o) born in the Gardens. OUR ASTRONOMICAL COLUMN. I Brooks's New Comet (18931:).— In the Astronomical \fournal (No. 306), Prof. E. E. Barnard briefly describes a I photograph of this new comet, which he was able to obtain with I a 6-inch Wiliard lens. The exposure was made under con- ; ditions not very conducive to good results, owing to the low position of the comet and the presence of the zodiacal light. The negative exhibits, however, many points of interest, and its characteristic features are described as similar to those shown ■ i in the photographs of Swift's comet 1892 I. Prof Barnard's I ; description is as follows : — '• The plate shows the tail to a dis- I \ance of 3^'. This tail irregularly divides into two slightly I divergent branches. There are two narrow straight rays spring- ! ' ing out from the head on opposite sides, and nearly symmetrical j ■ with the main tail. The north ray, which seems to leave the 1 NO. 1255, VOL. 49] s region of the nucleus, is inclined to the body of the comet by about 45' ; the southern, which leaves the comet 10' or 15' back of the head, is inclined about 30^ They are both about .V' long. There are faint evidences of several other rays from the southern side of the comet." BiELA Meteors. — The return of the " Andromedes " this year is looked forward to with special interest, owing to their great abundance last year. It will be remembered that in 1892, instead of arriving on November 27 or 28, as was expected, the maxima occurred about the 23rd, or four days in advance of the predicted time, so that observers this year must be on the Old vivc early. The director of the Pulkova Observatory, M. Bredichin, accounts for this retrograde motion by supposing it to be caused by the perturbations of Jupiter, which during 1890 were very great. Besides a retrogradation of the node amount- ing to 4', the inclination of the orbit has largely diminished. The Planet Jupiter. — Jupiter's red spot, although preserv- ing its oval form, is very dim, and is less sharp than in preced- ing years. The general aspect of the disc seems to have sensibly undergone changes and shows many more details, as if the cloudy atmosphere of the planet had been more than usual dis- turbed. Numerous observers are now scanning his disc, and some recent results are contained in the current number of V Astronomic (No. ii^. M. Guiot has made a series of draw- ings which are there produced ; they show how the equatorial belt has gradually advanced to the west relatively to a small black spot indicated in the drawing, and has consequently made the latter appear to have a motion in the opposite direction, i.e. eastwards. The motion is clearly shown by a change of inclination in a line connecting the same two spots in the series. A New Variable Star. — The Rev. T. E. Espin announces from the Wolsingham Observatory that a red star (anonymous) at R.A. igh. 7m. i6s., Deck -f25"'46, is variable. Its magni- tude on August 21 was 9*0, but it has diminished to I I'D mag. Photographs taken with the Compton telescope have confirmed the variability of Es. 329 (R.A. I9h. 59m. 6s., Deck -(- 36^-25). The "Observatory " for November. — In thecurrent num- ber of this monthly, Mr. T. Lewis concludes his interesting survey on the various methods of computing double-star orbits. Mr. H. H. Turner describes briefly a short method of obtaining a star's right ascension and declination from a photograph, the results being correct to less than a second of arc. Mr. Dunkin, in a letter to the editors, gives the text of the ''Adams Me- morial," lately placed in the north transept of Truro Cathedral, and erected at the expense of a few Cornish friends and admirers, both resident and non-resident, as a mark of their high esteem for him as an astronomer and mathematician, and also for the strong afiection he always entertained to the end of his life for the hills and dales of his native county. The translation is as follows : — In this place, as is his due. We commemorate our own [West] countryman John Couch Adams Tracing his way By the sure clue of Mathematics Through the boundless night of space He found the outermost of the planets. Faithfully pursuing the paths of the Sciences With single-hearted modesty and clearness of intellect, He loved God Whom he saw in the Face of Christj For him, as well as for Henry Martyn, Cornwall and Cambridge Owe each other mutual debts. He died, dearly loved by all who knew him, On the 2ist of January 1892, Aged 72 years, 7 months, 16 days. Solar Observations at Catania, Rome, &c.^Prof. Ricco, in the August number of the Memoire della Sociela a'egli Spectroscopisti Italiani, gives a detailed account of the observa- tions of solar protuberances observed at the Royal Observatory of Catania during the year 1892. The same number contains two of the large diagrams showing the sun's limb as observed at Catania, Palermo and Rome, one for Februar}--March 1892, and the other for March-April of the same year. 68 NA TURE [November i6, 1893 THE STIGMATA OF THE ARACHNIDA, AS A CLUE TO THEIR ANCESTRY. T F on a diagram of an Arachnidan body we mark every segment -*■ on which stigmata are said to occur, the result is somewhat remarkable. The subjoined figure is such a diagram, and stigmata, functional or vestigial, are known on all the segments except the second and third. On the left hand of the diagram I have recorded the form which the tracheal invaginations from each pair of stigmata assume, i.e. whether they are tubular or laminate ; and on the ri|^ht hand I have lioted the genera in which the stigmata occur, with a straight underline if their trachere are tubular, and a wavy underline if their trachere are laminate. The marks which re- present the stigmata are not intended to denote their real positions on the segments, but only to indicate their presence, although there is reason for thinking that they may well repre- sent their primitive positions. On the first segment we have stigmata recorded on the dorsal surface at the bases of the mandibles in some Acaridje. This remarkable position may be in in some way connected with the formation and dorsal arrangement of the " cephalic lobes," ^ which accompanies the translocation of the mandibles from a post oral to a pre-oral position. All the other tracheae of the Arachnida are associated with limbs, the Arachnida agreeing in I 7ui(iUr H M TV Tuiu^Uy it 7:Ualiy TTii.UtT -J a T.Vu.ls.y- 1 ''' Lim.Cn iic /3 /^ /S 'Ji. fie^nlA. I ' L^m^i^ny^ sent the closed stigmata of vanished tracheae, which trachea, if we may judge from the ram's-horn organs and the functiona- trachere on the second and third abdominal segments, were all most certainly tubular. From these facts we are justified in concluding (i) that the tracheal invaginations of the ancestor of the Arachnids were strictly segmental, and (2) that these invaginations were of some simple tubular type, from which the laminate forms could be easily developed. The ram's-horn organs of the Chernetid?e, with the simple air chambers in their epithelial cells as recently de-cribed {I.e. supra), might well represent such primitive in- vaginations. An impartial review of the facts must convince everyone that the laminate form is the more specialised. The tubular form i& by far the most widely distributed, being not only universal among the Hexapoda and Peripatida:, but far more common among Arachnids than the laminate. Tubular trachese occur universally in the Acaridre, which have some claim to be con- sidered as fixed larval forms {JoiiryLinn. Sac. Zool. vol. xxiv. p. 279) ; in the Phalangida?, which a^e so specialised that they must have br.inched off very early from the main Arachnidan stem ; in the Chernetidse, which again are very difficult to class, and may claim to be an independent group ; and lastly in the Galeodida;, which in many respects are the most primitive of all Arachnids. The Araneidae, with their highly specialised abdomen, possess both laminate and tubular forms, while the Scorpionidae and related Pedipalpi are the only Arachnids, and indeed/ the only Arthropods (except a few Myriapods), which have exclusively laminate tracheae.. The laminate trachese of the Myriapods cannot possibly be deduced from the laminate tracheae of the Arachnids, but both forms of laminate tracheae can be deduced from a primitive tubular organ. Returning to the diagram, the facts therein, epitomised presuppose the existence in the ancestor of the group of simple limbs on . and Sidney Sussex. The examinaiions will be held in December and January, next. Trinity College, Dubli.v. — There is during this term a large increase in the number of students interested in the study of biology ; so large, in fact, that the accommodation in the Botanical Laboratory has had to be increased. This is a pleasing feature in a university so long devoted to classical pursuits. At the recent Moderatorship Examinations, three candi- dates, C. J. Patten, -F-. K. Boyd, and N. H. Alcock, obtained Senior Moderatorships, and were awarded gold medals in Natural Science (Botany, Zoology, Geology, and Physiology). During the week the University Experimental Science Associa- tion" held its opening meeting, when a very large audience assembled to hear Dr. Joly, F. R. S., deliver a lecture on '■ Some Applications of Photography." The Provost, Dr. Salmon, occupied the chair. The British Medical yournal %:iy% that steps are being taken to arrange for a deputation representing the university colleges in England to wait, shortly, upon the Chancellor of the Exchequer, to urge upon him the propriety of increasing the annual parliamentary grant. A sum of ;,{^is,ooo has been granted annually since 1890, and when this sum was first placed upon the estimates, it was understood that the question would be reviewed at the end of five years. A Treasury Committee, consisting of Sir Henry Roscoe, Mr. George Curzon, Prof. Bryce, Mr. R. G. C. Mowbray, and Mr. W. J. Courthope,' have reported recently in favour of the grant being doubled, pointing out that all educational work connected with science is increasing yearly in cost, and that the growth in the number of students and the enlargement of the teaching staff have con- tributed to strain the resources of the colleges. SCIENTIFIC SERIALS. Bulletin of the NewYork Mathematical Society, vo\. iii. No. i. (New York: Macmillan, October, 1S93.) — A congress of mathe- matics and astronomy was opened at Chicago on August 21, and this number commences with Dr. Felix Klein's inaugural address. It is brief but not witty, and merely sketches some of the papers to be read, and closes with the remark that mathematicians must go farther than to form "mathematical societies." "They must form international unions, and I trust that this present congress at Chicago will be a step in that direction." Prof. T. H. Safford narrates briefly, in his remarks on "instruction in mathematics in the United States," the history of the noteworthy rise in the general standard of mathematical teaching within the last few years. Prof. Ellery Davis reviews four recent geo- metries, viz. those by Hopkins, Dupuis, \V. B. Smith, and Halsted. Prof. Tyler analyses the papers read at the Chicago congress, and Prof. Waldo ^'ives a brief account of the Ameri- can Association meeting at Madison on August 16-23. Th'-ee ];ages cf notes cf mathematical doings, and eight pages of new puhlications f-.Uow. This last feature of the Bulletin is a very p'oniirent and highly valuable one. The Aincricau Meteorological y oiirnal for November contains an account of the second annual meeting of the American Asso- ciation of State Weather Services, held in Chicago, on August 21-23, 1593. The meeting was well attended, and resolutions were adopted on various subjects, among which may be mentioned the issue of weekly crop bulletins. It was also recommended that the bottom of thermometer screens should be four and a half feet above the ground ; this would make the thermometers about a foot higher than is recommended in this country. It is stated that experiments made during the jiast year prove the former elevation to give the best results. — Mr. C. E. Linney read a paper on the value of frost predictions, and the best method of making them locally. The author is of opinion that with a knowledge of the ordinary weather signs an observer can, by the aid of the wet and dry bulb thermome- ters, form a good idea of what minimum temperature to expect during the night. In the Transactions of the Aust>ian Geological Survey we remark an important communication, made by Mr. Friedrich Teller, "On the so-called Granite of the Bacher Mountains in South Steiermark." It seems that the familiar term, "granite of the Bacher," has been eatirely misapplied. In the eastern part of these mountains the rock is granitic ^;/mi, forming a dome-shaped core beneath the crystalline schists ; while the so- called granite in the western part is an intrusive porphyrite, younger than the whole series of schists and phyllites, and pos- .«ibly of the same age as the porphyrite which penetrates Triassic and Jurassic strata in the neighbouring district. — Dr. A. Kornhuber gives the name of Carsosaurus Marchesetti lo a new Saurian genus from the Karst district. It was found in the same cretaceous shales as Acteosaurus, a genus described thirty years ago by Hermann Meyer, and was erroneously thought to be merely a larger specimen of Meyer's genus. SOCIETIES AND ACADEMIES. Pa:^is. Academy of Sciences, November 6. — M. Lcewy in the chair. — On Goubet's Joint and its application to marine screw- propellers, by M. H. Resal. This is a mathematical investiga- tion of the action of a joint capable of making the propeller act as supplementary steering ^ear, and of adapting it to submarine navigation. It is shown to possess several advantages over the NO. 1255, VOL. 49 J 72 NATURE [November i6, 1S93 similar American Clemens joint. — On a class of differential equations whose general integral is uniform, by M, Emile Picard. — Sigr.i.icance of the variety of organs in the gradation of vegetable species, by M. Ad. Chatin. — On a Nymphaea bed recently found and explored in the Aquitanian of Manosque, by M. G. de Saporta. — On equations of the second order with fixed critical points, and univocal correspondence between two surfaces, by M. Paul Painleve. — On certain ordinary differential equations, by M. Alfred Guldberg. — On certain families of gauche cubes, by M. Lelieuvre. — On the nature of the reflection rif electric waves at the end of a conducting wire, by MM. Kr. Blrkeland and Ed. Sarasin. — Observations upon the preceding communication of MM. Birkeland and Sarasin, by M. H. Poincare. This is an application of Maxwell's theory to the phenomena of propagation of energy into space round the end of a conducling wire along which electric waves are passing. It is shown that the deductions from the theory are in general accord with the facts observed. — On the measurement of co- efficients of induction, by M. H. Abraham. The employment of a differential galvanometer in these measurements permits of an accurate determination within i percent., and a reading to within o'l per cent, without much difficulty. The induced currents from a commutator regulated by a stroboscopic method are sent through one circuit of a differential galvanometer, the deflection being compensated by a continuous current derived from the same battery. The commutator is then stopped, and a current equivalent to the induced current is derived from the primary circuit through a resistance r, and sent through the secondary circuit, r being chosen so as to establish equilibrium in the differential galvanometer. Then this actual resistance r may be put equal to the fictitious resistance nM. obtaining while induction was going on, and we have M = ^ where M is theco- n efficient of mutual induction, and n the frequency of the com- mutator. The resistance r may be constituted by a standard ohm coil. M. Abraham has found by this method that ihe coefficient of mutual induction is reciprocal in the case of two circuits free from iron, but that this reciprocity is disturbed if they contain iron cores. — On vision of opaque objects by means of diffracted light, by M. Gouy. If an opaque and non-reflecting object is examined by means of a microscope or telescope, the object being placed in the path of a beam of light, the image is formed both by the rays following geometrical paths and by those diffracted by the outlines of the object. If the former are intercepted, the diffracted rays only form the image. This may be done by placing a small screen at the focus of the object-glass inside the telescope, so as to intercept the rays from a very distant source which converge there. The outline of the object is then seen as a thin bright line on a dark background, and with sufficient enlarging power this line is seentoconsist oftwo,very close together, and separated by a very sharp black line. This black interval disappears on intercepting the diffracted rays either inside or outside the geometrical shadow, thus showing that it is due to the inter- ference of these two beams. They possess a difference of phase nf half a wavelength, and equal amplitudes. An arrangement such as this may prove useful when the outlines of an object re- quire to be sharply defined. — On a new method of preparing methy- Inmine and on the constitution of hexamethylene-tetramine, by MM. A. Trillatand Eayollat. — On the alkaline methyl-tartrates and ethvl-tartrates, by M. J. Fayollat. — Researches on the homo- logues of gallanilide ; preparation ofgalloparatoluide, by M. P. Cazeneuve. — Experimental hereditary influences, by MM. Gley and Charrin. — On a phenomenon of inhibition in Cephalopoda ; paralytic constriction of chromatophores, by M. C. Phisalix. — r»n the serial craniological continuity in the genus Lepus, by M. Remy Saint-Loup. — On the genus Polydora Bosc {Leiicodore Johnston), by M. F. Mesnil. — The Callibrachion, a new reptile of the Permian of Autun, by MM. M. Boule and Ph. Glangeau. — On the glacial and erratic phenomena in the Cachapoal Valley (Andes of Chili), by M. A. F. Nogues. The phenomena of transport by water and glaciers have contributed to the formation of the erratic system in the valleys of the Chili Andes. There must have existed lakes or deep terrace ponds. The glaciers must formerly have descended further than they do at present, and at the Cachapoal they are actually retreating now. — An earthquake shock at Grenoble, by M. Kilian. This happened at 4h. 13m. 40s. A.M., Paris time, on November 5, in a direction from N. to S., and was recorded by the seismometer of the Geological Laboratory of the Faculty of Sciences. BOOKS, PAMPHLETS, and SERIALS RECEIVED Books.— Social Eng!.^nd : edited by H. D. Traill, vol. i. (Cassell).— Xew Technical Educator, vol. ii. (Cassell). — Guelphs and Ghibellines : O. Brown in? (Methuen).— Intensity Coils, 18th edition (Perken). The Magic Lan- tern, 2nd edition (Perken). — British Fungus Flora: G. Massee, vol. 3 (Bell), — Weather Lore: compiled, &c., by R. Inwards (Stock). — Les Courants Polyphases : J. Rodet et Busijuet (Paris, Gauthier-Villars). — Pour Devenir Financier: R. Chevrot (Paris, Gauthier-Villars).— Golf : a Royal and Ancient Game : edited by R. Clark, 2nd edition (Macmillan). — Aberration Problems: Prof. O. J. Lodge (K. Paul).— Eighth Annual Report of the Bureau of Ethnology : J. W. Powell (Washington). — Diamonds and Gold in South Africa : T. Reunert (btanford). — The Incandescent Lamp and it.s- Manufacture : G. S. Ram (" Electrician" Co.). — Eine Botanische Tropen- reise. Prof. Dr. S. Haberlandt (Leipzig, Engelmann). — Der Botanische Gaiten "'s Lands Plnutentuin " zu Buitenzorg auf Java (Leipzig, Engel- mann).— Grundziige der Physiologischen Psychologie : Prof W. Wundt, Zweiter Band (Leipzig, Engelmann). — Die Allmacht der Naturiiichtung : Prof. A. Weismann (Jena, Fischer). — Australasia, vol. i. : — Australia and New Zealand: Dr. A. R._ Wallace (Stanford). Pa.mphlets. — Fenomeni Geodinamici che precedettero, accompagnarono e Seguirono I'eruzione Etnea del Maggio Guigno i8£6, S. Arcidiacono.- Electro-Cultur? : P. de Puydt (Bruxelles). — Ethnography of the Ara» Islands, Co. Galway, A. C. Haddon, and C. 'R. Biowne (Dublin). — Bibliography of the Chinookan Languages : J. C. Pilling (Washington). — Catalogue of a Stratigraphical Collection o Canadian Kocks prepared for the World's Columbian Exposition, Chicago 1893 : W. F. Ferrier (Ottawa), — Das Karstphiinomen : Dr. J. Cvijic (Wien, Hulzel). — Uie Biologie ali» selbstiindige Grund wissenschaft : H. Driesch (Leipzig, Engelmann). — Tafe! des Integrals : B. Kampfe (Leipzig, Engelmann). — On the Volcanoes and Hot Springs of India: Dr. V. Ball (Dublin). Serials. — Kansas University (Quarterly, October (Lawrence, Kansas). — American Journal of Science, November (Newhaven, Conn.). — Bulletins der la Sociit^ d'Anthropologie de Paris. Nos. 8 and 9, 1893 (Paris). — L'Astro- nomie, November (Pans). — Zeitschrift fiir Wissenschafrliche Zoologie, Ivi. Band, 4 He(t (Williams and Norgate). — American Naturalist, October (Philadelphia). — Morphologisches Jahrbuch, 20 Band, 3 Heft (Williams and Norgate). — Physical'Society of London, Proceedings, vol. xii. Part 2 (Taylor and Francis). — American Journal of Mathematics, vol. xv. No. 4 (Baltimore). — Proceedings and Transactions of the Queensland Branch of the Royal Geographical Society of Australasia, vol. 8 (Brisbane). CONTENTS. PAGE Romanes on Weismann. By P. C. M 49 Extra-Tropical Orchids. By R. A. Rolfe 50 Our Book Shelf:— Gore: " An Astronomical Glossary " 51 A Son of the Marshes : " With the Woodlanders and By the Tide" 51 Taylor; " Pitt Press Euclid, V.-VL " 53 Furneaux ; " The Out-door World, or Young Col- lector's Handbook" 52 Briggs and Bryan : " Worked Examples in Co-ordinate Cieometry" 52 Letters to the Editor : — Sir Henry H. Howorth on " Geology in Nubibus." — Dr. Alfred R. Wallace, F.R.S 52 The Erosion of Rock-Basins.— Prof. T. G. Bonney, F.R.S 52 "The Zoological Record." — R. I. Pocock; F. A. Bather ; B. B. Woodwrard 53 Recoostulate, which would have won the hearts of the old school- men. Henry H, Howorth. 30 Collingham Place, Cromwell Road, November i6. Rock Basins in the Himalayas. There is one statement in the interesting communication of my colleague, Mr. T. D. LaTouche, which seems to require qualification. After a tolerably extensive experience of the Himalayas, I should be inclined to say that rock basins are of lairly frequent occurrence, of all sizes from the largest to the smallest, but they are almost without t xception filled with stream deposits, and only occasionally -can their formation have been due to glaciers ; for they are usually found where there are no traces of glacial action to be seen, and at levels to which we have no reason to suppose that glaciers ever reached. In the liills of eastern Baluchistan, where the rainfall is much less than in the Himalayas, rock basins more or less filled by recent sur- face deposits are even more common, and here their origin by deformation of the surface can generally be established. The same cause probably accounts for the Himalayan rock basins, as there are abundant proofs that the elevatory movement has been far from uniform, and that the variations in its intensity have been both extensive and often extremely local. There are fre- quent occurrences of suiface deposits which appear to have originally been formed in rock basins, but have since been cut into by the streams, owing to the corrasion of the barrier, and we may attribute the absence of lakes in the Himalayas to the rapid current and large burden carried by the streams, in con- sequence of which they have been able to fill up the basin, and often to corrade the barrier, as fast as it was formed. R. D. Oldham. " Composite " Dykes. Prof. Jui>d's excellent paper in the current issue of the Quarterly /otcrnal of the Geological Society (p. 536) calls to mv mind some common and similar examples among the " elvans " of Cornwall (whicli are dykes in the ordinary acceptation of the term), and but little has tieen published offering some explana- tion of their bea ing on urroundinij rocks. I have observed, notably in the district of Cligga Head (nine uiiles N. W. of Truro), the marked difference between the structures exhibited by dykes in the parts in contact with the rock through which tfiey intruae (in the Cligga instance Devonian slate), and their centre, amounting almost to a rock distinciion. In the appended sketches I have endeavoured to illustrate my meaning from ac ual instances. Fig. I represents a section of an elvan or dyke outcropping slightly to the north of Cligga promontory, and from its position apparently connected with the main mass of Cligga Head granite, k bursts through the slate. The centre {l>) of the dyke con- sists of a rock of homogene'>us tex'ure, quartzo-felspathic base, and some scattered p arphyritic felspar crystals. The sides (a a) NO. I 256, VOL. 49] in contact with the slate {s i) show a rock of apparently similar base, but shot with long a^icular crystals of schorl, the whole rock being of a very dark colour, due probably to the presence of wolfram. Fig. 2 is a section of a very common form of Cornish elvan, consisting of alternate laminre of granite {(id) and " schorl rock," that is, rock consisting of schorl and quartz, generally in about equal proportions {cc). These bands are very common in the slates and in the granitic bosses. Further, an analysis of a typical " schorl rock " of this class showed a silica percentage of Gy6 {vide Judd's l aper, s ^ Fic. I. p. 1545), and of a typical granitic band of 74 "8 (De La Beche, " Report on Geology of Cornwall, Devon, and West Somer- set," p. 189). It is very doubtful, however, if either of the above instances is a case of a d}ke putting on such differences in mineralogical and chemical character in its several parts as to amount to a difference of rock species. As De La Beche points out, the schorl rock may be simply a f raniie in which the felspar and mica are replaced by schorl. An instance, however, of a rock one may call " a dyke within a dyke " is the Cligga mass itself, which is nothing but a gigantic d)ke. De La Beche, in his work above cited (p. 164), has figured it. The d}ke is so strikingly split into layers as to appear stratified, the hard comparatively small-grained layers standing out in bold relief from the contiguous layers of more easily decomposed rock with their large porphyritic felspar crystals. Besides the difference in size of the felspar crystals, the harder rock is much darker in colour (being of a red hue) than the softer, which is pale pink and in places whitish. These physical differences, however, count for little in drawing a distinc- tion of rock species between the layers, and I was unfor- tunately unable to avail myself of any published analyses of the different parts, but their superficial characters are so distinct as 78 NATURE [November 23, 189^ to render the stratifiefl appearance of the rock very marked at comparatively great distances from them. There is in many cases a crack marking the junction of con- tiguous layers. As an illustration of these "composite " dykes, I append a diagrammaiic sketch representing a section of the coast about 200 or 300 yards south of the Cligga promontory, which is very difficult of approach. A has all the appearance of a bed of sandstone, the strata curved, owing to the intrusion of the dyke B (granitic) ; C is an // '3^ Fig. old tin burrow. As a matter of fact, each is a granitic dyke, A finer grained than B, and very like sandstone in all petrological features. The reinarkal)le fact is the apparent stratification of the beds A, which are rrally bands of several dykes — a continuation of those figured a' p. 164 in De La Beche's book. He does not seem to have observed this instance, or at any rate does not mention it ; his figure is from the cliff immediately in contact with the Clig>ja promontory, and north of that I have figured. Further instances of this very interesting kind of composite dyke would hel,' in many cases to unravel the seeming com- plexity of such geological features as those I have lojched upon in Cornwall. Henry E. Ede. 45 Walker Terrace, Gateshead-on-Tyne, October 4. Weismannism. I NEVER answer reviews, save in so far as they may be mis- leading on matters of (act. As this is the case with "P. C. M.'s" notice of my "Examination of Weismannism" (Nature, November 16), I should like to say a few words touching the more important of such matters. It setms that in seeking to do justice to all sides in the heredity question, I have been too careless in expressing my own view. At all events, any one reading the review must gather from it that I am a Lamarckian engaged in fighting the theories of Prof. Weismarin. in the book, however, it is stated that I have been an adherent of the theory of Stirji ever since it was published by Mr. G:dton in 1875. It is also staled that this theory is, in my opinion, identical, as regards all main principles, with that of Gtrmplasm in the present phase of its numerous metamor- phoses. Therefore, far from fighting the Weismannian theory of heredity, I see in all its main features, as it now stands, a " re-pul)lication" of the one which I have held for close upon twenty years. It is further stated that the only points of much secondary importance wherein I can perceive the two theories to differ are, / . that while Gallon coifined him.self to publishing a theory Heredity, Wei mann proceeded to rear upon this basis {i.e., ilic hypothesis (.f "continuity") a further and elaborate theory of otgmic evolution ; and, (/;), that Weismann has not gone so far a- Gabon did in expressly recognising the possibility of an occasioT'al transmission of acquired characters, in faint though presumably accumulative degrees. As regards these two points of difference, 1 have endeavoured to show, [a), that Weismann has now himself withdrawn nearly all his previous generali.'a- tions with regard to organic evolution, while largely modifying his the..ry of heredity ; and, [b), that he has only to expand cer- tain hints \\hich he has already given— and which, if expanded, would eiitail much less modification of his original system than those which he has now made in other parts thereof— m order as NO. 1256, VOL. 49] fully to recognise as Galton did the possibly occasional trans- mission of acquired characters. Hence, such opposition as I have found any reason to express with regard to Weismann's system in the late-t phase of its development arises, almost exclusively, aga nst the inordinately speculative character of his method. The history of science furnishes no approach to such a disproportion between deduction and induction. Thus it seems to me that any wriier on Weismannism who aims at impartiality must fail in his aim, if he does not give due prominence to this the most distinctive feature of Weismann's method. And, unless the reviewer is prepared to defend such a method as scientific, he has no reason to quarrel with what he calls my "hard words," since they all have reference to it, and are statements, not of opinions, but of facts. On the other hand, I have endeavoured by "soft words" to fully rec ignise the great merit of Wei>mann's work in con- sti'uting the heredity questi >n one of world- Aide interest. And any bias that I may have with regnrd to this question is as- suredly on the side of " continuiiy," although 1 cannot hold that the subordinate question is closed — i.e., as to whether sucli continuity can never, under any circumstances or in any degrees, be interrupted. GejRGE J. Romanes. Hyeres, November 20. Correlation of Solar and Magnetic Phenomena. Mr. Ei.lis, in his letter (Nature, November 9), has dis- cussed the coincidence between Carrington's o!)servation of a solar outburst in 1859 and the magnetic movements observed at Kew and Greenwich. He comes to the conclusion 'hat the dis- turbance of the magnets corresponding to this outburst was small, and that, although many greater magnetic movements have occurred since, no corresponding minifesiation has been seen, although the sun has been so closely watched. He appears to have overlooked an observation mide at Sher- man, by Prof. Young, which shows a very striking series of coincidences, and which is described in his work, " fhe Sun'" (p. 156), in the following words: — "On Au^ju t 3, 1872, the chromosphere in the neighbourhood of a sun-«|)Ot, which was just coming into view around the edge of the sun, was greatly disturbed on several occasions during the forenoon. Jets of luminous matter of intense brilliance were projected, and the dark lines of the spectrum were reversed by hundreds for a few minutes at a time. There were three especially notable parrxysms at 8.45, 10.30, and II.50 a.m., local time. At dinner the photographer of the party, who \n as making our magnetic observations, told me, before knoA'ing anything about what I had been observing, that he had been obliged to give up work, his magnet having suung clear off the scale. Two days later the spot had come round the edge of the limb. On the mornin.jof August 5, I began ol seivations at 6.40, and for about an hour witnessed some of the most rematkal)le phenomena I have ever seen. The hydrogen lines, wiih many others, were brilliantly reversed in the spectrum of the nucleus, and at one point in the penumbra the C line sent out what looked like a blowpipe jet, projecting toward the up|)er en I of the spectrum, and indicating a motion along the line of sight of ab )ut 120 miles per second. The motion would die oai and be renewed again at intervals of a minute or two The disturbance ceased before eight o'clock, and was not renewed thai forenoon. On writing to Englarid, I received from Greenwich and Stony- hurst, through the kindness of Sir G. B. Airy and Rev. S. J. Perry, copies of the photographic magnetic records for those two days On August 3, which was a day of general magnetic disturbance, the paroxysms I noticed at Sherman were accompanied by peculiar twitches of the magnet in England. Again, August 5 "■'^-s a quiet day, magnetically speaking, but ju-t during that hour, when the sun-spot was acive, the magnet shivered and trembled. So far as app' ars, too, the magnetic action of i he sun was instantaneous. After making allowance for longitude, the magnetic dis'uibance in England was strictly simulianeous, so far as can.be judged, with the spectroscopic disturb ince seen on the Rocky Mountains." These observations of Prof. Young's seem to invali late Mr. Ellis's statement that " no second occuirence similar to that of 1S59 has come to light," and that although there undoubtedly exists a relation between suii-spo's and magnetism, "it has not yet been found possible to trace direct correspondence in details. Cambridge, November 12. A. R. IliNKS. November 2t„ 1893] NATURE 79 The circumstances spoken of by Prof. Yonng, as alluded to in the accompanjing letter, tell of special solar activity at the time of magnetic di>tuibance, observed solar paroxysms occurring apparently in ciTrespondence with magnetic move- ments ; but the ques ion whether definite connection exists-, is the really critical point, as in the Carrington observation of 1859. Prof. Young himself says ("The Sun," p. 159) : — " So far as appears, the magnetic action ofthei-un was instantaneous. After making allowance for longitude, the magneiicdisturbance in England was strictly simultaneous, so Jar as can be Judged, with the spectroscopic disturbance seen on the RocUy Moun- tains." ( The italics are mine.) Without being over-cm ical, it may be remarked that the terms "instantaneous" and "strictly simultaneous " are somewhat strong, in the circum- stances o! the case. Feeling that too much importance had been by various writers attached to the Carrington observa'ion, I may have been led to the expression of a too pronounced opinion thereon. Rather it might be said that direct connection is not pr(.ved. It is to be remembered that the cases of recoided occurrence together of solar and magnetic phenomena are few, whilst solar change (such as is s(mietniics actually observed, or as is remarked in the changed solar appearance from day to day) withuut magnetic action, and very frequently magnetic action without recorded sohir change, both occur in greater degree than, on the supposition of direct connection between the two classes of phenomena, would be expected. Prof. Young, indeed, further says : — "No two or three coincidences such as have been adduced are sufficient to establish the doctrine of the suu's immediate magnetic action upon the earth, but they make it so far probable as to warrant a careful investigation of the matter — an investi- gation, however, which is not easy, since it implies a practi- cally continuous watch of the solar surface." One main diffi- culiy is here pii^s, vol ix. p. 23). But, in the necessarily brief remarks to which I must limit myself this evening, to indicate Prof Klein's claims to distinction by dwelling upon individual subjects which he has treated, would, I think, be warning in perspective and proportion. Great as is the reputation which he has acquired in connection with particular branches of mathematical research, that which would seem to be his especial merit is the comprehensiveness of his view, and the uniformity of his treatment. For him the study of one of his special subjects is the study of all ; the binding influence b ing the theory of discrete groups, a theory he has made his own. With this unity of concep- tion he combines a great power of simple, elegant, and interesting expression. The expositions of his method contained in his early " Comparative Review of Recent Researches in Geometry,' and his more recent " Lectures on the Icosahedron," in which the formal identity of investigations apparently the most diverse is made apparent, belong to the romance of mathematics. The important influence which his mode of investigation has had and is destined to have on the progress of the higher mathematics, the encouragement of largeness of view, rather than the elaboration of minutiffi, and the stimulating influence he exercises upon pupils who now hold positions of eminence in Germany, must take a foremost place among the grounds upon which we honour Prof. Felix Klein to-day by the award to him of the De Morgan Medal. NOTES. The agricultural exhibit of Sir John Lawes and Sir Henry Gilbert at Chicago appears to have been much appreciated by our American cousins. The Association of American Agri- November 23, 1893] NA TURE 81 cultural Colleges and Experiment Stations have passed a special resolution expressing the value they attach to the exhibit, and the Director- General of the Exposition has forwarded the same to England, wi h the added thanks of the Exposition, for "the great benefit done to American agriculture by this excellent and instructive exhibit." A Pasteur Institute has been opened in New York, with Dr. Paul Gibier as its director. ]\I. O. Callandreau, of the Paris Observatory, has been appointed Professor of Astronomy at the Kcole Polytechnique. Dr. Treadwell has been appointed Professor of Analytical Chemistry in the University of Zurich. Dr. a. K. E. Baldamus, known for his work in connection with ornithology, died on October 30, at the age of eighty-two. Mr. J. Bailey Denton, whose name has long been known to agriculturists and civil engineers, died on November 19, at Stevenage, Herts, in his seventy-ninth year. We regret to announce the death, at the age of eighty-one, of M. Chambrelent, a member of the Rural Economy Section of the Paris Academy of Sciences. Mr. William Dinning, of Newcastle, a lover of natural science and a promoter of its interests, d'ed on November 13. Shortly before his death, he offered his collection of fossils from the coal measures to the Newcastle Natural History Society, on the condition that the society would provide cases to properly exhibit it and the collection already existing in the local museum. The society was without the necessary means, but Lord Arm-trong has promised to contribute asum of ;i^i500 for this purpose. Mr. Dinning was an engineer by profession, but all his leisure was devoted toscientific pursuits. His death will be greatly felt in local circles. It is reported that a severe shock of earthquake was ex- perienced on November 17 in Kashan, Western Asia, a large part of the town being destroyed. Great damage was also done at Samarcand. Mr. Lloyd Bozward, Worcester, informs us that on No- vember 17 a fine shower of Leonid meteors was seen throughout the night. The meteors are said to have been so numerous that several persons unacquainted with their nature mistook the display for an exhibition of fireworks. The Swiney prize of a cup, value .j^ioo, and money to the same amount, to the author of the best published work on jurisprudence, will be awarded by the Society of Arts and the College of Physicians in January next. The prize is awarded every fifth year, the recipient in 1889 being Dr. C. Meymott Tidy, for his work entitled " Legal Medicine." At the beginning of next year the first number of an " Index der gesamten chemischen Litteratur " will be published by H. Bechhold, Frankfort. The index will appear monthly, and after the end of each year an index comprising all the papers published during the year in pure and applied chemistry will be issued. The editor of the forthcoming publication is Dr. Julius Ephraim. Messrs. W. H. Allen and Co. have in preparation a series of volumes founded upon Jardine's Naturalist's Library. The editor of the series. Dr. Bowdler Sharpe, will undertake several of the ornithological volumes. The authors of other sections are Mr. R. Lydekker (Mammalia), Mr. H. O. Forbes (Mammalia and Birds), Mr. W. R. Ogilvie Grant (Birds), Mr, W. F. Kirby (Insects), Prof. R. H. Traquair, F.R.S. (Fishes), The first volumes will be issued early in 1894, and will consist of British Birds, vol. i., by Dr. R. Bowdler Sharpe ; Monkeys, NO. 1256, VOL, 49] by H. O. Forbes ; and Butterflies (with special reference to British species), by W. F. Kirby. We have previously referred to the fact that on the first of this month Italy adopted the time of Central Europe. All the Italian time-tables have, by order of the Minister of Public Works, been printed with the hours marked up to twenty-four from midnight to midnight. The railway clocks have also been modified, and the hours from 13 to 24 printed in red Arabic characters in a circle interior to the old one. It may be well to remember that at the Paris Exhibition in 1867, Sig. G. Jervis, the Keeper of the Royal Industrial Museum of Turin, exhibited a clock face having a double series of hours, the higher numbers being placed on the exterior circle on account of the greater space there available. He also exhibited a time-table drawn up on the 24-hour plan, and possessing many advantages over those in use even at the present time. Mr. Jervis has thus had the satisfaction of seeing the adoption of the improved clock- dial and the 24-hour time-table, proposed by him nearly a third of a century ago. During the past week this country has experienced some of the most destructive, if not the most violent storms that have occurred for some years. The reports received by the Meteoro- logical Office on Thursday morning, the i6th instant, showed that a deep disturbance was approaching our shores, and storm signals were hoisted on our coasts. On the afternoon of that day the storm broke with great violence over the west of Ireland, the direction of the wind being south-easterly with a moderately high temperature, while the barometer was below 29 5 inches. The centre of the storm passed across England and Scotland, taking the ordinary north-easterly course, and by 6 p.m. on Friday it lay off the extreme north-east coast of Scotland, and the barometer had fallen to 28 5 inches ; the wind, as usual in the rear of storms, shifted to the north-westward, causing a sudden fall of temperature with heavy snow and hail in many places. At this point the track of the disturbance took a very unusual direction, and during Friday night the centre moved quickly to the southeastward down the North Sea, and at 8 a.m. on Saturday, the 18th instant, the centre lay off the north-east coast of England, while the pressure rose rapidly over the western portion of the kingdom, causing steeper gradients and bitter northerly and north-easterly winds. The storm first broke over London and the southern parts of the country on Saturday afternoon, and blew in terrific squalls during the whole of Saturday night, the centre again resuming an easterly course across the North Sea to the Dutch and North German coasts. The greatest strength of the wind appears to have been experienced near Holyhead, where the force on Saturday morning was reported as 12 of the Beaufort scale, while force II was reported from Wick and Scilly. In the neighbourhood of London the heaviest gusts were experienced in the early part of Saturday evening ; the anemometer at Greenwich recorded a pressure of 17 pounds on the square foot at about 6 p.m. On Sunday and Monday the wind force was still high in the south-east of England, as well as in the English Channel, and a very high sea was running on our coasts. The storms were also very violent on the other side of the Channel, and were accompanied by heavy falls of snow in many parts of the Continent. The Pilot Chart of the North Atlantic Ocean shows that the first half of October was marked by much bad weather north of latitude 45^^ between Newfoundland and the British Isles. One of the storms caused immense loss of life and property in Louisiana, owing to a tidal wave encroaching over the low- lying lands. A supplement issued with the chart shows clearly the actual weather conditions between the 23rd and 28th of 82 NA TURE [November 2^, 189; August last, west of longitude 50° W, During this period two severe storms occurred ; the first struck the coast in the vicinity of New Yorl<, where much damage was done to shipping, the second struck the coast near Savannah, and occasioned frightful loss of life along the coasts of South Carolina and Georgia, the barometer falling to 28 29 inches at 6 a.m. on August 28. This was the storm referred to in our issues of 51st August and 7th September. Tke annual meeting of the Royal Geological Society of Cornwall was held at Penzance on November 10, when the president, Mr. Howard Fox, delivered an address, in which he reviewed the past history of the society. In the course of his remarks, he said that the rocks of West Cornwall had been subjected to precisely the same conditions as those of Moffat and Girvan, in South Scotland, described by Prof Lapworlh. They show, in fact, a repetition of the same phenomena, except that as yet no band of fossiliferous rock characteristic of a special geological zone has been discovered as a horizon of reference. It is, therefore, worth consideration whether the radio- larian cherts of Mullion Island, described in the Quai terly y our. iial of the Geological Society for this year, will not answer the same purpose. The Mullion Island cherts consist of easily-recog- nised bands of mostly black flint-like rock, generally reticulated with thin but conspicuous white quartz veins. They are extremely hard and resistant of both atmospheric and subter- ranean agents of destruction. They are of sufficient thick- ness to form a distinctly marked feature in the ascending sequence, and having been originally deposited on the floor of a deep ocean as radiolarian ooze, they necessarily occupy a wide horizontal extent of country. They occur in distinct bands, mostly in shales or crushed dark slates ; they break with a conchoiilal fracture, and when sheared or impure the micro- scope can generally determine their nature. The fossils are radiolarian dee|)-sea forms like those of the present day. Messrs. Teall and Lapworth have traced these cherts with Mr. Fox for 800 yards in the cliffs and on the foreshore north of Porthallow in-Meni.age, and during the past summer they have been traced at intervals through the parishes of Veryan, Gorran, and Caerhayes. Pebbles have been found on the north coast, which under the microscope show radiolaria with their structure still visible, but the parent rock has not yet been found in situ. It will therefore be agreed that these cherts most certainly should be traced wherever they appear in Cornwall. Their age is undoubtedly Ordovician, yet the precise zone to which they belong can only be determined by discovering some typical fossils in the shales and slates associated with them. In South Scotland officers of the geological survey have recently traced such cherts with radiolaria from sea to sea just beneath the Llandeilo rocks, fixing horizons exactly. The cherts in Cornwall, possibly of the same age, and certainly of the same character, are equally promising in the midst of the entangled rocks around, to form the datum line, or clue to the succession. A COLLECTION of land and marine shells of the Gala pago Islands was made during the voyage of the U.S. Fish Com- mission steamer Albatross in i8g7-88. A report on this mollusc fauna, prepared by Dr. R. E. C. Stearns, has recently been issued from the U.S. National Museum. It is not an | exhaustive review of the collection, but includes the principal collections previously made, and also a few notes of interest. The extreme tenacity of life of land snails in every stage of growth is well known. Dr. Stearns gives the following instances that came under his own observation :— " In December, 1865, the Stearns collection, now in the National Museum, was en- riched by the acquisition of several examples of Helix Veatchii, Newcomb, now regarded as a variety oi H. areolala, that were NO. 1256, VOL. 4q] collected by Dr. Veafch on Cerros or Cedros Island off the coast of Lower California in 1859. The specimens were given by Dr. Veatch to Thomas Bridges, and upon the death of the latter came into my possession with the remainder of the Bridges shells. One day, upon a careful examination, I discovered that one of the specimens was apparently still alive, and placed it in a box of moist earth ; after a while it protruded its body from the shell and commenced moving about, and seemed to be no worse for its long fast of at least six years. H. Veatchii, it will be observed, beat the time of the famous British Museum example of H. desertortim, which lived without food within a few days oi four years. In March, 1S73, Prof. George Davidson, of the United States Coast Survey, while at San Jose del Cabo, Lower California, collected a number of specimens of Bulimus pallidior, and subsequently gave me a part of them, which I put in a box, where they remained undistuibed until June 23, 1875, when they were placed in a glass jar with some chick-weed and a small quantity of tepid water. They soon woke up and began to move about apparently as vigorous as ever after their long nap of t^oo years, two months, atid sixteen days. '' The delicacy of the sense of taste among Indians has been tested by Mr. E. II. S. Bailey, and the results compared with those obtained from whites {Kansas University Quarterly). The method of testing was by solutions of different strengths, the substances quinine sulphate (bitter), sulphuric acid (sour), bicarbonate of soda (alkaline), cane sugar (sweet), and common salt (salt) being selected as representing classes of the common familiar substances most likely to be recognised. The only one of these that experience has shown is not familiar is the alkaline taste. From an examination of the results it appears that the order of delicacy is about the same for the two races. By this it is meant that the smallest proportion of quinine was detected ; acid solutions come next in the order of action upon the organ of taste, and then salt. In the case of whites, sweet solutions were more detectable than alkaline ones, but the reverse was the case with the Indians. This does not count for much, how- ever, as the Indians had great difficulty in distinguishing between the alkaline and salt solutions. As might have been expected, the ability to detect the different substances when they are in very dilute solution is less in the Indians than in the whites. The males of both races are able to detect a smaller quantity of salt than the females, but in all other cases the females appear to have the more delicate organ of taste. The question as to whether gases are capable of emitting heat has been investigated by many physicists, most of whom have come to the conclusion that the characteristic spectra of glow- ing gases are chiefly, if not solely, due to some chemical action going on within the gas. Hiitorf heated air in platinum tubes a few centimetres long over a Bunsen, and Siemens treated air, carbonic acid, and steam in a similar manner, using longer tubes and higher temperatures. Both were unable to discover any radiation by the gases when thus simply heated, and Pringsheim, after more recent work, came to the conclusion that emission spectra cannot be obtained by simple heating. Mr. F. Paschen has, however, quiet recently (iVied. Ann. No. Il) succeeded in discovering and mapping such spectra by a modi- fication of Tyndall's experiment with gases rising from an in- candescent body, substituting the bolometer for Tyndall's thermopile. The hot body employed was a spiral band of platinum forming a narrow tube, which was heated by pa- sing an electric current through the platinum. The gases were sent through this spiral, and thus acquired a temperature of about 1000° C. The temperature was measured by means of a platinum : platinum-rhodium thermocouple with an excessively small j unction. The spectrum was formed by a fluorspar prism November 23, 1893] NA Tl RE 83 and two concave mirior?, adjustanle automatically to minimum deviation for any wave-length. The gases examined were air, oxygen, carbon dioxide, and steam. Only the last two gave positive results, some small deflection in the first two being due to slight traces of moisture. Carbonic acid showed a very sharp maximum far in the infra-red. The bolometer strip was to > broad to determine whether it was a line or a band, but it is most probably a somewhat ill-d-fined line. Steam showed about ei^ht maxima, which must be described as bands. A comparison of the spectrum of the Bansen flame with that of the hot products of combustion arising from it showed that the spectra obtained are similar and of a'most equal intensity ; so that it is very probable that the spectra of hot gases are chiefly due to temperature, and not to chemical action. A curious and hitherto unexplained observation is that of a slight shifting of the maxima towards the more refrangible end of the spectrum when the temperature is lowered. To determine correctly the values of the critical constants of a substance is a matter of considerable difficulty : the estimation of the critical temperature, however, is generally believed to he both expeditious and accurate. The usual method of taking an observation of the critical temperature consists in heating the liquid in contact with its saturated vapour in a closed space to a temperature above th^ critical temperature, allowing the substance to cool, an 1 noting the temperature tc at which the meniscus of the liquid just appears in the misty contents of the closed space. In the current number of Wiedemann' s Annalcii, Herr Galitzini gives evidence to show that tc thus determined, although it is independent of the amount of substance contained in the closed space, is lower (it may be considerably lower) than the true critical temperature, or the temperature at which liquid ani saturated vapour have the same density. By very slow and regular cooling he also finds that the peculiar misty appearances which are usually held to be invariably associated with the critical state are not observed. Amongst other conclusions, his experiments, which it is to be noted were made on ether, lead him to believe that at temperatures even considerably higher than the critical temperature a substance at constant pressure may have different densities, different in some cases to the extent of 25 per cent. This last result the author attributes to the presence of molecular complexes in the substance : if its validity is established, it will of course overthrow the generally accepted idea that at any temperature above the critical tempera- ture for a given value of the pressure there is only one value of the volume. Ax interesting paper on the various electric wave systems obtained by Lecher's method has been communicated to the R. Accademia della Scienza di Torino by Signor Mazotto. The effect of varying the lengths of the primary and secondary wires, and the distance apart of the plates of the condensers, has been studied. As an indicator of the points of maximum difference of potential along the wires, the author uses two short wires partly coiled round india-rubber tubes, which slide along the secondary wires, the ends of the wires being brought to within about 2 cm. of each other. If, when the apparatus is working in the dark, the fingers are brought near the platinum tips of these wires, two small luminous stars appear at these tips when the bridge over the secondary is in the vicinity of a node. When at a node these sparks become very conspicuous, even without the presence of the fingers. This indicator is said to have the advantage over the Geissler tube used by Lecher, that it shows more distinctly the maxima and minima, is less fatiguing to the eyes, and less capricious in its action. The number of nodal systems formed when, the primary system being kept consant, the bridge on the secondary wires is moved to different parts, were found to be more nu-xierous than Lecher's observations NO. 1256, VOL. 49] would seem to indicate. The " harmonics " of the fundamental system were not the only higher systems that were produced^ it being found possible, by altering the position of the bridges to produce any system intermediate between two harmonics It was also found, when the second bridge was placed at a fixed piint, that the nodal system •; obtained by moving the first bridge were independent, in position and intensity, of the state of the system beyond the second "^ridge. The wave-lengths obtained experimentally were compared with those given by the formula of Salvioni, and found to agree fairly well. The curves obtained by the author, and a full account 6f his method, has been published in the Electrician, vol. xxxii. p. 60. The following translation of a rq^Iy given by Prof Galileo Ferraris to a young lady who asked what electricity was, is given by the Electrician. Prof. Ferrari-; his conferred a great benefit on all those who are supposed to have any knowledge of that magic science electricity, and are therefore continually being asked this question, though whether the reply satisfied the questioner is rather doubtful. His reply was : — " Maxwell has demonstrated that luminous vibrations can be nothing else than periodic variations of electro-magnetic forces ; Hertz, in proving by experimentsthat electro-magnetic oscillations are propagated like light, has given an experimental basis to the theory of Maxwell. This gave birth to the idea that the luminiferous ether and the seat of electric and magnetic forces are one and the same thing. This being established, I can now, my dear young lady, reply to the question that you put to me : What is electricity ? It is not only the formidable agent which now and then shatters and tears the atmosphere, terrifying you with the crash of its thunder, but it is also the life-giving agent which sends from heaven to earth, with light and heat, the magic of colours and the breath of life. It is that which makes your heart beat to the palpitations of the outside world, it is that which has the power to transmit to your soul the enchantment of a look and the grace of a smile." The current Comptes yicv//?« contains an important correction to the numbers given by M. Blondlo". for the velocity of an electric disturbance in high conductivity copper ( Comptes Rendiis, October 23). The values were expressed in kilometres per second instead of thousands of kilometres per second, so each of the velocities given in our issue of November 9 (p. 37) must be increased by one thousand, in order to be correct. A VERY important paper, by Dr. Uschinsky, on the cultivation of pathogenic bacteria in media, devoid of all albuminoids, appears in the Archives de mcdecine cxperimentale, No. 3, 1893. Pathogenic organisms thus grown do not lose their virulent properties and, moreover, elaborate toxic substances, for on pass- ing the media in which they have been cultivated through a Chamberland filter, the filtrate was found to be toxic. In a more recent paper, published in the Centralbla't filr B.ikteriolorie, vol. xiv. No. 10, 1893, Dr. Uschinsky states that in order to obtain more satisfactory growths of the bacteria in question, he has introduced some modifica'rions into the composition of the culture medium, which now affords as suitable a pabulum for their cultivation as ordinary bouilbn. The following is the composition of this non-albuminous medium : — Water, iodd ; glycerine, 30-40; sodium chloride, 5-7 ; calcium chloride, o'l ; magnesium sulphate, 0'2-o-4 ; dipotassium phosphate, 2-2-5 ; ammonium lactate, 6-7 ; sodium aspartate, 3 '4. The organisms of cholera, diphtheria, tetanus, typhoid and others have all been grown successfully in the above. The poisonoas substances elaborated by bacteria are, therefore, not necessarily due to their decomposition of the albumen contained in the ordinary culture media employed, but must rather be regarded as the result of synthesis ; the materials produced, says Dr. 84 NATURE [XOVEMHEK 23, 1893 Uschinsky, belonging in all probability to the proteid bodies, and bearing much resemblance to ferments. Dr. UscHiNSicv has male a special study of the tetanus bacillus when grown in this medium, and has examined in some detail the nature of the toxic products thus elaborated. A more satisfactory growth of this organism was procured by adding from one to two per cent, of grape-sugar to the solution, and ihe anaiirobic conditions necessary for its cultivation were obt:iined by pouring liquid paraffin on the surface. The filtrate of such tetanus culiures was about equal in virulence to that derived from ordinary broth-cultivations of the bacillus. On the other hand, the poisonous properties of the former were far more easily removed than was the case with the broth-cultures, being destroyed by preci]>itation with alcohol, and also fre- quently by evaporation in vacuo at 33-36° C, this being especially the case when the latter was carried out in the piesence of light. By addiiion of strong alcohol a precipitate was obtained, in which, besides salt, small quantities of albuminous bodies were present, as indicated by Millon's re- agent and the xanthoproteic reaction. This precipitate was, however, without any toxic properiies. The second edition has been issued of a general guide to the Manchester Museum, by Mr. W. G. Hoyle, Keeper of the Museum. The book should be useful in directing attention to the most impoitant specimens, and explaining their character. Its value would be greatly incieased, however, by the addition of an index. " k BiBLlOGRAPHYofVertebiate Embryology," by Mr. C. S. Minot, has been published by the Boston Society of Natural His- tory. 1 he titles are grouped into subjects, and the subjects are alphabetically arranged, so there is no diffi.ulty in finding the original source of any paper, the title of which is known. An index of authors is also given to faciliiate reference. Biological investigators will find the bibliography of great a«si-tance. The volume of selections from the philosophical and poetical works of Miss Constance C. W. Naden, compiled by the Misse-; E. and E. Hughes, and publisiied by Messrs. Bickers and S'ln, is one of the daintiest that we have seen for some time. The selections fiom her e>say on induction and deduction contain some remaikably fine expressions, and many other parts of the book are of great interest. Mr. p. Axderso.nt Graham's " All the Year with Nature" (Smith, Elder, and Co. ) contains a number of reprints of articles originally contributed to various magazines. The author has a chatty siyle, and his heterogeneous collection will serve to while away an hour or two. The connection of many of the articles with the seasons is not very apparent, and some of the statements are not scieniifically accurate, but, taken as a whole, the book is well worth reading. Part I. of the sixth edition of Prof. Michael Foster's well- known "Text-Book of Physiology" has been published by Messrs. Macmillan and Co. It comprises the first book of the original volume, and deals with the blood, the tissues of move- ment, and the vascular mechanism. A number of important modifications have been made in the section devoted to the phenomena and mechanism of the heart-beat, but with this ex- ception few changes have been introduced. Since the publica- tion of the first edition, seventeen years ago. Prof. Foster's work has been recognised to be the best of its kind, and the issue of a new edition shows that it retains its position as a physiological " classic." The fourth volume of Alembic Club Reprints, published by Mr. W. V. Clay, Edinburgh, is bsfore u-. It deals with the foundations of the molecular theory of gases, and comprises NO. 1256, VOL. 49] papers and extracts of papers by Dallon, Gay-Lussac, and Avogadro. There is no better way of studying ihe development of an idea than by reading such reprints as those issued under the auspices of the Alembic Club, for they enable the student to >ee the many difficulties that have to be overcome before a theory crystallises into shape. We therefore v\elcome this last addition to an excellent series of books. The Cambridge University Press has published the first volume of the series of manuals of biological science edited by Mr. Arthur E. Shipley. The book to which we refer is " Elementary Paljeontology," by Mr. Henry Woods. In it the author gives a concise account of invertebrate palaeontology, chiefly considered from a strati.^raphical point of view. The plan of the book is excellent, the zoological features of each group being first described, then the genera of importance geologically are classified, and with this knowledge the student is able to understand the following section dealing with the dis- tiibution of the group. Instead of giving archaic illustrations of genera, Mr. Woods includes figures required to explain structure and terminology. The student will benefit by this change. Remarkable pictures of peri'ectly preserved fossils may suit the popular mind, but the student must study fossils in collections, and he needs more detailed instruction concerning their characteristic-^. As an introduction to the study of paljeontology, Mr. Woods' book is worthy of high praise. Notes from the Marine Biological Station, Plymouth. — The past week has been one of the s'ormiest of the year. Work outside the .Sound was quite impossible in our small boats, and even within the harbour was attended with difficulties. The captures included specimens of the Actinian Cylista vidiiata, and of the D.)ridi) 9-1 (<■) 9-1 The results show that Mrs. Fleminsi's star is brighter than ((?), scarcely dimmer than {b), and a little dimmer than {c). Its magnitude then in July and August, 1887, could not have been more than 92. The Natal Observatory. — Mr. Nevill, the Government Astronomer for Natal, has to work under great difficulties. The grant of ^800 per annum, made by the Natal Government to the Observatory, is certainly not enough to keep the estab- lishment efficient. When the Observatory was first erected it was a substantially built, rectangular red brick edifice, carrying a light wooden upper structure, which formed equatorial and transit rooms, but there was only one room below, and this had to serve the double purpose of a computing room by day and sleeping room by night. Mr. Nevill has a^ked the Government to give him more accommodation, but his application has not been granted, the plea being shortness of funds ; so he has had extra rooms built entirely at his own expense, and even now the four assistants of the Observatory woik in a room which is nothing more than an enclosed verandah. The principal points under in- vestigation at the Observatory are : the parallactic inequality in the motion of the moon, the lunar diameter, the effects of irra- diation and its variations upon the moon's apparent semi- diameter, and lunar libration. Magnitude and Position ok T Aurig.-e. — The current Couples Rendiis (November 13) contains a number of observa- tions of Nova Aurigre, made by M. Bigourdan, at the Paris Observatory. The star's magnitude was compared with that of neighbouring stars on October 10 and 12, and on November 8, II, and 12. The observations show that from the middle of October to the Sth inst. the light diminished very definitely, and afterwards increased, but on the date of the last observation it liad not attained the magnitude observed on October 10. In 1892 M. Bigourdan micrometrically measured the position of the Nova with respect to a neighbouring star, and a repetition of his measurements, after an interval of eighteen months, shows that no change of position has taken place. Period of Jupiter's Fifth Satellite. — Prof. E. E. Bar- nard's new measures {Astronomy and Astro- Physics for Novem- NO. 1256, VOL. 49] ber) for the times of elongation of the fifth satellite give a period P = iih. 57m. 22-56s. The value obtained fiom his last year's value was P = iih. 57m. 23 061. While Mr. A. Marth, from the same observations, derived a period of P = iih. 57m. 21-883. The new determination falls, as will be noticed, nearly mid- way between the two values quoted, and covers a period of 743 revolutions of the satellite. GEOGRAPHICAL NOTES. The fate of the Bjorling exploring expedition, concerning the safety of which much anxiety has been lelt in Sweden, has now been ascertained. Messrs. Bjorling and Kalstennius, two young Swedish naturalists, hired a small schooner, the Ripple, at St. John's, in June, 1892, and set cut for a collecting trip along the west Greenland coast, accompanied by a crew of three men. After leaving the Danish settlements on the west coast last summer, no further news was received from the expedition, and the captains of the whaling vessels at work in Davis Strait this summer were specially requested to look for \.xz.ct%oi \.\i& Ripple and her party. Captain AIcKay, of the Dundee whaler Aurora, who returned last week, reports that he visited the Carey Islands at the entrance to Smith's Sound on June 17 this jear, and found there the wreck of the Ripp.e, a number of documents, and the body of one of the ill/ated crew. One of the papers written by Bjorling on August 17, 1892, on which day he had visited the Carey Islands to get provisions from the cache left by Sir George Nares, st ated that on leaving the schooner ran aground , and the party had to land. A later note, dated October 12, shows that they attempted to reach Foulke's fjord to winter there, but alter reaching Northumberland Island circumstances com- pelled their return. At the date of writing Bjorling intended to start immediately to endeavour to reach the Eskimo settle- ments at Cape Faraday or Clarence Head in Ellesmere Land, with the hope of returning to Carey Islands by July i, 1893, to meet any whsler. In case of not finding a vessel he intended to push on to the Danish settlement. On receiving this news Captain McKay at once headed for Ellesmere Land, but the ice closed in, and he had to turn back. As the provisions would only last until January i, it is to be feared that the whole party has perished, unless they were successful in reaching the Eskimo. If they did so, and were subsequently able to make their way to the Dani>h settlements, there may still be hope, but no news can be received until next summer. The Times announces that the Peruvian Government has awarded a gold medal to Mr. Clements R. Markham, F.R.S., President of the Royal Geographical Society, for the great services he has rendered to Peru in elucidating its geography, and in giving expression "with upright impartiality" to the facts of its history. Mr. W. H. Cozens-Hardy, who has just returned from a summer spent in exploration on the borders of Montenegro and Albania, has succeeded in making a number of observations of high geographical value. He has been able to lay down on a map for the first time the present frontiers of the principality, and from his knowledge of Slavonic languages and the free access accorded to him to the Montenegrin archives, he can also give a most interesting account of the past changes in the boundaries, frirnishing, in fact, a chapter in the historical geography of the Balkan peninsula. The Arctic skipper Hans Johannensen, of Hammerfest, Norway, has heard from old Yakutsks that fion the highest points of the northern shores of the New Si lerian Islands a lofty land has been discerned to the north- west, at a distance of about fifteen nautical miles. He thinks, therefore, that should Nansen not steer too close to the coast, this new land might be seen from the masthead. And should the state of the ice be at all favourable, Nansen will, in all probability, attempt to take up his winter quarters there instead of the New Siberian Islands. From a recent number of the R'olnische Zeititiig we learn the somewhat lemarkable .<^act that Cologne is the largest city in Germany, taking account of the area it covers, Berlin coming only fourth in order. In Cologne, however, only eight per cent. 86 NA TURE [November 23, 1893 of the area is built upon, the remainder being streets and open spaces. The Paris Geographical Society has awarded the grand prize for geographical research to M. Maistre, for his great journey from the Congo to the Shari. FLAME} 'T'flE subject on which I have the honour to address you this evening is, I am aware, one of the most hackneyed among the topics that have served for popular scientific lectures. I can only hope that it has not quite lost its charm. The chemist is often twitted with having to deal with mere dead soulless things, which at the best only set themselves into angular and unpalpita- ting crystals. There may be a certain amount of truth in this, but in fiamt'S we surely have phenomena of some liveliness. Our flame must be fed ; it has its anatomy and varied symmetry ; it is vigorous, mobile, and fleeting. I do not wish to make extravagant claims, but I do think that one may be excused for feeling almost as much interest in the study of flame as, for example, in the contemplation of the somewhat torpid evolutions ot an amoeba or the circulation of water in a sponge. To our guileless ancestors, at any rate, flame was a phenomenon of the rarest mystery ; unable as they were to discriminate between the material and the immaterial, unable to track the solid or liquid fuel to its gaseous end, this radiant nothingness called flame became to them one of the primary in- scrutable, irresolvable things of Nature — an all-devouring element, often of peculiarly divine significance. The essential nature of flame appears to have been discovered at the beginning of the seventeenth century by the Belgian, Van Helmont. This remarkable man is well known to chemists as one of the acutest and least superstitious of the whole band of alchemists. He was somewhat speculative in the domain of physiology, but in chemistry Van Helmont made discoveries of fundamental importance From our immediate point of view, one of the most important things he did was to sweep away the mystery that had so long attached to the gaseous state of matter. In so far as he distinijuished between different gases obtained from different sources, he may be said to have been the first to bring aeriform matter within the range of substantial things that might be submitted to expeiimental investigation. It was in conse- quence of this that he was led to the di>covery of the nature of flame. I will quote the important passage from his writings. "But the flame itself, which is nothing but a kindled smoke, being enclosed in a glass in the very instant perisheth into nothing. "The flame indeed is the kindled and enlightened smoke of a fat exhalation ; be it so ; but as the flame is such and true fire it is not another matter, being kindled and not yet kindled, neither doth it difler from itself; but that light being united in its centre, hath come upon a fat exhalation which is the same as to be inflamed. " Let two candles be placed which have first burned awhile, one indeed being lower than the other by a span ; but let the other be of a little crooked situation ; then let the flame of the lower candle be blown out ; whose smoke, as soon as it shall touch the flame of the upper candle, behold the ascending smoke is enlightened, is burnt up into a smoky or sooty gas, and the flame descendeih by the smoke even unto the smoking candle. Surely there is there, the producing of a new being, to wit, of fire, of a flame, or of a connexed light ; yet there is not a pro- creation of some new matter or substance. " For the fire is a positive artificial death but not a privative one, being more than an accident and less than a substance." We can best understand the meaning of this somewhat ora- cular statement by repeating Van Helmont's experiment. We take a bundle of lighted tapers so as to get a large flame, we hold over "in a little crooked situation" another lighted taper, and now blow out the lower flame. We note the ascend- ing column of smoke, and observe that when it touches the upper flame it ignites, and the flame descends several inches through the smoke to the bundle of tapers. Flame therefore, says Van Helmont, is burning smoke ; it is not a new substance nor a mere chance occurrence, but the incandescence of a vapour or smoke that already existed. Van Helmont only recognised in a vague way the important part played by the atmosphere in the phenomenon. This was 1 An evenins discourse to the British Association at tlie Nottingham meeling, September 15, 1893, by Prof. Arthur Smithells. NO. 1256, VOL. 49] realised much more perfectly soon afterwards by Hooke, whcv speaks of "that transient shining body which we call flame '\as "nothing but a mixture of air and volatile sulphureous parts^of dissoluble or combustible bodies which are acting upon each other whilst they ascend," an action so violent, he says, " that it imparts such a motion or pulse to the diaphanous parts of the air" as was requisite to produce light. Without entering further into early historical details I may say that it was only towards the end of last century that the ■ essential chemistry of the phenomenon was fully expounded by the great Lavoisier. He showed that, as Hooke had surmised, flame is the region in which combination attended by the evolu- tion of light takes place between the components of a gaseous substance and the oxygen of the air. The next step in the history of our knowledge of flame brings us to the memorable researches of Humphry Davy, whose name more than that of any other man is associated with this sub- ject. Of Davy's work I shall have moe.to say presently ; but at this moment I will only make one allusion to it, an allusion which will provide us with a proper starting-point this evening. It is interesting to note that Davy's discoveries concerning flame were the consequence and not the cause of the discovery of the miners' safety-lamp. In this case practical application preceded purely scientific discovery. I need not describe the safety-lamp to you in Nottingham, v;here it has recently received such important improvements at the hands of Prof. Clowes. When the lamp is placed in an exjilosive mixture, you know what happens — the explosive mixture burns with a quiet flame within the lamp, but the flame cannot pass through the wire gauze to ignite then ixture outside the lamp. I can demonstrate this by means of this large gas-burner, which is primarily a Bunsen burner, that is, a burner which by means of holes at the base of the tube draws in sufficient air to enable the gas to burn with a practically non-luminous flame. Il I turn on the gas and apply a light to the top of the burner, you observe that I get a flash and a small explosion within the tube, but no continuous flame. The fact is that the mixture of gas and air within the tube is highly explosive. Placing a gauze cap over the burner and applying a light, I now get a steady flame. The explosive mixture made in the tube passes through the gauze and is inflamed, or, if you like, exploded ; but the explosion cannot pass through the gauze, because the metallic wires withdraw the heat so rapidly that the mixture below it never reaches the temperature of ignition. Above the gauze we have the continuous flame. " These results are best explained," says Davy, " by con- sidering the nature of the fl ime of combustible bodies, which in all cases must be considered as the combination of an explosive mixture of inflammable gas or vapour and air ; for it cannot be regarded as a mere combustion at the surface of contact of the inflammable matter." Davy, then, regarded flame as being essentially the same as explosion ; it was, in fact, a kind of tethered explosion. Since Davy's time we have learned much about the nature of gaseous explosions, and we now know that such explosions, when fully developed, proceed with enormous rapidity and are of great violence, incapable of arrest by such simple means as we have just used. Still there is not much to correct in what I have said. I think I cannot do better than show you the transi- tion of flame into explosion by an experiment which was first shown by Prof Dixon in the lecture w hich he gave at the meeting of the British Association in Manchester in 1887. I The apparatus before you consists simply of a Bunsen burner surmounted by a long glass tube. If I turn the gas on and light it I obtain at the top of the glass tube a steady flame. The mixture ascending the tube can scarcely be called ex- plosive at present, but if I aber the proportions of gas and air suitably it becomes distinctly explosive. Observe what happens when this is the case. The flame can no longer keep at the top of the glass tube ; it passes within it, and descends with uniform veli)city till at a certain point it flickers and then shoots down almost instantaneously to the bottom. This sequence of events is exhibited in all cases when flame develops into explosion, We are concerned only with the first phase, viz. that of com- paratively slow inflammation and a flame, we may say, is a gaseous explosion brought to anchor in the period of incubation. There is one other point connected with explosion that we must note on account ol its important bearing on the chemistry ol flame. When we are dealing with explosive mixtures of gas and air, we find practically that the composition of the November 23, 1^93] NATURE 87 mixture may vary considerably and still retain its explosive pro- perties. There i<, of course, a certain mixture which presents the greatest expl sive power; a further quantity of the com- bustible gas or of ihe air will diminish the explosibility, but not entirely destroy it till a large excess is used. With hydrogen, for example, two and a half times the volume of air (which contains exactly the oxygen requisite to combine with the hydro- gen and produce water) is the right quantity for the maximum explosive effect, but we still get explosion when we have much mere than two and a half times as much air as hydrogen, or u-hen, on the other hand, we have much less. In one case there will be oxygen left uncombined, in the other case hydrogen. T dwell upon this in order that we may be prepared to find the same thing in flames, in order that we may not be sur prised to find combustion taking place in mixtures where either gas or air is in excess of the quantity actually required for the purpose of chemical combination. Bear- ing this in mind, let us revert to the experiment that I have just shown. It consists, you remember, in mixing air with gas before burning it, to such an extent that the flame strikes down the tube. On a close examination we find that this is not quite a correct statement, for when I regulate the air with nicety you see that it is only part of the flame that strikes down the tube. There remains all the while at the top of the tube ano her part of the flame which is not mobile. With a little care I can adjust the proportion of air and gas so that the part of the flame which is mobile shall move up and down the tube like a piston. All the while you see the pale steady flame at the top of the tube. When in this critical condition a little more air determines the descent of the movable part of the flame, 1. little less sends it to the top. Let us now turn to the explanation of this phenomenon. It i-; clear, in the first place, that coal-gas and air form an explosive mixture long before there is enough air to burn all the gas. For it is only part of the flame that descends the tube, and there is jnough gas passing through this part to form a second flame as lon as it reaches the outside air at the top of the tube. There s, as a matter of fact, only about two-thirds as much air enter- ing the tube at the bottom as would be necessary to burn the whole quantity of ga<. We see, in the next place, that the ex- plosibility varies greatly according to the proportions of gas and air. For what is the cause of the descending flame? It is simply that we have an explosive mixture in process of inflam- mation. The inflammation is tending downwards ; opposed to it is the movement of the explosive mixture upwards. If the upward movement of the unburned mixture is more rapid than the downward tendency of the inflammation, the flame cannot descend. W.e can only make it descend by making the down- ward tendency greater. This we do by adding more air, and making the mixture more explosive. We see that we can balance these two opposite velocities with the greatest nicely by a careful adjustment of the proportions of the explosive mixture. In order to ascertain what proportion of gas is being burnt in this movable flame, and what is the chemical character of the products there formed, it is necessary to keep the two parts of the flame separate, and to take out some of the gases from the intervening space. This is very easily done. The flame descends, we have seen, i because its rate of inflammation is greater than the rate of I ascent of :he combustible mixture. If now we can make this rate of ascent more rapid at one part of the tube than it is any- where else, we may expect to stop the descent of the flame at I that point and keep it there. We can do this simply by ch' king \ the passage, for just as a river must flow rapidly where its banks I are close, so must the stream of gas rush more rapidly where the tube is choked than either below or above, where there is i a wide passage. If, then, I replace the plain glass tube by one I that has a constriction in one part, and if I cause the inner cone j of the flame to descend as before, it stops, as you see, at the I constriction, and will remain there any length of time. Its rate • of descent is greater than the rate of ascent of the gas where \ the tube is wide, but not 50 great as that where it is narrowt-d I by the constriction. We have now got the two cones of flame [ widely separated. In this state of things we can, if we choose, 1 draw off the gases from the space between the two cones by I putting in a bent glass tube and aspirating. We could then : analyse these gases and see what has happened in the first cone. (Fig. i, A.) I will now show you another method in which the two cones NO. 1256, VOL. 49] can be separated. It is based on the same principles as the one just used. I have here a iwo-cmed flame burning at the top of a glass tube. I shdl let the air supply t)e liberal, but not quite sufficient to cause the descent of the inner cone. The rate of ascent of the gas is now just a trifle greater than the rate of descent of the flame. If now I retard the rate of ascent of the gas, the balance will be disturbed and the inner cone will descend. I can easily do this by laying an obstacle alotip, the stream of gas, for at the en^l of it there will he no more current than you would find over the stern of a boat anchored in mid stream. I take this obstacle, then, in the form of a glass rod fixed centrally along the current of gas ; I push it up until it touches the tip of the inner cone, and then pull it down again. Vou observe v\ hat has happened. The cone has followed the rod into the tube, and remains attached to it. You will notice, too, that the cone is inverted. That is easily understood. » It is only at the tip of the rod that the current is slowed down ; there only is the rate of ascent of the stream less than the rate of inflammation. The tendency in every other part of the stream is for the cone to go to the top ; hence the inversion. (Fig. i, v..) h\ n ^ h n ^y '^^.— fc iA A BCD Fig. I. — ^Methods of separating tfie two cones of an air coal-gas flame. We can get a still more convenient apparatus by a modification of the first method. Instead of choking the bore of the single lube by a constriction, we may use two tubes of different diameter, one sliding wiihin the other This apparatus is shown in Fig. I, C ; a is the wider tube, 6 the narrower one. The two tubes are connected by an india-rubber collar (c), and kept steady by the brass guide (d). The outer tube can be slid up and down the inner one as desired. If we place this apparatus over a Bunsen burner and turn on the gas, we shall have a tolerably rapid upward current in the inner tube, but as roon as the gas emerges into the wider one its velocity will of course diminish. The consequence is that if we now light the gas and gradually increase the air supply, the inner cone will descend until it reaches the orifice of the narrower tube ; but at that point, meeting with the rapid stream, its p-ogress is arrested, and it remains perched on the end of the tube. By sliding the tubes we can thus separate the cones any desired distance, or we can bring their orifices level and restore the original flame. Lastly, we can reverse the experiment, for we can begin with a two- coned flame burning at the protruding end of the nairower tube, and by sliding up the wider tube detach the outer cone and carry it upwards. (Fig. I, D.) Having now learnt the relation of flame to explosion, having 88 NATURE [November 23, 1893 discovered that flames have separable regions of combustion, and having armed ourselves with an appliance for dissecting the flame, we may proceed to discuss the main question. I do not intend this evening to enter seriously into chemical details, but there are one or two simple points to which I must draw your attention. Flame, we see, is a region in which chemical changes are taking'place with the evolution of light. It is to be expected, therefore, that the character of a flame, its structure and appearance, will vary according to the chemical changes that give it birth ; and we should naturally anticipate that the more complex the chemical changes the more complex would be the flame. The kind of complexity to which I refer is illustrated by the diagram. Products Name Composition Partial Combuation Hydrogen ] waier Carbon monoxide ' carbon and oxygen \ carbon dioxide Carbon ' 1 carbo monoxide Cyanogen carbon and nitrogen ! carban monoxide and nitrogen Hydrogen sulphide ] hydrogen & sulphur (?) Hydrocarbons hydrogen & carban carbon m-^noxide carbon dioxide hydrogen & water Complete Combustion water carbon dioxide carbon dioxide carb m dioxide and nitrogen water and sul- phur dioxide carbon dioxide and water In the first column are the names of five combustibles ; their chemical composition is stated in the second column. All these substances in burning combine with the oxygen of the air. The case of hydrogen is the simplest. This gas, when it burns, unites with half its volume of oxygen, and forms steam. The process is incapable of any complica- tion. We might predict, therefore, a very simple structure for a hydrogen flame. The same is true for the next gas carbon monoxide, which, although a compound, unites at once with its full supply of oxygen and burns, forming carbon dioxide. The third combustible, carbon, presents a new feature ; in burning it can combine with oxygen in two stages, forming in the first instance carbon monoxide, which, as we have just seen, can itself combine with more oxygen to form carbon dioxide. We cannot vaporise carbon and use it as a gas, so that we shall not actually deal with this example. But the next combustible on the list, cyanogen, will serve almost as well, for it is a compound of carbon with nitrogen, and nitrogen is, under ordinary cir- cumstances, practically incombustible. To use cyanogen is thus much the same as to use carbon vapour. We may expect some complexity in the cyanogen flame in consequence of the fact that carbon can burn in two steps. The next combustible, hydrogen sulphide, presents a further degree of complexity. It is composed of two elements, each of which is coml^ustible on its own account. Lastly, we come to the great class of hydro- carbons, which includes all ordinary combustibles, oil, tallow, wax, petroleum, and coal-gas. The carbon and hydrogen are both separately combustible elements, and one of them — carbon — is, as we have seen, combustible in two steps. We will now consider the problem in its simplest aspect. For this purpose I choose the gas carbon monoxide. I should choose hydrogen were it not for the fact that its flame is almost in- visible. We will allow a stream of carbon monoxide to issue from the circular orifice of this glass tube. Lighting the gas we get a blue flame. On examining this flame closely we perceive that it is simply a hollow conical sheath of pretty uniform charac- ter. I need scarcely demonstrate that it is hollow, but I may do so in a moment by using Prof. Thorpe's simple device of thrusting a match-head into the centre of the flame — a pin passii/g through the stick of the match, and its ends resting on the tube. The match-head is now thrust well up inside the flame, and you observe that it remains there sufficiently long without burning, to make it quite clear that there is no combus- tion within the cone. The conical form of the flame is easily explained. As the stream of gas issues from the tube the out- side portions become mixed with the air and burn. The inner layers must successively travel further upwards, like the succes- sive tubes of a tele-cope, before they can get enough air to burn, and in this way we a-tive at the conical form. There still remains one thing to account for, and that is the luminosity and culour of the flame. The questions here involved are p'jrhaps the most interesting of all, but they are complicated, and I will not say more than a few words about them. The most (ibvious answer to the question, " Why is the flame (uminous?"is to say that the heat developed during the chemical combination raises the product of combustion to a temperature at which it glows — a " blue heat " in the present case. Now if we put a thermometric instrument into the carbonic oxide flame, it does not register at any point as high a temperature as 1500° C, but if we take carbon dioxide and heat it in a tube by external heating to I500°C. we get i^o signs of luminosity what- ever. On these grounds several eminent investigators have been led to abandon the simple explanation above given, and to say that the luminosity of a carbon monoxide flame must depend not ■ on the heat of chemical combination, but on something in the nature of electrical discharges between the combining substances, which discharges produce the disturbances of the ether percep- tible as light. This view seems to be fraught with a fundamental error. The temperature registered by any instrument introduced into a flame is an average temperature, uncorrected for losses by conduction. It is not the temperature of the newly-formed gas, but of the mixture of that and the unliurned gases. If we had a very small instrument which we could apply to the particles of newly-formed gas, we should undoubtedly find them at a very much higher temperature than any indicated by the ordinary thermometric apparatus, and it is not unlikely that the tempera- ture would be several thousand degrees, approximating indeed to the temperature at which we arrive by calculation from the heat of combustion of the gas and the heat capacity of the product. We cannot say that the flame is luminous from some other cause than simple hotness, for we have no means of seeing whether carbonic acid glows when raised by external heating to a tem- perature of several thousand degrees. At the same time one cannot help remarking on the similarity between such a flame as that of carbon monoxide and the ap- pearance presented by an attenuated gas when submitted to the NO. 1256, VOL. 49] Fig. 2. — Typical Flames, (ir) Carbon monox'de, single coned ; {h) Cyanogen, two coned ; (<) Small coal-gas flame. electrical discharge in a Geissler tube. I have here such a tube, containing carbon dioxide, and I have placed a mask over it, so that we see a long triangular piece of it. When I pass the discharge you see it lights up and presents an appearance strikingly like that of our conical flame of carbon monoxide. There may be a close relationship between the phenomena, but we cannot affirm it yet. No doubt we shall soon learn a good deal more about both phenomena. We have now done with the simplest kind of flame. We see that it consists of a single conical sheath of combustion, at every point of which the same chemical change is taking place, and every point of which in consequence has the same appear- ance. We pass to the cyanogen flame. This flame is one of remarkable beauty ; it consists, as you see, of two distinct parts : one a rose or peach-blossom coloured cone, surrounded by a paler cone, which is bright blue where it is near the inner cone, and shading off to a kind of greenish grey. What is the cause of this double structure? It might be that part of the gas is burning round the orifice, the rest further out in the second cone ; but a similarity of the chemical processes in the two parts of the flame is here ren- dered improbable by the difference in colour. The only satis- factoiy way of answering the question is to separate the cones, and analyse the gases in the intervening space. This we car> easily do in the cone-separating apparatus. November 23. 1893] NA rURE 89 I now form the flame at the top of our cone separating apparatus, and supply a certain amount cf air along with the cyanosjen. Vou observe the rose-coloured cone contracts somewhat. The gas burning there now gets its air supply ea-ily, and has not to wander outwards. If I still further increase the air supply, and make the ascending mixture explosive, you see the inner cone begins to descend into the tube, and passes down until its progress is checked at the narrow tube, where the up- rush of gas is more rapid. We have now got the cyanogen flame dis-ected, and by taking out a sample of the gases from iliis interconal space and analysing it, we shall find what chemical change has taken place in the inner rose-coloured cone. The analysis shows that what takes place is the combustion of the carbon of the cyanogen to form carbon monoxide almost exclusively ; the carbon monoxide then ascends, and when it meets with more oxygen in the outer air, burns in a second cone to form carbon dioxide. Reverting then to the flame of the pure unmixed gas burning at the top of a tube, we see that the gas and air will interpene- trate. When there is just enough oxygen to burn the gas to carbon monoxide, we get the rose-coloured cone, and outside it, where this carbon monoxide gets more air, we have a second cone. The two-coned structure corresponds then to two chemical stages of combustion. Nov/ we might go further and anticipate that if we supplied a very large quantity of air to the cyanogen, as in a blowpipe, the two-coned structure would disappear, for the carbon should be burnt up at once to the ultimate product, carbon dioxide. We can easily try this. I will separate the two cines again in our apparatus, and increase the air supply s'ill further. When I do 50 you observe that the second cone gradually fades away, and now the whole of the combustion is taking place at the end of the inner tube. Though this is so, the flame is not quite a simple cone. It is, as you see, surrounded by a greenish halo. This hal > is due, I believe, as Prof. Dixon has suggested, to the fact that the nitrogen of the cyanogen is not, strictly speaking, incombustible. This has been proved by Mr. Crookes in his beautiful air flame, and besides, the greenish iialo is frequently noticeable in cases of combustion where oxides of nitrogen are ]")re=;ent. Keeping to our list we ought next to deal with ths combustible hydrogen sulphide or sulphuretted hydrogen. This gas, you remember, is composed of two separately combustible elements, each burning in one stage. The flame is, as you might expect, two-coned, buf I will not dwell upon this case — partly because it is not yet fully worked out, and partly because any prolonged experimenting with this gas would, I feel sure, be resented even by the most indulgent audience. I am obliged, therefore, to pass to compounds of carbon and hydrogen, in which there are not only two combustible ele- ments, but one of them, as we have seen, combustible in two chemical stages. Here we have an almost unlimited choice of materials, for we come amongst the combustibles which ordi- narily supply us with light. I shall, for the sake of convenience, use coal-gas. This is really a very complex combustible, con- sisting one half of hydrogen, the other half of at least a dozen different compounds of carbon and hydrogen. But experience has shown that the chemical phenomena attending its com- I bustion are quite of the same character as those to be observed 1 with a single compound of hydrogen and carbon. It will, I imagine, be scarcely necessary for me to point out the various parts which are to be seen in the flame of a candle or of coal-gas. There is on the diagram (Fig. 2, c) before you the pic- ture of a somewhat small coal gas flame, produced at a circular orifice. It is, of course, enormously enlarged in the diagram. jFour distinct parts are to be recognised. First, the central and I darkest part ; this contains the unburnt gas, just as we saw in the case of the carbon monoxide flame. Perhaps it is wrong to (speak of this at all as part of the flame, for it is really a region iof no flame. At the base of the flame are two blue strips em- ibracing the lower portion of the flame. This appearance you will understand results from the mode in which we view the Jilame. The strips are really due to a sheath which goes right jround the flame like an uninterrupted calyx. It looks bright (where we view it edgewise. When we look through, as in the jmiddle of the diagram, it is very pale indeed. Next we have to inotice the bright yellow patch, so bright in the reality as to nia>k the other parts. Though it looks bright and dense, it is merely a hollow sheath. Lastly, there is surrounding the whole flame a pale mantle of flame of very slight luminosity. and of an almost indescribable tint, which perhaps we may call lilac. These parts are discernible in all ordinary name--. They d > not always occupy the same relative space. In the flame given by a good gas-burner the yellow part is made by intention as large as possible ; in the flame of a piece of string or a spirit - lamp you will see the outer investing mantle very ditinctly developed. If we are to understand flame, then, we must find an intel- ligible explanation of the existence of these distinct pans of its anatomy. One important point we can settle at once. An ordinary flime owe; its differeniiated structure to the slowness with which it gets the oxygen necessary for combustion. If there is an immediate and sufficient supply of air, the characteristic structure disappears. This we can secure bv making the stream of gas sufficiently rapid. I have here a steel cylinder containing coal-gas at very high pressure. If I allow the gas to escape slowly, we get a flame in which we should find the ordinary parts. But if now I allow the gas to is>ue rapidly, the admix- ture with air is so rapid, and, as you see, we have a pale flame quite undifferentiated in structure. We reach the same result by introducing a strong current of air into an ordinary flame, I as in the blast blow-pipe. The flame, you see, is then homo- geneous, as in the previous case. We see then that the structure of an ordinary gas flame is largely dependent upon the slowness with which the gas gets the air necessary for combustion. There is s'ill one other evidence of this. It is obvious that a very small flame will have a much better chance of getting its oxygen quickly than a larger flame. It is, I am sure, within everyone's knowledge that a very tiny gas flame is blue, and, as a matter of fact, we can learn a great deal about flame structure by carefully watch- ing the development of a very small flame. I am going to show you on the screen a series of photographs of actual flames. The photographs hjave been tinted as faithfully as pissible. The first slide (Fig. 3, a) shows a liny gas flame burning at the end of a glass tube ; it consists of a bright blue cone surrounded by a fainter one. Both are quite continuous. By puitinsj in another slide, and using the " dissolving view" arrangement of the lantern, I will show you the effect of turning on the gas. The flame (Fig. 3, b) you see is larger, and now is observed a third region in the flame— namely, a patch of bright yelliw at the tip. The original cones are still there, but are slightly interrupted at their apices. Turning on more gas, the flame (Fig. 3, f) again enlarges, the yellow patch increases in size, and the original cones are further broken into. But you see the yello.v jiatch is indented at points corresponding to the inner cone, which, as it seems, is striving to maintain its integrity. Turning on still more gas, we have now a great preponderance of yellow, the original blue cone is reduced to mere vestiges, and the outer cone forms a faint surrounding to the whole flame (Fig. 3, d). This is flame as we ordinarily know it. I wish now to show you another series of changes. We must suppose the gas supply fixed, and the photo- graphs I will show represent the changes which take place in the flame when air is gradually added beforehand to the coal- gas. The supply of coal-gas is, I repeat, the same in all cases. The first change seen is, you will notice, that the yellow patch diminishes in extent (Fig. 3, f). If I add more air it diminishes still more, and the inner cone is growing in distinctness (Fig. 3, /). If I add a trifle more air, the yellow patch disappears altogether, and we have now complete and distinct inner and outer cones (Fig. 3, g). I think you will admit that these two sets of photographs show a close correspondence, and you can see it more plainly if I throw them on to the screen in a group. There is really nothing sarprising in this similarity. The smallest gas flame has obviously the best chance of getting air, and when it gets enough it burns in a two-coned flame. The same effect is reached by adding air to the gas before it is burned. If we have a larger gas flame it has, of course, less chance of getting its oxygen rapidly, and we see that in whatever way we starve the flame of oxygen, we lose the simple structure, and come upon the yellow patch. Now, when we come to inquire into the chemical changes occurring in such a flame, we may, I think, feel confident that the chemical actions which determine the existence of the blue cone and the outer cone are the same, whether these cones are complete, as in a small flame, or fragmentary, as in a larger one. If that is so we can soon make progress, for, as I have shown you, we can easily separate these cones and find what is going on in each. I again use the cone-separating apparatus. First we have an ordinary luminous gas flame at the top of the outer NO, 1256, VOL. 49] 90 NA TURE [November 23, 189; tube. I pass in air, the flame loses luminosity, and rapidly be- comes an ordinary two-cone d Bun^en flame. I push the sir Mipply further ; the inner cone enters the tube, and descends uniil it rests on 'he end of the inner lube. The two cones of a h3dr< carbon flame art- ihus widely separated ; we can aspirate a sami le of the i^a-es, and see what changes have taken place in the first region ol cmbu-tion. The result is one that we might await wiih curi. sity, for we have now a competition. There are both caibon and h\drogcn to burr, and not enough oxygen to bum 1 o'h : ihe question is, which will have the pie- ference ? I think I nay say that ihe ofl'-hand opinion of any chemist who has not had bis attention drawn specially to this point would be that the hydrogen would easily have the pre- I'erence. Bu', as a matter of fact, this question was settled long ago by Dalton, ar.d in the opposite sense, and in the present case analysis would confiim ills conclusion. Jf we analysed d c About two-thirds of the carbon is burnt to form carbon montxide, one third to form carbon dioxide, whilst rather li-ss than two-thirds of the hydrogen is burnt, and more than one-third remains altogether unburnt. We need not dwell on the details, especially as the analysis of ihe gases was ma le after th^y had cooled. The four gases — cnrtion monoxide, carbon dioxide, steam, and hydrogen — act upon one, as a matter of fact, while ihey are cooling do"n, and the distribution of the oxyj^en that we find in our analysis of the cold gas is not |)recisely that which exis's in the gases a-- they just leave the inner cone. We shall only draw a general inferenc, and it is one that has been recently verified in a very complete manner by Prof. Dixon and his pupils. This inference is simply that the carbon in the inner cone is for the most part burnt to carbon monoxide, and that the hydrogen to a considerable extent is set free. So much then for the inner cone. The outer cone is b a ^ e f g Fig. 3. — ^, /■, r, d, flames with successively increasing quantities of coal-ga". d, e,/, g, flames with fixetl supply of coal-gas and siicces.'ivtly increasing quantities lT air. the gases we should find that all the carbon is burnt in the first cone, whilst a coiisideiable part of the hydrogen passes through unburn!. The change is not quite so simple as these words might apply, as you will see from the actual figures of analysis. Analysis ok Inter conal Gases from a Coal gas Air Fla.me. Caibon m.noxide 8"7 1 . > .•,, Hydr g.n 92 1 ^7 9 combustible gases. < arbon dioxide 4-1 Water 16 Nitrogen 62 ^.' [ 20'i burnt gases. Amount of air used 78-5 ( 9^yS^" l^'5 ' -' \ Nitro. en 620 Amount of air still needed ... 42-9 ( Oxvgen 90 ^ ^ { Nitro.^en ..... 33'9 NO. 1256. VOL. 49] due simply to the burning of the carbon monoxide and hydrogen which escape from the inner C' ne. When they meet with oxygen in the free air their combustion is completed. We are now in possession of the explanation ol the two-coned gas air flame. Applying this to the tiny gas flame to which no air has been previously added, we see that the inner cor e will be formed where the air has penetrated the gas .-ufhc enily to produce such a gaseous mixture as we had in the lower cone ol our separator. T he gases coming from this burn further out when they meet with more air, and form a second cone. The last thing we have to explain in the ordinary gas flame is the production of the yellow luminous patch, which, from the illuminating point of view, is the most iin) ortant feature of all. Now I need scarcely remind yuu tl at the general opinion is November 23, 1893] NATURE 91 ihat this yellow patch in the flime is dae to glowing carbon in a solid and very finely-divided state. The very familiar fact that a cold object introduced into the yellow part b'C>mes coaled with a black solid dep isit, composed almost wholly of solid carbon, confirms this view. That this carbon or soot is shIkI in the tlame, is shown by the fact that it is deposited as a solid even when a highly-heated object is jilaced in the flame, and there are other proofs — some of them very pretty — which I cannot show for lack of time and of a means of magnifyinti. Tiiis ex|)lanation is due to Davy, and constitutes hi^ most celebrated discovery on the subject of flame. He desciibes it in the following words : — " When a wire-gauze safe-lamp is made to burn in a very explosive mixtui e of coal-gas and air, the light is feeble and of a pale c 'lour, whereas the flime of a current of coal-gas burnt in the atmosphere, as is well known by the phenomena of the gas-lights, is extremely brilliant. ... In reflecting on the circumstances of the two species of combustion, I was led to imagine that the cause of the superiority of the light of the stream of coal-gas might be due to the dcconiposiiion of a part of the gas towards the inteiior of the flame where the air was in smallest quantity, and the dep 'sition of solid charcoal wliich, fi st by li^igiiilioii, andafterwards l>y its <:Ifm. "I held a piece of wire-gauze of about 900 apertures to the square inch over a stream of coal gas issuing from a small pipe, and inflamed the gas above the wire-gauze which was abn 1st in contact with the orifice of the pipe, when it burned with its usual bright light. On raising the wire-gauze so a> tocau-e the gas to be mixed with more air before it inflamed, the lii^ht became feebler, and at a certain distance the flame assumed tnc ]>iecise character of that of an explosive mixture burning within the lamp, but though the light was so feeble in this last case, '.he heat was greater than when the light was much more vivi^l, and a piece of wire of platinum held in this feeble blue flame became instantly white hot. "On reversing the experiment by inflaming a stream ofcoal- gis and iiassing a piece of wire-gauze gradually from the summit of the flame to the orifice of the pipe, the result was s'dl r,()re instructive, for it was found that the apex of the flame inter- cepted by the wire gauze afifirded no solid charcoal, but in passing it downwards solid charcoal was given off in consider able quantities, and prevented frqin burning by the cooling agency of the wire-gauze ; and at the bottom of the flame, where tlie gas burnt blue in its immediate contact with the atmosphere, charcoal ceased to be deposited in visible quantities." Only one attempt has been made to disturb the conclusion here draun by Davy. In 1S68 Prof. Edward Frankland, to whom we are indebted for many important discoveries respcc - ing flame, came to the cimclu>ion that the light-giving agen y in flames was not solid carbon, hut certain complex vaporous compounds of carbon and hydrogen. I regret very much that time will not admit of my detailing the evidence in favour ol this vie>v, or the counter evidence by means of which most chemists have been persuaded that Davy's explanation was, after all, the correct one. It is, however, right to remaik that Prof. Frank- land not only adheres to his own view, but promises to adduce further evidence in Us favour. Let us for the present, at any rate, stick to the opinion of the majority, and a, the composi- I a i, b f) c i ition of the distillate at any instant is calculated. Taking a = i4, /■ = 2, and c = I (numbers nearly i^roportional to the vapour 'pressures of methyl, ethyl, and propyl acetates), numerous curves jare plotted showing the progress of the separation at various stages of fractionation. These curves show distinctly that lahhough fractions containing large proportions of the liquids I NO. 1256, VOL. 49J A and C, of lowest and highest boiling points respectively, can be easily separated, the middle substance, B, is much more difficult to obtain in a state of purity. Consideration of these curves led the authors to see that by carrying out the fraction- ation in a particular way, it was possible to separate the mixture into two portions, one containing only A and P., and the other B and C. These mixtures of two liquids could then be frac- tionated in the usual manner. Ttiis process was cirried out on a mixture of methyl, ethyl, and propyl acetates, the results of which are given in considerable detail in the paper. The remarkable agreement between the densities of the ethyl acetates obtained respectively from the mixtures A and B, and B and C, as well as the fact that the densities of the separated liquids were the same as before the mixing, show conclusively that the method employed was highly successful. Prof. Ramsay said the paper was a most valuable one, and would be a great aid to chemists. Distillations were usually carried out by mere " rule- of-thumb," with the result that absolutely pure liquids could rarely be obtained. The President inquired whether curves representing the progress of distillation could be constructe-t district, the author described in detail its strati- graphy. The oldest sedimentary rocks are Silurian, but the floor on which they rest is unknown, and the author stated that it was probai ly fufed up and incorporated in the granite, which is descri ed in the paper. The Silurian rocks may have been folded before il.e granite was erupted ; in any case, the granite produced a zone of contactmelamorphism, whilst almost all the Silurian n cks may be considered to be examples of regional mtlam(ir|.hism, though the agents producing the metamorphism were least active to the east of Baihurst, where the Silurian limestones are very little altered. An anticlinal was probably produced at the time of the granitic intrusion. After a time there was subside nee, but at first it need not have been very ex- tensive, since the Devonian conglomerates, sandstones, and shelly limestones were probably deposited in a comparatively shallow sea. They contain Lepidodeudron anstrale. At Rydal they al ui against the uplifted Silurian rocks of the Bathurst area. At ihe end of Devonian times there appears to have been a long interval, during which both Silurian and Devonian rocks weie greatly denuded, and the granite exposed in idaces. The Upper Carboniferous and Permian rocks were deposited in the Liihgow district, but it is doubtful if they ever extended to Bathurst. There is nothing to show what happened in this region during Mesozoic and early Tertiary times. The Hawkes- bury Sandstone (probably Triassic) may have approached nearer to Bathurst than it does now. In late Tertiary tiuies stream-deposits were formed on the granitic rocks, and after- wards covered with thick basaltic lava-flows, which have since undergone much denudation. A discussion followed, in which the Pres dem, the Rev. H. H. Winwood, and Mr. J. E. Marr look pait. — Thegfology of Matte Grosso(particularly of the region drained by the Upper Paraguay), by Dr. J. W. Evans. The district includes a portion of the Brazilian hill country, and also of the low-l}ing plains to the south-west The rocks principally dealt with are unfossiliferous, and of unknown age, except that they appear to be older than the Devonian. They may be classified as follows :— (5) Matto Shales (relations not shown) ; (4) Rizama Sandstone (perhaps some unconformity) ; (3) •Curumba and Arara Limestones (very marked unconformity) ; (2) Cuyaba Slates (strong unconformity); (i) ancient crystal- line rocks. The Devonian and later rocks were briefly described. The President, Mr. Spencer Moore, fellow-traveller with Dr. Evans in Matto Grosso, Mr. H. Bauerman, and Mr. K. D. Oldham spoke on the subject of the paper. — Notes on the oc- currence of mammoth-remains in the Yukon district of Canada and in Alaska, by Dr. George M. Dawson, C.M.G., F.R.S. In this paper various recorded occurrences of mammoth-remains were noted and discussed. The remains are abundant in, if not strictly confined to, the limits of a great unglaciated area in the north western part of the North American continent ; whiLt within the area which was covered by the great ice-mass which the author has described as the Cordilleran glacier, remains of the manimoth are either entirely wanting or are very scarce. At the time of the existence of the mammoth the North Ameri- can and Asiatic land was continuous ; for an elevation of the land sufficient to enable the mammoth to reach those islands of the Bering Sea, where these bones have been found, would result in the obliteration of Bering Straits. The bones occur, along the northern coast of Alaska, in a layer of clay resting on the somewhat impure " ground-ice formation " which gives indica- tions of stratification; anel above the clay is a peaty layer. The author c>nsidered this " giound-ice ' was formed as a deposit when more continental conditions prevailed, by snow I'all on a region \\ithout the slopes necessary to produce moving glaciers. The inammoth may be supposed to have passed between Asia " and America at this time. At a later date, when Bering Straits were opened and the perennial accumulation of snow ceased on the lou lands, the clay was probably carried down from the highlands and deposited during the overflow of rivers. Over this land the mammoth roamed, and wherever local areas of decay of ice arose bogs would be produced which served a. veritable sink traps. The author considered it probable that the accumulation of "ground-ice" was coincident with \\\t second (and latest) epoch of maximum glaciation, which was followed by an important subsidence in British Columbia. In the discussion of the paper. Sir Henry Howorth remarked upon the long and careful survey of North- West Ameiica which has been made by the author, and upon the value of the conclusions which he has come to: firstly, in legarel to the absence of ancient glaciation in Alaska and its borders ; secondly, in regard to the existence of a great glacier in the Cordilleras, whose products are quite independent of and have nothing to do with the Laurentian drift; and thirdly, in regard to the dis- tribution of I he mammoth. It was a new fact to him, and one of great importance, that mammoth-remains had occurred in Unalashka and the Pribilof Islands in Beriig .Straits, proving that in the Mammoth age there was a land bridge here, ai many inquiiers had argued. It would be very interesting to have the western frontier defined where the mammoth-remains cease to lie found. It would be very interesting to know how far south on the west of the Cordilleras the true mammolh, as dis- tinguished from Elephas Columbi, has occurred. Regarding one conclusion of Dr. DawsonV, Sir Henry could not agree with him, namely, about the age of the strata of ice sometimes found under the mammoth-beds in Ala'-ka as they have been found in Siberia. The speaker was of opinion that this ice had accumulated since the beds were laid down, and was not there when the mammoth roamed about in the forests where he and his companions lived. Humus and soil cannot accumulate upon ice except as a moraine, and there are no traces of moraines or of great surfaceglaciation in Alaska and Siberia. Nor could either the flora or fauna of the memmoth age have survivid conditions consistent with the accumulation of these beds of ice almost immediately below the surface, or consistent with their presence there. The speaker considered that these beds were due to the filtration of water in the summer down to the point where there is a stratum of frozen soil, through which it cannot pass and where it consequently accumulates, freezes, raises the ground, and in the next season grows by the same process until a thick bed of ice has been formed. The evidence goes to show that the present is the coldest period known in recent geological times in Siberia and Alaska, and that the period of the mammoth and its companions was followed and not preceded by an Arctic climate where its remains occur. Dr. H. Woodward remarked that the most interesting point in Dr. Dawson's paper was the mention of the remains of mammoth on the Aleutian Islands, proving that this was the old high road for this and other mammals from Asia into North America in Pleistocene times. Linnean Society, November 2. — Prof. Stewart, President, in the chair. — -The secretary having read a list of the donations to the library since the last meeting, the President moved that the thanks of the society be given to the donois and to Lady Arthur Russell for the valuable collection of engraved portraits of naturalists which she has been so good as to present to the society in the name of her husband, the late Lord Arthur Russell, a motion which was passed unanimously. The Presi- dent then referred to the improvement which had been carried out during the recess in the society's apartments by the intro- duction of the electric light, for which they were indebted to the liberality of the treasurer, Mr. Crisp, who on former occasions had shown himself so generous a benefactor, and moved that the hearty thanks of the society be given to Mr. Crisp for his munificent present. The resolution was carried by acclamation. Referring to the deaths of Fellows of the society which had oc- curred since the last meeting, the President alluded especially to the Rev. Leonard Blomefield, whose connection with the society, extending over seventy years, had recently been maWe the subject NO. 1256, VOL. 49] Ndvember 23. 1893] NA TURE 95 of a c )'itjriiulaory ad Iress, to Mr. F. P isc «e, the ilistingiiished entom )lo^ist, and to Vir. Gi )igj Hro-.ik, who>e limiO'ed decease had caused th- vacancy in the Council which they no at had to fill. The ballot hiving then been taken for the elec'ion of anewcoun cillor in the place of Mr. George Brook, deceased, Mr. Henry Seebohm was declarexi lisation. ■ — Mr. Holme showed some new British marine algfe, and made remarks on their affinities. — Dr. Prior exhibited the fully developt-d fruit of Pytis jiponica from Rogate, Sussex, seldDm seen, although the plant is common, and alluded to its use as a cons-Tve if if could be o'ltained in sufficient quantity. — Mr. Spencer Moore lead a paper on the phanerogamic botany of an expfditi >n to Mato Grosso, upon which he acted as botanist. Starling from Cuyaba, the expedition first visited theChapada Pla'ean, 'o the east of tliat city, where many plants were collected. Tnencf a journey was made to thenewsettlement of Santa Cruz, "n th'' Paraguay, about half-way between Villa Maria and Diamantino. The flora here is of mixed character, nearly 37 percent, of 1 he plants being common to tropical South America, upwards of 27 per cent, occurring in the N. Brazil Guiana province "f F,ni;ler, with 20 '5 per cent common to that province and the S. Brazilian, and only 13 per cent, of S. IJrazilian ty es. From Santa Cruz a party penetrated through the primeval forest lying to the north, and reached the Serra de Sapirapuan. The forest flora is markedly Amazonian in character, nearly 50 per cent, of the plants being natives of Amazonia or of the neighbouring countries within the N. Brazil Guiana province, or related th reto, while the proportion of species common to tropical America falls to rather more than 28 per cent, the S. Brazilian element being present only to the extent of 9 "5 per cent. Returning to Santa Cruz, the Rio Bracisto was partly explored, and the Paraguay as- cended to the neighb lurhood of Diamentino. The party then came down the Paraguay to the Ci)rumba, where many plants of interest were found. The expedition was partly disbanded at Asuncion. Am mg the Amazonian plants found at Siuta Cruz, or in the forest, may be mentioned Randla Ruiziana, Bcrtie>'a gifa>iensis, the Loranthad Orvcta'itkes ritji aulin whch ensued — Mr. W. L. Distant communicated a paper en'itled "On the Homop- terous genus Pyiops, with descriptions of tw > new species." — The President read a paper, written tiy himself and Mr. J. Edwards, entitled " A revision of the genus CEneis" which he characterised as the most cold-loving genus of iiutterflies. He also exhibited his complete collection of siecies of this genus. A long discussion ensued, in which Prof. Poulton, Mr. McLach- Ian, Mr. Salvin, Mr. Bethune-Baker, the Rev. Dr. A'alker, Mr. Kirby, Mr. Merrifield, iMr Barrett, Mr. Blaudford, Dr. Sharp, and Mr. Jac iby took part. Zoological Society, November 7. — Sir W. H. Fl nver, K.C.B., F.R.S., President, in the chair. — Mr. Sclater read some notes on the most interesting animals he had seen during a recent visit to the Zoological Gardens of Stuttgart, Frankfort, and Cologne. — An ext'act was read from a letter addressed to the Secretary by Mr. J. G. Mdlais, relating his en leavours to obtain specimens of the White Rnino:eros {Rhiiioccos siiiius) in Mashiinaland. — .\ communication was read from Babu Ram Bramha Sanyal, describing a hybrid monkey of the genus Sc»iiiopithecus, born in the Z )o!ogical Garden:, Cal- cutta.— Mr. Tegetmeier exhibited a specimen of a hybid grouse between the blackgame (Telrao teirix) and the red grouse (LagopKs scotictis). — Mr. Boulenger read a paper on a Nothosaurian reptile from the Trias of Lombardy, apparently referable to Lari siuriis. Plis descri|)!ion was baser! onasmall, nearly perfect specimen from Mount Pcrle io, showing the ventral aspect, belonging to the Senckenberg Museum in Frankf )rt-on- Main, which had been entrusted to him by the directors of that institution, and was exhibited before the mr-eting. The author pointed out the presence of a series of minute teeth on the pterygoid bones, and of an entepic mdvlar (ulnar) f)ramen in the humerus. The number of phalanges was 2, 3, 4, 4, 3 in the manus, and 2, 3, 4, 5, 4 in the pes ; the terminal phalanx was flattened and obtusely pointed, not claw-shaped. In dis- cussing the affinities of this reptile the au'hor stated that the Lariosa'ivus described by Diecke did n )t appear to he generi- cally distinguishable from \.\\& A'cnslicoiaiirits "f Sseley, which he referred to the LarlosafiridiC, regarding tnat family as inter- mediate between the Mesosaurida and the Nothosauridcr, th .ugh nearer the latter. The M.sosatiridtr, in his opinion, formed one sub order,the LarijsauridcE and iVl?,'/^'i■flMr/(/(^ ogether a second sub-order, of the order PUsiosauria.—Dx. A. Giinther, F. R S.. read a second report on specimens of reptiles, ba'rachians, and fishes transmitted by Mr. H. H. Johnston, C.B., from British Central Africa. Dr. Giinther also rrad descriptions of some new reptiles and fishes, of which spi'cimens had been ob- tained on Lake Tanganyika by Mr. E. Coode-H )re. — Mr. Edgar A. Smith gave an account of a co'lection of land and freshwater shells transmiited by Mr. H. H. Johnston, C. B., from British Central Africa. The specimens in this collection, obtained by Mr. R. Crawshay from Lake Mweru, were almost all new to science. —Mr. Edgar A. Smith al-o read descriptions of two new species of shells of the genus Ennea. — A communi- cat'on was read from Dr. Arthur G. Butler, containing an account of two collections of Lepidop'era sent by Mr. H. H. Johnston, C.B., from British Central Africa.— A communi- cation was read from Mr. Edwyn C. Reed, containing a list of the Chilian Hymenoptera of the family OJyiieridie, with descriptions of some new species. — A comiuunicati an from Prof. Newton, F.R.S. contained the description of a new species of 96 NA TURE [iXoVEMBER 23, 1893 bird of the genus Drepanis, discovered by Mr. R. C. L. Perkins in the island of Molokai, Sandwich Islands. Paris. Academy of Sciences, November 13. — M. Loe*y in the chair. — On the new s!ar of 1892, T Aurigas = 1953 Chandler, •>y G. Bigourdan (see our Astronomical Column). — Observalions of the comets 1893 II. (Rordame) and 1893 c (Brooks, 1893, October 16), made at the Paiis Observatory, by the same author. Observations of position ere given, extending from November 6 to 8. — Elements of Brooks's comet, by M. Schulhof. The elements of this comet closely resemble those of the comet 1864 T. — Control of the trunnions of a meridian instrument by Fizeau's interferential method, by Maurice Hamy. — Measure- ment of the absorption of light by thin laminae possessing metallic reflection, by M. Salvador Block. — Dc;termination of the true atomic weight of hydrogen, by M. G. Hinrichs, Taking a; abscissse the weights of hydrogen employed by Keiser, Dittmar, and Morley, in their respective determinations of the atomic weight of hydrogen, and as coordinates the values found, the author has obtained a diagram which indicate^ that the values vary according to the weight of gas used in the ex- periments. In his opinion this proves that the ratio of H to O is absolutely as i is to 16. — On bar) ta emetic, by M. E. Maumene. — On the production of sucrose during the fermentation of barley, by M. L. Lindet. The experiments described indicate that sucrose and invert sugar increase proportionally to the decrease of starch during the fermentation of barley. — On the nitrification of prairie lands, by MM. J. Dumont and J. Crochetelle. The following conclusions seem to bejustified by the experiments : (1) Nitrification is forwarded in soils rich in humus by the addition of small quantities of potassium carbonate (2 or 3 pans per 1000) ; on the other hand, large quantities of the carbonate are hurtful. (2) Potassium sulphate is efficacious, and favours the production of nitrates when about seven or eight jiarts per thousand are used. (3) Chloride of potassium only exercises mediocre action. (4) Sodium carbonate does not ap- pear to favour nitrification. — On the influence of mineral poisons on lactic fermentation, by MM. A. Chassevant and C. Richet. This paper is in continuation of a previous one. The authors divide the toxic action of metallic salts on lactic fermentation into two parts, terming the dose that retards the reproduction and pullulation of the ferment atitigcnetique, while chat which arrests functional activity is called antibiotiqite. It appears that the antigentic dose may be as much as three times greater than the antibiotic dose, though for certain metals the two quantities are the same. DIARY OF SOCIETIES. London. THURSDAY, November 23. RovAL Society, at 4.30—00 the Photographic Arc Spectrum of Electro- lytic Iron: Prof. Lockyer, F. K.S. —Magnetic tjbscrvations in .'^ene- gambia : Prof. Thorpe, F.R.S., and P. L. Gray. — Alternate Current Klectroly-is : Dr. Hopkinson, F.R.S, E. Wilson, and F. Lydall.— A Certain Class of Generadng Functions in the Theory of Numbers: Major MacMah.)n. F.R.S. —On ihe Whirling and Vibration of Shafts: S. Uunkerley. — On Plane Cubics : Charlotte Angas Scott. iNsriTUTiON OP Electrical Engineers, at 8. — The Electrical Trans- mission of Power from Niagara Falls : Prof. Geo. Forbes, F.R.S. (L)is- .cussion). Sanitary Institute, at 8.— Metallic Dusts, Cutlery, Tool Making, and olhcr Metal Trade ; Dr. jincla.r White. FRIDAY, NOVE.MBER 2». Physical Society, at 5. -The Magnetic Shielding of Concentric 'Spherical Shells : Hrof A. W. Riicker, F. K.S— Ihe Action of Electro-Magnetic Radiation on Films containing Metallic Powders: Prof. G. M. Mmchin. A^ateuk Scientific Society, at 7. — Exhibition ol Lantern Slides of Raceiit Photographs of Volcanoes : L. \V. Fulcher. At 8.— The Dawn- ing of Life : J. Wilson Wiley, SATURDAY, November 25. Royal Botanic Society, at 3.45. SUNDAY, November 26. Sunday Lecture Society, at 4.— Cur.osities of Bird Life: Dr. R. Bowdler Sharpe. MONO A Y, November 27. Royal Geographical Society (at the University of Lonlon, Burlington Gardens, W.), ai 8.30.— Aritarctic Exploration : Dr. John Murray. NO. 1256. VOL. 49] TUESDA Y, November 28. ' Institution of Civil Engineers, ai S. — TheTansa Works for the Water- S'lpply of Bombay : William J. B. Gierke. — The Baroda Water-Works; Jagannath Sadasewjee. — Ihe Water-Supply of Jeypore, Rajputana: Col jnel S. S. Jacob. — On the Design of Masonry Dams : Prof. Franz Kreuter. (Discussion.) THURSDA Y. November 30. Sanitary Institute, at 8. — Textile Manufactures, Silk, Cotton, Woollen, and Linen Industries : Dr. J. T. Arlidge. FRIDAY, December I. Geologists* Association, at 8. — Notes on a Discovery of Fossils at Little Stairs Point. Sandown Bay, I.'-le of Wight: Thos, Leighton. — Notes on the Sharks' Teeth from British Creiaceous Formations : A. Smith Woodward. — The Breaking-up of the Ice on the St. Mary River, Nova Scotia, and its Geological Lessons : Geoffrey F. Monckton. Institlition OF Civil Engineers, at 7.30. — Forms of Tensile Test-Pieces; Leonard H. Appleby. BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books. — Alembic Club Reprints, No. 4 : — Foundations of the MoUcular Theory: J. Dalton, &c. (Edinburgh, Clay). — Practical Agricultural Che- mistry: J. B. Coleman and F. 'I. Addyman (Longmans). — Methods of Practical Hygiene, 2 Vols. : Prof. Lelimann, translated by W. Crookes (K.. Paul). — Suicide and Insanity : Dr. S. A. K. Strahan (Sonnenschein). — Mechanics of Hoisting Machinery : Dr. J. Weisbach and Prof. G. Herrmann, translated by K. P. Dahlstrom (Macmillan). — In the High Heavens: Sir R. S. Ball (Isbister).— Collected Mathematical Papers of Arthur Cayley, vol. vi. (Cambridge University Press). — Cancer, Sarcoma, and other Morbid Growths considered in Relation to the Sporozoa : J. J. Clarke (Baill.cre). — International Maritime Congress, London, 1893, Sections i to 4. Minutes ot Proceedmgs and General Report (Unwin Brothers). — Report of the Com- missioner of Education for the Year 1889-90, v >N. 1 and 2 (Washington). — Royal Natural History, vol. i, part r : edited by R. Lydekkur (Waine). — The Beauties of Nature : Sir J. Lubbock. 5th edition (Macmillan). Pamphlet. — Owens College Museum Hand-books — General Guide to the Contents of the Museum, 2nd edition (Manchester, Cornish). Serials. — BuUeiin Astronomique, October (Paris). —Meteorological Re- cord, vol xiii. No. 49 (Stanford). — Quarterly Journal of the Royal Meteoro- logical Society, October (Stanford) — Journal of the College of Science, Imperial University, Japan, vol. 6, part 3 (Tokyo). — Journal of the Franklin Institute, November (Philadelphia) — Proceedings of the Aristotelian Society, vol 2, No. 2, Part 2 (Williams & Norgate) — Brain, Part 63 (Macmillan). — Boletin de la Sociedad Geografica de Madrid, Tomo 35, Nos. i, 2, 3 (Madrid). — Journal of Marine Zoology and Microscopy, No. i (Jersey, Sinel and Hornell). — Journal of the Polynesian Society, vol. 2, No. 3 (Welling- ton). CONTENTS. PAGE Watson's Kinetic Theory of Gases. By Prof. P. G. Tait 73 A History of Crustacea 74 Our Book Shelf :— Mukhopadhyay " : "An Elementary Treatise on the Geometry of Conies " • • . 75 Briggs and Edmondson : "The Geometrical Proper- ties of the Sphere" -75 Carroll : " A Key to Carroll's Geometry " 75 Letters to the Editor :— " Geology in Nubibus " — A Reply to Dr. Wallace and Mr. LaTouche. — Sir Henry H. Howorth, K.C.I.E., M.P., F.R.S 75 Rock Basins in the Himalayas. — R. D. Oldham . . 77 "Composite" Dykes. {I/Zztsiraiec/.)— Henry E. Ede 77 Weismannism. — Dr. George J. Romanes, F.R.S . 78 Correlation of Solar and Magnetic Phenomena. — A. R. Hinks ; William Ellis, F.R.S 78 Artificial Amoeba? and Protoplasm. — Dr. John Berry Haycraft 79 The Royal Society Club 79 Tne De Morgan Medal So Notes ... So Cur Astronomical Column: — Mechanical Theory of Comets 84 The New Star in Norma 85 The Natal Observatory 85 Magnitude and Position of T Aurigse 85 The Period of Jupiter's Fifth Satellite 85 Geographical Notes ... ... ... 85 Hame. {Illustrated.). By Prof. Arthur Smithells . . 86 University and Educational Intelligence 92 Scientific Serials 92 Societies and Academies 93 Diary of Societies 9^ Books, Pamphlets, and Serials Received 9^ NA TURE 97 THE MUMMY. The Mummy. By E. A. Wallis-Budge, LL.D., F.S.A. (Cambridge : University Press, 1S93.) TEN years ago, and even less, the English readers of hieroglyphs might be counted on the fingers of one hand, without the thumb. They may now be reckoned by the score. The reasons for this movement — we can hardly term it a revival — are partly the opening of the Nile to any English tourist who can afford to travel at all. This is chiefly due to the ubiquitous Mr. Cook. But it would not be fair to mention it without also mentioning such authors as Dr. Budge, who have made what used to be a sort of secret knowledge, a sort of occult science, into one of the easiest branches of learning any one, especially an Englishman, can study. Hieroglyphs appeal to several different kinds of minds. People pictorially disposed find the representations of all kinds of common objects easy to remember, and very interesting to copy. The naturalist finds these curious old birds, beasts, fishes, and reptiles well worth learning, if only to find out why they stand for letters. The astronomer must work a little at them, on account of the light they throw upon the stars of a time so remote that a Draconis was then the Pole Star, and not a Ursa M maris. To the ordinary lover of languages the grammar of ancient Egypt is full of delightful surprises, as well as pitfalls, while he unravels a tongue spoken by Aryans, with Semitic inflections and Hamitic roots. We might go through the whole catalogue of 'isms and 'ologies, and yet find none in which hieroglyphs would not give some help ; and, above all, they are so absurdly easy. The ancient Egyptian was quite determined that whensoever people did learn to read his inscriptions, there should be no kind of mistake as to his meaning, and one result is that many beginners find it possible, without knowing the pronunciation of more than a dozen words, to ascertain the sense of whole passages. There is one thing more. At the very root of all literary learning lies this marvel- lous invention of the Egyptians. Hieroglyphs are the parents of the writing of the Phenicians, Hebrews, Syrians, Greeks, and Romans ; and consequently they are the by no means remote ancestors of our own alphabet, every letter of which is itself a modified hieroglyph. ., It is therefore curious to remark that the printing and publishing of Dr. Budge's book is the first effort on the part of any university in the three kingdoms to encourage the study of Egyptology. A kind of excep- tion may be made in favour of University College in Gower Street, which accepted a legacy left by the late Miss Edwards to found the chair now occupied by Prof. Flinders Petrie. But the work now accomplished by the Syndics of the Cambridge University Press, must be followed in the sister universities, and there are signs already of a movement in this direction. Dr. Mahaffy of Trinity Collepe, Dublin, is known to have acquired a share in the wisdom of the Egyptians, and the university of O.xford has given the honorary degree of D.C.L. to Mr, Petrie. Under these circumstances, therefore the appearance of Dr. Budge's book is opportune. Only a few NO. 1257, VOL. 49] weeks ago a young gentleman was found trying to learn hieroglyphs from Sir Gardiner Wilkinson's six volumes of mingled learning and ignorance. Even in Dr. Birch's great three-volume edition of Wilkinson, there is nothing practical to be gleaned. From this time there will always be a handy work, which can be recommended to the would-be student, a work as profound in linguistic learning as it is easy and simple in communicating it. There are points in which we differ with Dr. Budge, yet we cannot exactly impute them to him as errors. For example, we do not always like his transliterations, in which he is loyal to the system now long in vogue among the best class of scholars on the continent. He has not gone in for the recent French absurdities in this respect, nor, on the other hand, has he followed Herr Erman into his impossible quests after exact pronunciation. This is not the only point on which we are inclined to quarrel with that learned and whimsical German ; but it must not for a moment be supposed that there is anything controversial about the calm pages of Dr. Budge's " Mummy." On the contrary, when we con- sider that there ^is not a statement in the book that has not at one tim.e or another been called in question, not a chapter that has not been fiercely debated, we must con" cede to the author a credit for moderation very re markable. True, he has disdained even to mention the difficulties to which such books as the French catalogue of the Gizeh Museum, or M. Maspero's later works, expose a student. The method pursued by Dr. Budge is the safest. Con- ceivably, better systems may be constructed, but we must remember that it is by the present system that the great discoveries of Lieblein, Lepsius, Marriette, Birch, and so many others have been made. Dr. Budge tells us in the preface that this volume was originally written to form the introduction to the Cata- logue of the Egyptian collection in the Fitzwilliam Museum. It is, however, a complete book in itself, and forms, in a series of condensed, but perfectly clear essays, a very handy encyclopaedia of all branches of Egyptology. The first five chapters are historical, and are followed by a list of the dynasties and the dates assigned to them by different authorities. The divergences here are startling. Champollion Figeac placed the first dynasty at B.C. 5867 ; Wilkinson at B.C. 2320. Dr. Budge evi- dently prefers the B.C. 4400 of Brugsch. Lists of nomes and of cartouches follow, and then we have one of the most interesting chapters in the book, that on the Rosetta stone and the recovery of the Egyptian alphabet. The priority of Young to Champollion is clearly made out, though Herr Erman is doubtful ; and Mr. Renouf prefers the claims of Champollion. But Dr. Budge clearly proves that, though Young has precedence of Champollion, Akerblad, a Swede, has precedence of both. Some fifty pages are occupied by this interesting dis- cussion, and then we come to the "piece of resistance," the title role of the whole book, namely, the Mummy. An Egyptian funeral is minutely described. Next, we are told how the mimimy was prepared ; a subject to which we must briefly return when we have described the rest of the contents. Mummy cloth, embroideries, canopic jars and chests, come next. Eight pages are devoted to the Book of the Dead, and then we have a careful description of the different amulets, such as inscribed F 98 NA TURE [November 30, 1893 scarabs, figures, hearts, and so on, which are found in tombs. The names and figures of forty-six gods are next identified, and after them twenty-eight sacred animals. There are some interesting notes on coffins, followed by accounts of pyramids, mastabas, and tombs. A chapter contains particulars of Egyptian writing ; and after some minor articles the book concludes with two lists, one of common hieroglyphic signs, and one of the determina- tives most frequently observed. As the determinative is always .'.he beginner's surest guide, this last list will pro- bably be taken first by many readers. The scope and probable usefulness of this remarkably complete treatise will have been gathered from the above summary. We now turn back to the middle of the volume. Dr. Budge cannot decide whether the art of mummifying was known to the aboriginal inhabitants of the lower Nile valley, or was imported from Asia by the first Aryan settlers. He speaks of the venerable stele of Shera, a dignity of the court of Sent, the fifth king of the second dynasty, whose date is placed at about B.C. 4000. This monument is preserved at Oxford, but Dr. Budge ought to have mentioned here that a portion of it is in the Gizeh Museum. The French cataloguer of that collection omits all mention of the Oxford stele. So they are even ; but each portion gives different items of information. On this monument Shera prays the gods "to grant sepul- chral meals," from which Dr. Budge infers " that the art of elaborate sepulture had reached a high pitch of per- fection in those early times." He notes incidentally that a redaction was made in the reign of this king Sent of a medical papyrus, from which it is clear that the Egyptians were already possessed of anatomical knowledge sufficient to enable them to preserve the human body as a mummy or otherwise. Manetho, the Ptolemaic chronicler, ex- pressly states that Teta, the second king of Egypt, wrote a book on anatomy, and also studied the properties of drugs. His mother, Shesh, invented a hair-wash. Al- though, then, some form of mummifying must have been in use at a very early period, it does not follow that it was always practised. Bodies were sometimes preserved in honey, as, for example, that of Alexander the Great; and Dr. Budge quotes a gruesome story from Abel el Latif, about the body of a child found in a jar of honey. The body of Mycerinus, now in the British Museum, seems to have been wrapped in cere-cloth — if the Egyptians had honey, they also had wax. Skeletons of this ancient period usually fall to pieces when exposed to the air. The oldest mummy, strictly so called, which has been identified, is that of Seker-em-sa-f, B.C. 3200, a king of the sixth dynasty, which is now at Gizeh. A few fragments of the mummy of Unas, of the fifth dynasty, are in the same collection — part of the skull, only, and a hand. As to mummy cloth, Dr. Budge corrects a prevalent error. Almost all the older writers asserted that mummies were wrapped in cotton. Jomard thought linen was also used ; but a learned Fellow of the Royal Society, having obtained, in 1834, four hundred specimens of bandages, ascertained that they were all of linen. A piece of fine texture was found to have five hundred and forty threads to the inch in the warp, and one hundred and ten in the woof. Nobody who has seen the wrappings, of a delicate salmon colour, which were in the coffin of Thothmes III., can forget that they were as fine as the finest lady's handker- NO. 1257, VOL. 49] chief of the present day. Dr. Budge's views on the sub- ject of pyramids will not tally with those of numerous very worthy persons now, we may hope, of a more reasonable mind. In Cairo, a very short time ago, the only book on pyramids to be had by tourists was that of the late Scottish Astronomer Royal, which was written to prove that the Great Pyramid was erected to embody the truths of revealed religion. Dr. Petrie's book was no- where to be seen. Now all is changed. Messrs. Cook and Son employed Dr. Budge to write a little book on the Nile voyage, a copy of which is in the hands of every tourist, and the pyramid inch and the great passage theory have become curiosities of history. Dr. Budge says briefly, " the royal tombs of the early dynasties were built in the form of pyramids, and they are, to all intents and purposes, merely mastabas." ESKIMO LIFE. Eskimo Life. By Fridtjof Nansen.1 Translated by W.. Archer. 350 pp. (London : Longmans, Green and Co., 1893.) WHEN Dr. Nansen reached the west coast of Green- land, after his memorable journey across the continent, he found that the last ship of the year had left for Europe, although he had altered his plans and steered for Godthaab instead of the more northerly Christianshaab, partly in order to avoid being detained in the country during the winter. He was, however, com- pelled to spend the winter among the Eskimos, and his observations and reflections on the character and every- day life of the race are embodied in the book before us.. Dr. Nansen admits the impossibility of attaining a complete and thorough knowledge of so peculiar a people in so short a time as one winter, but his own experiences and impressions have been supplemented by reference to the writings of all the most competent authorities — the Egedes, Crantz, Rink, Holm, and others. The early history of the Greenland Eskimo is obscure,, and anything like certainty dates back no further than 172 1, when Hans Egede, the Norwegian missionary, took his wife and children, and settled on the west coast with a view of improving and civilising the native race. From that time to the present, however, the history of the people is well known, and a study of this period affords one of the best examples of the development and changes which so-called lower races undergo, when subjected to the influence of western European civilisation. The first part of Dr. Nansen's book is concerned with the daily life of the modern civilised Greenlander, and the chapters on the kaiak, or skin-boat, and the weapons used in hunting the seal and other characteristic game of the Arctic seas are excellent. It is interesting to note that this section of the Eskimo race use the throwing-stick, which enables them to throw the harpoon and bird-dart with greater force and accuracy than with the unaided arm alone. This instrument is only met with among two or three races of men, so widely separated from each other as to preclude the idea of a common origin of the invention. The character and social life of the people is portrayed in three or four of the succeeding chapters. ^Little November 2)0, 1893] NATURE 99 acquaintance with the writings of Nansen is necessary before it is seen that he possesses a flexibility of mind and deep sympathies which enable him to enter into peculiar touch with a race of this character. Chapter xiii. deals with the religious ideas and myths of the Eskimo. This part of the volume is necessarily second-hand ; but so far as the facts are concerned, nothing remains to be desired. It seems to us, however^ that there is too great a tendency to look upon these legends and tales as matters derived from foreign in- fluence, notably that of the early Scandinavian explorers, from the time of Erik the Red (986 a.d.) to about 1400 A.D. There is some similarity between the legends of the Scandinavian and the Eskimo, but Dr. Nansen, in dealing with the origin of those possessed by the latter, does not apparently allow enough for the possibility of spontaneous growth of the same idea in two widely separated races. The Vikings have had little influence upon the daily life of the Greenlander, and it is very improbable that the latter would borrow recondite philosophy, or lore of any kind, from the former. If true similarity does exist in such cases, it is more likely to be due to the inherent similarity of the powers of the human mind to invent explanations for incorrectly understood phenomena. In the concluding chapters are given the results which have been achieved since the introduction of Christianity 1 50 years ago. The first European settlement found a people who were nearly blameless, full of practical socialistic sentiment, generous and open-hearted, truthful, private property almost unknown, poverty non-existent, able to live peacefully and contentedly in surroundings in which Europeans, with all modern resources, are taxed to the utmost to exist through winter, healthy and full of patience. To-day disease, poverty, and distress are abundant. These changes, which must be looked upon as bad for the Eskimo, whatever the intentions of the settlers may be, are brought about by causes which are to a large extent obvious, and Dr. Hansen's advice to all those who have the welfare of the native race at heart, is to leave the country, and allow the people to make the shortest cut back again to their pristine state. The translator's work has been admirably done. J. P. OUR BOOK SHELF. La Voie Lactee dans I'He'jmsphere Boreal. By C. Easton. With a preface by Prof. H. G. van de Sande Bak- huyzen. (Paris: Gauthier Villars et Fils, 1893.) The Milky Way, "that broad and ample road, whose dust is gold and pavement stars," almost defies accurate delineation. Its irregular outlmes and indefinite struc- ture tease the eye of the artist, and renders his task most difficult. In all probability the largest amount of information with regard to this celestial zone " pow- dered with stars" will be obtained from photo- graphs taken by means of portrait lenses having a wide field, similar to that employed by Prof. Bar- nard for his beautiful pictures. There is much to be gained, however, by the multiplication of maps such as those of M. Easton, in which the aspect of the Galaxy to an observer having normal eyesight is shown. The maps are finely drawn and reproduced, and well show the delicate gradations of galactic light. A detailed descrip- NO. 1257, VOL. 49] tion and historical notice give the atlas additional interest, while a catalogue of the patches and streams of luminosity, and the dark regions, will be of use to those who theorise on the structure of the stellar universe. A comparison of the maps with those drawn by Boeddicker reveals many differences, but it cannot be said on this account that either of the observers is wrong. No two observers have eyes exactly alike, or are favoured with precisely the same observing conditions, hence drawings of the Milky Way, like those of nebulae, simply represent the appearances presented to certain visions, and are only approximations to the truth. M. Easton'smaps are published in a very handy form, and may be added with advantage to every astronomical library and observatory. An Elejnentary Treatise on Analytical Geotnetry. By W. J. Johnston, M.A. (Oxford: Clarendon Press, 1893-) In these 400 pages Mr. Johnston has ably succeeded in producing a very excellent treatise which leads the beginner by easy stages from the first principles of the subject to the more complicated theorems in trilinear coordinates. In the first ten chapters the student is made thoroughly familiar with the properties of the Ellipse, the Parabola, and the Hyperbola, after having been well exercised in the more preliminary parts of the subject as regards co-ordinates, the straight line, loci, &c. In these chapters it seems that the beginner can hardly fail to obtain a thorough grip of their contents, unless indeed he goes out of his way to do so, for more details could hardly be added. The numerous worked-out exercises should also be valuable, as they show him how to apply the knowledge gained from the various theorems learnt as book work. The next three chapters deal with the general equation of the second degree, con- focal conies, and abridged notation, the last-mentioned including a large number of miscellaneous exercises; in these may be mentioned some additional methods of tracing a conic whose Cartesian coordinates are given, and an investigation of the equation of a diameter due to Prof. Purser. The remaining chapters treat of trilinear coordinates, envelopes, and methods of transformation. Here may be noticed Prof. Genese's proof of Feuerbach's theorem, Pascal's theorem, and many others of interest. As an elementary book one may say that, from a be- ginner's point of view, we have here a sound and clearly written volume that will be sure to find favour with students and teachers. Perhaps it may be better for those commencing the subject to pursue the limited course recommended to them by the author, but a little more of an insight will show them what to read. Advanced students will also find much of interest in the latter chapters, and to them we can specially recommend the working out of some of the numerous and well-chosen examples. Zur Kenntniss der Postembryonalen Schiidelmetamor- phose7i bei Wiederkauern. By H. G. Stehlin. (Basel: Benno Schwabe, 1893). This publication deals with a branch of osteology which up to the present time possesses no special literature of its own, and is an attempt to trace the changes which take place in the skulls of ruminants from the time of birth up to adult age. The skulls of Bos, Capra, and Portax are stuoied in a most exhaustive manner at different ages, and comparisons drawn ; elaborate measurements being given in every case. Special attention is paid to the effects produced by the develop- ment, final size, .ind position of the sinuses, teeth, and horns ; also, the differences between the skull at birth and at adult age are considered in relation to rate of growth of the animal, and its lenj.th of life. In the last chapter the three types. Bos, Capra, and Portax, are con- trasted with each other, and a number of other forms described, their relations to these types being indicated. lOO NATURE [November 30, 1893 The plates illustrate most fully the points made out, in many cases a longitudinal section of the skull of the animal at birth being printed in red over a drawing of one of adult age, both drawings having been reduced to scales which render comparisons of form possible. LETTERS TO THE EDITOR. [T/te Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected inani'scripts intended for this or any other part «?/" Nature. No notice is taken of anonymous co7mnunications .\ Suggested Nomenclature of Radiant Energy. Having recently had occasion to develop the first principles of the theory of inter-stellar radiation, I soon felt the want of some short and convenient word to express that form of ethereal wave-effect known as "radiant energy," "radiant heat," "light," "rays of the spectrum," &c. Radiant energy is doubtless the most accurate of these expressions, but it is sutjject to the objection of being a description rather than a name. The nomenclature of the subject has come down from a time when it was supposed that there were three distinct kinds of rays in the spectrum, severally known as light, heat, and actinic rays. It is, I believe, not much more than half a century since several eminent physicists and teachers supposed that the heat rays of the spectrum could be separated from the light rays having equal refrangibility by the absorption of a transparent medium ; and that even the light rays of different colours might be separated in the same way. I cannot but think that the general under- standing and application of the now received theory of the subject, which recognises in this form of energy no differences of kind except wave-length, has been materially retarded by the want of a corresponding nomenclature. The use of the word "light" for ethereal waves having a length between certain definite limits, while there is no corres- ponding word for other waves, is evidently unscientific. Not- withstanding the great practical usefulness of light, its distinnive property of affecting the optic nerve in a certain way can claim only a secondary place in physics. Indeed, it has long seemed to me that the banishment of the word " light " from physics was a desideratum. After various attempts I hit upon the very simple term radiance, as one which seemed well-fitted to supply the want in question. The vague and poetic idea hitherto associated with it IS an advantage, because it enables us to adapt it to the case in hand with greater readiness than we could adapt a word which already had some well-defined meaning. Shakespeare speaks of the " sacred radiance of the sun " ; while Milton describes the Deity as "Girt with omnipotence, with radiance crowned." We can thus adopt the word to express scientifically what we now consider to be electro-magnetic waves, or ethereal waves, with- out that clashing of ideas which might arise from making a new application of an old word, and without the awkwardness of coining a new one. The necessary derivatives and compounds of the word can be formed with as much ease as we should expect in the case. The verb "radiate " will mean to emit radiance. I do not think any confusion will arise if we use the word " illuminate " to signify the throwing of radiance upon a material body, although in ordinary language it implies light. Possibly the extent to which it is used in a tropical sense may facilitate the widening of its literal meaning. Radiometry would mean the measure of radiance, and an instrument for effecting such a measure would naturally be called aradiometer. It is perhaps unfortunate that the instrument in question should then assume the name of Crookes' beautiful little instrument, but an apology may be found in the fact that the latter has not been used for the purpose of exact measurement. The use of the word "radiometry" offers no such difficulty. I am still a little perplexed for a word which shall express the quality hitherto called transparency, diathermancy, &c. Apparently we have no alternative but to continue the use of one of these objectionable words, or invent some such new word as transradiant, or transradious. The proper measure of radiance, and the only measure which can be regarded as of real i mportance in physics, should be the amount of energy radiated in unit time. This measure is equivalent to NO. 1257, VOL. 49] that of heat generated in unit time in the absorption of radiance by a perfectly black body. If we reflect that this, and this alone, measures the actual loss of internal energy by a radiating body of any kind, whether ball of iron in a laboratory, planet, star, or nebula, the importance of some simple nomenclature of measurement will be evident. I should be much pleased if physicists would find by actual trial whether the use of the pro- posed words comes as natural to them as it has to me. Simon Newcomb. The Postal Transmission of Natural History Specimens. It has always been recognised that scientific research is greatly furthered by the exchange of the various objects with which that research is concerned. For the transmission of objects of Natural History from one country to another, the mails have offered a cheap, speedy, and trustworthy means. Heretofore, through the laxity with which the regulations on the subject have been enforced, it has been possible to enter such objects in the mails of the Universal Postal Union as samples of merchandise and under the rates of postage there- for. From ofhcial information lately received from the Post Office Department of the United States it appears that such a rating is entirely unauthorised by existing provisions, and that objects of Natural History may be mailed to countries of the Union only, at the rates required for letters. The United States Post Offics Department also stated that it had recently sub- miued a proposition to the countries composing the Postal Ui.ion to modify the regulations so that such specimens might be received into the mails at the same rates as samples of m 5rchandise, but that a sufficient number of those countries had voted against the proposition to defeat it. This Academy has therefore resolved to address the various scientific bodies, with which it is in communication, in those countries whose Governments have voted against the proposi- tion, and to request those scientific bodies to memorialise their respective Governments in favour of the same. The Governments of Austria, Bolivia, British India, Canada, Germany, Great Britain, Guatemala, Hungary, Japan, Norway, Portugal, Russia, Spain, Sweden, Tunis, Uruguay, and Venezuela having voted in the negative, this Academy respect- fully requests the favourable conhideration of this question by scientific societies, and begs that they take such steps as they deem advisable to inform the Postal authorities of their respective Governments of the manifest advantages to scientific research which would result from the adoption of the proposed modification, and to request those authorities to take such steps as may result in the adoption of the same. The letter rate for postage (Universal Postal Union) is ten times that required for samples of merchandise ; such a rate for specimens of Natural History is virtually prohibitive. This Academy would respectfully urge upon scientific societies prompt action in this matter, if it meets with that approval which we so strongly desire. Isaac J. Wistar, President. Edvv. j. Nolan, Recording Secretary. Philadelphia, November 14. Flame. 1 However thoroughly a B.A. audience may have allowed Prof Smithells, by means of his beautiful experimental demon- strations, to hypnotise them into unquestioning belief in his conclusions, those who read the account of his lecture in the pages of Nature will not all be equally disinclined to question the validity of some of his arguments. To tell us that Dalton, as a matter of fact, long ago settled the question as to which has the preference — the carbon or the hydrogen — when a hydrocarbon is burnt with insuflicient oxygen, is, after all, but to appeal to the gallery ; and this and other conclusions arrived at by Prof. Smithells appear to me to involve the use of that process of circular reasoning which con- sists in taking for granted that which is to be proved — a method which at the present day finds such favour in certain quarters. As I discussed this matter somewhat in detail in a correspon- dence with Sir G. G. Stokes last year (Chem. Soc. Proceedings, 1892, No. 106, p. 22), it is unnecessary to go fully into it now. Any number of analyses showing the presence of hydrogen in the products of combustion may be quoted without materially ad- November 30, 1893] NA TURE lOI vancing the settlement of the question. In my opinion, there is no improbability inherent in the assumption that hydrogen is but a secondary product, resulting from the interaction of the primary products — ^water and either carbon or carbon monoxide. The rate at which the interactions take place in flames are such, and the conditions are such, that the products collected are prob- ably far from being \.he products of the initialinterchanges, as in- deed Prof. Smithells himself admits to be the case. It is scarcely likely that the settlement of such a question can ever be achieved by direct observation. Our ultimate views on the nature of the changes occurring in flames must depend on the gradual growth of a true understanding of the nature of chemical interchanges in general, and especially in gases. I am inclined to take the same view with reference to Davy's explanation of the luminosity of flame. If eventually, as is not improbable, we come to regard the expressions chemical inter- change and electrolysis as interchangeable equivalent terms, much more will have to be said on behalf of Frankland's hy- pothesis. I had the good fortune to attend the philosophic lectures at the Royal Institution in which Frankland, in 1868, first fully stated his views on this subject, illustrating his ar- guments by a series of most striking experiments. No course of lectures ever impressed me more, and to the present day I have the most vivid recollection of all that passed. An account af the lectures was published in the yotirnal of Gas Lighting at the time of their delivery. It has always appeared to me that Frankland's arguments are of a most weighty character, and that owing to their appearance in an obscure publication they have never yet been sufficiently widely considered. The study of flame affords problems of the highest interest and importance, but of proportionate complexity and difficulty. There is little doubt, however, that we are inclined to take too narrow a view of this as of many other inquiries — that we have an unreasoning belief in what we are pleased to call facts, for- getting that these same "facts" are but phenomena interpreted by our own limited intelligence; On studying the views that have been taken at various times, it is only too obvious that fashion is not confined only to garments, nor is dogma the ex- clusive privilege of theologians ; and it is time that we realised that very many of our conclusions regarding chemical interchanges are but the crudest dogmas, based on a thoroughly superficial consideration of the phenomena. If we are to de- serve the title of scientific workers — workers exact in deed, thought, and word — we must be far more careful in the choice of our language, and guarded in our conclusions. Henry E. Armstrong. " Geology in Nubibus." 1 Sir Henry Howorth wishes to continue the discussion of glaciation in the pages of Nature, but I find in his last letter very good reason why this cannot be done. No discussion can lead to definite results unless the parties to it accept as data what they themselves have recently and deliberately admitted. But when I stated that the Rhone glacier did reach the Jura, and deposit on it erratic blocks between Geneva and Soleure, I did so because it was one of the data already admitted by Sir H. Howorth. In his " Glacial Nightmare," pp. 169-173, he gives a full summary of Charpentier's first memoir on the erratic blocks of Switzerland, describing the glacial phenomena exhibited along the whole course of the old glaciers from the Alps to the Jura, and showing that they " even climbed that range and went over to the other side of it." Sir H. Howorth then says : "I have quoted at considerable length from this excellent memoir, because I look upon it as having definitely applied inductive methods to this question with results which are for the most part sound and unanswerable.'" (Italics mine.) In the same chapter (pp. 195-202) Charpentiers second memoir is sum- marised still more fully, and his general conclusion is thus quoted : " It goes without saying that not only all the valleys of the Valais were filled with ice up to a certain height, but that all lower Switzerland, in which we find the erratic debris of the Rhone valley, must have been covered by the same glacier. Consequently all the country between the Alps and the Jura, and between the environs of Geneva and those of Soleure has been the bed of a glacier." Agassiz and other writers are quoted as giving further evidence of the same kind. Nowhere in the whole of this chapter can I find a single objection to the conclusions of the chief writers quoted, and the concluding paragraph, at p. 208, frankly accepts them. It declares that NO. 1257, VOL. 49] they are supported by "every form of converging evidence," and that — " So far there is no question at issue." Yet, when I take these same conclusions of Charpentier as admitted data, Sir H Howorth says : "This form of dogmatic argument is assuredly incomprehensible ! " Charpentier's proof that the Rhone glacier reached Soleure, was, a year ago, " sound and un- answerable," and was an example of " definitely applied induc- tive methods " ; but when I accept these same results as some- thing to reason upon, I am told that I am making use of " hypotheses outside the laws of nature." I have now justified my opening statement that a discussion carried on in this manner can serve no useful purpose. Alfred R. Wallace. Correlation of Magnetic and Solar Phenomena. In Mr. Ellis' letter on this subject (Nature vol. xlix. pp. 30), he says : — " To sum up, the points of the matter may be thus stated : — (i) The solar outburst in 1859 was seen independently by two observers : the fact of its occurrence seems therefore undoubted. (2) The corresponding magnetic movement was small. (3) Many greater magnetic movements have since occurred. (4) No corresponding solar manifestation has been again seen, although the sun has since been so closely watched." Now, in the year 1882, I was acting as assistant to the Solar Physics Committee, and on November 17 there was a dense fog, so that it was not possible to take the usual solar observations. Mr. Lockyer was present in the morning, and then left for some reason ; after he had gone, a telegram came for him : he returned late in the afternoon, and sent for me, told me the telegram was from Mr. Preece, of the Post Office, asking him whether there was a solar disturbance, as there was such a violent electrical storm raging, that communication had been cut off from the continent, and that it was difficult to maintain communication in England. I at once went to the instruments, and as the fog cleared just before sundown, was able to ascertain that there was a large group of spots near the sun's meridian, attended with most violent uprushes of luminous matter ; indeed, if my memory serves me aright, it was the most violent disturbance I saw during the whole of my observations, extending from 1879 to 1886. On reporting to Mr. Lockyer, he said we should probably see an aurora in the evening ; and as soon as it was dark, there was a most brilliant auroral display that exhibited some quite new features (Nature, vol. xxvii. pp. 82 et seq.) Doubtless, had this spot been kept under observation, luminous outbursts similar to those observed by Carrington and Hodgson would have been seen ; indeed, Mr. Whipple's letter (loc. cit. p. 83) seems to contain such an observa- tion. I believe, but am not quite sure, as the records of the observa- tions are in Mr. Lockyer's possession, that it was in this spot that he and I first noticed that some of the so-called iron lines in the spot spectrum were in motion, while others were not. H. A. Lawrance. Gunnersbury, November 19. New Variable Star in Andromeda. A STAR that should be added to the list of variables is -f 26°43, of t^he Bonn Durchmusterung, in which work its mag- nitude is given as 87. In reply to a letter of mine, in which I expressed a doubt as to this star's existence. Dr. Kiistner, of Bonn, informed me that although he had on the 7th of this month looked in vain for the star with the 6-inch refractor of Bonn Observatory, yet it seemed pretty certain that a star had twice been observed in the specified place in September, 1855. I have subsequently been informed by Sir Robert Ball, that the star was twice observed at Cambridge (England) in 1878. The dates and places of the various observations, as well as the esti- mated magnitudes, are : — Sept. 7, 1855, Bonn, 9-0 (but perhaps 9'2). Sept. 10, 1855, Bonn, 83. Nov. 29, 1878, Cambridge, 87. Dec. u, 1878, Cambridge, 87. The star's mean place for i894'o is R.A. oh. i6m. S^-'Z^- Decl. -f26° 24' 27" Thomas D. Anderson. 21 East Claremont Street, Edinburgh, November 22. I02 NATURE [November 30, 1893 Protective Habit in a Spider. Mr. R, I. Pocock's interesting paper in your issue of November i6, leads me to place on record an observation I made last summer in the island of Arran. Sitting by a little clear pool in the granite of Glen Sannox, I noticed a spider whose web was spun in the heather which partly overhung the stream. On disturbing her, she dropped on to the granite a few inches above the water, anci running rapidly down, entered the pool and hid under a tuft of weed. After remaining thus hidden for 2| minutes, she returned to the surface and, reeling herself up by her thread, regained the web. Disturbed again, she repeated the action, remaining under water if minutes. A puff of tobacco smoke sent her down a third time, when she remained hidden for 2\ minutes. In each case she hid in the same place, and in each case regained the nest by her thread. I have placed the spider in Mr. Pocock's hands. He informs me that the species is Epeira corniita, or Y>o^i\h\y paiagiata. University College, Bristol. C. Lloyd Morgan. THE LOSS OF H.M.S. " VICTORIAN FOUR weeks ago the Admiralty issued a minute upon the proceedings of the Court-Martial appointed to inquire into the loss of H.M.S. Victoria ; and also a further minute upon the construction and stability of the ship, and a report by Mr. W. H. White, the Director of Naval Construction, upon such parts of the evidence given at the Court-Martial as throw light upon the causes of the foundering or capsizing of the ship. In the first-named minute the Admiralty concur with the finding of the Court-Martial, as regards the causes of the collision with the Camperdown, and the distribution of blame among the officers concerned : — matters with which we shall not now attempt to deal. The other two relate to the construction, buoyancy, and stability of the ship, and discuss facts and questions relating to these points, which demand the careful attention of all who are interested in the efficiency of the Navy. These minutes deal with matters for which the Admiralty is felt to be responsible, and to be, to some extent, upon its trial. The question of Admiralty responsibility for the efficiency of the Victoria, and her power to withstand such a blow as she received, has been hitherto treated and discussed as though it were merely one of who designed the ship. In this case, the circumstances are somewhat peculiar, for her original designer, Sir N. Barnaby, retired from the Admiralty service in 1885, immediately after the vessel was ordered to be built, and before she was even in frame. Many alterations were afterwards made during the progress of construction, and everything considered necessary for safety or efficiency was done by others, during the five years that passed before she was finally completed. Whether the early design were good or bad, the responsibility for the ship as she was com- pleted and commisssioned, and passed into the Navy as a first-class battle-ship in 1890, surely rests with those whose duty it was to watch her construction, and to ultimately certify to her fitness for the class in H.M. service in which she was placed. The question of who was responsible for the design of the Victoria as it first stood, has now little more than an historical interest. That of the responsibility for completing and fitting her out for sea, and passing her into the Navy as a first-class battle-ship, is the only one of real practical importance at the present time, if it be thought necessary to discuss the matter. This being the state of the case with regard to the question of responsibility, we can only regard the minutes relating to the buoyancy and stability of the Victoria as the best defence of the ship that is possible. It may be a perfectly good defence, but it is obviously ex parte, and can only rightly be judged as such. Had a Committee of Inquiry been appointed, these minutes represent the case that would have been laid before it by the Admiralty, NO. 1257. VOL. 49] and would have been examined from various points of view, and adjudicated upon. The Admiralty has pre- ferred to treat the public as competent judges, and to lay their case before them in a form which bears the outward semblance of a judicial decision. The minutes are, how- ever, upon some points more in the nature of a pleading than a judgment ; while they are, at the same time, much too technical and complex for any but the most competent experts to judge. It is to be regretted, in the interests of the Navy and the country, that the facts and opinions thus put forward are not referred to a competent and impartial body for examination and report. Mr. White's report summarises the evidence respecting the behaviour and movements of the Victoria after she was struck by the Catnperdown, and gives the results of calculations respecting the effect of filling com- partments in the neighbourhood of the blow, which appear to agree, in the main, with the reports of observers. The calculations employed are, as he states^ quite simple in character ; and no one who knows the Construction Department of the Admiralty, or the men in it who perform this class of work, could doubt their substantial accuracy. An important point in con- nection with them is, however, the assumptions upon which they are based. Some of these may be more or less open to question ; while nothing is said as to the information the officers had respecting the rapidity with which the Victoria might be sunk if rammed. It appears evident that no one on board imagined the ship could sink, after such a blow as she received, without giving time to close the water-tight doors ; and it appears,, also, that some of the water-tight doors could only be closed by going into compartments into which the sea first obtained access. These questions, and the more general one of the light that is thrown upon the efficiency of other ships of the same class by this sad disaster, respecting which the Admiralty minutes say nothing directly, though they imply that nothing unsatisfactory is indicated, appear deserving of close and careful consideration. The following remarks will be devoted to an attempt ta describe how the matter, and the light thrown upon it by the recent Admiralty minutes, strikes one who is intimately acquainted with the ships of the Navy, and has studied the technical questions which have been raised, from time to time, respecting them. The subjects treated of in the two minutes now under consideration may be classified as follows: — (i) The nature of the blow received by the Victoria; (2) her after-movements and behaviour up to the moment when she capsized and sank ; (3) the extent to which water found access into the ship ; (4) the effect of the water thus admitted upon the line of flotation and the stability ; and (5) the lessons that are taught by various circumstances attending the loss that have come to light. I. The nature of the blow received by the " Victoria.'' — Before the commencement of the manoeuvre that im- mediately preceded the disaster, the ships of the squadron were steaming in two parallel lines, about 1200 yards apart, at a speed of about 84 knots. The course was ordered to be reversed by turning the ships inwards between the lines. The Victoria's helm was put hard to starboard, at an angle of 35^, and the Ca;/!pcrdoa'n's helm was put over to port, at an angle of 28^. With these helm angles the Victoria would turn in a circle of 600 yards diameter, and the Cainperdozvn in a circle of Soo yards diameter. A collision was therefore inevitable with both ships continuing at the same speed. When both had turned through eight points, or a right-angle, they were end-on to each other, at a distance apart which was estimated at 400 to 500 yards. It was then seen that a collision was imminent, and the port engines of the Victoria and starboard engines of the Cainperdown November 30, 1893] NA TURE 103 were ordered to be reversed at almost the same instant, about one minute before the collision, in order to make the ships turn more quickly. Orders to go astern with both sets of engines followed immediately in each ship. The Cainpci'-downs speed on striking the Victoria was estimated at 5 to 6 knots, and appears to have been rather less than 6 knots. The Victorians speed ahead at the same time was about 5 knots. The blow was struck at an angle of about 10 abaft the beam of the Victoria, and at a distance of about 65 feet abaft the stemhead. The vertical portion of the Camperdoiun^ s stem pene- trated 5^ to 6 feet into the side of the Victoria, and the point of the ram, which projects 7 feet beyond the vertical portion of the stem, penetrated 9 feet within the bottom plating at a depth of about 12 feet below water. The breach thus made in the side of the Victoria appears to have been 220 or 230 square feet in area ; of which over 100 square feet was below the water-line. It extended vertically downwards 28 feet from the upper deck, and 18 feet from the water-line, and was 12 feet wide at the upper deck, and 11 feet wide at the water-line. The ships were locked together for over one minute, during which time their sterns swung together through an angle of 20^ As the blow was struck just before a water-tight trans- verse bulkhead, it appears probable that the water-tight- ness of the division thus formed was destroyed, either by the first shock or by injuries subsequently received, as the sterns of the two ships swung towards each other, while they were locked together. 2 . The movements a7id behaviour of the " Victoria^'' after beins; struck, up to the 7no)nent when she capsized and sank. — Mr. White gives a clear description of this, which agrees with the evidence of officers on board other ships, who observed carefully what was happening to the Victoria. The force of the blow given to the bow of the Victoria caused it to move over at first 60 or 70 feet to port. The two ships remained locked together about one minute,^ and as the CaDiperdoivn moved astern and cleared the Victoria settled down rapidly by the bow, and heeled towards the starboard side. The bow sank 10 feet during the first four minutes after the collision. Two minutes later the water had risen so high on the fore- castle, which was originally 10 feet above water, that the men working there had to be called away. In nine to ten minutes after the collision the sea was entering the open turret ports, 100 feet from the bow and 14 feet above the original waterline. The upper deck right forward was then 1 3 feet below water ; the armour-door in the bulkheadat the fore end ofthe upper deck battery, which was open, was partly under water ; and the two foremost gun ports on starboard side, also open, were awash. The forward part of the upper deck was thus submerged for nearly half the length of the ship, and the stern was lifted about 8 feet. Simul- taneously with this rapid depression of the bow and elevation of the stern, the ship was continuously increas- ing her heel to starboard up to about 20', and when this position had been reached, nine or ten minutes ■only after the collision, she gave a lurch to starboard, turned bottom up, and sank by the head. When the lurch began the vessel was steaming slowly ahead with both screws, and the helm was hard over to starboard. The speed ahead, due to an attempt to steam slowly towards the land, and the helm being over to starboard, tended somewhat, as Mr. White pomts out, to increase both the depression of the bow and the heel to starboard. Even a very low speed would have a serious eftect, after the fore end of the upper deck became submerged, in forcing it still deeper below water, and in driving water into the interior of the ship through the openings on and above the upper deck. The helm was kept over because the hydraulic steering gear ceased to act very soon after the collision, when it was in that position. The failure ' Some observers thought two minutes. NO. 1257. VOL. 49] of this steering gear is attributed to the inflow of water consequent upon the collision. Alternative hand-steering gear, which was available in a convenient position abaft the portion of the ship that was flooded, could not be brought into operation, owing to the short time the ship remained afloat. 3. The extettt to which water found access into the ship.— A very large portion of Mr. White's report is de- voted to a detailed discussion of the state of each com- partment in the forward part of the ship, and the probability of water finding access into it ; and, although the results thus arrived at are, doubtless, right upon the whole, it is not certain that they are correct in every par- ticular. He appears to go too far in asserting that the evidence given before the Court Martial, respecting the compartments which were flooded, is exhaustive ; while this is inconsistent with the list, given in Table II. of his report, of " Compartments shown by the evidence to have been probably or possibly filled through doors, hatches, &c." Two items in that list, at least, are quite doubtful, as judged by the published evidence, viz. the water-tight compartment in hold on port side, between frame stations 12 and 22, and the port ejector tank ; which would hold 108 and 35 tons of water respectively. Neither does it appear right to claim, with absolute certainty, upon the evidence as it stands, that the submerged torpedo room was flooded, although it is probable that it was. This is a point upon which further examination of the witnesses might have converted reasonable doubt into something approaching to certainty. There are, however, no scientific or practical questions relating to the case that would be seriously affected by proving absolutely that one compartment, or another, about which there might be any doubt, was or was not flooded. Events proved that sufficient water found its way into the fore-end of the ship to submerge the bow to the extent that was observed, and to ultimately cause her to capsize and sink. She would probably have kept afloat if all water-tight doors and scuttles had been closed, and if the entry of water had thus been limited to the compartments that were directly opened up by the breach made by the collision. The ultimate submersion and capsizing was apparently caused by the entry of water into compartments that were not damaged by the collision, through open doors and scuttles ; and the circumstances and causes ofthe catastrophe can therefore be thoroughly discussed whether Mr. White be right or wrong in his conclusions as to the precise number and positions ofthe compartments that were flooded. It thus appears, adopting Mr. White's figures in the aggregate — which must be fairly correct in order to account for the facts — that the weight of water which entered the ship was approximately as follows : — (i) Into compartments that would have been flooded, in consequence of the collision, if all water-tight doors and hatches had been closed : 75 tons above the protective deck, 330 tons upon the platforms under the protective deck, and 271^ tons in the hold, being 6765 tons in all. (2) Into compartments that were subsequently flooded through doors, hatches, &c., that were left open : 334 tons above the protective deck, 353 tons upon the platforms under the protective deck, and 47 tons in No. 7 coal bunker and shoot. (3) Into compartments which may have been flooded, but as to which the evidence is doubtful : 322 tons above protec- tive deck,^ 200 tons upon the platforms under the protective deck, and 143 tons in the hold. In addition to the above about 100 tons of water must have entered the boatswain's and carpenter's stores above the protec- 1 The compartments into which this 322 tons of water may have entered are the air-compressing room, sail room, chest room, torpedo room, and turret support, and it is pointed out in a foot-note to Mr. White's minute that these compartments are within the limits of the armour belt. We do not understand how this affects any of the points in the case. 104 NA TURE [NOVEAIBER 30, 189;; tive deck, through the riding bitts on the upper deck, after the tops of these became submerged. We thus obtain a total of 1,110 tons of water which entered the ship through the breach made by the col- lision and passed into other compartments, besides those directly laid open to the sea, through open doors, hatches, &c. , a further amount of 100 tons that entered after the tops of the riding bitts became submerged ; and 665 tons about which there may be doubt as to the precise positions of the compartments it entered. 4. The effect of the water thus admitted upon the line of flotation and the stability.— The i,i 10 tons of water above mentioned would, according to the Admiralty calculations, considering its position at the fore-end of the vessel, de- press the bow to the extent of 21 feet, and raise the stern 8 feet. This change of Vv^aterline is considered to have necessarily flooded the other compartments, respecting which the direct evidence is doubtful ; and certainly to have filled the boatswain's and carpenter's stores through the riding bitts. The turret ports, and also the door on starboard side, and the ports, in the upper deck battery, would thus be brought under water, and the position of the ship be rendered hopeless. Mr. White states, with regard to the stability, that as the Victoria floated before the collision, she had a meta- centric height of 5 feet— z>. the centre of gravity was 5 feet below the point at which its righting effect would be nil — and that after the collision, when the bow had sunk deeply and she had heeled considerably — by how much is not said — the metacentric height was reduced to about eight-tenths of a foot. When water had entered the battery and turret through the open door and ports, as observed when the fatal lurch began, the meta- centric height had become altered by the changed con- dition to minus I'S feet ; and the final capsize was inevitable. A consideration of the fifth subject treated in these minutes, which is the lessons taught by circumstances connected with the loss — the most important of all for the future— will require an article to itself, and must therefore be postponed till another week. The points mentioned in this connection are : the effect of longitudinal bulkheads upon safety in such circum- stances as are those under discussion ; whether the closing of the battery doors and ports would alone have been sufticient to save the ship ; whether the closing of all water-tight doors and scuttles would have done so ; whether the water-tight doors fitted to the ship were the best for the purpose ; the value of an armour- belt at the ends for the purpose of resisting damage ; and whether the blame rests wholly upon the officers of the Victo7-ia for not knowing how rapidly the ship would be likely to sink when damaged as she was, and for not taking steps sooner to close the water-tight doors and scuttles and prevent the final catastrophe. Francis Elgar. JUPITER AND HIS RED SPOT. JUPITER is now, with his northern declination of 18^ and an equatorial diameter of 48", a very fine object visible above our horizon during more than 15 hours at a time. Thus, on December i he rises at 3h. 7m. and sets at i8h. 23m., shining nearly throughout the long nights now prevailing from a position about (f south- south-west of the Pleiades. As an object for telescopic study Jupiter is undoubtedly the most interesting planet of our system. The activity apparent everywhere on his surface, the number and variety of the forms displayed, and the comparative ease with which they may be observed, attest that this object IS practically without a rival, and that the investigation of his phenomena is certain to be productive. NO. 1257, VOL. 49] The present time is eminently a suitable one for study- ing his surface markings, and redetermining their proper motions. As the planet's rotation period is less than 10 hours, the times of transit of the same spots may some- times be obtained twice on one night, for if a marking crosses, say, 3 hours after the planet's rising, the same object will again reach the central meridian about 2I hours before the planet sets. It is well known that the visible surface of Jupiter con- sists of a number of light and dark zones interspersed with irregular forms which exhibit great differences in their rates of velocity. Certain white spots, bordering the equator, move very swiftly, and complete a rotation in considerably less time than the red spot. Some dark spots, which have appeared at various times on a double belt about 25° N. latitude, have moved more rapidly still, and shown a rotation in seven minutes less time than the red spot. But it is a peculiar feature of the different markings that they do not maintain the same rate of motion during their existence ; in fact, a lengthening of period seems to generally affect them. Thus the red spot in 1880 gave a rotation of gh. 55m. 34s., while in re- cent years it has been about Qh. 55m. 41s. The equa- torial white spots, which thirteen years ago had a period of 9h. 50m. 6s., have been gradually moderating their speed until in the last few years their period seems to have been gh. 50m. 30s. It is certain that the various markings are carried along in atmospheric currents, and are subject to remarkable differences, of which we do not comprehend the cause, though we may readily trace the effects. The red spot situated in Jupiter's S. hemisphere, and on theboundary of the tropical and temperate zones of the planet, is still perceptible, and it is highly probable that the spot existed long before it first came conspicuously into notice in July, 1878. During the last fifteen years there has been little change either in its oval shape or in its dimensions, though its colour and visibility have suf- fered some trying viscissitudes. It has been successively presented as a brick-red spot, as a faint pink ellipse, as a grey shading, and it is now so feeble that only the out- line of its following side can be distinguished, the preced- ing part of the spot having apparently lost i4:s definite outline. In fact, there seems a prospect of losing the object temporarily if further decadence goes on, but in view of past experience and the probability of recurrence in the Jovian markings, we may certainly expect the spot to reappear, and to present a more conspicuous aspect than it does at the present time. The following are some eye-estimates of the transits of the spot during the present apparition ; they were made by Mr. A. Stanley Williams, of Brighton, and by myself at Bristol : — Date Red spot IMarth's Red 1893 ' at zero spot Observer. transit. meridian. precedes. h. m. h. m. m. Aug. 9 • • 14 5 • 14 i3'6 ... 8-6 .. W. F. D. 14 . • 13 15-5 ■ . 13 221 ... 6-6 .. A. S. W. 16 . • 14 52-2 ) 15 0-6 \ 8-4 .. ,, 16 . • 14 55 S I 5-6 . \Y. F. D. Sept. 4 • ■ 15 31 ■ . 15 41-8 ..IO-8 .. A. S. W. 14 . . 13 52-2 . ■ 13 57-5 •■ 5-3 •• Oct. 8 . ■ 13 35-8 ■ 13 43-6 ... 7-8 .. 18 .. . II 50-4 •• . II 58-0 .. 7-6 .. 30 II 45 • . II 500 ... 50 .. Nov. 6 .. . 12 29-2 . • 12 34-9 •. 57 •• 23 • . II 25 • II 33-9 .. 8-9 .. W. F. D. The spot therefore transits a few minutes before the zero meridian based on the daily rate, Sjo-2j° ( = 9h. 55ni. 4065s. for one rotation). System II. in Mr Marth's ephemerides {Monthly Notices, May, 1893). Mr. Williams writes me that he has recently been able to make out the whole outline of the red spot except the preceding end, and on one very favourable night. November 30, 1893] NATURE 105 November 6, he glimpsed the spot in its entirety, and describes it as of a pinkish colour. The following and south following part of the spot had quite a dark and definite outline. On October 31 the red spot was seen with the 16-inch refractor at the Goodsell Observatory, Northfield, U.S.A. It was not a difficult object, though the colour is stated as being very faint. " The S. side of the spot and a belt of similar tint appeared to merge into one another without the slightest change in intensity of colour." On November 23 I observed the spot with an 8^-inch reflector belonging to my friend, Mr. J. Harvey Jones, of Bristol ; but the night was not very good. The red spot was faintly seen, and must have been central at about iih. 25m. Other details were also noticed as follows : — A faint, narrow, dark belt, like an irregular pencil-line, on the equator. A similar belt running from about the p. end of the red spot to W. limb of the planet. The shouldering of the S. equatorial belt N. of the ends of the red spot was distinctly seen, though that part N. of the p. end was very faint. The f. shoulder shows a much more gentle slope than formerly. Numerous reddish spots were seen on the N. side of the N. equatorial belt. These were large and conspicuous, as were a series of bright spots p. and S. of the red spot. A remarkably brilliant spot on the N. side of N. equatorial belt was central at loh. exactly. The general appearance of the planet betokened a more disturbed condition than usual, the belts being full of irregularities. The great size, durableness, and special character of the red spot have naturally attracted much discussion, and a number of theories have been broached to explain the nature of the spot, and to account for its long endu- rance. Some writers have regarded it as part of the solid material of Jupiter, but this theory is practically negatived by the fact that it has shown an irregularity of motion. Unless we admit that the rotation period of Jupiter is extremely variable, and has experienced con- siderable retardation in recent years, we cannot allow that the red spot forms a portion of the sphere. Others believe the spot to represent a condensation of material floating or suspended above the surface of the planet, and that variations of motion and tint are impressed upon it by the action of the Jovian atmosphere, which is con- stantly in a state of turmoil. Another idea has been mooted to the effect that the spot may possibly be an opening in the atmosphere, through which the surface of Jupiter has been exposed, and that the recent feebleness of the object is occasioned by the filling in of the cavity with highly reflective vapours. The Rev. E. Ledger remarks that at one time he felt inclined to believe that the permanency of the spot "seemed to indicate that it might be something which, while coagulating or solidifying, in some way caused a gap or break in the cloudy regions above it, or by its cooling condensed the vapours incumbent upon it, and thus increased its own visibility ; in fact, that we might be watching in it the gradual formation of a huge con- tinent upon Jupiter." The theory has also been advanced that the spot was originally formed by ejecta from a volcanic region immediately underlying it, but it must be admitted that no hypothesis appears to be entirely satisfactory in its application, and certainly we cannot regard any one of them as capable of being definitely proved. In a word, it must be avowed that though we have become familiar with the red spot, its motion, shape, and variable tints, during observation extending over more than fifteen years, we are yet far from, understanding the mystery it involves. Its production was doubtless the outcome of the energy and activity prevailing above, and possibly on, the planet's surface, but in what particular way the spot NO. 1257, VOL. 49] was generated it is impossible to say. Nor is the specific date of its first apparition known ; it may be a modern resuscitation of the spot which delighted Hooke and Cassini about two centuries ago, or it may only have been initiated into existence just before those memorable nights in July, 1878, when it exhibited an intensely red colour, and struck observers, instantly, as being a most anomalous feature. But though the spot forms an unsolved mystery, it will continue to be watched with interest by telescopic ob- servers, who will much regret if its present faintness is but the prelude to final dissolution. It can be justly said that no planetary marking visible in modern times has encouraged as much observation, and incited the same amount of interest as the familiar " red spot on Jupiter." Possibly the further study of this remarkable formation may yet enhance our knowledge of the physical condition of the "giant planet," and throw some light upon the singular variations so rife upon his expansive surface. W. F. Denning. THE PREPARATION AND PROPERTIES OF FREE HYDROXYLAMINE. A CONSIDERABLY improved method of isolating -^"^ hydroxylamine is described by Prof. Briihl, of Heidelberg, in the current Berichte, by which a tolerably large quantity of the pure substance may be prepared without danger in a short space of time, and which may therefore be of general interest on account of its suit- ability for lecture and demonstration purposes. It may be remembered that M. Lobry de Bruyn, who first isolated solid hydroxylamine two years ago {znde Nature, vol. xlv. p. 20), prepared it from a mixed solution of the hydrochloride and of sodium methylate in methyl alcohol. This solution, after removal of the precipitated common salt, was first concentrated over a water bath, under the diminished pressure of 100 m.m.,and afterwards subjected to fractional distillation over a flame at the still lower pressure of 40 m.m. A continuous fractionating vacuum- apparatus was considered unsuitable, and the change of receivers could only be conveniently effected by tem- porarily arresting the distillation. This mode of operating frequently led to violent explosive decomposition of the heated hydroxylamine, and, moreover, the yield rarely exceeded 17 per cent, of the theoretical. Prof. Briihl, desiring to obtain a considerable quantity of the pure base for spectrometric purposes, has been led to devise the following much more convenient method : — The methyl alcohol solution is first separated from the precipitated salt, and then immediately transferred to a slightly modified form of the well-known apparatus of Prof. Briihl for fractional distillation in vacuo. This apparatus consists essentially of a distilling flask, pro- vided with thermometer and entrance tube furnished with tap, a condenser, and a receiving arrangement which provides for the repeated and rapid change of receiver without impairing the vacuum and without arresting the distillation. This receiving arrangement consists of a short but wide cylinder of stout glass, into which the end of the condensing tube is introduced through a tubulus fitted with bored caoutchouc stopper ; inside the cylinder is a circular stand carrying six receiving tubes, which are capable of rotation by means of a rod passing, gas-tight, through a tubulus and its caoutchouc stopper in the top of the cylinder, and terminating in a handle outside. By suitable manipulation of the handle, each of the six receivers may be brought beneath the end of the con- densing tube in turn while the distillation is proceeding. The distillation of the methyl alcohol solution contained in the distilling flask is effected by reducing the pressure to the lowest possible amount, and supplying the necessary heat by immersing the flask in a bath of hot water. On io6 NA TURE [November 30, 1893 account of the explosive character of hydroxylamine, it is dangerous to employ even a small naked flame, which is liable to effect local superheating. The temperature of explosive decomposition lies in the neighbourhood of 130" ; by uninterrupted distillation in the manner indi- cated, and at a pressure not exceeding 22 m.m., the hydroxylamine passes over entirely at a temperature of 56-57'', and by maintaining the water bath at only a few degrees superior to this temperature all danger of ex- plosion is avoided. The methyl alcohol is practically entirely removed by the pump. Instead of leading the distillate through a warmed condenser, as recommended by M. de Bruyn, a practice which materially diminishes the yield by decomposition of a portion of the product, Prof. Briihl finds it much more advantageous to feed the condenser with a constant supply of iced water ; for although the melting point of hydroxylamine is 33°, it does not resolidify even at temperatures only a few degrees above zero, so that stoppage of the condensing tube does not occur. It solidifies instantly, however, in contact with a vessel immersed in ice and salt. The cylinder containing the receivers is therefore immersed in such a mixture, so that each drop of hydroxylamine solidifies the moment it enters the receiver. The hydroxylamine thus obtained in one operation is sub- stantially pure. From thirty grams of the hydrochloride about ten grams of the base may be obtained in one hour, a yield of 66 per cent, of the theoretical, which is four times that obtained by the method of M. de Bruyn. In the case of hydroxylamine becoming a commercial preparation, on account of its extraordinarily great anti- septic power, it would be quite easy, by introducing suitable additional condensers, to recover the whole of the methyl alcohol employed. The pure white crystalline hydroxylamine melts accord- ing to the mode of heating and the size of the containing tube at 32-34°, and its boiling point for a pressure of 22 m.m. is 56-57°. It may actually be cooled below 0° without solidifying, if allowed to remain at rest ; but, like most other substances which exhibit the property of superfusion, it solidifies the moment it is agitated. In the solid state it does not appear to be liable to decom- position. Even in the liquid state at 0° indications of decomposition have not been observed. At 10°, however, bubbles commenced to form in the liquid, and at 20" a continuous evolution of gas, mainly nitrogen, occurs, be- coming more and more violent as the temperature rises, until sudden explosion takes place. Hence in a warm summer hydroxlamine cannot be preserved in sealed glass tubes. Thus a specimen, after keeping for eight days in July, was found to be no longer capable of solidification even at -6°, although there was sufficient of the base left undecomposed to explode with a certain amount of violence upon heating, less, however, than in the case of freshly-prepared hydroxylamine. When just prepared one drop warmed in a test tube over a flame explodes with a report equal to that of a gun-shot. It is suggested that hydroxylamine might be safely preserved in metaUic vessels, for it appears likely that the notable action of the liquid upon glass causes the commencement of the decomposition. At the temperature of 23"5° the relative density of pure liquid hydroxylamine is 1-2044. Its refractive index at the same temperature varies from r4375 for light of the wave-length of the red lithium line to i^SU for light corresponding to the blue hydrogen line Hy. The sub- stance thus exhibits a small refractive power and a sur- prisingly small dispersion. Indeed, its molecular dispersion is about the same as was found by Prof. Briihl for nitrogen itself in triethylamine, so that the atom of oxygen and the three atoms of hydrogen would appear to exert no dispersive action if the same value for nitrogen be assumed to be equally operative. The only possible explanation is that the nitrogen here united to NO. 1257, VOL. 49] oxygen and hydrogen possesses a lower spectrometric constant than when attached to carbon in triethyla- mine. From a systematic study of the spectrometric constants of the free base, and of the methyl derivative CH3NH.OH prepared by his assistant Dr. Kjellin, an account of which was given in the Notes of Nature of November 9, Prof. Briihl has been enabled to prove two important facts. The first is that the con- stitution of hydroxylamine can be none other than ^\ ^N - O - H. The second is that the molecular refrac- W tion and dispersion of the nitrogen present in these com- pounds is the same as that of the nitrogen in ammonia gas, much lower than that of the nitrogen in triethylamine, and that the probable values of these constants of nitrogen linked in this manner, for sodium light, are respectively 2"495 3.nd 0*072. This addition to our knowledge of the spectrometric constants of nitrogen will be of invalu- able aid in unravelling the intricate subject of the consti- tution of the class of nitrogenous organic substances known as " oxims," a subject upon which Prof. Briihl is now concentrating his attention. A. E. Tutton. NOTES. It is with much regret that we announce the death of Baron von Billow, at Kiel. Von Billow's Observatory, better known, perhaps, as Bothkamp Observatory, was the first in Germany devoted to astro-physical researches, and it stands as a splendid monument to his interest in astronomy. By his death astro- nomical physics has lost one of its most enthusiastic sup- porters. The meeting of the Vienna Academy of Sciences was ad- journed on November 16, as an expression of regard for Dr. Alexander von Bach, who died on November 12. The memorial to Sir Richard Owen is to take the form of a full-length marble statue, executed by Mr. Thomas Brock, and placed in the Natural History Museum, South Kensington. A BOTANICAL section has been added to the Zoological Station at Naples, with a small laboratory for algological studies and researches in vegetable physiology. Dr. Oswald Kruch has been appointed to the Conservator- ship of the Royal Botanical Institute of Rome, recently resigned by Dr. A. Terracciano. A Reuter's telegram from Montreal announces that the worst earthquake ever experienced in Canada occurred there at noon on November.27. As far as has been ascertained, no lives were lost, but considerable damage has been done to property, and the walls of many buildings have been cracked. A SEVERE earthquake was felt at Peshawur, and other places in the Punjab, about nine o'clock on the morning of November 5, but fortunately no very serious damage was done. The wave apparently extended over a large area, including the Tamrud plain and Nowshera. An international Photographic Exhibition will take place at Milan from May until October next year. There will be a sec- tion for professional photography, another for amateur photo- graphy, and a third for technical and industrial applications of photography. The Department of Science and Art has received, through the Foreign Office, a dispatch from her Majesty's Minister in Chili calling attention to an exhibition which it is proposed to hold next year at Santiago, dealing with the subjects of mining and metallurgy. The exhibition will be opened in the second November 30, 1895] NA rURE 107 fortnight of April, 1894, but the exact date is not yet known. The eight sections of the exhibition will comprise electricity, mining machinery, mechanical preparation of minerals, metal- lurgy, chemical industries, statistics and plans, and mining and metallurgical products respectively. The Municipal Council of Lausanne has been considering a scheme for the electrical transmission of power (says La Nature). It is proposed to obtain work to the extent of about 1200 horse- power from the Grand-Eau river, at a distance of forty kilo- metres from Lausanne This energy will be utilised to supply about 5000 lamps and 16 arc-lights during the night, while in the day it will furnish the motive power for electric trams, and motors for domestic use, besides pumping the town's water- supply to the proper level. The new examination laboratories of the Institute of Chemistry will be opened on Friday, December 8. The last of the Gilchrist lectures, in connection with the Bethnal Green Free Library, will be given on Thursday, December 7, by Dr. Andrew Wilson, on "Brain and Nerve and their Work." Prof. Bornmlller has returned from his extended botanical journey in Persia. A COMMITTEE has been appointed by the Italian Botanical Society for the study of the flora of Italy, both phanerogamic and cryptogamic. The reports from the various members will be collated by Prof. Arcangeli, and published in the BuUetino of the Society. Bulletin No. 38 of the Experiment Station of the Kansas State Agricultural College is occupied by a preliminary report on rusts of grain, accompanied by three plates illustrating the mode of development of Puccinia graminis, P. riibigo-vera, and P. coronata. In Kansas the two former of these are found chiefly on wheat, while the last is apparently confined to oats. Evidences of the existence of mau in Nicaragua during the early Neolithic age were discovered by the Spaniards about the beginning of the sixteenth century. They mainly consist of flint-heads of arrows and spears, stone statues of men, and numerous fragments of pottery made of clay, containing fragments of volcanic rocks, unadorned and originally unburned. Of these evidences, those indicating the geological time or epoch in which they were made are, according to Mr. J. Crawford (Proceedings of the Boston Society of Natural His- tory, vol. xxvi. p. 49, 1893) :(i) Several well-executed stone statues found in the same locality, and all of the same brachy- cephalic type, carefully sculptured from blocks of hard rock, with brittle tools of flint, jasper, and felsite ; (2) oblong blocks of partly metamorphosed rocks, in their natural state or but slightly shaped by man, apparently forming the foundations for an oblong temple or observatory extending east and west ; (3) fragments of unadorned pottery found near the stone images, cemented in the debris of a well-marked subsidence, all discovered in the small valley on the west face of the moun- tain island of Momotombito. This island is situated near the volcanic cone Momotombo, and an unobstructed view of the Pacific Ocean, about twenty-seven miles to the westward, can be obtained fiom the observatory or temple. Mr. Crawford's examination of the locality and the handiwork leads him to believe that "the aborigines cf the sculptors of the stone images found on the island came from Polynesia, over the land route or chain of almost connected islands then existing across the Pacific Ocean, and that the latest subsidence of twenty-five feet, as recorded on the island and the western part of Nicaragua, and the consequent synchronous activity of all the volcanoes in NO. 1257, VOL. 49] that region, both occurring during the time when the sculptors were carving stones into images of types of their own people, caused the sculptors and their tribe to migrate eastward (the only safe route) and seek a home on the side of the very fertile and non-volcanic Amerrique mountains, where their probable descendants — the Amerriques — now reside." The first of the three articles in the current number of the Internationales Archivfiir EthnograpIiie(y\. parts 4 and 5) is by Prof. H. H. Giglioli. It is entitled " Notes on the Ethno- graphical Collections formed by Dr. Elio Modigliani during his recent Explorations in Central Sumatra and Engano." Dr. Modigliani published in 1890 a valuable book, " Un Viaggis a Nias," giving an account of his anthropological investigations in that little known island. Giglioli's communication, which is fully illustrated, appears to be a preliminary notice of a forth- coming work by Modigliani, and it gives to English readers a foretaste of the extremely interesting and important investiga- tions made by that skilled observer and excellent collectof. Modigliani was not allowed by the Dutch colonial authori- ties to remain long among their foes the Battaks of Lake Toba, but he made good use of his time, and also discovered a magnificent waterfall. Giglioli gives an admirable summary of the arts and crafts, habits and superstitions of these literally cannibals. The islanders of Engano remarkably resemble the Nicobarese, but the faces of some of them recall Polynesian and especially Micronesian types. Like other islands, the old order is rapidly changing, and the population of about 8,000, ten years ago, is now reduced to 840. Prof. A. C. Haddon has a paper on " The Secular and Ceremonial Dances of Torres Straits," illustrated by wocdcuts and four admirably executed coloured plates. This is the first time that any Papuan dances have been adequately described. The dances are classified into festive dances, war dances, ceremonial dances (including initiation and seasonal dances), turtle processions, and funeral ceremonies. The descriptions of the dances and the decoration of the per- formers are given in great detail ; the initiation and funeral ceremonies were carefully built up, so to speak, from the accounts of the natives. Here also so much change has taken place, that in a short time it will be impossible to gather any further information of any value. Prof. W. Joest has an illustrated paper on various toys ("Allerlei Spielzeug"). There are also the usual notes, reviews, and bibliography. We have received from Sgr. Arcidiacono a pamphlet con- taining the results of observations of the geodynamic pheno- mena which preceded, accompanied, and followed the Etna eruptions of May and June, 1886, carried out under the direction of the late Prof. Orazio Silvestri, of the Uni- versity of Catania. This work forms a valuable addition to geodynamic literature, and contains a detailed account of the movements, both microscopic and sensible, observed in the various seismological stations around Etna from May iS to June II, a table of all the shocks recorded, with their general character, direction, and intensity, and a reproduction of the seismograph diagram in the form of a curve about 15 feet long, which shows the course of the phenomena as recorded between the dates May 8 and June 16. The general aspect of calm was first broken on May 12, where slight and slow per- turbations are recorded. These were repeated more emphati- cally on May 14 and 15. The 17th was calm, but at 10.30 a.m. on the 1 8th the explosion of the central crater occurred, which threw the barometer stile right off" the scale. This was followed by a continued succession of violent shocks during the same day, and by the eccentric explosion of the southern flank on May 19. The eruption then followed a regular course until May 26, the disturbances being much smaller and of nearly constant average amplitude for each hour. A steady diminution of the eruptive io3 NA TURE [November 30, 1893 force took place until May 31. This and the following day were visited by two considerable shocks, followed by another strong concussion on June 5, which marked the close of the eccentric eruption. The 9th witnessed some disturbances ac- companying a mild eruption of the central crater, and calm was tiuJ.Iy re-established on June 14. A coincidence worth noticing is tha-. of the highest barometric pressure observed during all that time, a pressure of 771 mm., with that of the great central eruption on May 18. The greatest disturbances were pro- duced along a line passing through the focus in a direction from east-north-east to west-south-west, this being at right angles to a radial line which was the seat of the 1883 eruption. Measurements of the amount of light absorbed by thin me- tallic films of various thicknesses are incapable of affording a true measure of the absorptive power of these films unless the films compared have the same reflecting power at normal incidence. M. Salvador Bloch has been for some time experimenting with collodion films coloured with fuchsine, and thus made to exhibit a metallic aspect. According to an account published in the CovipUi RendiiSf he has succeeded in obtaining films of different thicknesses and of equal reflecting powers. Two pellicles formed by pouting layers of different thickness over glass plates, and evaporating under the same conditions, show, if all goes well, a strong resemblance as to reflecting powers. This wasUested by studying with a Babinet compensator the ellipticity of the green rays near the E line reflected from the pellicle. The employment of sunlight enabled the observer to measure differences of phase down to oj^ of a wave-length. For two such pellicles no difference of phase exceeding or even approaching that limit was observed in any portion of the films. Three such films, called A, B, and C, and of thicknesses ; 744, 1921, and 1964^^1, respectively, were used for determining the index of absorption for the yellow D rays. The index of ab- sorption was taken as defined by the fact that a vibration progressing in the absorbing medium through a length — has 27r its amplitude reduced in the ratio i : e~y, where 7 is the index of absorption. From A and C combined, •> was found to be o"o88, and from A and B o"oS4. Films of such thickness were opaque to green, but another set of films, of thicknesses 353, 504, and 627ujLt, respectively, were found thin enough for mea- surements in the case of green light. The two corresponding values found were o'529 and 0'505. The spectrophotometer used was analogous to a half shadow polarimeter. A polarised beam of sunlight fell normally upon a biquartz. The light then passed through an analyser with divided circle, and then through a lens, which projected an image of the biquartz upon the slit of a spectroscope provided with an eye-slit. The spectrum then consisted of two superposed portions, each corresponding to one of the quartz plates. The_film was then cut half off the 'glass, and placed so that the edge coincided with the junction of the biquartz, with the result that the light suffering absorption passed through one of the quartzes only. Equality was estab- lished by turning the analyser. A special advantage of this arrangement is that it requires only one source of light. - '• ^ There exist at present numerous arrangements for "turning down" an electric light, the chief peculiarity of them all being that nearly as much electrical energy is consumed when the lamp is only glowing feebly as when it is giving its normal amount of light. An arrangement to which this objection does not apply is described in the Proceedings of the American Institute of Electrical Engineers for September, by Mr. F. Moore. In the circuit of the lamp there is placed an automatic interrupter, consisting of a small electromagnet and an armature held back by a spring ; the contacts being so arranged that as the armature vibrates the current is interrupted during part of NO. 1257, VOL. 49] the oscillation. By this means different amounts of current can be passed through the lamp, for by moving the electromagnet nearer to or further from the armature, the speed with which the latter vibrates can be varied. To avoid the destructive effect of the sparks at the contacts the whole armature is enclosed in a glass globe from which the air has been ex- hausted. Under these conditions it is found that platinum contacts remain good for a considerable time. When the inter- rupter is at work the sparks produce in the exhausted globe a phosphorescent glow which the author thinks may possibly be made use of for the purpose of giving light. Another applica- tion of the above is for running lamps on circuits of much higher voltage than they are intended for. Wiedemann ^ Annalen der Physik und Chcmie for November contains an interesting paper by R. Hennig, on the magnetic susceptibility of oxygen. The method employed, namely, the measurement of the displacement in a magnetic field of a short column of liquid in a slightly inclined capillary tube, due to the difference in the susceptibility of the two gases (oxygen and air) at the two ends of the liquid column, would hardly seem at first sight capable of giving very accurate values. The author, how- ever, has obtained very fairly consistent results, and finds the value 0'0963 x 10"'' for the difference between the susceptibility of oxygen and air at a temperature of about 26"' C, and at pressures varying from 75 cm. of mercury to 328 cm. lu order to measure the strength of the magnetic field a small coil was suspended by a bifilar-suspension close to the capillary tube, and from the deflection, when a known current was passed through this coil, the strength of the field was calculated. The results obtained by this method were also compared with those found by the rotation of polarised light in a piece of heavy glass, and by means of a small induction coil which could be rapidly moved out of the field. Some interesting investigations on the vitality of the cholera organisms on tobacco have been made by Wernicke {Hygien : Rtindschau, 1892, No. 21). Small pieces of linen soaked in cholera broth-cultures were rolled up in various kinds of tobacco, and the latter made into cigars. At the end of twenty-four hours only a few bacilli were found on the linen, and none on the leaf. On sterile and dry tobacco leaves, the bacilli disappeared in one- half to three hours after inoculation. On moist, unsterilised leaves they disappeared in from one to three days, but on moist and sterile leaves in from two to four days. When introduced into a five per cent, tobacco infusion (10 grams of leaves to 200 grams of water), however, they retained their vitality up to thirty-three days ; but in a more concentrated infusion (one gram of leaves to two grams of water, they succumbed in twenty-four hours. When enveloped in tobacco smoke, they were destroyed, both in broth-cultures as well as in sterilised and unsterilised saliva, in five minutes. Tassinari, in his paper, "Azione del fumo di tabacco sopra alcuni microrganismi patogeni " (/^;^«a/^ deli Istituto d'Igiene, Rome, vol. i., 1891), describes a series of experiments in which he prepared broth- cultures of different pathogenic microbes, and conducted through them the smoke from various kinds of tobacco. Out of twenty- three separate investigations, in only three were the cholera organisms alive after thirty minutes' exposure to tobacco fumes. But in actual experience the apparent antiseptic properties of tobacco have not unfrequently been met with ; thus, during the influenza epidemic in 1889, Visalli {Gazetta degli Ospedali, 1889) mentions the remarkable immunity from this disease which characterised the operatives in tobacco manufactories ; that in Genoa, for example, out of 1 200 workpeople thus engaged, not one was attacked ; whilst in Rome the number was so insignificant that the works were never stopped, and no precautions were considered necessary. November 30, 1893] NA TURE 109 The Deutsche Scewarte has published No. xi. of the results of observations taken in the North Atlantic on ships supplied with instruments either belonging to that institution, or verified by it. Each part contains all the observations made in a ten- degree square, which is again subdivided into lOO one-degree squares, grouped in such a way that anyone can make use of them as they are, or they can be eventually combined with the observations made by any other institution. The tract now covered by these volumes extends from latitude 20^-50° N., and longitude 10^-50° west (with the exception of one square), and this district joins on to that for which the data were dis- cussed some years ago by the Meteorological Council, and ex- tending from 20° N. to 10° S. latitude ; so that for nearly all that part of the North Atlantic which is traver.'ied iby_long- voyage ships a large amount of useful data is available, either for scientific inquiry or for the purpose of navigation. The winds are tabulated under sixteen points, and storms under four quadrants, while the mean values of pressure, temperature, &c., are deduced from the total number of observations in each sub-square. This work is quite independent of the syn- optic weather charts of the North Atlantic, which are regularly prepared by the Seewarte, in conjunction with the Danish Meteorological Institute. The Kansas University Quarterly , vol. ii. No. 2, contains three articles by Prof. S. W. Williston. In one of these, entitled " Kansas Pterodactyls," a previous article is referred to, in which the opinion was expressed that the genus Pteranodon occurs in Europe. Since then Prof Williston has seen papers by Prof. Seeley, in which the same view is held, and an atten- tive examination of the evidence leads him to say: "I am satisfied that there can no longer be any reasonable doubt of the congenerousness of our species with those included in the genus •Ornithostonia. Seeley, a generic name antedating Pteranodon Marsh by some five years." Mr. R. L. Jack, the Government Geologist at Brisbane, has prepared a report on the progress of the geological survey of Queensland during 1892. Attention has been confined to detailed mapping of small areas of economical importance. For a general colony map it is thought that the scale of sixteen miles to an inch permits sufficient detail to be shown. As visiting the different mines will occupy some considerable time, it is intended to publish, in the meantime, a map showing the geological features, which will also be useful in the hands of miners and the general public for its topography. On the map, which is now being drawn on stone, are shown the out- crops of most of the reefs, as at present understood. A subse- quent edition will show the actual or inferred outcrops of all the reefs, the underground workings, and the geological inform- ation acquired in the course of the underground survey by the Geological Staff. On the completion of the work, it is in contemplation to construct a glass model, the surface of which will be coloured, and the outcrops of the reefs shown in the same way as in the geological map, and the extension of under- I ground geological boundaries, so far as ascertained, will be 1 represented. Its main advantage, however, will be that the exact position of the reefs with relation to the surface features and artificial boundaries will be understood at a glance, and the depth at which any given reef would be met with in any position could be ascertained by a simple calculation. A PAPER read by Dr. V. Ball, before the Royal Irish Academy on January 23 of this year, has been reprinted from the " Pro- ceedings " (3rd Ser. vol. iii. No, i, pp. 151-169). The title is " On the Volcanoes and Hot Springs of India, and the Folk- Lore connected therewith." Dr. Ball shows how the evi- dences of past volcanic activity in India — the metamorphism of sedimentary rocks by the Deccan traps into porcellanic shales, NO. 1257, VOL. 49] the agates, cornelians, &c. produced, the peculiar appearance of old craters, the " Lonar Lake," the natural caves and pillared temples of basaltic rock, &c. — have formed a nucleus of truth around which the religious spirit of the people has wrapped coil upon coil of myth and the marvellous. Sometimes undue credence has been given by travellers to native tales of smoke emanating in present times from peaks in W^estern Bengal and the Central Provinces. For these no better foundation could be discovered by Dr. Ball than the ordinary atmospheric effects of mist and cloud. Bhawani Patna, in the Central Provinces, is an example of a "mythical volcano." Hot springs have more especially appealed to the superstition of the people, and served the purposes of the native priesthood. Dr. Ball stated that the total number of recorded sites where hot springs occur in India is about 300. He gave then a concise account of the most important scientific phenomena associated with the hot springs, and details, in some cases, of the particular virtues, medical and spiritual, ascribed to them by the people. He called attention, in concluding, to the local character of the vegetation near hot springs, and of the fauna which are some- times present in their waters, e.g. the famous Magar Pir, seven miles north of Karachi, with its numerous crocodiles. The August number of the Records of the Geological Survey of India, vol. xxvi. part 3, has been sent us. An important paper is the "Geology of the Sherani Hills," by Mr. T. D. La Touche, with a geological map of part of the Sulaiman Range and several sections and sketches (pi. i.-v. ). The first part of the paper is devoted to the physical features. The strati- graphical geology of the Sherani Hills is not complicated ; the deposits in the area examined range from Cretaceous to recent and sub-recent time, and a complete table of the succession and the relative thicknesses of the rocks is given on p. 82. Dr. Fritz Noetling describes "Carboniferous Fossils from Tenasserim " ; good specimens of I.onsdaleia salinaria, and new species of Lithostrotion and of Schwagerina are figured on the accompanying plate. Details are given by Mr. R. D. Oldham, Superintendent Geological Survey of India, of a deep boring at Chandernagore, and a "Note on Granite in the Districts of Tavoy and Mergui " (with plate), by P. N. Bose. Especial comment is made in the " Tri-Monthly Notes of the Geological Survey of India Department" upon the com- pletion of the second edition of the " Manual of the Geology of India," by Mr. Oldham. The calendar for the year 1893-4 of the University College of North Wales has just been issued. We note with pleasure that the Oxford University Press has published two more editions of the " Oxford Bible for Teachers," containing the excellent " Helps to the Study of the Bible " reviewed in Nature of October 5. We have received a " Record" of results of observations in meteorology and terrestrial magnetism made at the Melbourne Observatory and at other localities in the colony of Victoria, Australia, from July to December, 1892, under the superintend- ence of Mr. R. L. J. Ellery, the Government Astronomer. In the future this "Record "will be issued quarterly instead of monthly. Messrs. William Wesley and Son have issued their Ii8th " Natural History and Scientific Book Circular." The catalogue includes a number of works from the library of the late Sir G. B. Airy, in addition to transactions of scientific societies, periodicals and serials. Government reports, and works dealing with the history of science. It should be in the hands of every bibliophile. The sixth edition of a book known to most chemists, viz. " Laboratory Teaching," by the late Prof. C. L. Bloxam, has no NA TURE [November 30, 189^ been published by Messrs. J. and A. Churchill. Mr. A, G. Bloxam, the editor of the new edition, has made several im- portant additions and alterations, and these changes will doubtless enable the book to retain its high position among the many works that now exist on practical chemistry. What are happily termed " Drum-and-trumpet Histories" have not been so numerous since the publication of the late Mr. Green's famous narration of the development of the English people. A more pretentious work of a similar kind is " Social England," edited by Dr. H. D, Traill, and published by Messrs. Cassell and Co. In this history a section of each epoch is devoted to a description of the conditions of science and learning, and another to trade and industry. The departure cannot be too highly commended, for the truest epic of a nation's life is that in which the interests of all classes are recited. Lanternists will be glad to learn that Messrs. Perken, Son and Rayment have introduced a new oil-lamp, possessing three times the candle-power of those hitherto used for lantern projection. This gain of brilliancy is obtained by dividing the oil reservoir, so as to provide central air-shaft. The combustion is thus rendered more perfect, and the odour that usually accom- panies ordinary lamps is correspondingly decreased. For small audiences the lamp will suit a lecturer's purpose quite as well as the lime-light. Doubtless the recent fatal result of the break- ing of an oxygen cylinder at Bradford will considerably increase the demand for perfected lamps of this kind. The success of Sir John Lubbock's book on " The Beauties of Nature " has induced Messrs. Macmillan to issue a cheap edition, without illustrations. Though the book possesses a good table of contents, its value would be increased by the addition of an index. The author will be glad to have his atten- tion called to one or two slips. On p. 207, Jupiter is said to have four satellites, whereas Prof. Barnard's discovery has brought the number up to five. Nitrogen should be removed from the list of elements in comets (p. 213), and Clarke (p. 223) should be Gierke. These slips, however, are but spots on the sun, for there are few books that will enlighten the general reader more than the one before us. A REMARKABLE new substance, i^ocyanogen tetrabromide, Br2C = N- N:=CBr„, has been obtained by Dr. Thiele in the laboratory of the Munich Academy of Sciences, and an account of it is contributed to the current Berichte. It was prepared by the reduction of azotetrazine, anew substance very rich in nitro- gen (concerning which Dr. Thiele promises a further communi- cation), and by treatment of the reduction product, hydrazotetra- zine, with bromine. Isocyanogen tetrabromide is readily vola- tile in steam, insoluble in water, but soluble in organic solvents, particularly in ether. It crystallises from glacial acetic acid in large prisms, which rapidly lose their brilliancy, however, upon removal from the mother-liquor. The crystals melt at 42^, emitting a most pungent, irritating odour. The crystals nor- mally in the cold evolve the same odour, although not so strongly as when warmed. Concentrated sulphuric acid, at the tem- perature of a water-bath, rapidly dissolves them with produc- tion of hydrazine and evolution of carbon dioxide, hydrobromic acid, and smaller quantities of free bromine and sulphur dioxide. Water precipitates from this solution a large quantity of hydra- zine sulphate, which may easily be identified by its melting- point (256°), its reduction of silver solutions, and its formation of a difficultly soluble double sulphate with copper sulphate. The reaction for the decomposition by sulphuric acid is probably as follows : Br2C = N-N = CBr2-f4H20 = 4HBr4-2C02-t-N2n4. Dilute hydrochloric and sulphuric acids only attack the tetra- bromide after long-continued heating to 300"=, the former then converting it into nitrogen and ammonia, and the latter oxidising NO. 1 257. VOL. 49] it. Its reaction with alkalies is specially interesting. It dissolves readily in them, and upon subjecting the alkaline liquid to dis- tillation another new compound, which is probably isocyanogen oxide OC = N-N=:CO or a polymer of that substance, passes over with the last portion of distillate. If a reducing agent, . such as alcohol, a ferrous, manganous or stannous salt, is added to the alkaline solution, a powerful odour of the well-known isonitrile kind is at once emitted. This same odour is produced when the alcoholic solution of the tetrabromide is decomposed with zinc dust and a little chloride of zinc. It appears most probable that the odour is due to the hitherto unisolated isocy- anogen, C = N - N = C. The supposition is further justified by the fact that the strongly odourous substance is expelled by boil- ing in a current of carbon dioxide, and i? capable of absorption by hot dilute sulphuric acid with formation of a solution of just such powerfully reducing proclivities as might be expected from a solution of hydrazine and formic acid. The first results of an important research in connection with the melting-points of the more refractory inorganic salts are likewise communicated to the current Berichte by Prof. Victor Meyer and Dr. Riddle. The observations have been made with the object of ascertaining the relations of the melting-points o' definitely connected salts, those already investigated being the chlorides, bromides, and iodides of sodium and potassium, and the sulphates of those metals. The method adopted in order to measure such high temperatures witn accuracy was essentially as follows : — The salt was heated considerably above its melting- point in a capacious platinum crucible, by means of a Perrot furnace. The crucible was then removed from the furnace, and an air thermometer, constructed of platinum and on the compen- sating principle, was inserted into the liquid salt. As soon as solidification of the latter commenced the temperature remained constant for some little time, quite sufficient to enable the air, or in the cases of very high melting-points, the nitrogen contained in the thermometer, to be displaced by hydrochloric acid gas, and its volume measured over water. The results obtained are the following : — The chloride, bromide, and iodide of sodium melt at 851°, 727°, and 650°, respectively ; the analogous salts of potassium fuse at 766°, 715°, and 623°. In each case a lower- ing of the melting-point accompanies the increase of the atomic weight either of the halogen or of the metallic element. Potash (presumably the oxide) melts at 1045", and soda at 1098°, the same rule again applying. In the cases of the sulphates, however, sodium sulphate is found to melt at 843°, and potassium sulphate at the much higher temperature of 1073°, a result contrary to the rule for the halogen salts, but which is quite in keeping with other well-known diff"erences which the oxy-salts of sodium and potassium exhibit. The additions to the Zoological Society's Gardens during the past week include a Chacma Baboon {Cynocephahis porcarlus, i ) from South Africa, presented by Mr. W. S. Cox ; two Common Marmosets [Hapale jaccJms) from Brazil, presented by Dr. S. Steggall ; a Pallas' Goat {Capra cylindricornis, 9 ) from the Caucasus Mountains, presented by Mr. H. H. P. Deasy ; a Duyker Bok {Cephalophiis inerge7ts, i ) from South Africa, presented by Miss Gertrude A. Winiy ; three Palm Squirrels {Sciuriis pahnarum) from India, presented by Mrs. S. W. Maclver ; a Meyer's Parrot [PcEocephalus meyeri) from South Africa, presented by Mrs. B. Searelle ; a Great Eagle Owl {Bubo maximus) from China, presented by Major Boyd Bredon; two Puffins {Ftatercula arctica) British, presented by Mr. E. Hamond ; a Brown Capuchin {Cebus fatuelhis, 6 ) from Brazil, a Rhesus Monkey (Macacus rhesus, ? ) from India, six Meyer's Parrots {Paocephalus meyeri), an Alario Sparrow (^Passer alario) from South Africa, deposited; two RtdiShaxiVs {Totamts calidns), British, purchased. November 30, 1893] NATURE III OUR ASTRONOMICAL COLUMN. Otto Struve's Double-Star Measures. — The most im- portant addition to double-star astronomy during the last year is without doubt the work which we owe to OUo Struve, and which is entitled "Mesures Micrometriquesdes Etoiles Doubles" {Observations de Poulkova Tome IX. (avec un supplement) et Tome X.). The period which the observations cover is very large when one considers that it is for one observer, commencing as it does with the observations made in the year 1837, when Otto Struve was only seventeen years old. Readers who are unable to approach these volumes themselves will find that M. Bigourdan, in the October number of the Bulletin Astronomique, gives a general summary of the whole of the contents. As one would expect, the introductions to the volumes contain a mine of important information, both with regard to the measures and to the puzzling question of the " personal equation," a question on which even to-day astronomers hold different views. Otto Struve busied himself especially in this direction, making, in the years 1853-1876, a series of measures of artificial double stars. The expressions for the corrections which he obtained assumed considerable proportions, as will be seen below, the first being that for angles of position, and the second that for distance : — Position angle 5" "2 , 4"-4sin(2()> - 27° 13') Corr. = -I- I 4- 0'20^ I -h 0-14(3 "3 - gf 5°-6sin(4(^ - 25° o') Distance Corr. = 6'-oif>{g - 2'o) 4- I -^ o'2o^- o"'i5 cos(2<^ - 28 '4) I -f o-09(4-2 - gf I + o 06(5 -2 - gf when^ represents " I'angle visuel du couple considere experime €n prenant pour unite celui qui correspond au grossessement de 708 fois," and ^ is the angle of the line between the two stars and the vertical. Whether such corrections as these, made under non-observa- tional conditions, should be applied to measures actually made in the sky is still open to much doubt. Otto Struve discusses also the observations made at Pulkova with those made at the same epoch by different observers ; the comparison, to take an •example, shows that Dawes's position angles in his early mea- sures appear free from systematic error, while those made later require a correction of -f i^'8 ; his distances up to 8" seemed all to be desired. Dembowski's measurements of angles also re- quired no correction, but his distances, especially about 6", demand a small positive correction (o"22). In the second volume one finds the measures of W. Herschel's classes V. and VI., couples with large proper motion, including measures for the determination of parallaxes, and for the determination of the relation of the number of optical to physical binary, stars dis- covered by M. Burnham and other astronomers, and a continu- ation of W. Struve's and O. Struve's measures. Double-star astronomy is already possessed of two fine monuments in the works of W. Struve's " Mensurse Micrometricas " and of Baron Dembowski's " Misure Micrometriche," and to-day we may, as M. Bigourdan adds, name a third in the " Mesures Micro- metriques des Etoiles Doubles" of M. Otto Struve. Method of Pivot Testing. — By means of interference fringes, employed by M. Fizeau in his researches on crystals, M. Maurice Hamy describes a method of studying the form of pivots of a meridian instrument {Comptes Rendiis, No. 20, Nov. 13th), which indicates errors not discernible by the ordinary course adopted. The great advantage to be gained by it is that the state of the pivots can be very easily, and with the expenditure of a very little time, ascertained. The arrange- ment consists in placing a metallic block astride a pivot, the block being supported further by a pointer fixed to a part of the telescope. The extremity of this pointer fits into the bottom of a horizontal groove, parallel to the meridian, in the pier. Contacts between the pivot and the pointer is thus en- sured by the pressure of several weights, while displacements iOf the whole arrangement against slipping are totally eliminated. On the block rests, at one of its extremities above the centre of the pivot, a lever which is movable about an axis on the pillar on a vertical plane ; this carries a small horizontal piece of glass, fixed in a certain manner. Between this mirror and the front of the lens of a fixed collimator are produced the inter- ference fringes, the source of light (monochromatic) being placed at the focus of the lens. Turning the telescope on its NO. 1257, VOL. 49] axis, the block remains still, but movements of a small nature in the vertical direction were observed which were sufficient to indicate the imperfectness of the pivot. To obtain at a glance the order of the magnitude of such errors, a plane mirror was fixed at some distance from the axis of the lever, so determined that the fringes were displaced by a row when the inclination of the telescope experienced a perturbation of O'Ois. by the action of one of the irregularities. The method of observation consists simply in counting the number of fringes which exceed a fixed limit when the telescope is turned, the number thus obtained expressing in hundredths of a second in time the order of the error. A trial of the above method shows that irregu- larities on the surface of pivots can be easily observed, and, moreover, the errors " ne sont pas completement negligeable au point de vue des observations." A Bright Meteor. — The following are a few facts about a bright meteor which Prof. Schur, of Gottingen, has been good enough to send us : — The meteor was observed on Monday, November 27, at 5h. 54m. mean time, and the direction of its path lay between ^ Perseii and towards a Piscium. At first it appeared as bright as a Tauri, and then quickly excelled Jupiter in brilliancy, the light gradually fading away afterwards. The duration of the phenomenon was estimated at about ten seconds, and the trail was observed to be of a yellowish-red colour. Curiously enough, three minutes later a fainter meteor shot across the heavens from the zenith, its direction being nearly at right angles to that of the preceding one. Astronomical Photography. — Mr. H. C. Russell, F.R.S., President of the Astronomy, Mathematics, and Physics Section of the Australasian Association for the Advancement of Science, traced the history of astronomical photography in his presidential address at the recent Adelaide meeting. " In many departments of astronomy," he declared in the opening para- graph, " the observer must stand aside while photography takes his place and works with a power of which he is not capable, and I feel sure that in a very few years the observer will be displaced altogether, while his duty will be done by a new sen- sitive being — a being not subject to fatigue, to east winds, to temper, and to bias, but one above all these weaknesses, calm and unrufHed ; with all the world shut out, and living only to catch the fleeting rays of light, and tell their story." " Vierteljahrschrift der Astronomischex Gesell- schaft." — The third part of this year's publication gives an account of the work done at the observatories usually included in this list, each director, as has been done in former numbers, summing up in a few words, and stating the work being, and about to be, accomplished. We must refer our readers to the publication itself for individual information. GEOGRAPHICAL NOTES. UAfrique gives a brief account of the last exploring journey of the late M. Georges Muller in Madagascar. He had returned to Antananarivo from a successful visit to Antsirabe, where he went to collect bones of epiomis, and in June he set out for Lake Alaotra, which, in company with Father Roblet, he explored, adding a number of features to the maps of the district. Parting from his companion, Muller pushed on with the view of reaching Mojanga on the west coast, but near Mandritsara he was attacked and murdered by a party of Fahavalos, one of the independent tribes who still contend against the Hova supre- macy of the island. The Madras Mail says that the Indian Marine Survey vessel Investigator has proceeded to the Laccadives to continue the survey of those islands, which has been in course of preparation during the last two years. From the Laccadives the Investigator will go to Madras, and will be engaged for a few weeks in completing the East Coast Marine Survey from Pulicat Lake, where work was left off' last year, to Madras Harbour. Finally in February the Investigator will proceed to Palk Straits, and a thorough survey of the dividing sea between India and Ceylon will be made, ostensibly with the object of testing the practic- ability of constructing a canal and a railway. The distance from the Indian mainland to Ceylon is sixty miles, of which twenty constitute Adam's Bridge proper. The bridge is said to consist of an irregular ridge formed of rock and sand partly dry at low water, but intersected by small intricate channels navi- gable only for native boats of very light draught. Average I I z NATURE [November 30, 1895 spring tides rise only about two feet, so that the construction of the railway works and their future maintenance would be greatly facilitated. It is thought that the works required would consist of an iron and steel viaduct of considerable length, but in short spans, no large span being required except over the exist- ing navigable channel, where a swing bridge would probably be necessary. Until a detailed survey of the strait has been made, however, it is impossible to speculate upon the details of the railway or the canal project with any degree of certainty ; and the Government of India is determined to settle the question once for all by making a thorough survey of the coast and dividing ica. Full particulars have lately been received of the death by drowning, in September last, of Mr. H. M. Becher, while on his way to visit the mountain known as Gunong Tahan in the province of Trengganu in the Malay peninsula. He had come within sight of the mountain, which had never before been seen by a European, and roughly estimated its height at between 8,000 and 9,000 feet, when his camp on a low island in a river was submerged by a sudden flood, and the boat in which he at- tempted to reach the shore capsized. His companion, Mr. H, Quin, escaped, but did not continue the journey. A LONG letter just received from Mr. Astor Chanler, who is travelling in East Africa, is published in the December number of the Geographical yotirnal. It contains the unfortunate tid- ings that his companion, Lieutenant von Hohnel, whose pre- vious successful travels in East Africa are well known, had been seriously wounded by a rhinoceros, which rendered his imme- diate return to Europe necessary. Mr. Chanler, although he has suffered greatly from loss of men and animals, is determined to push on to the north in the hope of reaching Berbera or Zeila. At the time of writing, September 20, the party had returned to Daicho, near Mount Kenia, after a visit to the Ren- dile tribe, who live in the country to the north. These people appear to have strong Somali affinities, and were more intelli- gent than the Masai, but equally fierce and intractable. The loss of von Hohnel's services will detract from the geographical value of the expedition, as he is an accomplished surveyor. In our last issue we gave, without comment, an abstract of one of the rumours regarding the Nansen expedition, published by an evening newspaper. It is right to add, however, that the report of high land north of the New Siberian Islands is no new thing, and that Nansen has no thought of taking up winter quarters on any land, his intention being to get fast in the ice, and drift wherever it carries him. His only object in touching at the New Siberian Islands was to send letters home ; but if the sea was as favourable as we believe it to have been, he would probably strike straight northward without calling anywhere. ANTARCTIC EXPLORA TION. A T the meeting of the Royal Geographical Society on Monday ■'*■ evening Dr. John Murray, of the Challenger Expedition, read a paper on the renewal of Antarctic exploration. He sketched the history of voyages to the far south, and of the notions which prevailed as to the nature of the South Polar region from the earliest time down to the present day. He showed that while the huge southern continent believed in by the geographers of past ages had been vastly diminished by in- creased knowledge, the probability is that around the South Pole a land area of about 4,000,000 square miles actually exists. He indicated thepresentstate ofourknowledgeoithe region, which is extremely meagre, and then went on to show that until this knowledge was greatly increased many problems in science must remain unsolved. Until we had a complete and continued series of observations in the Antarctic area the meteorology of the globe could not be understood. Important problems in geology, in biology, in physics, in oceanography, demanded the renewal of research on an adequate scale in the South Polar area. Dr. Murray concluded as follows : — Within the past few months I have been in communication with geographers and scientific men in many parts of the world, and there is complete unanimity as to the desirability, nay, necessity for South Polar exploration, and wonder is expressed that an expedition has not long since been fitted out to under- take investigations which, it is admitted on all sides, would be of the greatest value in the progress of so many branches of natural knowledge. To determine the nature and extent of the Antarctic continent ; to penetrate into the interior ; to ascertain the depth and nature of the ice-cap ; to observe the character of the underlying rocks and their fossils ; to take magnetic and meteorological ob- servations both at sea and on land ; to observe the temperature of the ocean at all depths and seasons of the year ; to take pen- dulum observations on land, and possibly also at great depths in the ocean ; to bore through the deposits on the floor of the ocean at certain points to ascertain the condition of the deeper layers ; to sound, trawl, and dredge, and study the character and distribution of marine organisms. All this should be the work of a modern Antarctic expedition. For the more definite de- termination of the distribution of land and water on our planet ; for the solution of many problems concerning the Ice Age ; for the better determination of the internal constitution and super- ficial form of the earth ; for a more complete knowledge of the laws v/hich govern the motions of the atmosphere and hydro- sphere ; for more trustworthy indications as to the origin of terrestrial and marine plants and animals, all these observations- are earnestly demanded by the science of our day. A dash at the South Pole is not what I now advocate, nor do I believe that is what British science, at the present time, desires. It demands rather a steady, continuous, laborious, and systematic exploration of the wholesouthern region with all the appliances of modern investigators. This exploration should be undertaken by the Royal Navy, Two ships, not exceeding one thousand tons burthen, should, it seems to me, be fitted out for a whole commission, so as to extend over three summers and two winters. Early in the first season a wintering-party of about ten men should be landed somewhere to the south of Cape Horn, probably about Bismarck Strait at Graham's Land. The expedition should then proceed to Victoria Land, where a second similar party should winter, probably in Macmurdo Bay near Mount Erebus. The ships should not be frozen in, but should return to the North, con- ducting observations of various kinds towards the outer margins- of the ice. After the needful rest and refit, the position of the ice and the temperature of the ocean should be observed in the early spring, and later the wintering parties should be communi- cated with, and, if necessary, reinforced with men and supplies for another winter. During the second winter the deep-sea observations should be continued to the north, and in the third season the wintering parties should be picked up and the exi>edi- tion return to England. The wintering parties might largely be composed of civilians, and one or two civilians might be attached to each ship ; this plan worked admirably during the Challenger expedition. It may be confidently stated that the results of a well- organised expedition would be of capital importance to British science. We are often told how much more foreign govern- ments do for science than our own. It is asserted that we are being outstripped by foreigners in the cultivation of almost all departments of scientific work. But in the practical study of all that concerns the ocean this is certainly not the case ; we have to acknowledge no superiors nor equals in this branch of investigation, and if we be a wise and progressive ■ people, British science will always lead the way in this direction. Twenty or thirty years ago we were in profound ignorance as to the condition of all the deeper parts of the great ocean basins ; now we have a very accurate knowledge of the conditions'which obtain over the three-fourths of the earth's surface covered by the waters of the ocean. This is the most splendid addition to earth-knowledge since the circumnavigation of the world, and is largely due to the work and exertions of the British navy in the Challenger and other deep-sea expeditions. This country has frequently sent forth expeditions, the primary object of which was the acquisition of new knowledge — such were the expeditions of Cook, Ross, and the Challenger ; and the nation as a whole has always approved such action, and has been proud of the resultSj although they yielded no immediate return. Shall it be said that there is to be no successor to these great expeditions? A preliminary responsibility rests on the geographers and re- presentatives of science in this country. It is necessary to show that we have clear ideas as to what is wanted, to show that a good workable scheme can be drawn up. When this has been done it should be presented to the Government with the unani- mous voice of all our scientific corporations. Then, I have little doubt, that a Minister will be found sufficiently alive to the spirit of the times, and with sufficient courage to add a few NO. 1257, VOL. 49] November 30, 1893] NATURE 113 thousand pounds to the navy vote for three successive years, in order to carry through an undertaking worthy of the maritime position and the scientific reputation of this great empire. An animated discussion, in which the Duke of Argyll, Lord Charles Beresford, Sir Joseph Hooker, Sir George Nares, Sir Vesey Hamilton, Capt. Wharton, Sir W. Turner, Sir W. Flower, Dr. Buchan, and Mr. W. S. Bruce took part, followed the reading of the paper. All the speakers strongly expressed their conviction that the time had come to make a vigorous at- tempt to resume the long-interrupted line of advance into the south polar regions by means of a Government expedition. PHENOMENA OF THE TIME- INFINITESIMAL} OCIENCE consists in the extension of our knowledge of the •^ external universe, and it brings about this extension in I great part by reinforcement of our senses. To bring into the I field of observation the very distant and the very small, are therefore regarded as important scientific achievements, and the telescope and the microscope, by means of which this widening of the realm of knowledge has been made, as important imple- ments of research. Man's relation to time is such that it is difficult to conceive of an instrument which should bring distant events to hand in like manner for inspection. Our time vision turns chiefly in one direction — towards the past — and is obscured by the interven- tion of something very like a medium or atmosphere, through which we see dimly. As to the future, our thoughts are neces- sarily confined to matters found by experience of the past to be periodic, or to changes already begun and known by the obser- vation of analogous processes to be likely to run some definite course. In the interpretation of the future by the past, there is much of interest to the physicist ;_ but it is not of this that I would speak to-day. Let us turn our attention rather to the study of minute time intervals in physics — to a consideration of the methods by which we may record what takes place during infinitesimal elements of time. The interest of the physicist in time is confined really to a study of phenomena. He ascribes no property to time itself, beyond defining it after Riemann, as a complexity of the first order.- As between the study of the infinitely great and the infinitesimally small, whether of space or of time, there is a peculiar value to be attached to the latter, because the only methods which have proved the least fruitful in the analysis of the more complex changes which are going on around us, are those which begin with the infinitesimal. We consider an element of mass or of volume, or sometimes merely the element of a surface or line, proceeding then to extend our statements so far as our powers of mathematical expression will permit. Now the element of time is, of course, purely relative. In certain phenomena the time infinitesimal is so short as compared with any time interval with which we are able to cope experi- mentally as to be out of reach, just as in special relations the dimensions of the molecule and atom are such that we dare not hope to render these ultimate particles of matter visible even under the microscope. There are periodic phenomena, on the other hand, the periods of which are so great that a life- time, indeed the entire era covered by history and tradition, affords us a glimpse of but a single time element. Lying between these two there is a great range of phenomena for which the element of time is within our reach. It is by the study of what takes place in such time elements, and the extension of the results thus obtained by analytical processes, that much of our know- ledge of physics has been gained. It is to the extension of our powers in the observation of the phenomena of the time interval that we must look in great part for further progress. It has seemed worth while, therefore, to bring together f jr purposes of comparison some of the methods which have proved fruitful in , this respect, and to consider along what line they may be further I developed. It is an investigation which will lead us into all de- *] partments of science ; for phenomena into which the element of time does not enter are unknown. 1 An address delivered by Prof. E. L. Nichols before Section B (Physics) of the American Association for the Advancement of Science. Madison meeting, August, 1893. - " Eine einfach aus^cedehnte Mannlgfaltigkeit." (Riemann-: Ueber die Hypothesen welche der Geometric zu grunde liegen. Werke p. 257.) NO. 1257, VOL. 49] Since all study of phenomena involves the time element, th° consideration of all dynamical problems must begin with th- phenomena of the time-infiniteiinial. There are two cases of chief importance: — (i) The study of the time elements of periodic phenomena ; (2) the study of beginnings of changes which result from a sudden variation in the condition of equili- brium. The methods which have been found most useful in the investi- gation of the phenomena under consideration may be classified as follows : — (i) Visual methods : {a) vision by instantaneous ex- posure, (1^) vision by periodically interrupted exposure, (c) vision by the aid of the revolving mirror. (2) Photographic methods : (a) instantaneous exposure of a stationary film, (/') photography by the aid of the revolving mirror, (y surrounding the sensitive flame with a mantle of free oxygen (after the method of what was once known as the " Budde " light), sufficient actinic in- tensity may be obtained to ensure an excellent photographic record on a rapidly moving plate. The results of such photo- graphs applied to the analysis of vowel sounds give evidence of the extraordinary fidelity of the sketches published by Kcenig. They also afford a basis for the study of timbre of the sounds to which they correspond, which is open to one objection only, viz. to the uncertainty as to the influence of the inertia of the diaphragm upon the character of the image. Of this source of error I shall have more to say in connection with some other researches. Other interesting examples of the study of the time-element might be drawn from this field ; indeed, the science of sound is of necessity largely made up of such work. The beautiful photographs of vibrating strings by Menzel and Raps {Annalen der Physik, N.F. 44, iSgr, p. 623), which are so fitting an appendix to the earlier labours of Helmholtz {Die Tonemp- findmigen, p. 137), may serve to illustrate the usefulness of the method of photography on a moving plate. In the study of periodic phenomena two distinct methods of investigation have been established. The first of these consists in the isolation of a desired element of the cycle at each repe- tition for as long a lime as may be necessary to obtain a satis- factory record of the existing conditions. By the selection successively of many neighbouring elements, we get in this way at last the data from which to construct a complete diagram of the cycle. This principle has been most fruitful in enabling us to analyse periodic processes not easily approachable by more direct means. The most notable application has been that which is commonly spoken of as the " method of instantaneous contact," well known to the student of alternating current phenomena. It is to Joubert ^ (1880) that we owe this ingenious adapta- tion of the device of properly timed repetitions of instantaneous observations of periodic phenomena (a principle which underlies the phenakistoscope and similar well-known instruments). He made use of it in the study of the changes of potential in the circuit of the alternating current dynamo, and between the terminals of the Jablochkoff candle. In the same year the method was discovered independently, and applied to the study of the Brush arc-lighting dynamo by B. F. Thomas.- Joubert pointed out the method of using the quadrant electrometer in alternating circuits, also that the gal- vanometer might be utilised. (" On peut mesurer cette inten- site par I'electrometre mais on peut aussi employer le galvano- metre puisque les contacts successive correspondent toujours a une mcme phase du courant.") He discovered the retardation of phase in the current curves of the alternating dynamo, and the peculiar distortion of the curves in the circuit containing an arc lamp, a matter more fully investigated at a later day by Tobey and Walbiidge.^ Thomas during this first period in the history of the Joubert method used a ballistic galvanometer and condenser. The periodic phenomena of the alternating current circuit have been among the most important to which the study of the time-element has been applied, and it is to the method of in- stantaneous contacts that we owe much of the progress of the last thirteen years. It is interesting to note the extension of 1 " Sur les Courants alternatifs et la force electromotive de Tare elec- trique. ' Comptes Kendns. vol. xci. p. i6i, July 19, 1880. - " Observations on the electromotive forces of the Brush dynamo-electric machine." (title only.) Proceedings A.A.A.S. vol. .xxix. p. 277 (1880). Prof. '1 homas gave the results obtained, and described the method eleven years later in a communication to the Institute of Electrical Engmeers, entitled " Notes on Wiping Contact Methods for Current and Potential Measurements," 1 ranslations of the American Institute of Electrical Engineers, vol. ix. p. 263. •i " Investigations of the Stanley Alternate Current Arc Dynamo." Trans Am. Inst. Electrical Engineers, vol. vii. p. 567. NO. [257, VOL. 49] November 30, 1^93] NA TURE I r this method in the study of a variety of allied phenomena. After the publication of Joubert's papers the method seems to have come into common use in the physical laboratories, par- ticularly in the exploration of the fields of continuous current dynamos and motors. In i888 it was applied by Duncan, Hutchinson, and Wilkes ("Experiments on Induction Coils," ^/t'cVr/ca/ World, vol. ii. p. 160, 18S8) to the study of induction coils and transformers. To them we owe the first set of complete diagrams relating to the performance of this class of alternating current apparatus. In the same year Meylan("Sur les Appels Magnetiques," La Lumicre Ehctrique, xxvii. p. 220, 1888) used an interesting modification of the method in the investigation of the vibratory magnetic call-bell of Abdank. In the same year appeared the first definite data with reference to the Westinghouse alternating dynamo, at the hands of Messrs. Searing and Hoffmann (" Variation of the Electromotive Force in the Armature of a Westinghouse Dynamo," yoiiriial oj the Franiliti Institute, vol. cxxiii. p. 93), of Stevens Institute. Then followed in the order named the researches of Ryan and Merritt ("Transformers," Trans. Am. Inst. Electrical Engineers, vol. vii. p. I, 1889),' Humphrey and Powell (" Efficiency of the Transformer," Ibid, vol. vii. p. 311), Tobey and Walbridge (Ibid, vol. vii. p. 367), of Marks (Ibid, vol. vii. p. 324), of Herschel {Ibid, vol. vii. p. 328), of Fortenbaugh and Sawyer (Ibid, vol. vii. p. 334). In all these investigations the methods under consideration liave been used with varying accessories in the problem of the transformer. In 1890 it was applied under much more difficult conditions to the analysis of the "ball and point effect" by Archbold and Teeple (see Nichols, " On Alternating Electric Arc between a Ball and Point," American J ottrnal of Science, vol. xli. p. i). In 1891, Thompson ("Study of an Open Coil Arc Dynamo," Trans. Am. Inst. Electrical Engineers, vol. viii. p. 375) deter- mined the intricate changes of induction in open coil arc lighting machines by means of the same method, and Ryan (" Relation of the Air Gap and the Shape of the Poles to the Performance of Dynamo-electric Machinery," Ibid, p. 451) utilised it in his investigations of the influence of the air gap upon the perform- ance of dynamos and motors. In 1892, Duncan ("Note on some Experiments with Alternating Currents," Ibid, vol. ix. p. 179) described modifications of the method of instantaneous contacts by means of which the rapidity of reading is greatly enhanced. During the present meeting, you will doubtless have the pleasure of listening to a description of the applications of the same device to the study of electrostatic hysteresis. (Reference is here made to the paper presented by Messrs. Bedell, Ballan- tyne, and Williamson: "Alternate Current Condensers and Dielectric Hysteresis," Physical Review, vol. i. p. 91. Subse- quent note.) Such has been, in brief, the history of a method by means of which in greater degree than of any other we have been able to extend and complete our knowledge of alternating current phenomena. To the practical electrician and to the theorist alike, the do- main has been one of the most attractive of those which have been developed in recent years. To the electrical engineers of ::he younger generation the very complexity of alternate current iheory has proved a benefit. It has forced them to increased mathematical proficiency and to more rigorous thinking; it has, ndeed, served as an excellent source of discipline. What the 3roblems of submarine telegraphy did for the English electricians jwho served their apprenticeship during the early days of the ':able-laying industry, compelling the development of those turdy qualities which have been so highly serviceable in every Jranch of electrical progress since, the intricacy of alternate :urrent practice is unquestionably doing for the younger school ' vhich is growing up to-day in this country. The difficulties vhich have to be met and overcome in this field of work will ave an excellent influence upon the manner in which the > iioblems of the future will be approached. I Another investigation, which owes its existence to a most in- enious application of this same principle of instantaneous ontacts periodically repeated, is well known to all of you. I efer to Prof. E. H. Hall's ^ study of periodic heat- flow in the J^ "A Thermo-Electric Method of Studying Cylinder Condensation in team-Engine Cylinders." Trans. Am. Inst. Electrical Engineers, vol. NO. 1257, VOL. 49] cylinder walls of the steam-engine by means of therrno-elements embedded within the metal and connected momentarily during a selected time-element in the course of each stroke with a sen- sitive galvanometer. To my mind no more interesting example of the indirect method of studying the phenomena of the time element could be found than this suggestive memoir. The method of instantaneous contacts has been a fruitful one, and productive of high results, but it does not yield a knowledge of any individual time-element, nor the picture of any single completed cycle. Numerous attempts to record single cycles have been made, the results of which are of considerable interest, because they deal with the more direct study of the time-infinitesimal. The device which lay nearest to hand, and which by its per- formance seemed to promise success in this direction, was the magneto-telephone. The investigations of Mercadier [jourjial j de Physique, vol. ix. pp. 217 and 282) had already paved the way to some extent, when P'roehlich described his experiments i upon the optical representation of the movement of the i diaphragm of the telephone, followed almost at once by j Thomson. I Froehlich 1 reported his preliminary results to the Electro- technische Verein of Berlin, in 1887. Elihu Thomson ("An : Indicator for Alternating Circuits." La Luinicre Electriqtie, \ vol. xxvii. p. 339 (1888) brought out his indicator for alter- j nating circuits, an instrument in which the movement of a i diagram was amplified by levers, and then made visible by optical means (or photographed) in the same year. Froehlich's method in its complete form, including the photography of the images from the involving mirror,-' was first described in the year 1889. Some of the curves published in the papers just cited, and particularly the experinients shown in the exhibition • of the method at the Frankfort Electrical Exposition of 1891, are most striking, but considering the method by which they are produced, the question inevitably arises as to the part played by the ineitia of the moving masses. Froehlich himself points out the necessity of great care in the matter of the adjustments, and of distinguishmg the natural oscillation of the plate, which are frequently superimposed upon those to be recorded. Some experience with Froehlich's method has convinced me that not only is extraordinary skill necessary in order to obtain, by means of a mirror attached to the dia- ' phragm of a telephone, curves which should represent, even with a fair approximation, the law of whatever periodic changes we may desire to record, but that the attainment of the proper i adjustment is a matter so entirely fortuitous, and its maintenance I so uncertain, as to deprive the method of much of its useful- ness. One may indeed hope to get, by means of successive ad- justments, curves which correspond to a known type, but whether in passing to new and unknown types the apparatus retains its faithfulness, is always a question. By way of illustration, I introduced three of an extended series of curves obtained by this method with a telephone in circuit with an alternating current dynamo. The character of the cycle had been determined by the method of instantaneous contacts. The true cycle was represented by a curve of sines, but with the apparatus under consideration complex curves of the kinds shown in figures 2 and 3 were the rule ; curves even approximating to simple sinuosity were the rare exception. The difficulties of the method lay not merely in the tediousness of adjustment, but rather in the tendency to revert to complex forms under changes of condition so slight as to be entirely beyond control. The remedy clearly consists in the elimination of mechanism and the reduction of inertia of the moving parts. Following the suggestion of an assistant, Mr. E. F. Northrup, I tried the following experiments : — A mercury stream flowing from the contracted nozxie of a funnel (Fig. 4) was made to pass between two metal terminals which were attached to the poles of a large Holtz machine. A portion of the falling column of mercury within the electrostratic field was illuminated by means of an arc lamp, and so much of it as could be seen through a horizontal slit was photographed by transmitted light. The sensitive plate was given rapid vertical motion through the field of the camera. When the machine was out of action there resulted a vertical trace running the length of the developed plate. As soon as the machine was put 1 "The Optical Representation of the ]Movements of a Telephone Dia- phragm." La LuiniLfc Elei:triquc, vol. xxv. p. 180 (1S87). - Froehlich : " Ueber eine neue Methode zur Darstellung \on Schwing- ungskurven." Electrotechnische Zcitschrift, bd. .x. pp. 345, 369 (1SS9). ii6 NATURE [November 30, 1893 into operation, deflection of the mercury stream occurred. It was the object of the experiment to determine the performance of the stream under the sudden fluctuations of the field which occurred when the Holtz machine was under rapid discharge. =5 Fig. 5 is from a photograph taken when nearly one hundred sparks a second were passmg between the poles. Other photographs were obtained in a similar manner, the deflecting forces, however, being due to the action between the Fig. 2. lines of a stationary magnetic field and those of an alternating current traversing the mercury column. The arrangement of the apparatus is shown in Fig. 6. The mercury stream was introduced into the circuit of the alternating current dynamo, already made use of in the experiments upon Froehlich's method. It flowed through a strong magnetic field with horizontal lines. The transverse oscillations of the mercury under these con- ditions were very apparent. When photographed by means of a cxmera with optical axis parallel to the lines of force, the stream strongly illuminated from behind and viewed through a narrow horizontal slit, as in the previous experiment, a sinusoidal trace was obtained. All the com plexities of the telephonic trace disappeared ii these records, and curves corresponding to thise of themjthol of instantane ous contact were always pro- .^ ■o o- duced. The experiment was made by Mr. Henry Floy, to whose efforts the photographs by Froehlich's method are also due. This method has not been further developed. I introduce it here to show that increased accuracy of record may be looked for as the result of reducing in any practicable manner the mass of the indicating device. NO. 1257, VOL. 49] Another attempt to record single periods in dynamo-electric work should be mentioned here. It is described by Moler^ in a recent paper. By means of a D'Arsonval galvanometer with a period of vibration of a few thousandths of a second curves of varying potential are traced, which show excellent agreement wzth measurements by the method of instantaneous contacts. The instrument is not free from the errors due to inertia. It is reliable only in recording changes of period con- siderably greater than its own, but its use is a step in a direc- tion along which progress may he looked for. Thus far I have dealt with methods of studying periodic changes, the time-elements of which are easily within reach i_ _ -" \ - - i ^ ^ M ^ 'n a C'llection of Coleoptera sent by Mr. H. H. Johnston. C.B., from British Central Africa: C J. Gahan.— On a Collection of Petrels from the Kermadec Islands: Captain F. W. Hutton, F.R.S. Institi'tion of Civil Engineers, at 8. — Impounding- Reservoirs in India, and the Design of Masonry Dams: Mr. Gierke, Mr. Sadasewjee, Colonel Jacob, and Prof. Krtuter. (Discussion.) WEDNESDA Y, December 6. Geological Society, at 8.— The Purbeck Beds of the Vale of Wardour: Rev. W. R. Andrews and A, J. Jukes-Browne.— On the Variety of Am- monites (Stephanoceras) subarmatus. Young, from the Upper Lias of Whitby : H. W. Monckton.— On a Piciite and other Associated Rocks at Barnton, Edinburgh H. W. Monckton. Entomological Society, at 7 — On a Collection of Lepidoptera from Egipt: George T. Bethune-Baker.— 1 he Rhynchophorous Coleoptera of Japan : Part III. Scolytids : Waher F. H. Elandford. THURSDAY, December 7. ''^ Royal Society, at 4.30.— The Organogeny of Asterma gibbosse : E. W. MacBride.— Reptiles from the Elgin Sandstone: Pescription of Two New Genera: E. T. Newton, F.R.S.— A Dynamical Theory of the Electric and Luminiferous Mediam: J. Larmor, F R.S.— Note on the Action of Copper Sulphate and Sulphuric Acid on Merallic Copper : Prof. Schuster, F.R.S. — On Copper Electrolysis z« vacuo: W. Gannon.— On a Chart of the Symmetrical Curves of the Three-Bar Motion: W. Brennand. Linnean Society, at 8.— Catalogue of the Described Neur.ptera Odonata (Dragonflies) of Ceylon, w.th Description of New Species: W. F. Ki.by.- On the Cause of the Fall of the Corolla in V^erbascum : Signor U. Martelh. Chemical Society, at 8.— An Apparatus for the Estimation of the Gases dissolved in Water: Dr. Truman.— Metallic Oxides and the Periodic Law : R. M. Deeley. NO. 1257, VOL. 49] fRIDA Y, December 8. Royal Astrono.mical Society, at 8. Sanitary Institute, at 8. — Metallic Poisons, Lead and Arsenic : Prof. T, Oliver. SATURDAY, December 9. Physical Society, at 5. — A Potentiometer for Alternating Currents: J. Swinburne. — Ttie Specific Resistance of Sea- Water: W. H. Preece, F.R.S. — The Calculation of the Coefficient of Self-induction of a Circular Current of a Given Cross-Section and aperture ; and The Magnetic Field of a Cylindrical Coil: Prof. G. M. Minchin. Royal Botanic Society, at 3.45. BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books. — By Moorland and Sea: F. A. Knight (E. Stock). — Laboratory Teaching: C. L. Blo.\am, 6th edition (Churchill). — An Elementary Treatise on Theoretical Mechanics, Part 2 — Introduction to Dynamics, Statics: A. Ziwet (Macmillan). — Micro-Organisms and Fermentation ; A. Jorgenson, translated by A. K. Miller and E. A. Lennholm, new edition (Lyon), — Concrete, its Nature and Uses: J. L. Sutcliffe (Lockwood). — The Sacred City of the Ethiopians : J. T. Bent (Longmans). — University College of N. Wales, Calendar 1S93-4 (Manchester, Cornish).— The Pamirs, 2 vols: Earl of Dunmore (Murray). — Against Dogma and Free Will, and for Weis- mannism : H. C. Hiller, 2nd edition (Williams and Norgate). — The Wilder Quarter-Century Book (Ithaca, N. Y. Comstock Publishing Company). — The Story of Our Planet : Prof. Bonney (Cassell). — The Elements of Applied Mathematics : C. M. Jessop (Bell). — A Year amongst the Persians : E. G. Browne (Black). — The Principles of Waterworks Engineering: J. H. T. Turner and A. W. Brightmore (Spon). — Science and Education: r. H. Hu.xley (Macmillan). — Letters of Asa Gray, 2 Vols. : edited by J. L. Gray (Macmillan). — Oxford Bible for Teachers, with Helps (two styles) (Frowde). Pamphlets. — A Check List of the Slugs: Prof. T. D. A. Cockerell (Dulau). — Temperature and Vertebrae? Dr. D. S. Jordan (Ithaca, New York). — Sulle Osseivazioni Mareografiche in Italia, &c. : G. Grablovitz (Genova). Serials. — Notes from the Leyden Museum, Vol. xiv. No. 3, and Vol. XV. No. 4 (Williams and Norgate). — Sitzungsberichte und Abhandlungen der Naturwissenschaftllchen Gesellschaft Jsis in Dresden, 1893, Jan. bis Juni (Williams and Norgate) — Botanische Jahrbucher iiir Systematik, Pflanzengeschichte und Pflanzengeographie, Siebzehnter Band v. Heft (Williams and Norgate). — Zeitschrift der Gesellschaft fiir Erdkunde zu Berlin, Band .\xviii. 1893, No. 3 (Berlin). — Mittheilungen von Forschungs- reisenden und Gelehrten aus der Deutschen Schutzgebieten, vi. Band, 4 Heft (Berlin). — Bollettino della Societa Geografica Italiana, Serie 3, Vol, 6, Fasc. 8-Q (Roma). CONTENTS. ^^ The Mummy 97 Eskimo Life. By J. P 98 Our Book Shelf:— Easton : " La Voie Lactee dans I'Hemisphere Boreal 99 Johnston: "An Elementary Treatise on Analytical Geometry " 99 Stehlin : " Zur Kenntniss der Postembryonalen Schiidelmetamorphosen bei Wiederkauern "... 99 Letters to the Editor : — Suggested Nomenclature of Radiant-Energy. — Prof. Simon Newcomb, F.R.S ico The Postal Transmission of Natural History Speci- mens.— Isaac J. Wistar; Edw. J. Nolan . . . 100 Flame. — Prof. Henry E. Armstrong, F.R.S. . . xoo "Geology in Nubibus." — Dr. Alfred jR. Wallace, F.R.S loi Correlation of Magnetic and Solar Phenomena. — H. A. Lawrance loi New Variable Star in Andromeda. — Rev. Thomas D. Anderson loi Protective Habit in a Spider. — Prof. C. Lloyd Morgan io2 The Loss of H. M.S. "Victoria." By Dr. Francis Elgar 102 Jupiter and his Red Spot. By W. F. Denning . . . 104 The Preparation and Properties of Free Hydfoxy- lamine. By A. E. Tutton 105 Notes 106 Our Astronomical Column: — Otto Slruve's Double-Star Measures Ill Method of Pivot Testing in A Bright Meteor ill Astronomical Photography ill VierteJjahrschrift der Astronomischen Gesellschaft . in Geographical Notes in Antarctic Exploration 112 Phenomena of the Time-Infinitesimal. {Illustrated.) By Prof. E. L. Nichols 113 University and Educational Intelligence 117 Scientific Sertals 117 Societies and Academies 118 Diary of Societies 120 Books, Pamphlets, and Serials Received 120 NA TURE 121 THURSDAY, DECEMBER 7, 1893. ELEMENTARY PRACTICAL SCIENCE. Eletne7itary Course of Practical Science. Part I. By Hugh Gordon, M.A. (London : Macmillan and Co. 1893.) IN the teaching of science, as of any other subject, the importance of method is most apparent in deahng with the elements. Of late years, since laboratory in- struction has been generally introduced into our colleges, the teaching of science to advanced students may be said to be based on correct methods. But so much can- not yet be said for the teaching of the elements of science to young children. If, however, science is to obtain a recognised place in the curriculum of our primary and secondary schools, it is most important that the means adopted for the teaching of science should be educational in character. Very rarely is science so taught to young children and junior pupils in schools as to bring into active exercise the very faculties of the mind which it is supposed to develop. The teaching of science follows too closely the older education, by appealing to the memory, and storing the'niind with facts and information of more or lebs value ; and the methods employed in- volve a mental discipline too similar in kind to that of ordinary mathematics. Mr. Hugh Gordon, in Part I. of his " Elementary Course of Practical Science," recently published, has broken comparatively new ground. His little book gives a very satisfactory answer to the question : How can the elements of science be so taught as to become a means of ^^/^r^/zVzg- young children ? In arranging a course of practical instruction in the rudiments of science, two principles have to be observed : first, the instruction must be introductory to science as a whole, and not to any branch of it ; and secondly, the aims of the teaching must be strictly educational. In other words, the in- formation imparted must be such as is equally applicable to physics, chemistry, and biology, and the methods must I be those by which the student, at every stage of his progress, is enabled to learn by himself. Indeed, the real end of science teaching should be kept in view from the commencement of the study, and the pupil should be exercised, through his science lessons, in accurate ob- servation, and in interpreting the results of experiments. The book under review is the practical outcome of the experience gained by the author in superintending a course of science teaching in fifteen schools under the London School Board, and is based on a scheme drawn up by Prof. Armstrong for a committee of the British Association. Mr. Gordon has had the advantage of working for some time in the laboratory of Prof. Arm- strong, to whom he very readily acknowledges his indebtedness for many valuable suggestions. The book is an endeavour to show how the most elementary science teaching may be made scientific. The author truly says : " Science had much better be left alone altogether than be taught unscientifically " ; and it is only too evident that science is often so taught as to be of little or no value in the real work of education. Matthew Arnold said somewhere, " that all learning is scientific which is NO. 1258, VOL. 49J systematically laid out and followed up to its original sources, and that a genuine humanism is scientific." This is true, and it is because the humanistic studies have been for so many years systematically pursued, that both here and in Germany they have proved more serviceable in teaching scientific method than science itself. The book before us is a collection of suggestions rather than a text-book or a science primer. It consists of 76 small pages, and contains a few exercises to be worked by the pupils, and for the guidance of teachers. Although an instalment only of a complete course, it indicates very fully the methods to be followed and the objects to be aimed at in teaching science to beginners. The key to the system is supplied in the question, addressed to the pupil, and constantly repeated in the text : " What is it you see ? What would you expect to find if the con- ditions were varied .'' " and by the reiterated instruction : " Try it for yourself ; try experiments to see if this is the case ; record your results." In the method of instruc- tion suggested by the author, the pupil is never passive ; he is always doing something, and is consequently in- terested in his work. He is observing, recording, antici- pating results, or experimenting. In dealing with the simplest matters, the methods of inductive inquiry are illustrated and practised. The teacher who follows Mr. Gordon does not instruct ; he guides and assists his pupils in questioning and interpreting Nature. And although the immediate aim of this instruction is educa- tion rather than information — the development and strengthening, by suitable exercises, of certain faculties of the mind, rather than the acquisition of knowledge, the pupil nevertheless gains, in the short course here sketched out, much actual knowledge which cannot fail to prove useful in any kind of practical work. Through the experiments he is made to perform, he learns the metric system, the use of the balance, the mechanical prin- ciple of the lever, methods of determining specific gravi- ties, the action of thermometers and of the barometer, facts concerning the expansion of solids and liquids, and applications to every-day phenomena of the principles of solubility and evaporation. Moreover, the child who has gone through this course will have learnt to be observant and accurate, and will have acquired a certain skill in the use of some of the simpler instruments of science. This is no small result of such a short course of lessons. Between Mr. Gordon's method of teaching the elements of science, and the lectures or lessons illustrated by ex- periments which answer for science teaching in so many of our schools, there is the widest difference ; and by showing in detail how this method may be applied, Mr. Gordon has made a very useful contribution to pedagogic literature. There is very little fault to be found in the subjects selected by the author to illustrate his method ; they are nearly all such as are familiar to the pupil in his every-day life. The early and constant use of squared paper is rightly insisted on in most of the exercises. It may be thought that there is too great an advance in the difficulty of some of the exercises towards the end of the book. But possibly this may have been intentional on the part of the author, to encourage the teacher to fill in the breaks in the reasoning, and to prevent the book from being used by teacher or pupils as an ordinary text-book. G 122 NA TURE [December 7, 1893 The book is clearly printed and illustrated, but would be improved if the numbers of the diagrams were given and referred to in the text. Where more than one diagram is found on the same page, it is not always evident to which diagram the lettering refers. The phrase "addition of interest " might also, with advantage, be changed to some other, less suggestive of commercial arithmetic. These, hu vvever, are small defects which can easily be corrected in a t:ubsequent edition. The merit of the book is not in wliat it teaches, but in how it teaches ; and not the least valuable part of it will be found in the introductory remarks addressed to the teachers. Philip Magnus. THE PYRENEES. Les Pyrenees. Par Eugene Trutat. (Bibliotheque Scientifique Contemporaine.) (Paris : J. B. Baillicre et Fils, 1894.) IN this volume Dr. E. Trutat gives a sketch, as the full title states, of the mountains, glaciers, mineral springs, atmospheric phenomena, flora, fauna, and man in the Pyrenees, illustrated by woodcuts and diagrams, to- gether with two small maps. The mountains differ from the Alps in their greater sirnplicity of structure, for they form " the most perfect type of a regular chain." Like the Alps, this consists of an axis of crystalline rocks, granites, gneisses, and schists, flanked on both sides by deposits comparatively unaltered. But there is one im- portant difference : in the Alps, systems anterior to the Carboniferous are only recognised in the extreme east ; in the larger part of the chain, rocks of that or of a later age rest on crystalline schists, which must be very ancient. But in the Pyrenees schists truly crystalline are succeeded by great stratified masses which have been much less markedly changed. The most ancient of these are assigned to the Cambrian, though as yet fossils either have not been found, or are too ill-preserved to afford any certain evidences of age. It seems, how- ever, clear that they are older than the Silurian system, for the different members of this can be identified in several places by their characteristic fossils. The Devonian system is well developed, and followed by limestones (marine), conglomerates, and slaty rocks of the Carboniferous period. The occurrence of Per- mian rocks is considered by Dr. Trutat to be doubtful. Trias, of the Lorraine type, is found, followed by re- presentatives of the various systems in orderly succes- sion up to the Neocomian. Between this and the Cre- taceous is a break, then the sequence continues till after the Nummulitic age. Then, as in the Alps, began the great series of movement, of what the present chain is the outcome. Masses of eruptive rock are con- nected with these disturbances. The enormous beds of conglomerate, called the Poiidingiies de Palassou, which sometimes surpass looo metres in thickness, recall the Alpine iiar^elfliihe. Strata partly marine, partly freshwater, represent the Miocene and the Pliocene ; the Quaternary deposits presenting a general resemblance to those of the Alps. The glaciers of the Pyrenees at the present day are comparatively small, the length of the largest not exceed- NO. 1258, VOL. 49] ing about 4300 metres, while that of the Great Aletsch is- 32 kilometres, but their former extent, as in the Alps, was much greater. They filled the valleys, and even de- bouched on the lowland ; that of the valley of Ariege must have been about 70 kilometres long. The glacial deposits have been assigned to two epochs, and Dr. Trutat claims for the earlier a considerable antiquity. In the Arirge he states that they underlie Pliocene marls, and near the plateau of Lannemezan pass under the Mio- cene deposits of Sansan. The sections which he gives are very rough, and further proofs of these statements, which involve obvious difficulties, are likely to be demanded. The Pyrenees owe their existence, as has been said, to post-Nummulitic disturbances, but they also afford evi- dence of great movements, both anterior to the Carboni- ferous and after the Neocomian, the latter apparently being less marked. Movements occurred after the great post-Eocene elevation, but of much less importance than they were in the Alps. The other topics, mentioned on the title-page, receive due notice, and the volume will be found useful, as it gives, in a concise and convenient form, much information about one of the most important mountain chains in Europe. T. G. B. OUR BOOK SHELF. Les Cotera?its Polyphases. Par J. Rodet et Busquet. (Paris: Gauthier-Villars et Fils, 1893.) To those desirous of obtaining a general knowledge of the principles used in the calculation of the efficiency and of the dimensions of polyphase motors, &c., this book will be of considerable use. In the first part, the calculation of the dimensions of, and losses in, the conductors conveying the currents are worked out at some considerable length, numerical examples being given. In the other sections the generation of polyphase currents, motors with rotating fields, and transformers are dealt with ; in each case the general principles of the machines now in use being described, though no account is given of the details of their con- struction. There is also a short account of some of the plants for the transmission of energy by polyphase cur- rents which have been installed, with a table summaris- ing the tests and measurements made during the Frank- fort Exhibition. Solutiofis of the Examples in iJie Elements of Statics and Dyftamics. By S. L. Loney, M.A. (Cambridge : Camb. Univ. Press, 1893.) Mr. Loney is indebted to a friend for these solutions, and also for the revision of the whole of the proof-sheets. We have glanced through many of the examples, and they seem to be fully and clearly worked out on the whole, very little being taken for granted. Students who cannot depend on the presence of a teacher, will find that with a judi- cious use of this key much may be self-taught. LETTERS TO THE EDITOR. [ The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to retuj-n, or to correspond with the writers of, rejected manuscripts intended for this or any other part t"/ NATURE. No notice is taken of anonyfiiozts co>nfmtnications.'\ Sir Henry Howorth and " Geology in Nubibus."' Sir Henry Howorth, in his repiy to Dr. Wallace and Mr. LaTouche, concerning the excavating power of ice, rernarks that he is "speaking to every man of science, geologist or December 7, 1893] NATURE 123 otherwise." Indeed, from the tone of his letter he would ap- pear to be defending modern science against the attacks of cer- tain unscientific persons who hold extreme views on glacial questions. As one who has taken a great interest in this subject for a number of years, I trust that I may be allowed to add a few words to the discussion. We are required by Sir Henry Howorth to establish two postulates. "(i) That ice can convey thrust for more than a moderate distance. (2) That glaciers, such as we can examine and report upon, are anywhere at this moment doing the ex- cavating work ..." Dr. Wallace postulates. In reply to the first, we have the undoubted fact that in hundreds and thousands of instances striated rock sur- faces do occur hundreds of miles from existing glaciers. On this point he remarks : " If glaciers travelled further in former days, it was doubtless because glaciers were larger in former days, because they descended longer slopes, and had larger gathering grounds ; that is to say, because the country where they grew was more elevated." So the glacial period resulted from elevation, and all glaciated regions con- veniently rose together to produce it, and as conveniently sank down again. I was quite unaware that this was the accepted view. We have no proof whatever that the striated slopes down which the old glaciers moved were steeper in glacial times than they are now. Indeed, the proof is all the other way, and we may consider it as proved that at long distances from their sources, and on comparatively level plains, glaciers have moved, and have polished, ground, scratched and grooved the rocks over which they passed. The only point about which there may be legitimate discussion concerns the possible extent of the abrasion. In his mechanics Sir Henry Howorth is, I am afraid, rather unsound. There are really two factors upon which the possi- bility of motion in a viscous body depends. One is, of course, the slope of the surface over which it passes, and the other is the slope of the upper surface of the viscous body. Fracture and regelation have little to do with the question, for fracture only occurs near the surface, and fracture must not be con- founded with shear. Sir Henry Howorth makes one statement which seems to account for the conclusions he has come to. It is " a viscous body, unless the viscosity approaches that of a liquid, cannot move by mere hydrostatic pressure." In fact he as- sumes, without adducing a particle of evidence in support of the assumption, that there is an inferior limit to the stress required to deform glacier ice. I always regarded viscosity as something which retarded motion, but did not in any way interfere with the ultimate result. I have personally made mechanical tests of ice, and also of many thousands of samples of steel, iron, copper, brass, tin, &c. All these substances yield elastically and permanently under stress, some of them under very small stresses, but ice is the only one of them that yields continu- ously from the moment the stress is applied until it is again removed. It is not, properly speaking, pressure from behind that forces the ice forward. Ice being viscous, every individual particle moves in the direction of least resistance at a rate depending upon the stress and the viscosity. Sir Henry Howorth may term this "Geology in Nubibus," and call it unmechanical ; but I would point out to him that I regard the question from the point of view of a mechanical engineer, which I am afraid he does not. During the past summer I had the pleasure of seeing some of the Norway glaciers, and also of crossing the Folgefond snow field. It was interesting to note that although the streams coming from the hills and uplands free from ice were quite clear, those escaping from the glaciers were charged with sediment. In this connection I would call attention to a calculation made by Prof. G. F. Wright, giving the rate of erosion of its bed by the Muir Glacier. From the volume and turbidity of the water he makes the figure one-third of an inch per annum over the whole of the 1200 square miles of area occupied by the glacier. In fact, erosion goes on much more rapidly when the rocks are covered by moving ice than when they are not. Although we may feel absolutely certain, both by fact and reason, that the erosion beneath glaciers when they are moving with relative rapidity is very great, and be as sure as we reason- ably can be of most things that such erosion must result in the formation of lake basins, I am afraid that we shall be un- able to satisfy Sir Henry Howorth on the point. We cannot remove a glacier, and if there should prove to be a rock basin NO. [258, VOL 49] below measure of its depth, then replace the ice, and measure again, say, in a thousand years. This is the kind of proof the second postulate seems to demand. R. M. Deeley. The " Zoological Record." In reference to the letter of Messrs. Pocock and Bather, on the subject of the Zoological Record, in Nature of No- vember 16, I desire to state that the council of this Society (to which the Zoological Record at present belongs) quite agree with the above-named gentlemen in their wish to render the Zoological Record more complete by combining palao- zoology with it. With this view the council some time since addressed the Geological Society, and suggested what in their opinion would be an equitable arrangement for carrying out the plan. This arrangement, however, as will be seen by the copy of the correspondence enclosed herewith, was rejected by the council of the Geological Society. It remains, therefore, for Mr. Bather and such members of the Geological Society as may share his sentiments, to do their best to induce the council of the Geological Society to alter their views upon this question. I have good authority for stating that the editor of the Zoological Record is not really of a different opinion to Messrs. Bather and Pocock on this subject, as would seem to be interred in their letter. I believe that he only suggested that the paleontologists should start a record for themselves because of the refusal of the Geological Society to co-operate with us in our work. P. L. Sclater. Zoological Society of London, 3, Hanover Square, London, W. (Copy.) To the Secretary, the Geological Society, Burlington House, W. Dear Sir, — I am instructed by the council of this Society to apply to the council of the Geological Society under the follow- ing circumstances : When the Zoological Record (which is now carried on by this Society) was established twenty-eight years ago, it was not con- sidered that palceozoology came within its scope, and the re- corders were instructed to notice only such palasontological works as appeared to be "of interest to the student of living forms " in their records. This part of the subject has, however, received a continually increasing amount of attention from the recorders, and the council of this Society, being desirous that paloeozoology should in future be treated of in the Record as completely as recent zoology, asks the assistance of the Geolo- gical Society in carrying out this object. The Zoological Society bears at present a loss of about ;^3SO per annum, arising from the publication of the Zoological Record, and, as the inclusion of palseozoology in an exhaustive manner would materially increase the work of the recorders, and necessitate an addition to their remuneration (which is even at present too small), the council of this Society asks the council of the Geological Society to make a grant of ;i^ioo annually towards the expenditure thus incurred. It is thought by some members of the Council that the Zoo- logical Society, bearing, as it does at present, the whole loss arising from the publication of the Record, should not increase its expenditure thereon, and the sum mentioned above, ;^ioo, would, it is estimated, be sufficient to relieve this society from the additional expense that the inclusion of palaeozoology, in its record of zoological literature, would involve. In return for this assistance, the council of this Society will make every effort to treat the subject of palaeozoology exhaustively, and will add to each A'6'C(7r(f a reference to palaeozoological memoirs stratigraphi- cally arranged, besides dealing with those memoirs in detailed analysis in the systematic records. In order that the interests of palseozoology may be more carefully attended to, the council of this Society will undertake to place a nominee of the Geological Society upon the com- mittee of their body appointed every year to supervise the publication of the Zoological Record. Should these proposals meet with acceptance from the Geo- logical Society, the council will further undertake to place one hundred copies of the Zoological Record at the disposal of the Geological Society, and, if it be wished, will alter the title of the Record to The Record of Zoological and PalcEozoological Literature, from The Record of Zoological Literature. 124 NA TURE [December 7, 189; Trusting that these proposals will meet with the approval of your council, I am, dear sir, Yours faithfully and obediently, (Signed) P. L. Sclater, January 21, 189 Secretary. (Copy.) Fio?n the Geological Society, Biirlingtofi House, W. L'i:AR Sir. — Your communication, dated January 21, 1893, was this day submitted to the council of the Geological Society, and I was asked by the council to inform you that they regretted that they were unable, in the present state of the Society's income, to recommend to the Fellows of the Geological Society an in- crease of ex|jenditure such as would be necessitated by acceding to your request that a grant of one hundred pounds should be made to aid the publication of the Zoological Record. Whilst regretting their inability to comply with your request, the council thank you for the conditional offer which accom- panied it. I am, dear sir. Yours faithfully and obediently, (Signed) John E. Marr, February 22, 1893. Secretary. The Proposed Continuous Polar Exploration. Your excellent summary of the proposed continuous Polar exploration (November 2, p. 18) conveys a wrong impression in its closing sentence. The system may in the future assume large proportions ; but the beginning, to be made next year, will be very small. It will consist merely in the establishment of the principal station at the south-east angle of Ellesmere Land, and 80 days' exploration along the west coast of that land. At most, an advanced depot, erected some 100 miles farther west, may be so fitted out as to serve at once as a secondary station. It is not easy to see why this work should be postponed till Peary and Nansen have returned. Their fields are far from ours, and their results can shed no light on the area west of Ellesmere Land. As well might you say that the exploration of the Medi- terranean should not be begun until that of the Baltic was completed. As you say, the possibility of continuous Polar exploration is not demonstrated. There can be no doubt, however, of the value of a permanent station at the entrance of Jones Sound, nor of the practicability of its maintenance, so long as the whalers con- tinue to visit that region. How far exploration may be carried with that station as a base, it is impossible to foretell, but at any rate the existence of a secure base will be an advantage possessed by no previous expedition in that direction, and, in the words of the "Encyclopaedia Britannica," will "make disaster on a large scale, humanly speaking, impossible." U.S. Geological Survey. Robert Stein. On the Classification of the Tracheate Arthropoda. — A Correction. In No. 423 of the Zoologische Anzeit^er (1893) I ventured to propose a new classification of the Tracheata, including under this heading those Arthropoda that are usually known as myriopods and insects. The principal changes suggested were the abolition of the name Myriopoda as indicating an unnatural assemblage of beings and the union of the Chilopoda, Symphyla, and Hexapoda in a division (Opisthogoneata), which was based upon the situation of the generative apertures at the hinder end of the body. But in referring the Symphyla to this category by adopting the assertions of Menge and Latzel respecting the position of the orifices in question, it appears that I fell into error ; for Dr. Erich Haase has kindly written to me from Bangkok, with the information that by means of a series of transverse sections he was able, although with considerable diffi- culty, to confirm Grassi's statement to the effect that the gene- rative apertures in Scolopendrella are situated upon the fourth I body-segment. This genus is therefore progoneate, like the Diplopoda and Pauropoda ; but whether it should be ranged with these two classes, or occupy an independent position between the Progoneata and Opisthogoneata, is a question for future discussion. R. I. POCOCK. NO I 258, VOL. 49] THE LOSS OF H.M.S. ''VICTORIA:'^ n. Al /"E dealt last week with the circumstances relating to * * the loss of H.M.S. Victoria., and the causes of her sinking with such startling rapidity after she was rammed. The facts, so far as they are known, are fully and, in our opinion, fairly summarised by Mr. W. H. White, in No. 3 of the Admiralty Minutes, just issued ; and Mr. White demonstrates clearly, from the results of calculations made in the Construction Department of the Admiralty, that the movements and behaviour of the ship after the accident, and the observed effects upon her line of flota- tion and her stability, are precisely what would be caused by the entry of water into the compartments at the fore end of the ship, which are known, or believed, to have been filled before she foundered. These calculations serve, therefore, the useful purpose of showing that the water known to have entered those forward compart- ments that were proved, by evidence given before the Court Martial, to be filled, was quite suflicient to account for the subsequent capsizing and sinking of the ship ; and for the capsizing and sinking to happen exactly in the manner that was observed. This is so, as already stated, whether Mr. White be absolutely right or not with regard to the precise state of each separate compartment after the damage ; as the evidence is sufficiently con- clusive, upon the whole, respecting the various compart- ments, to reduce the probability of error to a very small amount, such as would not materially affect the practical results of the demonstration. The Admiralty calculations thus remove all reasonable doubt as to whether the compartments known to have- been filled were sufficient in themselves to account for the final disaster ; and they make it unnecessary, in order to explain what happened, to speculate as to the probability of the collision having been more far-reaching in its effects upon the structure, or internal arrangements, of the ship than the evidence indicates. The evidence, as it stands, is shown to completely account for the facts ; and to furnish a solid basis for investigation, or argument, as to the lessons that may now be learned from the loss of the Victoria. The Lords Commissioners of the Admiralty, in the first of the three Minutes lately issued, dated October 28 last, on the finding of the Court Martial, stated that the question of closing the water-tight doors of the Victoria, and the construction and stability of the ship, would be dealt with separately. Their lordships accordingly issued the second Minute, dated October 30. This Minute states that, in consequence of the Court Martial finding " that it does not feel itself called upon, nor does it feel itself competent, to express an opinion as to the causes of the capsizing of the Victoria," their lord- ships instructed the Director of Naval Construction to make a thorough examination and analysis of those parts of the evidence which throw light on these points. The report prepared by Mr. White, in accordance with these instructions — No. 3 of the present Minutes — was dealt with in our article of last week ; but we then left over for subsequent consideration the references made in the Minutes to the lessons taught by the various circum- stances of the case. These points being dealt with authoritatively in the second Admiralty Minute, dated October 30, we shall deal principally with that Mmute in the following remarks. It commences by adopting the figures and the conclu- sions stated in Mr. W^hite's report with regard to the nature of the blow received by the Victoria, the after movements and behaviour of the ship, the extent to which water found access into her, and the effect of such water upon her flotation and stability. We have nothing 1 Continued from p. 104. December 7, 1893] NATURE i25 further to say upon the subjects dealt with in this portion of the Minute, which appears to accord with the evidence, and also with the known effects that would be produced by filling the compartments that were opened up directly to the sea, or into which water could pass freely through open doors, hatches, &c. The Admiralty Minute next expresses the opinions of the Board upon the following points ; and we will take these in the order named in the concluding paragraph of our former article : (i) The effect of longi- tudinal bulkheads upon the capsizing of the ship ; (2) what would probably have happened if the doors and ports in the upper-deck battery had been closed ; (3) what would probably have happened if all doors, hatches, &c. had been closed before the collision took place ; (4) the efficiency of -the water-tight doors to the bulkheads, and the means of closing them quickly ; (5) the value of an armour belt at the ends for resisting damage ; (6) the sufficiency of the stability possessed by the ship ; and (7) the steps that should be taken "to prevent the recur- rence, under similar circumstances, of the conditions which, after the collision, resulted in the loss of the ship." I. The effect of longitudiytal bulkheads iipon the cap- sizing of the ship. — Mr. White points out that there was no continuous central longitudinal bulkhead in the Vic- toria. In the stokeholds and engine-room there were two such bulkheads on opposite sides of, and each several feet from, the centre line ; but these were far abaft the damaged portion of the hull, and do not appear to have been reached by water that entered the ship up to the moment of sinking. There were a few longitudinal parti- tions in the fore part of the ship ; but some of these were inoperative because of damage or open doors. The effect of tilling the compartments formed by these longitudinal partitions has been calculated, and it is stated that this would only cause an inclination of about 5° in the intact condition of the ship. This result does not, however, bear directly upon the actual effect produced in such cir- cumstances as are being considered, because the damage caused by collision not only admitted water into the ship, but it reduced, at the same time, her power to withstand the heeling effect of the excentric compart- ments that were thereby filled. The ship would only have heeled about 5" with these compartments filled, if the hull had been uninjured ; but if the hull had been uninjured, the compartments would, of course, not have been filled. Mr. White goes on to say : " It appears on investigation that in the damaged condition and at the extreme position which the Victoria occupied before the lurch began, the flooding of the compartments enumer- ated, and the accumulation ot water on the starboard side, account for the observed angle of heel, 18 to 10 degrees." This inclination — -which is what was really due, in the circumstances, to water being held over to starboard by the longitudinal partition above referred to ; as the accumulation of other water to starboard was merely the consequence of the heeling thus caused^ must have allowed the sea to enter the ports and door of the upper deck battery sooner than it otherwise would have done, and thus have hastened the capsizing of the ship. Tne Admiralty Minute states that "the evid- ence clearly shows that the existence of longitudinal water- tight bulkheads in the Victoria was not the cause of her capsizing. There were only a few minor longitudinal partitions in the fore part of the ship. Many of these were inoperative because of damage or open doors." This conclusion is doubtless correct so far as it relates to the continuous longitudmal central bulkhead to which the capsizing of the ship was prematurely, though con- fidently, attributed by certain hasty critics, because such a bulkhead did not exist in the forward part of the ship that was aftected by the collision. It clearly does not apply, however, to the minor longitudinal partitions above NO. 1258, VOL. 49] referred to, because these must have been contributory to the disaster according to the extent by which the water they held over towards one side caused the heel of the ship to increase as the bow became immersed, and the stability diminished. It is a question that could only be settled by further investigation, whether the reduction of stability and the heeling effect thus caused was greater or less in this particular case than would have occurred if the water had been free to pass from side to side of the ship within the fore-and-aft limits of the compartments it entered. 2. What Tvould probably have happened if the doors and ports in the upper-deck battery had been closed. — Mr. White says: " It is not possible to state absolutely that the Victoria., with turret and battery closed, could have been kept afloat permanently under the actual circum- stances of the collision " ; and he points out that there are many compartments into which water might have found its way eventually, through doors and hatches that were probably open. He considers, however, that " her capsizing would have been improbable even if she had eventually foundered." The Admiralty endorse this opinion in their minute, which states : " The great weight of water thus gradually admitted into the forward part of the ship might eventually have caused the ship to founder by the head." We see no reason to believe that the ship could pos- sibly have been saved by the closing of these doors and ports. By the time the sea had reached them the fore end of the ship was so deeply submerged, and there were so many openings by which water could then find its way into compartments not already filled, that it is difficult to conceive how even the rate at which she was so rapidly sinking could be checked. When the sea had reached the height of the turret ports and the upper-deck battery ports and doors, the ship was inevitably doomed. She might possibly have sunk by the head without capsizing, although this appears improbable. With her stability reduced to the extent described in the Admiralty Minutes, when the bow was under water, and the heel to starboard was great, it would appear that the effect of the increasing quantities of water in the ship would certainly be to capsize her very soon. But whatever might have been the precise manner in which she would have gone down, there appears no doubt that the vessel v/ould have gone to the bottom almost immediately after she did, even if the turret and upper-deck battery ports and doors had been closed. 3. What would probably have happened if all doors, hatches, &^c., had been closed before the collision took place. — We agree upon this point with the opinion, based upon the calculations of the Construction Department, which is expressed in the Admiralty Minute as follows : " While the loss of buoyancy must in that case have been considerable, yet, making all due allowances for probable damage, the ship would have remained afloat and under control, and able to make port under her own steam. Her bow would have been depressed about to the water level, her heel to starboard would have been about one- half of that observed before the lurch began {i.e. 9 or 10 degrees), her battery ports would have been several feet above water, and she would have retained ample stability." 4. The efficiency of the water-tight doors to the bulk- heads, and of the means of closing the/n quickly. — This question is one of the greatest importance in the present case, because, as we have seen, the Victoria might appar- ently have been navigated safely into port if all the water-tight doors, hatches, (S:c. had been closed soon enough to prevent water passing from compartments directly opened up by the collision into others from which they were separated by water-tight bulkheads or decks. The Admiralty expresses strong and unqualified opinions upon this point. Their lordships say " the detailed evi- 126 NATURE [December 7, 1893 dence establishes the fact that water-tight doors, hatches, iS:c. in the Victoria were in good order. It contains nothing which suggests a doubt of the efficiency of the system of water-tight subdivision existing in the Victoria. At the parts affected by the colHsion the subdivision was minute, but doors were left open. According to the established practice of the Admiralty in all classes of ships, the number of water-tight doors is made as small as po=;sible consistently with the essential conditions for working and fighting the ship. ... In conclusion, their lordsh>ps are of opinion that .... the arrangements of water-tight doors .... did not by any fault of principle contribute to the loss of the ship ; but that, on the con- trary, had the water-tight doors,'hatches, and ports ^ been closed, the ship would have been saved." Mr. White says, in his Minute: " No orders were given to close doors until one minute before collision. It is established by the evidence that the doors, &c. were in good order. The failure to close doors, therefore, was due entirely to the insufficiency of the time available, especially in compart- ments breached by the collision." The statement that the water-tight doors, hatches, «S:c. were in good order at the time of the collision appears justi- fied by the evidence ; except, perhaps, with regard to the door at the after end of submerged torpedo room, which slides horizontally, and could only be moved six or eight inches when the attempt was made to close it after the collision. Their lordships go on to say that the detailed evidence contains nothing which suggests a doubt of the efficiency of the system of water-tight subdivision. We cannot dis- cover, however, that this question was investigated by the Court Martial. Very complete evidence was obtained as to the exact state of each compartment, and of each opening into the compartments, at the time of the col- lision ; but the general question of the efficiency of the system of water-tight subdivision, which involves that of the water-tight doors and hatches to the various compart- ments, was not gone into. It would appear, indeed, to have been expressly excluded from the investigations of the Court Martial, since it can only be judged in rela- tion to the buoyancy and stability of the ship ; and the Court confined itself, as already stated in the quo- tation given from the Admiralty Minute, to placing upon the Minutes all evidence obtainable with regard to the closing or otherwise of water-tight doors, &c., but did not feel itself called upon, nor feel competent, to express an opinion as to the causes of the capsizing. While it may therefore be true that the evidence contains nothing which suggests a doubt upon these points, it is, on the other hand, equally true that it contains nothing which proves the assertion that the system of water-tight subdivision was efficient. One of the weak points in the water-tight subdivision ap- pears to have been the doors and hatches to openings in the bulkheads and decks ; and especially the impossibility of closing a sufficient number of them after the collision to keep the ship afloat. The doors upon the mess deck were all closed ; but this deck was about 3 feet above the water-line, and there was time to attend to the doors upon it before the inrush of water drove the men away. On the protective deck below, however, and on the plat- form in the hold, there was not time to get at all the doors and hatches before the water reached them ; while most of those that were got at and closed appear to have been only partially, and very imperfectly, secured. The plans of H.M.S. Victoria, appended to the Admiralty Minutes, show ten water-tight doors in the bulkheads on the protective deck, at the fore side of the armour belt. This deck is about 100 feet in length, and includes the whole of the area directly affected by the collision ; and there is only one important bulkhead in this space which lit has already been pointed out that the closing of the ports would appar- ently have had but little effect, and the Admiralty admit that the ship might still have foundered. NO. 1258, VOL. 49] does not contain a door, viz. that which divides the cable locker from the fresh-water tanks. On the platform in the hold, immediately under the protective deck, there are eight water-tight doors in the bulkheads, while there is in addition a water-tight door in the bulk- head at Frame Station 35, which forms the after boundary to the space. This was the door which could not be closed when the attempt was made to do it. There is no bulkhead upon this deck in the space referred to which does not contain a door. Besides these doors there are numerous openings, fitted with water-tight hatches, in the decks over the various compartments. The Admiralty Minute states that the number of water- tight doors was made as small as possible, in accordance with the established practice of the Admiralty. It would be difficult, however, to fit more doors than are shown upon the plans of the two decks that are below the water- line in the Victo7'ia — the protective deck and the deck below it in the hold. Judging by the Admiralty plans, it was only a certain number of these water-tight doors that were fitted so as to slide horizontally ; and some were merely hinged doors, which could only be closed by entering the com- partment in which they were situated, and were secured by a number of clips round the edge of the door. Some of these were upon the most important transverse bulk- heads, such as the two bulkheads which enclosed the submarine mining flat on the platform in hold. We have always considered that arrangements should be made for closing all doors in bulkheads that are essential to the efficient water-tight subdivision of the ship from a deck that is at a safe height above water, as well as in the compartments where the doors are ; and we believe, also, that this is the Admiralty rule — as it obviously ought to be. If doors are fitted below the water-line so as only to be opened or closed in the compartments where they are, they should seldom require to be opened, and never to be left open, unless the bulkheads to which they are fitted are not considered essential to the efficiency of the water-tight subdivision. It does not appear by the evidence, or by the Admiralty Minutes, that a single one of the many doors in the fore part of the ship on and below the protective deck could be closed from a deck at a safe height above water ; because the sliding doors could only be closed, we believe, from the main deck, which does not appear to have been more than 3 feet above water at the time of the accident, and was almost instantly immersed. In view of these cir- cumstances we cannot agree with the opinion of the Admiralty that there is " nothing which suggests a doubt of the efficiency of the system of water-tight sub- division existing in the Victoria. It appears, upon the other hand, quite practicable to improve the efficiency of this system by dispensing with some of the doors, and by arranging with reference to the others that every one which requires to be left open for even an instant, without the certainty of some one being in con- stant attendance upon it till it is closed, should be capable of being worked from a deck at a safe height above water. Mr. White says that the failure to close the water-tight doors in the forward part of the Victoria has caused sug- gestions to be made that automatic or self-closing doors should be adopted instead of existing arrangements. This suggestion was, he adds, carefully considered long ago, after certain experimental doors had been tried. He is satisfied that the existing arrangements are the best, and that their safety is only a question of good time being allowed for closing the doors. It must be re- membered, however, that when doors can only be closed in the compartments where they are situated, and these are below the water-level, the inrush of water would often effectually prevent the closing of the doors in bulkheads that separate the compartment that is breached from those December 7, 1893] NA TURE 127 adjacent to it. Also, with such arrangements below as those of the Victoria, it is impossible to ensure that an unforeseen accident would always allow of sufficient time to close the water-tight doors in the manner required. The efficiency of the water-tight hatches, and the chances of their being properly secured in an emergency when they are fastened by a number of clips round the ■edge, as at present, is also a question that appears to re- quire consideration ; while it is to be observed that the sliding horizontal door in the protective deck of the Victoria, which opened into a shoot through which coal was trimmed from the reserve bunkers at after end of protective deck, into the side bunkers in the stokehold, could not be closed from the shoot in which the men worked who were trimming the coal ; but had to be worked from the submerged torpedo room, a compart- ment below the protective deck. This open door had an important effect upon the capsizing, for Mr. White states that "one of the chief causes of inclination to starboard is to be found in the fact that, owing to open doors, water was able to find its way from bunkers above the protec- tive deck, down through the coal-shoot, and so to fill No. 7 bunker just before the forward starboard stoke- hold.^' It appears to us that one of the chief lessons taught by the circumstances of this disaster, is the necessity of reducing the number of water-tight doors and hatches, and of arranging that all of them which are essential to the efficiency of the water-tight subdivision, and are ever likely to be left without attendance while open, should be capable of being closed, either by a thoroughly satisfac- tory self-acting arrangement, or by appliances for work- ing them from a deck at a safe height above water. The points still remaining to be considered will be reserved for cur next article. Francis Elgar. REAPPEARANCE OF THE FRESHWATER MEDUSA {LIMNOCODIUM SO IVERBH). FOR three years nothing has been seen of the fresh- water medusa in the Regent's Park, and naturalists liad given up hope of carrying on any further investiga- tion into its life-history. It seemed as though this beauti- ful little organism -brought we know not how or whence into the midst of London — had, like some mysterious ■comet, unexpectedly burst on the zoological world, and as unexpectedly disappeared. I was, therefore, greatly astonished to hear in September, from my friend the Director of Kew, that the curator of the Sheffield Botanic Gardens (Mr. Harrow) had discovered it in quantity in the Victoria Regia tank under his care during the present summer, and I was soon after delighted by the safe arrival from Sheffield of a bottle containing living well-grown specimens of the familiar jelly-fish. Mr. Harrov/ informs me that he observed it in the tank at Sheffield for the first time in the beginning of June of this year (1893). Specimens were still observed as late as the middle of October — giving a duration of some fourteen weeks— an unusually long period. Mr. Harrow estimates the total number seen as at least 300. The last seen in the Botanic Gardens, Regent's Park, London, were taken from the new Victoria Regia tank on July 30, 1 890. The question as to how the jelly-fish got to Sheffield is easily answered. Water plants (Nymphae- aceee and Pontederia) were sent (as I am informed by Mr. Sowerby and by Mr. Harrow) from Regent's Park to Sheffield to re-stock the tank there on April 4, 1892, and on April 7, 1893. Hence there was the probability of some of whatever reproductive germs of Limnocodium existed in Regent's Park being transferred to Sheffield. The curious thing is that in 1892 and in i8gi no Limno- codium were seen in the original source — viz. the Regent's NO. 1258, VOL. 49] Park tank — nor in 1893, excepting a few sent from Shef- field and placed in that tank by Mr. Sowerby. This is the first instance recorded in which another Victoria Regia tank has been "infected" with Limno- codium from the original Regent's Park tank, excepting when the new tank in Regent's Park was in 1890 infected from the old one — by the transference to it of weeds and roots containing the germs of the jelly-fish. The tank at Kew has never been properly infected, for it is, I regret to say, the anti-zoological custom at the Royal Gardens to thoroughly cleanse, wash, and furbish up the Victoria Regia tank every year so thoroughly that the winter germs of the jelly-fish are removed or destroyed. Hence Limnocodium has flourished at Kew when sent there from Regent's Park, but has never " carried over " from one season to another. It is, fortunately, the custom in other botanical gardens to leave a quantity of " sludge " (including some old leaves and stems) at the bottom of the tank, when the water is drawn off and the soil prepared for a new season, and hence Limno- codium has been preserved from destruction for so many years. As to what is the precise nature of the process by which Limnocodium has been carried over from one season to another in the Regent's Park, we are still uncer- tain. The facts at first ascertained were these, viz. that the jelly-fish suddenly appear each year as early as April or as late as August, and remain for from five to twelve weeks, when they die down and absolutely disappear. During the first few weeks of their appearance the water is found to contain an immense number of minute young forms (jj\, of an inch in diameter), which I described and figured in the Quart. Joiirn. Micros. Science, vol. xxi. p. 194. Evidently these young were being pro- duced in quantity in the tank, and gradually developed to the full size of half an inch diameter. The form and appearance of these young were such as to lead me to the conclusion (subsequently found to be eri'oneous) that they had been developed from eggs. At the same time the remarkable fact was established by the examination in successive years of many hundred specimens that the adult Linuiocodia were every one, without exception, males. They produced abundant motile spermatozoa, but not a trace of an egg-cell was ever found in any one of them ! The hypothesis which I entertained in 1884 as an explanation of this curious state of things was — that the female was a non-motile, perhaps a fixed hydriform organism, and I accordingly searched for such a form in the mud and debris from the bottom of the tank. At last, in a large quantity of such material which I obtained when the tank was cleared out in the winter of 1884, my assistant, Dr. A. G. Bourne, found a very strange diminutive polyp adhering in numbers to the root- filaments of Pontederia. This polyp he carefully de- scribed in the same year in a communication to the Royal Society. There was very great probability that this little polyp, devoid of tentacles, and not more than |th of an inch long, was the " trophosome " of the Limnocodium medusa. That this was a true inference was subse- quently proved by Dr. G. H. Fowler, who in 1890 {Quart. Journ. Alicros. Science, vol. xxx.) the last year in which the jelly-fish were seen in London, showed that the little spherical young found floating in the water of the tank are nipped oft" by a process of transverse fixion from the free ends of the minute polyps described by Bourne. Fowler (whose observations were made in my labora- tory in 1888) found the polyps very abundantly upon floating water-plants widely scattered in the tank ; they were also detected by Mr. Parsons, of the Ouecket Club, in water which was the overflow of the tank, and accumu- lated in an outside reservoir. The immediate question then became " How do the polyps originate ? " The polyps account for the medusse, 128 NATURE [December 7, 1893 but whence do they themselves originate? And this question still remains unsolved. The polyps are observed to increase by budding, but they never form clusters of more than four " persons." How do they become distributed over the under surface of nearly all the floating leaves in the tank? How do they get carried to an outside reservoir? Is it not improbable that they would continue year after year to propagate t^emselves by budding as polyps, and in the summer to throw off successive crops of ;;m/^ medusae ? It is possible that this is the whoie history, but not quite probable. In any case, however, the existence of the minute polyps attached to water-plants is sufficient to explain the introduction of the jelly-fish to Sheffield. It also is sufficient to explain the original introduction of the jelly- fish to the Regent's Park, since in 1878 (two years before the first discovery of the jelly-fish) specimens of a re- markable water-plant {Pontederia) were brought from Brazil by a lady and presented to the Botanical Society, and placed in the Victoria Regia tank. A new interest has recently been added to that already attaching to Limnocodium by the description of another fresh-water jelly-fish, the Limnocnida Tangaiiyisice. This remarkable form was worked out in my laboratory in Oxford during last winter by Mr. R. T. Giinther, who received the specimens from his father, Dr. Giinther, F.R.S., of the British Museum. Dr. Giinther had written to the Mission on Lake Tanganyika in order to procure the specimens. Individuals of three kinds are described by Mr. Giinther, viz. males, females, and a-sexual in- dividuals which produce crops of buds on the manu- brium (see his papers in the A7tn. and Mag. Nat. Hist., 1893, and in the forthcoming number of the Quart. - Journ. Micros. Science). Whilst differing greatly from Limnocodium in most respects, Limnocnida agrees with it, in a most extraordinary way, in the minute structure of the marginal sense-organs. No light is thrown by Limnocnida on the problem of the life-history of Limno- codium. I subjoin a list of dates in reference to the history of Limnocodium, and may add that the columns of Nature already contain numerovs communications relative to it, viz. in vol. xxii. (1880), pp. 147, 177, 178, 190, 218, 241, 290, and in vol. xxxi. p. 107. 1880. — June 10, first observed in Regent's Park ; remained six weeks. 1881. — June 12 ; reappeared ; remained five weeks. 1882. — None observed. 1883. — April 28 ; twelve weeks. 1884.— April 27 ; twelve weeks (?). 1885. — April 5 (no record of duration). 1886. ^August 7 (no record of duration). 1887. — End of May (no record of duration). 1888. — May 10 (no record ; very few observed). 1889.— None. 1890. — New tank constructed and stocked ; July 10 a few. 1891. — None. 1892.— None. Plants sent to Sheffield April 4. 1893. — None in London. Plants again sent, April 7, to Sheffield. 1^93- — June 7 to mid- October, large numbers observed in tank at Sheffield. Hydroid trophosome discovered by Bourne in winter of 1884. Production of medusae by hydroid, observed by Fowler, in May, 1888. E. Ray Lankester. DEA TH OF PROF. TYNDALL. A NOTHERof our " Scientific Worthies "has/' crossed -^~^ the bar," leaving behind an honoured name and works that will perpetuate his memory. On Monday evening Prof. Tyndall passed away at his residence, near Haslemere. For some time previous he had been suffer- ing from insomnia and rheumatism, and very unfavour- able symptoms set in on Monday morning. He quickly NO. 1258, VOL. 49] became unconscious, and except for a brief interval at midday, remained in this state until half-past six o'clock,, when a peaceful change from life to death took place. It appears that the cause of death was an overdose of chloral, which Prof. Tyndall took as a sedative against insomnia. He had been in the habit of taking narcotics for several years past in order to overcome the sleepless- ness from which he suffered. On Monday about the usual quantity was administered to him, but his greatly weakened condition was unable to bear so much. The inquest on the body, which was considered necessary by the doctors, was held yesterday. A detailed account of Tyndall's life was given in these columns in August, 1S74, so it is only necessary to trace now a brief outline of his career. He was born in 1820, at Leighlin Bridge, near Carlow, in Ireland. But it was not until 1S47 that he began his career as a teacher of science, by accepting a post in Oueenwood College, Hampshire, where Dr. Frankland was chemist. A year later the two friends did what every young man of science should do, if possible — they went together to a German University, the University of Murburg, Hesse Cassel, rendered celebrated by Bunsen and others ; and to Bunsen, whose lectures he attended, and in whose laboratory he worked, Tyndall was never tired of express- ing his obligations. He was at Murburg when Knob- lauch, preceded by a distinguished reputation, and accompanied by a choice collection of instruments, went there as Extraordinary Professor. Subsequently, in con- junction with Knoblauch, Tyndall carried on his " classic " inquiries in connection with diamagnetism, afterwards prosecuting his research in the laboratory of Prof Magnus at Berlin. In i85r his life-long friendship with Prof. Huxley commenced, and in the following year he was elected a Fellow of the Royal Society. In February, 1853, he gave the first of his eloquent Friday evening lectures at the Royal Institution. Shortly afterwards, at the proposal of Faraday, he was appointed Professor of Physics in the Institution, a post from which he retired in 1887. The managers and members of the Institution marked their sense of the benefits he had conferred upon it by electing him as Honorary Professor, a title pre- viously borne by Davy and Brande, and by calling one of the annual courses of lectures " The Tyndall Lectures." His bust was also placed in the Institution in memory of his relations with it. A complimentary dinner was given to Tyndall on the occasion of his retirement from the Chair of Physics in the Royal Institution. The body of eminent men which met at the dinner was such as has seldom if ever been brought together to do honour to a man of science, and when the chairman, Sir George Stokes, the then President of the Royal Society, gave voice to the desire of the company that their guest should long enjoy the leisure which he had so well earned, it was not thought that after but six years of rest from labour he would be called away. The speeches made at the dinner are reported in Nature, vol. xxxvi. p. 222, and they show the high regard in which Tyndall was held throughout the world of science, art, and letters. In responding to the toast of the evening,, he gave an account of his life, including in his speech the following true remarks : — " To keep technical educa- tion from withering, and to preserve the applications of science from decay, the roots of both of them must be imbedded in the soil of original investigation. And here let it be emphatically added, that in such investigation, practical results may enter as incidents, but must never usurp the place of aims. The true son of science will pursue his inquiries irrespective of practical considerations. He will ever regard the acquisition and expansion of natural knowledge — the unravelling of the complex web of nature by the disciplined intellect of man, as his noblest end, and not as a means to any other end." This was the kind of spirit that actuated Tyndall throughout his career. It December 7, 1893] NATURE 129 was well shown in 1872, when he placed the balance of 13,000 dollars, that remained after his lecturing tour in the United States, in the hands ofa committee who were authorised "to expend the interest in aid of students who devote themselves to original research." It would be superfluous for us to enumerate Tyndall's explorations in the domain of science, or to expatiate upon his remarkable power of presenting a subject both in speech and in writing, for among men of science these facts are common knowledge. To such men as he — not only original discoverers, but also popular and powerful interpreters of scientific fact — we owe much of the ad- vancement that has been made during the last forty years. NOTES. Mr. H. H, Turner, of Greenwich Observatory, has been elected to the Savilian Professorship of Astronomy at Oxford, in succession to the late Prof. Pritchard. The Russian traveller Potanin, who has spent more than a twelvemonth in a botanical exploration of Thibet, is expected in St. Petersburg in January next. M. Dobrotworsky has arrived at Jenisseisk on the Jenissei, on a botanical expedition. Prof. Ben. K. Emerson, of Amherst College, and of the U.S. Geological Survey, who met with a serious railroad acci- dent last summer, and was reported killed, has so far recovered that he started in November on a trip round the world, for rest and recuperation. He visits Italy, Egypt, India, Java, and Japan. Prof. Emerson has been engaged for a long time in mapping the crystalline rocks of Central Massachusetts and Connecticut- Dr. Nicole has been appointed Director of the Bacterio- logical Institute of Constantinople. Dr. Seubert has been appointed Professor of Analytical and Pharmaceutical Chemistry in the University of Tubingen. Mr. W. F. C. Gurley has been appointed Director of the Geological Survey of Illinois. We learn that Prof. D. A. Gilchrist has accepted the Pro- fessorship of Agriculture at the University Extension College, Reading. Dr. K. von Dalla Torre has been appointed Professor of Botany in the Universityof Innsbriick, and Dr. H. Moller Professor of Botany in the University of Greifswald. Mr. W. T. McGee, known for his contributions to geology, has been appointed Director of the Bureau of Ethnology at Washington, U.S. The Chair of Comparative Anatomy and Zoology in the Biological School of the University of Pennsylvania has been accepted by Prof. E. D, Cope, and that of Geology and Mineralogy by Prof. A. P. Brown. The death of Dr. Webb, the well-known Principal of the Aspatria Agriculture College, is a severe loss to agricultural education. After a very brief illness, he passed away on Nov- ember 28, in the prime of life. Through his exertions the Col- lege at Aspatria has been raised from a very low condition to its present high standing. He was greatly respected by his students, and his place as a teacher of agriculture will not be easily filled. The first step towards the introduction of the decimal system into Russia will be taken on January 13, 1894, when, by order of the Czar, the chemists of the Russian empire will begin to use decimal weights and measures. A PRIZE of 1800 liras is offered by the Italian Geological Society for the best account of the state of knowledge of Palaeozoic and Mesozoic formation in Italy, the work to be in continuation of D'Archiac's " Histoire des progres de la Geologie," and to be presented before the end of March, 1896. NO. 1258, VOL. 49] Die Natur announces that the Berlin Academy of Sciences has granted Drs. Richarz and Krygar-Menzel two thousand marks for the carrying on of their investigations of the constant of gravitation. A like sum has been granted to Dr. Franz Reinecke for the furtherance of his ethnological and anthropo- logical studies. The ninth congress of Russian Naturalists will be opened at Moscow on January 15, 1894. The Mathematical and Physical Faculty of the Moscow University has undertaken its organisation. Reductions of railway fares are offered to per- sons who will apply for that purpose to the Dean of the Faculty before December 13. The first general meeting of the con- gress will take place on January 16, 'and the conference will close on the 23rd of that month. Mr. C. M. Irvine informs us that at four o'clock on the afternoon of December 4 a brilliant meteor passed over Lesmahagow, N.B., travelling true south. The altitude was about 45°. The arc through which it was visible was about 10°, and the duration of visibility nearly 3 sees. Colour, pale greenish blue. The sky was overcast with detached clouds. The passage of the meteor was slightly zigzag, deviating from a straight line by about l° on either side. The second series of lectures given by the Sunday Lecture Society begins on December 10, in St. George's Hall, when Sir Benjamin W. Richardson, F.R.S., will lecture on "The Mastery of Pain." Lectures will subsequently be given by Prof A. K. Rambaut, Royal Astronomer of Ireland ; Dr. R. D. Roberts, Prof. Percy Frankland, F.R.S., Mr. C. T. Dent, Mr, Arthur W. Clayden, and Prof. R. Meldola, F.R.S. The following are among the lecture arrangements at the Royal Institution before Easter : — Prof. Dewar, six lectures (adapted to a juvenile auditory) on air ; gaseous and liquid ; Prof. Charles Stewart, nine lectures on locomotion and fixa- tion in plants and animals ; Mr. W. Martin Conway, three lectures on the past and future of mountain exploration ; Prof Max Midler, three lectures on the Vedanta philosophy ; the Right Hon. Lord Rayleigh, six lectures on light with special reference to the optical discoveries of Newton. The Friday evening meetings will begin on January 19, when a discourse will be given by Prof. Dewar, on scientific uses of liquid nitrogen and air. Succeeding discourses will probably be given by Mr. A. P. Graves, Mr. T. J. Cobden-Sanderson, Prof. W. F. R. Weldon, Prof. Silvanus P. Thompson, Prof. John G. McKendrick, Dr. W. H. White, the Right Hon. Lord Rayleigh, and others. According to the Times correspondent at Cairo, Messrs. Garstin and Willcocks have inspected the four sites proposed for reservoirs in which to store water for irrigation purposes during the summer when the Nile is low, and their reports will shortly be presented. The Government will then invite three European hydraulic engineers of the highest reputation to come to Egypt and make a technical examination of the proposed schemes. This will probably be in February next. Three of these schemes are for the construction of dams across the river at either Kalabsheh, Assouan, or Silsileh ; the fourth proposes to utilise the natural depression of the Wady Raian, in the province of Fayoum, by conducting into it the flood-water of the Nile. The London County Council some time ago decided to estab- lish a pathological laboratory and museum in connection with the London lunatic asylums. Last week the Council accepted the plans prepared by Mr. G. T. Hine, and we understand'jthat they will shortly be put into execution at Claybury, A com- petent pathologist is now to be appointed, who will be supplied with material from the Claybury and other asylums under the supervision of the London County Councd. The necessity for 1 ^o NA TURE [December 7, 189; such a laboratory has long been felt, and although good work has been done in several asylums by enthusiastic workers, these investigations have hitherto been carried out at a great disad- vantage, chiefly owing to the want of assistance on the part of the governing bodies. So great have been these difficulties that in many asylums pathological science has been totally neglected. The task of electing a pathologist will not be an easy one. It is to be hoped the choice will falljon one who has made his mark in all the various branches of neurological science ; for the study of cerebral disease is so bound up with that of the spinal cord and nerves, that a knowledge of cerebral pathology -must prove useless if not combined with a thorough mastery of the clinicd.1 phenomena of spinal and peripheral nervous diseases, of their lesions, and of the methods of clinical and experimental neurological investigation. As might have been expected, the anti-vivisectionists, headed by the Lord Chief Justice of England, have memorialised the Viceroy of India and the members of the Executive and Legislative Councils. In this document the usual sentimental arguments against vivisection are stated. If with reference to the Indian Bill now under consideration for the regulation of vivisection experiments, it should be deemed advisable to legis- late on the subject, the signatories suggest (a) that the higher animals, such as horses, asses,«mules, dogs, and cats, for which special certificates are granted in England, and also monkeys, should be wholly exempted from experimentation ; {b) that it should be made essential to keep the animals under an anaes- thetic throughout the investigation ; {c) ^that the use of curare should be entirely prohibited ; {d) that :it should be provided that one inspector at any rate shall be selected on account of his recognised humanity, not his scientific knowledge. The execu- tive committee of the Society for the Protection of Animals from Vivisection have also recently transmitted to the Viceroy and the members of the Executive Council a protest against the establishment of a Pasteur Institute in India. They represent that similar institutes in Paris and elsewhere have so far failed to prevent deaths from the bites of dogs and other animals alleged to be rabid, and that 256 persons have died in spite of the preventive treatment invented by M. Pasteur. It is also remarked that the Pasteur system involves and depends upon the cultivation and perpetuation of the malady of rabies in series after series of sentient animals, to their great misery and suffering, but the benefits that mankind derives from it are naturally ignored. During the week ending the 2nd inst. several depressions passed across these islands, causing'gales on our northern coasts. In the rear of these disturbances northerly winds set in, with a great fall of temperature ; on the 1st and 2nd inst. the thermo- meter fell to 20", or less, in nearly all parts. In Scotland the lowest readings were between 12" and 15°. But by Sunday, the 3rd inst., the temperature rose rapidly in the north and west, and subsequently the rise extended to the southern parts of the country. The Meteorologische Zeitschrift for November contains a paper on the frequency of halo phenomena, by G. Hellmann. Few text-books have dealt with this subject, and those that have done so state that lunar halos are most frequent, an error which appears to date from the time of Aristotle. Certainly the moon offers less opportunity for such phenomena. Prof. Hellmann points out that only such observatories as record hourly observations afford the necessary materials for giving a satisfactory answer to the question. He has examined various records, and especially those of the Upsala observatory, the result being that the solar phenomena exceed the lunar by about five to one, by far the most frequent halos being those of 22' radius. The halos as well as mock-suns and mock-moons show a distinct yearly period. The solar phenomena are most NO. 1258, VOL. 49] frequent from April to June, and the lunar phenomena are most frequent in the winter half-year, being dependent on the length of the nights. These results are supported by observa- tions made in the United States, and also in Japan. The Pioneer Mail, of November 9, contains an article on the past monsoon in India, based upon the official reports of rainfall between June i and October 15. These reports show a generally satisfactory state of affairs, about half the country having had excessive, and half deficient rainfall ; some regions which generally receive only moderate rain had an excessive amount, while those which usually receive an excessive amount had a relatively light fall. The causes which bring about this half-yearly reversal of the winds are of especial interest, and offer a large field for study. Among the generally accepted theories, one attributes the origin of the rain-bearing current to the intense heating of the plains of Upper India, while another IS that the chances of a good monsoon vary inversely with the amount of snow during the preceding winter. The writer thinks that these theories have failed in the present instance, while admitting that the distribution of heat and, under some circumstances, the snowfall exercise an influence on the monsoon. He sets up another theory, viz. that the monsoons are caused by the heated air of Asia rising up and overflowing at a great height to the southern hemisphere, where it settles down and is impelled northward by its own energy and by pressure in the rear. A reference to the " Memorandum on the Snowfall, &c." issued by the Meteorological Reporter on June I last, shows that the general forecast was to the effect that the rainfall might be deficient to a moderate extent in north-west India, and would very probably be at least normal in other parts. If any modification of the accepted theories be necessary, it will doubtless be shown by a study of the daily charts of the Indian monsoon area, to which we recently alluded, and the publication of which began with the present year. One of the special objects in preparing these charts is to elucidate the conditions which determine the advances, and variations in strength of the monsoon currents Some interesting observations on the velocity at which crys- tallisation proceeds in a super-cooled substance are communi- cated by Mr. Moore to the current number of the Zeitschrift fiir Physikalische Chemie. The method of experiment resembles that originally used by Gernez. The substance is contained in a carefully cleaned U-tube, made of thin glass,which is immersed in a bath of liquid maintained at constant temperature, and which during an observation is kept open at both ends. When crys- tallisation sets in, in such a tube, the line of demarcation be- tween solid and liquid can readily be followed by eye, and the time can easily be noted which is taken by the crystallisation to travel a definite distance down a limb of the U tube. Satis- factory observations cannot be taken when the crystallisation is rising in a limb of the tube, owing to the disturbing effects of the thermal changes attending solidification. Experiments on acetic acid showed that at any temperature the velocity is uni- form, and is independent of the diameter of the tube, and obser- vations on acetic acid, phenol, [and mixtures^of phenol with water and with cresol, show that the velocity increases with the amount of super-cooling, and at a diminishing rate. For phenol it is -6 cm. per sec. with 4° -4 super-cooling, and 2-9 cm. with 15^-8 super-cooling. The addition of water and of cresol to phenol largely reduces both the velocity of crystallisation and the rate at which it increases with the amount of super-cooling. Several of the curves indicate a maximum velocity as the extent of super-cooling increases. Attempts to observe this maximum were rendered fruitless, however, by the spontaneous crystal- lisation of the substances. Diurnal movements of the ground have been noticed at Santiago for some years, and,have usually been attributed to the December 7, 1893] NATURE 131 action of heat upon the Santa Lucia mountain. According to La Nature, the observatory has recently been removed to a plain at the south of the city, and Dr. Obrecht, the director, has investigated the movements. It appears from his observations that from noon until nine o'clock in the evening, the ground to the north- east is raised, and then gradually descends until seven o'clock on the following morning. These curious variations sometimes attain an amplitude of 3" or 4". There is also evidence that from July to September the ground to the north-east is continu- ously raised, while from September to November, the part to the east of the observatory is continuously elevated. The total amplitude of elevation is said to be about 35". Mr. a, Sigson, a professional photographer at Rybinsk, contributes an account of his method of obtaining photographs of snowflakes to the Journal of the Russian Physico-Cheniical Society. He used a Zeiss microscope provided with an aplanatic lens and a long focus camera. This was placed near an attic window at a strong inclination to the horizon. The flakes were received on some rough cloth and transferred to a small net of cocoon fibres stuck on a card perforated in the middle. This card was placed on the stage of the microscope, and the illumin- ation was so arranged that half the field was uniformly illumin- ated, and the other half shaded off. For an enlargement of fifteen times the exposure lasted two to five seconds, with plates supplied by M. Lumiere. To avoid the melting of the flakes by the breath of the operator, the latter is obliged to breathe through a pipe bent backwards during the adjustment of the apparatus. In Bulletin No. 8 of the Geological and Natural History Survey of Minnesota, Dr. Andrew C. Lawson publishes two papers of great importance for the systematic grouping of volcanic rocks in North America. The first paper is on the " Anorthosytes of the Minnesota Coast of Lake Superior," and is prefaced by a long note, written by Prof. Winchell, on "The Norian of the North-West." In this note Prof. Winchell gives up many of his previously-formed ideas regarding the Minnesota rocks, in favour of the conclusions now obtained by Dr. Lawson. There occurs on the Minnesota coasts a rock almost wholly com- posed of a plagioclase felspar which had been included by Profs. Winchell and Irving in the Keweenian or Cupriferous series of volcanic lavas and sheets. For this rock, Dr. Lawson accepts the name of " Anorthosyte," given by Prof. Adams to similar rocks in the Norian series of Quebec ; and he proves conclusively that it is a Plutonic formation, solidified under deep-seated con- ditions, and exposed later during the long period of pre-Palse- ozoic erosion. On its eroded surface the volcanic lavas of the Keweenian series were poured out, no rocks belonging to the Animikie series being present in this area. The thickness of the Keweenian series had been estimated by Prof. Irving at 20,000 feet. Dr. Lawson is of opinion that the series is comparatively thin, ranging from zero to a maximum of a few hundred feet. Special interest attaches to the hummocky — rocJies moutonees — aspect of the old surfaces of the Anorthosyte 'rock at Beaver Bay, Carlton Peak, &c., as this is such a marked feature of the ancient erosion planes of Archsean rocks in North America. Dr. Lawson compares the Anorthosytes of Minnesota with the Norian series of irruptive plagioclase rocks invading Archaean gneisses in Quebec, but until there is sufficient evidence in favour of this correlation, he suggests that a local name of " Carltonian " be given to the Minnesota Anorthosytes, The second paper in the same Bulletin, by Dr. Lawson, is entitled "The Laccolitic Sills of the North-West Coast of Lake Superior." Extensive trap-sheets are in this region associated with the Animikie and Nipigon groups of sedimentary rocks, and have up to this time been described as contemporaneous flows. Mr, Ingall had observed the intrusive nature of some of these NO. 1258, VOL. 49] so-called flows, but drew no farther conclusions. Dr. Lawsoa now advances the view that "there are no contemporaneous volcanic rocks in the Animikie group, and that the trap-sheets are all intrusive in their origin, and are of the nature of laccolitic sills. " He supports this view by weighty evidence, such as the simplicity of the trap-sheets, their regularity and' persistence over wide areas, the passage of thick sheets from the Animikie series into the higher horizons of Keweenian strata, the absence of pyroclastic rocks, the alteration of the rocks above and below the intruded sheets, and the direct con- tinuity of the "trap-sheets" with dykes of the same intrusive rock. The "trap-sheets" occur as laccolitic sills both in the Animikie and Keweenian series, and are therefore later than these. Dr. Lawson thinks they may belong to the great series of trap-rocks intruded in the Silurian rocks of Quebec, but calls them for the present " Logan Sills," in honour of the late Sir William E. Logan. It is well known that electric currents may be produced by^ heating a single metal, if there be any variation in temper, or if the distribution of heat be very irregular, and the changes of temperature abrupt. Mr. W. H. Steele has made some experi- ments on these effects, in the Physical Laboratory of Melbourne University {Science, No. 562). A sensitive galvonometer put in circuit with a piece of iron wire showed a current when the wire was simply warmed with the fingers. This was the only metal which gave a carrent when at a temperature below 100° C. Altogether twelve different metals and four alloys were examined, and the effect noticed in each of them. In order to raise the wires to a high temperature without fusing them, they were passed through clay tubes (stems of tobacco-pipes), and, in the case of metals having low melting-points, the tube was completely filled with the metal. The highest electro- motive force obtained from iron w.is 0-002 volt ; 0-3 volt was observed with six different metals— lead, copper, gold, tin, zinc, and antimony ; while with others, e.g. silver and aluminium, the effect was exceedingly small. In the case of lead, the effect showed no sign of ceasing after the metal had been heated for half a day. Gold gave the highest effect, as much as half a volt being observed. Mr. Steele remarks that these phenomena are generally quite sufficient to mask the ordi- nary thermo-electric effect at a red heat, and that thermo- electric tables are consequently not trustworthy for high temperatures. The current number of the Comptes Rendus contains a note, by M. Ch. Andre, on the variation of the electric state of the high regions of the atmosphere in fine weather. Daring a previous attempt to investigate this point, the author unfortunately met with an accident which has prevented him personally making any more observations ; the measurements contained in this note have, however, been made under his direction. At oppo- site corners of the car of the balloon were fixed two cylindrical reservoirs, filled with distilled water, and insulated on plates of sulphur. To the base of each of these vessels an india-rubber tube, about 20 metres long, was attached, each tube having a small jet at its end. When the balloon had come to rest at any desired height, the difference of potential existing between two points, at a known vertical distance, was determined by means of an electrometer (Exner's pattern) connected metallically with the water reservoir. This difference of potential, the distance being kept constant, gave a measure of the strength of the electrical field. As a result of two series of ob- servations, the author considers that in fine weather the strength of the electrical field does not increase with the altitude, but is the same at a given instant at any point along the same vertical. 1^2 NATURE [December 7, 1893 In a paper communicated to the Reale Accademia delle Scienze, Torino, Signor Garbasso gives an account of his ex- periments on the reflection of electrical waves. The author allows the waves given out by a Hertz oscillator to fall upon a mirror consisting of a wooden plank 175 cm. long and 125 cm. broad, over which were stretched a large number (168) of parallel rectilinear resonators. These resonators were with- c.''; spark-gaps, and consisted of wires 20 cm. long with metal discs, 3*8 cm. in diameter, fixed at either end. When another resonator, having a spark-gap, is placed so that the radiation reflected from this mirror falls upon it, bright sparks are pro- duced, as has been shown by Trouton and others, when its length is parallel to the wires on the reflector, while no sparks are produced when it is at right angles to these wires. What seems curious, however, is that the radiation reflected, although it has such a large wave-length compared with the dimensions of the mirror, is not scattered but is regularly reflected. In No. 5, vol. xii. of the Zeitschrift fiir Physikalische ■Chemie, Mr. Harry C. Jones gives an account of an additional series of observations on the freezing-points of dilute aqueous solutions. The most dilute solutions employed were in general about 'ooi — normal. Of the inorganic substances examined ammonia exhibited the most striking behaviour. Although the bases potash and soda like hydrochloric and nitric acid seem to be almost entirely dissociated into ions, ammonia is only dis- sociated to the extent of some twenty per cent. Phosphoric acid apparently dissociates into the two ions H and H0PO4, and in the most dilute solutions is less dissociated than sulphuric acid, which in turn is less dissociated than the monobasic acids. The extent of the dissociation thus obtained agreed, in the main, with that deduced from Kohlrausch's observations on the electric conductivity of the solutions. The organic substances examined gave quite unexpected results. Cane-sugar, dextrose, urea, phenol, and ethyl and propyl alcohols, which, according to the new theory, cannot undergo electrolytic dissociation, be- haved in all cases in the most dilute solutions as if they were really dissociated, and gave molecular lowerings of the freezing- point which were much higher than the calculated value. Indeed, if one supposes for the moment that cane-sugar can dissociate into two ions, the observations on the freezing-point of its aqueous solutions, when treated as in the case of an elec- trolyte, would indicate that twenty-seven per cent, of the sugar is dissociated, or an amount greater than that found for ammonia. With rise in concentration the molecular lowering for all the organic substances diminishes, in some cases reach- ing a minimum and then increasing, or, as in the case of urea and the two alcohols, remaining constant. This constant mini- mum value of the molecular lowering agrees closely with the theoretical number. The explanation of these remarkable re- sults from the standpoint of the new theory will be awaited with interest. The marked increase in the vitality of the cholera bacillus in artificial culture media induced by adding larger than usual pro- portions of salt to the latter, was drawn attention to in these notes on August 24, in connection with the saline condition of the river Elbe at the intake of the Hamburg water-works during the great cholera epidemic. In a subsequent note, on September 28, it was pointed out how this property of the cholera organism had been taken advantage of by Koch and others in devising methods for the separate identification of this vibrio in water in the presence of other harmless saprophytic bacteria. Of extreme interest, therefore, are the experiments of Dr. M. N. Gamaleia, contained in a short paper, "Du cholera virulent et epidemique," •contributed to the Comptes Rendus, No. 5, 1893, p. 285. This investigator states that he was able to increase the virulence of the cholera organism by cultivating it in media containing from NO. 1258, VOL. 49] 3, 4, up to 5 per cent, of common salt. Nor were these results confined to one particular cultivation of the cholera bacillus, but were also derived with cholera cultures obtained from numerous diff"erent sources. On inoculating these salt-cultures of cholera vibrios into pigeons and guinea-pigs, symptoms of septicaemia developed, invading the blood and all the tissues. If one drop of the blood of these infected animals was taken and inoculated into others, the malady was transmitted. These observations support the theory that the unusual saline condition of the Elbe may have assisted in supplying the conditions which so greatly favoured the vitality and virulence of the cholera bacillus during the Hamburg epidemic. The last two numbers of the Botanische Zeitung, published on November i, are devoted to a memoir by E. Crato, " Mor- phologische und mikrochemische Untersuchungen ueber die Physoden." This memoir is stated to be an "Arbeit " carried on under the direct guidance of Prof. Dr. Reinke, at the University of Kiel, and the following is from the summary given by the author : — There lies at the basis of the vegetable cell a system of delicate lamellae, arranged in such a way as to form a foam-like mass (Lamellensystem, Geriistsubstanz). In those plants where the point has been carefully investigated, these lamella; do not give the ordinary proteid reactions. The spaces enclosed by the lamellae contain a clear, watery, slightly re- fractive fluid (Kammerfliissigkeit), whereto belong both cell-sap as well as enchylema. In these lamellae there glide about, apparently at will, minute, refractive, bladder-like formations (physodes, to which the greater part of the microsomes belong), swelling out the lamellae where they occur. These physodes certainly form readily transportable vehicles of chemical sub- stances for the plant. In the brown Algae these physodes con- tain substances similar to phenol. In all the Algae which were investigated, the Laminaria excepted (their investigation is not complete), phloroglucin was found. Further, it would appear that these phenol-like substances are used up for the formation of the lamellar substance (plasma, &c). Major J- W, Powell's eighth annual report, as Director of the U.S. Bureau of Ethnology, is a splendid addition to ethno- logical literature. In the first part of the volume the plans and operations of the Bureau are described, a brief account being given of the many investigations carried on during the fiscal year 1886-87 by the twenty-five assistants. The contributions con- tained in the volume are : "A Study of Pueblo Architecture, Tusayan and Cibola," by Mr. Victor Mindeleff, and "Cere- monial of Hasjelti Dailjis and Mythical Sand Painting of the Navajo Indians," by Mr. James Stevenson, this being his last official work before his death in 1888, In these papers "the prehistoric archaeology of the Pueblos in the special department of architecture is the most prominent single subject presented and discussed ; but the papers also include studies of the history, mythology, and sociology of that people, as well as of their neighbours and hereditary enemies, the Navajo." All these correlated studies are set forth in detail, and, are profusely illustrated. Mr. Mindeleff^s study relates to the ruins and in- habited towns found over a large territory in the interior south- western parts of the United States. His research leads him to conclude that there is no need for the hypothesis of an extinct race with dense population and high civilisation to account for the conditions actually existing in North America before the European discovery. Mr. Stevenson's paper is most interesting, and it has the advantage of being a statement of facts actually witnessed by the deceased author. Translations of six of the Navajo myths are also presented, some of which elucidate parts of the ceremony forming the main title of his paper. The whole work has been excellently done, and our only regret is that there should have been a delay of six years in its publica- tion. December 7, 1893] NATURE During the summers of 1891 and 1892 Mr. W. P. Hay took the opportunity, while visiting the caves of Southern Indiana, to observe the habits of the bUnd crayfish, Cambariis pellucidus. In some of the caverns, as at Shiloh Cave, the crayfish were extremely abundant. When observed in an undisturbed state, they were found resting quietly in some shallowj part of the underground streams on the clay banks. They lay with all their legs extended, and their long antennae gently waving about to and fro. They were easier caught by the hand suddenly seizing them than with a net. Noise did not seem to affect them. When first taken out of the water they were of a trans- lucent pinkish white colour, with the alimentary track showing through as a blue body, but they soon lost these hues. The variation in the general spininess is very great. As a rule, the farther north the specimens were taken the smoother they were. At Mayfield's Cave, in Monroe County, a variety was found entirely without spines ; this is described and figured as a sub-species. (Proc. U.S. Nat. Museum, No. 935, 1893.) In Wundt, Philosophische Studicn, ix. Bd., I Heft., Herr Bruno Kampfe brings together all the values of the integral for the probable error, i.e. (7)= -r -P^-''^^ fj-^ J a which gives the whole number of errors, both positive and negative, whose numerical magnitude falls between the given limits. The number of errors between any two given limits will be found by taking the difference between the tabular numbers corresponding to these limits. Since the total number of errors is taken as unity in the table, the required number of errors in any particular case is to be found by multiplying the tabular numbers of the actual number'of observations. Thus, to take an example, if there were 1000 observations, and we wish to employ the limits o'o and o'5, then looking in the column giving the values of y, we find against them the numbers 0*0000 and 0'5205, which when subtracted from one another, and multiplied by 1000 give 520"5 or 520 errors. If the limits had been i'5 and 2 'o, then we should have found the corre- sponding values 0"966i and o'9953, which i subtracted give •0"0292, and multiplied by 1000 give 29, i.e. 29 errors that lie be- tween these limits out of 1000 observations. This table is published also as a separatabdruck by Wilhelm Engelmann, Leipzig, which is in a more useful form for computation. The values of 7 can be read directly to three places of decimals. We have received a report of the meteorological observations made during 1893 at the Royal Alfred Observatory, Mauritius. The new issue of Mr. Edward Stanford's compendium of geography and travel includes a revised and partly rewritten edition of " Australasia." Under this title Dr. A. R. Wal. lace's excellent description of Australia and New Zealand has been published, and a second volume, embracing Malaysia and the Pacific Archipelagoes, by Dr. F. H. H. Guillemard, is in preparation. MM. J. B. Bailliere et Fils have added to their library of contemporary science a (volume entitled " Peches et Chasses Zoologiques," by the Marquis of Folin. The book is well illustrated, and, though much of the matter it contains is only of local interest, a large portion will be read with profit by students of natural history. It is very doubtful whether any useful purpose is served by the issue, from Mr. Edward Stanford's, of the series of maps ■edited by Captain A. Staggemeier, of Copenhagen. The maps show very little except the configuration of the land surfaces, the editor's idea being that they will be of service to physical geographers for placing observed facts of natural history, NO. 1258, VOL. 49] meteorology, &c., in their proper geographical position. There are five maps in the portfolio before us, two showing the Polar regions down to 30°, and three the zone between 45° of North and South latitude, on Mercator's projection ; hence the zones between latitudes 30° and 45" are represented on both projec- tions. It is intended to issue other maps on a larger scale, the whole series to comprise twenty-five plates, which will be published in six parts. It is encouraging to learn, from the forty- first annual repor of the working of the Manchester Public Free Libraries, tha during the year 1892-93, 77,878 volumes dealing with science and art were issued from the reference library, and 67,456 were referred to in the reading-room. The total number of books issued to borrowers by the nine branch libraries was 872,655, of which 45,526 are classified under science and art. Of the 100,123 volumes consulted in the reading-rooms of the branch libraries, 7869 were on science and art subjects. The record is a good one ; but if the committee were to classify science separ- ately from art, we should be better able to estimate from the figures the growth of interest in natural knowledge. Dr. Arthur Gamgee has just completed the second volume of his text-book on the Physiological Chemistry of the Animal Body, upon which he has been engaged for some years. Like the first volume, it constitutes an independent and complete treatise, dealing with the physiological chemistry of the digestive processes. It has been the author's aim to give the reader a very full and, so far as possible, independent account of the state of knowledge on the subjects discussed. Messrs. Macmillan and Co. will publish the volume immediately. Messrs. Macmillan and Co. are also about to publish a revised and enlarged edition of " Elementary Lessons in Steam Machinery and the Marine Steam Engine," by Messrs. Lang- maid and Gaisford, Instructors on H.M. S. Britannia. It will be followed by other works constituting a Britannia Science Series. Among those already in hand may be mentioned "Physics for School Use," by Mr. F. R. Barrett, Mr. A. E, Gibson, Rev. J. C. P. Aldous, and others ; a " Physics Note- Book," by Messrs. Gibson and Aldous; "Trigonometry for Practical Men," by Mr. W. W. Lane; and "Geometrical Drawing, Perspective, and Mechanical Drawing," by Mr. J. H. Spanton. The additions to the Zoological Society's Gardens during the past week include a Mozambique Monkey {Cercopithecus pygerythrns, i ) a Sykes's Monkey {Cercopithecus albigtdaris, t, ) a Bell's Cinixys {Cinixys belliana) from East Africa, presented by Mr. T. E. C. Remington ; a Red Tiger Cat {Felis chryso- thrix) from the Gold Coast, West Africa, presented by Mr. William Adams ; a Common Otter {Liitra vulgaris) from York- shire, presented by Mr. C. B. C. de Wit ; a Herring Gull {Larus argentatus) British, presented by Mr. J. G. Goodchild ; a Northern Mocking Bird {Mitnus polyglottus) from North America, presented by Miss Dorothy Williams ; a Viperine Snake {Tropidouotus viperinus) European, presented by Miss Ffennell ; five Barbary Partridges {Caccabis petrosa) from North Africa, deposited. OUR ASTRONOMICAL COLUMN. The Variation of Latitude. — In the Astronomical yournal, No. 19 (November 14), Prof S. C. Chandler gives the eighth of the important series of articles that he has been contributing on the variation of latitude. The special part of the subject which is referred to deals with the direction of the rotation of the pole and is accompanied by an explicit demon- stration which includes all the data bearing upon it. Owing to the insufficient extent of series of observations in widely dif- ferent longitudes to furnish independent values of the constants 134 NA TURE [December 7, 1893 for both terms of the variation, Prof. Chandler has thought well to combine short series made in nearly the same longitudes, and so deduced fourteen determinations of the numerical equa- tions for the latitude variation. Reducing the values so obtained to a common epoch, he found that the values of the observed Julian date when the latitude would be a minimum, or when the pole of figure would pass the meridian of the respective stations by virtue of the fourteen months' revolution alone, and of the s 'n's longitude on the observed date when the same phase would occur by virtue of the annual term alone, both decreased from Pu!l,-owa to'vai-ds Madison showing that the direction of the rotations in both the elements was from west to east. In the latter part of the article Prof. Chandler refers not only to our knowledge of the general law of latitude variation, but to the accuracy of the necessary constants which afford us a means of predicting the immediate future course. The minimum of the curve of April, 1893, will be followed by an interval of nearly two years, and will be marked by very slight fluctuations, so that from the maximum of October, 1893, to that of August, 1895, or from minimum April, 1893, to that near the beginning of 1895, "there will apparently be but a single decidedly marked period of, say 20-22 months," the total range amount- ing to o""io as against o""56 which prevailed in 1889 and 1892. In May, 1896, the same dimensions as in 1889 will be again attained, and the variation from that time forward to 1898 it will be in full play with the range of o" 5 or o" '6, a period of nearly 390 days which prevailed between 1889 and 1892. In § 2 of the article Prof. Chandler adds a few words as to the reality of these movements of the earth's axis as against the motions being "merely misinterpretations of the observed phenomena "or an illusory effect of instrumental error due to the influence of temperature. Those of our readers who are still sceptical on the subject will learn that the observed law of latitude variation includes two terms, one with a period of fourteen months, and another with twelve months, making the phases come in very different relations to conditions of tem- perature dependent on season, an argument greatly against that brought forward by temperature- variation believers. Meteor Shower for December.— No news is yet to hand with regard to the Biela meteors, but we hope soon to receive ac- counts of the display which will give us some idea of the quantity and also of the date of reaching their maximum. The following meteor radiant-points are given by Mr. Denning for the ensuing month, that for the loth lying approximately close to p Gemini in a prolongation of yS and p Gemini, and bemg defined as a "most brilliant shower." Date. Dec. 8 Radiant. Meteors. 145 + 7 ••• Swift ; streaks 8 ... 208 -f 71 ... Rather swift 10 ... 108 + 33 ••• Swift; short 24 ... 218 + 36 ... Swift; streaks 25 ... 98 + 31 ... Very slow Refraction Tables. — We have received a small pamphlet extracted from the Mitheihingeii aus dcr Deutschen Schutz- gebieten, Bd. vi., Heft 4, containing refraction tables computed by Dr. L. Ambronn, of the Gottingen observatory. These tables are not intended for such accurate values as are required in observatories with fixed instruments, but are intended to be used by those, who having made astronomical observations, wish to compute them on the spot, using approximate formula. Travellers, especially, will find these tables very useful for wide ranges, both as regards temperature and barometer argu- ments. The tables are based on Bessel's refraction- table formula, and by slightly combining the first two terms, which is no other than the mean refraction, and eliminating the term log T by reducing the height of the barometer to o°C becomes, employing the usual notation : log refraction = log a tan c -f A log B^ -f A log 7 or refraction = 0 tan 2;; B^,A X 7'' . . . . (i) To make the correction for the mean refraction additive, the expression can be put in the form : refraction = [a tan ;. -}- o tan 2; (7^ - i) ] B/ Table II. gives the expression for the second term in the brackets using the mean refraction (o tans) and the air tem- perature (7) as arguments. For the barometer correction, if NO. 1258, VOL. 49] a tan z represent the mean refraction corrected for temperature then in equation (i) we may omit 7 and write refraction = (0 tan s) x Bq^ or, refraction (a tan r) x (otan z) [B^^ - i] The second term is taken direct from Table III. using the the mean refraction (corrected for temperature) and the height of the barometer as arguments. To obtain the true refraction then, one simply (i) finds the mean refraction for the given zenith distance ; (2) adds then the correction for temperature, and with this corrected mean refrac- tion as argument ; (3) adds the corresponding correction for the height of the barometer. Accuracy up to less than half a second of arc can be obtained. GEOGRAPHICAL NOTES. The friends of the late Emin Pasha, at the suggestion of Dr. Schweinfurth, have resolved to collect subscriptions for a memorial to com.memorate his long labours in Africa as a naturalist, traveller, and;administrator. There must be many in this country anxious to have a share in such a tribute, and we shall shortly be able to intimate where subscriptions should be sent. The present proposal is to erect a monument in the Silesian town of Neisse. By the death of Mr. A. L. Bruce, at Edinburgh last week, the cause of geography and civilisation in Africa has lost a wealthy and judicious promoter. Mr. Bruce, who married as his second wife a daughter of Dr. Livingstone, wasi a director and one of the founders of the Imperial British East Africa Company. He was a devoted friend and warm supporter of Mr. H. M. Stanley, and took a leading position in organising and supporting the Emin Relief Expedition. Mr. Bruce was the originator of the Royal Scottish Geographical Society, of which he acted as treasurer, and in the prosperity of which he took the keenest interest to the last. GuiLio Grablovitz has published as a pamphlet a paper on tidal phenomena in the Mediterranean, read at the Itaban Geo- graphical Congress, and entitled "Sulla Osservazioni Mareo- grafiche in Italia e specialmente su quelle fatte ad Ischia." The work done with recording mareographs is of considerable importance and several diagrams are given showing the tidal range and its fluctuations. The mean rise of the water was 11 centimetres at San Remo, 24 at Genoa, 12 in the North of Sardinia, from 15 to 22 along the west coast of Italy as far as Ischia, 30 in the Li pari Islands, but only from 2 to 13 round Sicily. In the Adriatic the range increased from 9 centimetres at Brindisi to 48 at Venice, which was the only station showing a range greater than one foot. The curves are recorded on a large scale, the ripples of the calm water in which the mareograph worked bearing a comparatively large ratio to the total tidal amplitude. Mont Iseran, in the eastern Alps, is, or rather was, one of the most remarkable mountains on the map of Europe, where it flourished long, although without any physical representative on the mountain-range itself. M. Henri Ferrand, in an enter- taining little b)-ochtire relates its story, showing how it had come to be an accepted belief amongst cartographers that the river Isere had its source in a Mont Iseran. The mountain was fixed in latitude, longitude, and altitude by an Italian surveyor in 1809 ; but in the fifties, when Alpine climbing became fashion- able, the discovery was made by climbers that no one in the neighbourhood could point out Mont Iseran. There was a col of that name, but no peak. An exhaustive French survey con- clusively proved that the summit so long honoured on all maps had no real existence, and M. Ferrand tells the whole amusing history remarkably well as a lesson of the value of mountain- climbing, even to scientific topography. The telegraphic cable opened last month from Zanzibar to Mauritius and Seychelles is an important link in the cable net- work which is gradually eacompassing the globe. THE ANNIVERSARY MEETING OF THE ROYAL SOCIETY. 'T'HE anniversary meeting of the Royal Society was held in the apartments of the Society at Burlington House, on St. Andrew's Day, November 30. The auditors of the December 7, 1893] NA TURE 135 treasurer's accounts having presented their report, the secretary read the list of Fellows elected and deceased since the last anniversary. The Society has lost eleven fellows on the home list, and two foreign members, as follows : — Henry Tibbats Stainton, December 2, 1892, aged 70. Sir Richard Owen, December 18, 1892, aged 89. Dr. James Jago, January 18, 1893, aged 77. . Henry Francis Blanford, January 23, 1893, aged 58. Thomas William Fletcher, February i, 1893, aged 84. Edward Walker, March 2, 1893, aged 73. Alphonse de Candolle, March 28, 1893, aged 87. Henry Edward Stanley, Earl of Derby, April 21, 1893, aged 67. Ernest Edward Kummer, May 14, 1893, aged 84. Rev. Charles Pritchard, May 28, 1893, aged 85. Dr. John Rae, July 22, 1893, aged 80. Thomas Hawksley, September 23, 1893, aged 86. Sir Andrew Clark, Bart., November 6, 1893, aged 67. The Society next proceeded to elect the officers and council for the ensuing year. A list of those selected for election was given in Nature, November 9. Lord Kelvin, the President, then delivered his address. After briefly referring to the work -of the Standing Committees, he con- tinued as follows : — Not the least important of the scientific events of the year is the publication, in the original German and in an English trans- lation by Prof. D. E. Jones, of a collection of Hertz's papers describing the researches by which he was led up to the experimental demonstration of magnetic waves. For this work the Rumfoi'd Medal of the Royal Society was delivered to Prof. Hertz three years ago by my predecessor, Sir George Stokes. To fully appreciate the book now given to the world, we must carry our minds back to the early days of the Royal Society, when Newton's ideas regarding the forces which he saw to be implied in Kepler's laws of the motions of the planets and of the moon were frequent subjects of discussion at its regular meetings, and at perhaps even more important non-official con- ferences among its Fellows. In 1684 the senior secretary of the Royal Society, Dr. Halley, went to Cambridge to consult Mr. Newton on the subject of the production of the elliptic motion of the planets by a central force,^ and on December 10 of that year he announced to the Royal Society that he "had seen Mr. Newton's book, 'De Motu Corporum.'" Some time later, Halley was requested to " remind Mr. Newton of his promise to enter an account of his discoveries in the register of the Society," with the result that the great work " Philosophias Naturalis PrincipiaMathematica" was dedicated to the Royal Society, was actually presented in manuscript, and was communicated at an ordinary meeting of the Society on April 28, 1686, by Dr. Vincent. In acknow- ledgment, it was ordered "that a Setter of thanks be written to Mr. Newton, and that the printing of his book be referred to the consideration of the council ; and that in the meantime the book be put into the hands of Mr. Halley, to make a report thereof to the council." On May 19 following, the Society resolved that "Mr. Newton's ' Philosophias Naturalis Principia Mathematica ' be printed forthwith in quarto, in a fair letter ; and that a letter be written to him to signify the Society's resolution, and to desire his opinion as to the volume, cuts, &c." An exceedingly interesting letter was accordingly written to Newton by Halley, dated London, May 22, 1686, which we find printed in full in Weld's " History of the Royal Society" (vol. i. pp. 308-309). But the council knew more than the Royal Society at large of its power to do what it wished to do. Biology was much to the front then, as now, and the publication of Willughby's book, " De Historia Piscium," had exhausted the Society's finances to such an extent that the salaries even of its officers were in arrears. Accordingly, at the council meet- ing of June 2, it was ordered that "Mr. Newton's book be printed, and that Mr. Halley undertake the business of look- ing after it, and printing it at his own charge, which he engaged to do." It seems that at that time the office of treasurer must have been in abeyance ; but with such a senior secretary as Dr. Halley there was no need for a treasurer. Halley, having accepted copies of Willughby's book, which ■"• Whewell's " History of the Inductive Sciences." vol. ii. p. 77. NO. 1258, VOL. 49] had been offered to him in lieu of payment of arrears of salary^ due to him, cheerfully undertook the printing of the " Principia " at his own expense, and entered instantly on the duty of editing it with admirable zeal and energy, involving, as it did, ex- postulations, arguments, and entreaties to Newton not to cut out large parts of the work which he wished to suppress" as being too slight and popular, and as being possibly liable to provoke questions of priority. It was well said by Rigaud, in his "Essay on the first publication of the Principia," that "under the circumstances it is hardly possible to form a sufficient estimate of the immense obligation which the world owes in this respect to Halley, without whose great zeal, able management, unwearied perseverance, scientific attainments, and disinterested generosity the 'Principia' might never have been published." ^ Those who know how much worse than " law's delays" are the troubles, care^, and labour involved in bringing through the press a book on any scientific subject at the present day will admire Halley's success in getting the " Principia" published within about a year after the task was committed to him by the Royal Society two hundred years ago. When Newton's theory of universal gravitation was thus made known to the world Descartes' Vortices, an invention supposed to be a considerable improvement on the older invention of crystal cycles and epi-cycles from which it was evolved, was generally accepted, and seems to have been re- garded as quite satisfactory by nearly all the philosophers of the day. The idea that the sun pulls Jupiter, and Jupiter pulls back against the sun with equal force, and that the sun, earth, moon, and planets all act on one another with mutual attractions, seemed to violate the supposed philosophic principle that matter cannot act where it is not. Descartes' doctrine died hard among the mathematicians and philosophers of continental Europe ; and for the first quarter of last century belief in universal gravitation was an insularity of our countrymen. Voltaire, during a visit which he made to England in 1727, wrote: "A Frenchman who arrives in London finds a great alteration in philosophy, as in other things. He left the world full ; he finds it empty. At Paris you see the universe composed of vortices of subtle matter ; at London we see nothing of the kind. With you it is the pressure of the moon which causes the tides of the sea ; in England it is the sea which gravitates towards the moon. . . . You will observe also that the sun, which in France has nothing to do with the business, here comes in for a quarter of it. Among you Cartesians all is done by impulsion : with the Newtonians it is done by an attraction of which we know the cause no better "-• Indeed, the Newtonian opinions had scarcely any disciples in France till Voltaire as- serted their claims on his return from England in 1728. Till then, as he himself says, there were not twenty Newtonians out of England.'' In the second quarter of the century sentiment and opinion in France, Germany, Switzerland, and Italy experienced a great change. " The mathematical prize questions proposed by the French Academy naturally brought the two sets of opinions into conflict." A Cartesian memoir of John Bernoulli was the one which gained the prize in 1730. It not infrequently hap- pened that the Academy, as if desirous to show its impartiality, 1 It is recorded in the Minutes of Council that the arrears of salary due to Hooke and Halley were resolved to be paid by copies of Willughby's work. Halley appears to have assented to this unusual^ proposition, but Hooke wisely " desired six months' time to consider of the acceptance of such payment." . . The publication of the "Historia Piscium," m an edition of 500 copies, cost the Society £400. It is worthy of remark, as illusirative of the small sale which scientific books met with in England at this period, that, a con- siderable time after the publication ol Willughby's work, Halley was ordered by the Council to endeavour to effect a sale of several copies with a bookseller at Amsterdam, as appears in a letter from Halley requesting Boyle, then at Rotterdam, to do all in his power to give publicity to the book. When the Society resolved on Halley's undertaking to measure a degree of the earth, it was voted that " he be given £^0 or fifty ' Books of Fishes.'" (Weld's " History of ihe Royal Society," vol. i. p. 310.) - " The third [book] I now design to suppress. Philosophy is such an impertinently litigious lady that a man had as good be engaged in lawsuits as have to do with her. I found it so formerly, and now I am no sooner come near her again but she gives me warning. The first two books with- out the third will not so well bear the title of ' Philosophia; Naturalis Prin- cipia Mathematica,' and therefore I have altered it to this, ' De Motu Corporum Libri duo' ; but, upon second thoughts, I retain the former title.^ 'Twill help the sale of the book, which I ought not to diminish now 'tis yours." {Ibid., p. 311.) 3 Ibid., p. 310. ■1 Whewell's " History of the Inductive Sciences," vol. 11. pp. 202-203. 5 Ibid., vol. ii. p. 201. 1^6 NA TURE [December 7, 1893 divided the prize between Cartesians and Newtonians. Thus, in 1734, the question being the cause of the inclination of the orbits of the planets, the prize was shared between John Ber- noulli, whose memoir was founded on the system of vortices, and his son Daniel, who was a Newtonian. The last act of homage of this kind to the Cartesian system was performed in 1740, when the prize on the question of the tides was distributed between Daniel Bernoulli, Euler, Maclaurin, and Cavallieri ; liic last of whom had tried to amend and patch up the Cartesian hjrpothesis on this subject.^ On February 4, 1 744, Daniel Bernoulli wrote as follows to Euler : " Uebrigens glaube ich, dass der Aether sowohi gravis versus solem, als die Luft versus terram sey, und kann Ihnen night bergen, dass ich iiber diese Puncte ein volliger New- tonianei bin, vnd verwundere ich mich, dass sie den Principiis Cartesianis so lang adhariren ; es mochte wohl einige Passion vielleicht mit unterlaufen. Hat Gott konnen eine animam, deren Natur uns unbegreiflich ist, erchaffen, so hat er auch konnen eine attractionem universalem materiae imprimiren, wen gleich solche attractio JM/ra fa//?onding pheno- mena manifested both in ingenious and excellent experiments devised by himself and in natural effects of lightning. Of electrical surgings or waves in a short msulated wire, and ^ " Electrostatics and Magnetism," Sir W. Thomson, Arts. I. (1842) and II. (1845), particularly § 25 of Art. II. - 1837, "Experimental Researches," 1161-1306. •> " Modern Views of Electricity," pp. 369-372. ■* "Lightning Conductors and Lightning Guards," Oliver J. Lodge. F.R.S. Whittaker and Co. NO. 1258. VOL. 49] December 7, 1893] NATURE \'\^ of interference between ordinary and reflected waves, and posi- tive electricity appearing where negative might have been ex- pected, we hear first, it seems, in Herr von Bezold's "Researches on the Electric Discharge" (1870), which Hertz gives as the third paper of his collection, with interesting and ample recog- nition of its importance in relation to his own work. In connection with the practical development of magnetic waves, you will, I am sure, be pleased if I call your attention to two papers by Prof. G. F. Fitzgerald, which I heard myself at the meeting of the British Association at Southport in 18S3. One of them is entitled "On a Method of Producing Electro- magnetic Disturbances of comparatively Short Wave-lengths." The paper itself is not long, and I shall read it to you in full, from the " Report of the British Association," 18S3 : " This is by utilising the alternating currents produced when an accumu- lator is discharged through a small resistance. It is possible to produce waves of as little as two metres wave-length, or even less." This was a brilliant and useful suggestion. Hertz, not knowing of it, used the method ; and, makingas little as possible of the "accumulator," got waves of as little as 10 cm. wave- length in many of his fundamental experiments. The title alone of Fitzgerald's other paper, "On the Energy Lost by Radiation from Alternating Currents," is in itself a valuable lesson in the electromagnetic theory of light, or the undulatory theory of magnetic disturbance. It is interesting to compare it with the title of Hertz's eleventh paper, "Electric Radiation"; but I cannot refer to this paper without expressing the admiration and delight with which I see the words " rectilinear propaga- tion," "polarisation," "reflection," "refraction," appearing in it as sub-titles. During the fifty-six years which have passed since Faraday fir^t offended physical mathematicians with his curved lines of force, many workers and many thinkers have helped to build up the nineteenth century school of pleniun ; one ether for light, heat, electricity, magnetism ; and the German and English volumes containing Hertz's electrical papers, given to the world in the last decade of the century, will be a permanent monument of the splendid consummation now realised. But, splendid as this consummation is, we must not fold our hands and think or say there are no more worlds to conquer for electrical science. We do know something now of magnetic waves. We know that they exist in nature, and that they are in perfect accord with Maxwell's beautiful theory. But this theory teaches us nothing of the actual motions of matter con- stituting a magnetic wave. Some definite motion of matter perpendicular to the lines of alternating magnetic force in the waves and to the direction of propagation of the action through space, there must be ; and it seems almost satisfactory as a hypothesis to suppose that it is chiefly a motion of ether with a comparatively small but not inconsiderable loading by fringes ot ponderable molecules carried with it. This makes Maxwell's " electric displacement " simply a to-and-fro motion of ether across the line of propagation, that is to say, precisely the vibra- tions in the undulatory theory of light according to Fresnel. But we have as yet absolutely no guidance towards any under- standing or imagining of the relation between this simple and definite alternating motion, or any other motion or displace- ment of the ether, and the earliest known phenomena of electricity and magnetism — the electrification of matter, and the attractions and repulsions of electrified bodies ; the permanent magnetism of lodestone or steel, and the attractions and repul- sions due to it ; and certainly we are quite as far from the clue to explaining, by ether or otherwise, the enormously greater forces of attraction and repulsion now so well known aftec the modern discovery of electromagnetism. Fifty years ago it became strongly impressed on my mind that the difference of quality between vitreous and resinous electricity, conventionally called positive and negative, essentially ignored as it is in the mathematical theories of electricity and magnetism with which I was then much occupied (and in the whole science of magnetic waves as we have it now), must be studied if we are to learn anything of the nature of electricity and its place among the properties of matter. This distinction, essential and fundamental as it is in frictional electricity, electro- chemistry, thermo-electricity, pyro-electricity of crystals, and piezo-electricity of crystals, had been long olDserved in the old known beautiful appearances of electric glow and brushes and sparks from points and corners on the conductors of ordinary electric machines and in exhaustive receivers of air-pumps with electricity passed through them. It was also known, probably as many as fifty years ago, in the vast difference of behaviour of ' the positive and negative electrodes of the electric arc lamp. : Faraday gave great attention to it ' in experiments and observa- ■ tions regarding electric sparks, glows, and brushes, and parti- I cularly in his "dark discharge" and "dark space" in the 1 neighbourhood of the negative electrode in partial vacuum. In [1523] of his I2th series, he says, "The results connected with the different conditions of positive and negative discharge will have a far greater influence on the philosophy of electrical science than we at present imagine." His " dark discharge " ([1544-1554]) through space around or in front of the negative electrode was a first instalment of modern knowledge in that splendid field of experimental research which, fifteen years later, and up to the present time, has been so fruitfully cultivated by many of the able scientific experimenters of all countries. i The Royal Society's Transactions and Proceedings of the last years contain, in the communications of Gassiot,- Andrews and \ Tait,'^ Cromwell Varley,'* De La Rue and Miiller,'' Spottis- woode,'' Moultan," Plucker,'^ Crookes," Grove, ^"^ Robinson, ^^ Schuster,^- J. J. Thomson, i'* and Fleming,^"* almost a complete history of the new province of electrical science which has grown up largely in virtue of the great modern improvements in practical methods for exhausting air from glass vessels, by> which I we now have " vacuum tubes " and bulbs containing less than 1/190,000 of the air which would be left in them by all that could ^ be done in the way of exhausting (supposed to be down to i mm. of mercury) by the best air-pump of fifty years ago. A large part of the fresh discoveries in this province have been made by the authors of these communications, and their references to the discoveries of other workers very nearly com- plete the history of all that has been done in the way of investi- gating the transmission of electricity through highly rarefied air I and gases since the time of Faraday. Varley's short paper of 1871, which, strange to say, has lain almost or quite unperceived in the Proceedings during the twenty- two years since its publication, contains an admirable first in- stalment of discovery in a new field— the molecular torrent from the "negative pole," the control of its course by a magnet, its pressure against either end of a pivoted vane of mica according as it is directed by a magnet to one end or the other, the shadow ; produced by its interception by a mica screen. Quite indepen- dently of Varley, and not knowing what he had done, Crookes ! was led to the same primary discovery, not by accident, and not merely by experimental skill and acuceness of observation. He was led to it by carefully designed investigation, starting with an \ examination of the cause of irregularities which had troubled '" \ him in his weighing of thallium ; and, going on to trials for im- proving Cavendish's gravitational measurement, in the course of I which he discovered that the seeming attraction by heat is only ■ found in air of greater than i/iooo^'' of ordinary density ; and that there is repulsion increasing to a maximum when the density is decreased from i/iooo to 36/1,000,000, and thence diminish- ing towards zero as the rarefaction is farther extended to density 1/20,000,000. From this discovery Crookes came to his radio- meter, fir>t without and then with electrification, powerfully aided by Sir George Stokes.'" As he went on he brought all his work more and more into touch with the kinetic theory of gases ; I so much so that when he discovered the molecular torrent he I "Experimental Researches," Series 12 and 13, Jan. and Feb. 1838. - Roy. Soc. Proc, vol. 10, i860, pp. 36, 269, 274, 432. •' Roy. Soc. Proc, vol. 10, i860, p. 274 ; Phil. Trans. I ^ Roy. Soc. Proc, vol. ig. 1S71, p. 236 5 Roy. Soc. Proc, vol. 23. 1875, p. 356 ; vol. 26. 1877, p. S19 I '^'ol. 27, I 1878, p. 374 ; vjl. 29, 1879, p. 2S1 ; vol. 35, 1883. p. 202 ; vol. 36, 1884, pp. 151, 206 ; Phil. Trans., 1S78. pp. 55, 155 ; 1880. p. 65 ; 1883, 477. •> Roy. Soc. Proc, vol. 23, 1875, pp. 356. 455 ; vol. 25, 1875, pp. 73, 347 ; vol. 26, 1877, pp. 90, 323; vol. 27, 1878, p. 60; vol. 29, 1879, p. 21 ; vol. 30, 1880, p. 302 ; vol. 32, 1881, pp. 385, 388; vol. 33, 1882, p. 423 ; Phil. Trans., 1878, pp. 163, 2IO ; 1879, 165 ; 1880, p. 561. 7 Roy. Soc. Proc, vol. 29, 1879, p. 21 : vol. 30, 1880, p. 302; vol. 32, 1881, pp. 385, 388 ; vol. 33, 1882, p. 453; Phil. Trans., 1879, p. 165, 1880, p. 561. 8 Rcjy. Soc. Proc, vol 10, i8bo, p. 256. y Roy. Soc. Pioc, vol. 2i, 1879, pp. 347, 477 ; Phil. Trans., 1S70, p. 641 ; 1880, p. 135 : 1881, 387. 1" Roy. Soc. Proc, vol. 28, 1878, p. 181. II Roy. Soc. Proc, vol. 12, 1862, p. 202. 12 Roy. boc. Proc, v^l. 37, 1884, pp. 78, 317 ; vol. 42, 18S7, p. 371 ; vol. 47, 1S90 ; pp. 300, 506. 1-J Roy. S iC Proc, vol. 42, 18S7, p. 343 ; vol. 49, 1891, p. 84. l-* Roy. So;. Proc, vol. 47, 1890, p. 118. l-J Tribulation, not undisturbed progress, gives life and soul, and leads 10 success when success can be reached, in the struggle for natural knowledge. I'' Crookes. "On the Viscosity of Gases at High Exhaustions," § 655, Phil. Trans., February, i88r, p. 403. 1" Phil. Trans., vol. 172 ti88i). PP- 387, 435- NO. 1258, VOL. 49] i;8 NATURE [December 7, 189; immediately gave it its true explanation — molecules of residual air, or gas, or vapour projected at great velocities ^ by electric repulsion from the negative electrode. This explanation has been repeatedly and strenuously attacked by many other able in- vestigators, but Crookes has defended - it, and thoroughly established it by what I believe is irrefragable evidence of ex- periment. Skilful investigation perseveringly continued brought out more and more of wonderful and valuable results : the non- importance of the position of the positive electrode; the pro- jection of the torrent perpendicularly from the surface of the negative electrode ; its convergence to a focus and divergence thenceforward when the surface is slightly [convex ; the slight but perceptible repulsion betweed two parallel torrents due, according to Crookes, to negative electrifications of their con- stituent molecules ; the change of direction of the molecular torrent by a neighbouring magnet ; the tremendous heating effect of the torrent from a concave electrode when glass, metal, or any ponderable substance is placed in the focus ; the phosphorescence produced on a plate coated with sensitive paint by a molecular torrent skirting along it ; the brilliant colours — turquoise-blue, emerald, orange, ruby-red — with which grey colourless objects and clear colourless crystals glow on their struck faces when lying separately or piled up in a heap in the course of a molecular torrent ; " electrical evapor- ation ■"' of negatively electrified liquids and solids ; '* the seem- ingly red-hot glow, but with no heat conducted inwards from the surface, of cool, solid silver kept negatively electrified in a vacuum of 1/1,000,000 of an atmosphere, and thereby caused to rapidly evaporate. This last mentioned result is almost more surprising than the phosphorescent glow excited by molecular impacts in bodies not rendered perceptibly phos- phorescent by light. Both phenomena will surely be found very telling in respect to the molecular constitution of matter and the origination of thermal radiation, whether visible as light or not. In the whole train of Crookes' investigations on the radiometer, the viscosity of gases at high exhaustions, and the electric phenomena of high vacuums, ether seems to have nothing to do except the humble function of showing to our eyes something of what the atoms and molecules are doing. The same confession of ignorance must be made with reference to the subject dealt with in the important researches of Schuster and J. J. Thomson on the passage of electricity through gases. Even in Thomson's beautiful experiments showing currents produced by circuital electromagnetic induction in complete poleless circuits, the presence of molecules of residual gas or vapour seems to be (he essential. It seems certainly true that without the molecules there could be no current, and that without the molecules elec- tricity has no meaning. But in obedience to logic I must with- draw one expression I have used. We must not imagine that "presence of molecules \s Ihe essential." It is certainly an essential. Ether also is certainly an essential, and certainly has more to do than merely to telegraph to our eyes to tell us of what the molecules and atoms are about. If a first step towards understanding the relations between ether and ponderable matter is to be made, it seems to me that the most hopeful foundation for it is knowledge derived from experiment on electricity in high vacuum ; and if, as I believe is true, there is good reason for hoping to see this step made, we owe a debt of gratitude to the able and persevering workers of the last forty years who have given us the knowledge we have : and we may hope for more and more from some of themselves and from others encouraged by the fruitfulness of their labours to per- severe in the work. The President then presented the medals awarded by the Society as follows : — The Copley Medal to Sir George Gabriel Stokes, Bart., F. R. S., for his researches and discoveries in physical science; a Royal Medal to Prof. A. Schuster, F. R. S. , for his spectroscopic inquiries, and his researches on disruptive discharge through gases and on terrestrial magnetism ; a Royal Medal to Prof. H. Marshall Ward, F. R.S., for his researches into the life-history of fungi and schizomycetes ; and the Davy Medal to Prof. J. H. van't Hoffand Dr. J. A. Le Bel, in recog- nition of their introduction of the theory of asymmetric carbon, and its use in explaining the constitution of optically active carbon compounds. In the evening the Fellows and their friends dined together at the Whitehall Rooms, Hotel Metropole. 1 Probably, I believe, not greater in any case than two or three kilometres per second. - Address to the Institute of Telegraphic Engineers, 189. •• Roy. Soc. Proc. , June 11, 1S91. 7-HE TEMPERATURE OF IGNITION OF EXPLOSIVE GASEOUS MIX7URES. A N important contribution to our knowledge of this subject is communicated to Xhe. Berichte by Prof Victor Meyer of Heidelberg, in conjunction with his assistant, Herr A. Miinch. The interesting experiments which were carried out some eight- een months ago in the Heidelberg laboratory, concerning the conditions under which the explosion or silent combination of gaseous mixtures occurs, left the question of the precise tempera- tures of explosive combination undetermined, inasmuch as the necessary high temperatures were attained by the use of boiling salts whose temperatures of ebullition lay a considerable number of degrees apart. The researches have since been continued under conditions in which it has been found possible to deter- mine the actual temperatures with precision. In these experi- ments any possibility of the occurrence of appreciable amounts of silent combination has been avoided, in order that the deter- minations of the temperature of explosive combination might be unaffected by errors due to that cause. The conspicuous novelty of the method adopted consists in placing the small bulb contain- ing the mixture to be exploded inside the larger bulb of the air thermometer employed to determine the temperature, thus at once ensuringthattheexplosion bulb and the thermometer bulb shall be heated to precisely the same temperature. The objection which at first suggests itself, that the heat suddenly developed at the moment of explosion might exert a disturbing influence upon the indications of the air thermometer, was proved,by direct and repeated experiment to be without validity, such disturbance being found to be too small to be measured. The bulb in which the explosion is brought about is not closed, for the explosion of such detonating mixtures of gases at rest, that is to .'^ay, confined tea closed space, is so violent that if the glass escapes pulverisation it is much distorted, owing to the temperature to which it requires to be heated being about its softening point. The distortion usually takes the form of a shrinking from two opposite points, where the glass is drawn in and distended to such an extent as to produce two internal spheres. Such deformation would of course alter considerably the volume of the air thermometer. This is avoided by attaching a long stem to the bulb, open at the free extremity, and of passing a slow current of the gaseous mixture through the apparatus. The bulb of the thermometer was heated by means of a bath of a fused alloy consisting of equal parts of tin and lead, and it was found immaterial whether the thermometer was directly immersed in the molten metal or protected by means of a closely-fitting refractory metal sheath. The estimation of the temperature was effected by displacing the air of the thermometer, whose volume was known, by means of a current of hydrochloric acid gas, and measuring its volume over distilled water which had recently been freed from air by boiling. The first series of experiments were made with the detonating electrolytic mixture of hydrogen and oxygen. The gases were freed from ozone by passage through a solution of potassium iodide. They were then washed through water, with which a Woulfe's bottle was almost filled, after which they traversed a tube packed with numerous discs of brass gauze, which were found effectual in preventing the explosion from travelling back to the Woulfe's bottle. The mixed gases were then allowed to enter the explosion bulb by means of a capillary tube passing down the stem to the bottom of the bulb. The rapidity of the gaseous stream was found to exert no influence upon the tem- perature of explosion, within the limits imposed by the mode of experimenting. The bath was then gradually raised to the neighbourhood of the combining temperature, and the instant the explosion ensued the air contained in the thermometer was displaced by hydrogen chloride, collected over water in the measuring vessel, and its volume ascertained on the attainment of atmospheric temperature and pressure. By displacing the air the instant the detonation was heard, any appreciable augmentation of the temperature during the moment of explosion was prevented. As the result of several series of experiments carried out with four distinct sets of apparatus, the temperature of explosion of electrolytic hydrogen and oxygen is found to vary from 612° to 686°. It would thus appear, conformable with the supposition of Prof. Van t'Hoff from theoretical considerations, that this mixture is incapable of exhibiting a sharply fixed temperature of explosion. Moreover, it makes no difference whether the mixture is dry or moist ; for if dried a small amount of silent NO. 1258, VOL. 4q] December 7, 1893] NA TURE ^39 combination invariably renders it again moist before explosion occurs. It has been currently supposed that I he presence of sharp solid fragments, such as those of glass, exerts a lowering effect upon the temperature of explosion of hydrogen and oxygen. This supposition has been practically tested and found wanting in accuracy. Neither glass fragments nor sea-sand were found to reduce the temperature below the limits abovestated. A remark- able result, however, was obtained when pieces of platinum foil and wire were introduced into the explosion bulb. It was found impossible in their presence to bring about an explosion, even when the temperature of the bath was raised to 715°. Quiet combination invaiiably ensued. The size of the explosion vessel appears to be immaterial, except when reduced to very small dimensions, such as 4'5 mm. diameter, as in the case of the smallest bulb tested, when the range of molecular forces is approached. In six experiments with this small bulb no explosion occurred ; in others the explosion did not occur in the vessel, but the quiet combustion there initiated was transmitted along the leading tube, through the tube containing the brass gauze discs, and eventually occasiored an explosion in the wash-bottle, disastrous to the latter. In the cases of other explosive mixtures the admixture was effected, in the proper proportion, in a three litre flask, from which the gases were driven first through a wash-bottle, and subsequently through a test-tube, arranged likewise as a small safety wash-bottle, to prevent the explosion reaching the larger one. Carbon monoxide and oxygen, in the proportion to form carbon dioxide, were found to suffer, for the most part, silent combination in the apparatus, and the wide limits of the observed temperatures of explosion, 636" to 814°, in those cases when explosion did ensue, were found to be due to more or less of such silent combination. Gaseous mixtures of hydrocarbons and oxygen were found, however, with the exception perhaps of marsh gas and oxygen, to exhibit practically no quiet combination ; and these mixtures have afforded most trustworthy and constant temperatures of explosion. Mar.-h gas was found to explode, as a rule, with oxygen at temperatures varying from 656° to 678^, but occasionally quiet and complete combustion occurred. Other hydrocarbons never failed to yield an explosion. Ethane detonated with oxygen in three experiments at 622', 605°, and 622° respectively. A mixture of ethylene and oxygen exploded at 577°, 590°, and 577^ in three consecutive experi- ments. Acetylene prepared by Gatiermann's method, which in Prof. Meyer's experience yields it in a purer state than the more recent convenient method discovered by Maquenne, ex- plodes with oxygen with exceptional violence, the wash-bottle being destroyed in every experiment. The temperature of this explosion was very constant, 510°, 515°, and 509" being suc- cessively observed. Propane mixed with five times its volume of oxygen likewise exhibits a very constant temperature of ignition, 548°, 545°, and 548° being indicated in three deter- minations. Propylene exploded with four and a half times its volume of oxygen at 497°, 511°, and 499°. Isobufane mixed with six and a half times its volume of oxygen detonated at 549°, 550°, and 545° ; and isobutylene at 546°, 548°, and 537'. Finally, coal gas mixed with thrice its volume of oxygen was found to explode in three experiments at the remarkably con- stant temperatures of 649", 647°, and 647°. It was found im- possible, however, to induce a mixture of coal gas and air to explode under these experimental conditions. It will be clearly seen from the above experiments with gaseous mixtures of hydrocarbon and oxygen, that the tempera- ture of explosion falls as the content of carbon increases. Thus the mean temperatures for methane, ethane and propane are 667°, 616", and 547' respectively. Further, the temperature also falls with the degree of saturation, or in other words, the less saturated the hydrocarbons become the more readily do they ignite in contact with oxygen. Thus ethane, ethylene and acetylene explode wi!h oxygen at 616^, 580' and 511°; propane and propylene at 547° and 504° ; and isobutane and isobutylene at 548° and 543°. It will also be observed, liowever, as would be expected, that these differences due to difference of saturation diminish as the series are ascended. A, E. TUTTON. NO. T258, VOL. 49] UNIVERSITY AND EDUCATIONAL INTELLIGENCE. Cambridge. — Mr. Austen Leigh, Provost of King's, the Vice-Chancellor, has been appointed a member of the Geo- graphical Committee, in the place of Dr. Ferrers, resigned. The award of the Geographical Studentship of ^loo will be made towards the end of the Lent Term. The first award of the Walsingham Medal, founded by the Lord High Steward for the encouragement of biological research, has been made to Mr. E. W. MacBride, Fellow of St. John's, for his monographs in zoology. Mr. Arthur Wilt.ey, at present giving a course of lectures in Columbia College, New York, has been elected to the vacant Balfour Studentship by the Special Board of Biological and Geological Studies of the University of Cambridge. It is under- stood that the investigation prescribed for him will be that of the embryology of Nautilus poinpilius, for which purpose he will proceed to the South Seas. SCIENTIFIC SERIALS. The Quarterly yoiirnal of Microscopical Science for September, 1893, contains studies on the comparative anatomy of sponges : V. Observations on the structure and classification of the Cal- carea Heterocccla, by Dr. Arthur Dendy (plates IO-14). In this paper the author gives a general account of the anatomy, histology, and classification of the Calcarea Heterocwla, from the point of view of one who has for a long time past been engaged in an independent study of the group, and he brings together all that is known on the subject. While on the classification of the group he departs somewhat widely from the lines laid down by pre- vious writers, yet the necessity of doing so was forced upon him by a study of nearly fifty Australian species. The author finds neither the canal system nor the skeleton affords a reliable guide for classification, and a compromise is the only satisfactory way out of the difficulty. The families adopted are : (i) Leucasidse, (2) Sycettidse, (3) Grantid?e, (4) Heteropidte, (5) Amphoriscidae. — On some points in the origin of the reproductive elements in Apus and Branchipus, by J. E. S. Moore (plates 15 and 16). Calls attention to some important details in the spermatoge- nesis of Branchipus and in the ovigenesis in Apus. In the former, the observations bear out the general law as to the similarity of the male and female cells, their specific peculiarities being ])hy- siological in origin, without morphological import. The divi- sional phenomena of these cells are intimately related to a protoplasmic structure, which might be fitly described as " Schaumplasma," and one of the initial impulses towards metamorphosis is a fusion of some of the intra-nuclear globules ; while a considerable portion of the complicated karyokinetic figures, with their centrosomes, pseudosomes, and dictyosomes, appear to be the logical as well as the actual consequence of the continuance of this process. Some time before and always during the course of the chromatic changes bodies answering to the centrosomes in all details except in their numbers, which is much greater, make their appearance ; these the author provi- sionally names " pseudosomes." The term "dictyosomes" is given to bodies which make their appearance connected one to another and to the inner group of chromosomes by fine strands, and which remain uncoloured by reagents, and are more or less related to the cell periphery. (In connection with these, Farmer's notes and figures of like bodies in the Pollen mother-cells is of interest. (See Ann. of Bot. September, 1893).— Notes on the Peripatus of Dominica, by E. C. Pollard (plate 17). Miss Pollard's species is apparently very nearly related to P. echvardsii, but differs in the number of ambulatory appendages, there being 29 to 34 pairs in P. edwardsii, while in P. dominicir, sp. nov. , there are from 25 to 30. — Studies on the Protochordata, by Arthur Wiley, B.Sc. (plaies 18-20). II. The development of the neuro-hypophysial system in Ciona intestinalis and Clave- Una lepadijormis, with an account of the origin of the sense- organs in Ascidia meiitula. III. On the position of the mouth in the larvae of the Ascidians and Amphioxus, and its rela- tions to the Neuroporus. Symons's Monthly Meteorological Magazine, November. Mr. Symons gives a summary of all the rainfall observations known to have been taken in Persia ; the only places at which such appear to have been made are Ooromiah, in the north- I40 NATURE [December 7, 1893 west ; Bushire, on the eastern shore of the Persian Gulf, and at Teheran. At Bushire the annual mean for 1878-90 is I2'96 inches. Recent observations at Teheran give a mean of about 10 inches, and the older observations, taken at the Russian Em- bassy, give a mean of about li inches, of which nearly the whole falls in the winter half of the year. To the north of the great mountain range, between Teheran and the Caspian, the fall is nearly four times as great as in Persia. The same number of the magazine contains a summary of the few meteoro- iojical papers read at the British Association at Nottingham. SOCIETIES AND ACADEMIES. London. Royal Society, November 16. — "Experiments in Heliotro- pism. " By G. J. Romanes, F. R. S. I cannot find in the literature of heliotropism that any experi- ments have hitherto been made on the effects of interrupted illumination, when the periods of illumination are rendered as brief as possible — i.e., instantaneous flashes of light. Accordingly I have conducted an extensive research on heliotropism, where the flashes have been caused either by means of electric sparks in a dark room, or by the opening of a photographic shutter placed before the plants in a camera obscura with an arc light or Swan burner, at a distance of several feet on the other side of the shutter. The electric sparks were made either with a Wimshurst machine, induction sparks, or by means of the loUowing contrivance. Fr .m the binding screws of the condenser of a large induction coil copper \a ires were led to a cup of mercury, where, by means of an electro-magnet suitably actuated by clockwork, a current was closed and opened at any desired intervals : each break was there- fore accompanied by a brilliant spark. A thick plate of glass was interposed between the seedlings and the electrical apparatus. In all the experiments here described the plants employed were mus- tard seedlings {Sinapis nigra), previously grown in the dark until they had reached a height of between one and two inches. Save when the contrary is stated, in all the experiments comparative estimates were formed by using the same pot of seedlings : during the first half of a comparative experiment half of the seedlings were protected from the light by a cap of cardboard covering half the pot ; during the second half of the experiment this cap was removed, and the pot turned round so as to expose the previously protected seedlings to the influence of the light. The principal results thus obtamed, and frequently corroborated, were as follows : — I. Even having regard to the fact that for equal strengths of a stimulus excitable tissues are more responsive in proportion to the suddenness of the stimulus (or in a kind of inverse proportion to the duration of the stimulus), the heliotropic effects of such flashing stimulation as is above described proved to be much greater than might have been antecedently expected. This was shown to be the case whether the effects were estimated by the rapidity with which the seedlings began to bend after the flashing stimulation was begun, or by that with which they continued to bend until attaining a horizontal line of giowth, i.e. bending to a right angle. 'I'hus, at a temperature ol 70° Fahr., and in a moist camera, vigorously growing seedlings begin to bend towards the electric sparks ten minutes after ihe latter begin to pass, and will bend through 45° in as many minutes ; frequently they bend through another 45" in as many minutes more. This is a more rapid rate of bending than can be produced in the same pot of seedlings when the previously protected side is uncovered and exposed lor similar durations of time, either to constant sunlight or to constant diffused daylight. This is the case even if the sparks (or flashes) succeed one another at intervals of only two seconds. II. It would thus appear that the heliotropic influence of electric sparks (or flashes) is greater than can be produced by any other source of illumination. But in order to test this point more conclusively, 1 tried the experiment of exposing one half-pot of seedlings in one camera to the constant light of a Swan burner, and another half-pot of similar seedlings in another camera, placed at the same distance from the same source of light, but provided with a flash shutter working at the rate of two seconds intervals. The amount of bending in similar times having been noted, the pots were then exchanged raid their previously protected halves exposed to the constant and the flashing light respectively. In both cases, the rapidity NO. 1 258. VOL. 49] with which the bending commenced and the extent to which it proceeded in a given time after commencement, were consider- ably greater in the seedlings exposed to the flashing than to the constant source stimulation. I'he same is true if, instead of a Swan burner, the source of light is the sun. III. Many experiments were tried in order to ascertain the smallest number of sparks in a given time which would produce any perceptible bending. Of course the results of such experi- ments varied to some extent with the condition of the seedlings. But in most cases, with vigorous young mustard seedlings and careful observation, bending could be proved to occur within fifteen to thirty minutes, if bright sparks were supplied at the rate of only one per minute. The most extreme sensitiveness that I have observed in these experiments was that of percep- tible bending after half-an-hour's exposure to electrical sparks following one another at the rate of fifty in an hour. This result would appear to indicate that in heliotropism under flash- ing light there need be no summation or "staircase effect"; but that each flash or spark may produce its own effect inde- pendently of its predecessors or successors. IV. It is noteworthy that, while the heliotropic effects of flashing light are thus so remarkable, they are unattended with the formation of any particle of chlorophyll. In the many hundred pots, and iheiefore many thousands of plants, which have passed under my observation in this research I have never seen the slightest shade of green tingeing the etiolated seedlings which had bent towards flashing light. On one occasion I kept a stream of 100 sparks per second illuminating some mustard seedlings continuously for forty-eight hours ; and although this experiment was made for the express purpose of ascertaining whether any chlorophyll would be formed under the most suit- able conditions by means of flashing light, no change of colour in any of the .'eedlings was produced. With the exception of tho.'c mentioned in the last paragraph, all these results were obtained by using sparks from the coil condenser, as above explained. These sparks were very brilliant, and yielded the maximal results, which alone are here recorded. " Experiments in Germination." By G. J. Romanes, F.R.S. The primary object of these experiments was to ascertain whether the power of germination continues in dry seeds after the greatest possible precautions have been taken to prevent any ordinary processes of respiration for practically any length ol time. The method adopted was to seal various kinds of seeds in vacuum tubes of high exhaustion, and after they had been ex- posed to the vacuum for a period of .ifteen months to remove ihem from the tubes and sow them in flower-pots buried in moist soil. In other cases, after the seeds had been in vacuo for a period of three months, they were transferred to sundry other tubes respectively charged with atmospheres of sundry pure gases or vapours (at the pressure of the air at time of seal- ing) ; after a further period of twelve months these sundry tubes were broken, and their contents sown as in previous case. In all cases, excepting that of clover, the seeds sown were weighed individually in chemical balances, and seeds of similar weights taken from the same original packets were similarly sown as controls. The exhaustion of the tubes was kindly undertaken by Mr. Crookes, F. R. S., to whom I must express my best thanks for the assistance he has given. The kinds of seeds used were mustard, red beet, clover, peas, beans, spinach, cress, barley, and radish. In addition to vacuum tubes and control tubes con- taining air, others were charged with oxygen, hydrogen, nitro- gen, carbon monoxide, sulphuretted hydrogen, aqueous vapour, ether, and chloroform. With the exception of the beans, where only two were sown, ten weighed seeds were sown out of each of the tubes, and also out of each of the control packets which had been kept in ordinary air from the first. These results amply prove that neither a vacuum of one-millionth of an atmosphere, nor the atmospheres of any of the gases and vapours named, exercised much, if any, effect on the germinating power of any of these seeds. I may add that the same remark applies to an atmosphere of carbon dioxide, although in the particular series of experiments quoted this gas was accidentally omitted. A subsidiary object ol these experiments was to ascertain whether any appreciable variations would be caused in plants giown from seeds which, before germination, had been sub- mitted to the conditions above explained. Hundreds of plants December 7, 1893] NATURE 141 of the kinds named were grown from the seeds in the various tubes. But in no one instance was there the smallest deviation in any respect from the standard type grown from the corre- sponding control packet. In the case of the beet-root, a larger number of plants were developed in many of the pots than the ten seeds which had been sown in each. This I found to be due to the fact that beet-root seeds very frequently throw up two seedlings apiece. Not so frequently, but still very often, they yield three, and sometimes even four. Further experiments are in progress. " On hepatic glycogenesis," by Dr. Noel Paton, Superinten- dent, Research Laboratory of the Royal College of Physicians of Edinburgh. The object of the research is to determine the mode of con- version of glycogen to sugar in the liver. Is it due to a zymin, or to the metabolism of the liver protoplasm ? A study of the rate of conversion of glycogen in the excised liver at the body temperature shows that there is an initial rapid and a subsequent slow stage in the process. The former occurs before visible morphological changes can be detected in the cells ; the latter goes on after the cells are disorganised. The former is inhibited by destroying the cells (by pounding with sand), and by the presence of one per cent, of fluoride of sodium ; the latter is not stopped thereby. The product of the former is glucose ; of the latter, glucose with dextrin and, possibly, maltose. Agents, such as chloroform, ether, and pyrogallic acid, hasten the disintegrative changes in the cells, and accelerate the early rapid stage of conversion, but do not influence the later slower stage. During life the firsi may produce glyceemia by this action on glycogen conversion. They seem to act by hastening the katabolic changes immediately preceding cellular death. Drugs, such as curare, morphin, and nitrite of amyl, which cause glycsemia, do not do so by increasing the conversion of glycogen ; they do not accelerate the morphological changes in the cells. These observations show that the early rapid changes are due to the metabolism of the protoplasm. The later slower changes are not due to the acid which develops, nor are they, to any marked extent, due to the action of micro-orga^iism ; they seem to be brought about by a zymin developed as a result of the disintegration of the cells. November 23. — "Magnetic Observations in Senegambia." By T. E. Thorpe, F.R.S., and P. L. Gray. On the occasion of the recent Eclipse Expedition to Se »e- gambia we took with us a set of magnetic instruments of the Kew pattern, with a view of making observations in a district for which the magne ic elements have not hitherto been deter- mined. Observationsweremadeat Fundium, Senegal, and atBathurst, on the River Gambia. The results are as follows :— Fundium, Senegal, lat. 14° 7'"4 N., long. 16° 32' W. (approx.). The observations were made on April 4, 5, and 14, 1893, in the vicinity of the Eclipse Camp and on a partially enclosed piece of ground between the Administrator's house and the River Salum, about 80 yards from the shore. The temperature during the force observations was about 30° C. The results are as follows : — Declination ... ... = 18° 44' W. Horizontal force ... ... = o '30409 c.g.s. Dip = Needle i, 29° 9''i = ., 2, 29''8'-2 Bathurst, River Gambia, lat. 13° 28' N., long. 16° 37' W. The station was on a large piece of open ground and near the centre of McCarthy Square. All the observations taken were made on April 20, 1893. Declination ... ... = 18" 50' W. Horizontal force ... ... = 0*30514 c.g.s. Dip = Needle I, 28° 43'-4. ,, ... ... ... = ,, 2, 28° 42'"I. Physical Society, November 24. — Prof. A. W. Riicker, F.R. S., President, in the chair. — Colonel Maitland, C.B., was elected a member of the Society. Prof. S. P. Thomp- son then occupied the chair whilst the President read a paper on the magnetic shielding of concentric spherical shells. In this mathematical investigation the author considers cases in which the equipotential surfaces are surfaces of revolu- tion about a line through the centre of the shells, and the per- NO. T258, VOL. 49] meability (/u) of each shell is constant. Taking the common centre as origin, the potential within any shell is expanded in terms of zonal spherical harmonics, and the ratio of the shielded to the unshielded field determined. The following important result is arrived at, viz. if the permeabilities of the enclosed and external space be the same, then the ratios of the shielded to the unshielded fields are the %'i.'me. for each harmonic term, whether the part shielded be external or internal. It is also shown that the shielding effect on external space when a small magnet is placed at the centre of the shell is the same as the shielding effect on the enclosed space when the shells are placed in a uniform magnetic field. The case of a single shell with a small magnet at the centre is next considered where the permeabili- ties of the internal and external spaces are taken as unity. Here the shielding depends on the ratio of the outer to the inner radius (flj/afl). When the thickness of the shell is i/ioo of a^ the ratio of shielded to unshielded field (^/i^,,) 's 3/13 when fji = 500, and 3/23 when yu = 1000. For fi = 1000, in- creasing the thickness from a i/io to a 1/2 changes the shielding from 1/60 to 1/194, thus showing that after the shell is moderately thick, further increasing the thickness is not very effective. When the small magnet is displaced from the centre of the shell with its axis along a radius, then the shielding effect of the shell is greater on the side towards which the magnet is moved, and less on the opposite side. Thickening a single shell being inefficient, the effect of using two or three shells separ- ated by air-gaps is investigated. Here, as in the case of a single shell, the shielding is improved by adding permeable material either within the inner or without the outer shell. If the inner and outer diameters are given then when the difference in these diameters is small, one continuous shell gives the best result. For a larger difference, two shells separated by an air-gap are much more efficient than a single one, and filling up the air-gap would appreciably diminish the screening effect. When the permeability of the substance is high the best shielding is obtained when the radii of the bounding surfaces of the shells are in geometrical progression. The great value of lamination is shown in the following table, where the volume of the per- meable material is expressed in terms of that of the enclose*' space, and the shielding in each case being the best. Volume of External material used. field. Single shell 10 0018 Two shells ... 5-0 o-ooo6 Three shells ... 4-8 0 "000 1 6 Single shell 70 o-oioa The conditions for the best arrangement in each of the following cases are fully worked out in the paper, viz. Two shells when the largest and smallest radii and the volume of the material used are given ; two contiguous shells of different permeablities ; and three shells of different perme- abilities. The main results of the investigation are that with thin shells lamination is useless, while with thick shells it is essential, if the best effect is desired. Experiments made on actual shells had fully confirmed the theoretical conclusions. Prof. Minchin said the mathematical results were very simply expressed. Although the work was apparently restricted to zonal spherical harmonics, some of the important formulae apply equally to general spherical harmonics. Referring to the diffi- culty of shielding by single thick shells, he pointed out that the equation giving the relation between the shielded and unshielded fields with different thicknesses of shell represented a hyperbola with its asymptotes parallel to the axes ; hence the shielding tended to a definite limit as the thickness increased indefinitely. Mr. Evershed said he had been engaged for the last two years on the subject of magnetic shielding, with a view to screening measuring instruments from external fields. In such cases it was not possible to use closed shells, and this introduced trouble. The best results he had yet obtained was to reduce the disturbance to about one-fifth. Another difficulty was intro- duced by the fact of the shields being magnetised by the cur- rent passing through the coil, and owing to hysteresis, the per- meability was different according as the magnetisation increased or decreased. By using an outer iron shell a great improve- ment had been effected. To obtain the best results, it was important to have no joints in the shields. A coil fiame with two shields of bent iron was exhibited. Mr. J. Swinburne remarked that the subject divided itself into two, shielding of instruments and shielding sources. If a 142 NA TURE [December 7, 1893 dynamo itself be shielded, this did not prevent the currents in the leads producing magnetic disturbances. This was very im- portant in ships. By using an alternator vi'ith resolving fields all disturbances could be avoided. Dr. C. V. Burton inquired whether by considering the hydrodynamical analogue of a porous material the case of perforated shells could be elucidated? Mr. A. P. Trotter wished to know if the homogeneity of the shield was of much consequence? At Oxford it had been found that a screen of four inches of scrap-iron was better than boiler- plate. Mr. Blakesley asked if the effect of moving a magnet sideways in a sphere had been observed. He thought the mathe- niatics developed in the paper would be useful in working out the magnetic theory of the earth. Prof. S. P. Thompson thought that taking the permeability as constant would not be quite correct, for ^x. was a function of the magnetisation. Hence in the cases considered the outer shell would be the more per- meable. In his reply, the President said scrap-iron in contact was not like clear space, for there were comparatively free paths lor the induction at the points of contact. As regards the shielding of the dynamo at Greenwich, Mr. Christie had written to say that the credit was due to the makers of the machine and shields, Messrs. Johnson and Phillips. — Prof. G. M. Minchin read a paper on the action of electromagnetic radiation on films containing metallic powders. After noticing the resemblance of the phenomena exhibited by tubes containing metallic filings shown by Mr. Croft, on October 27, to those of photoelectric impulsion cells, he repeated some of the experiments with filings, and found the same effects when the filings were of ordinary fineness. He also noticed that the experiments did not succeed either when the filings were coarse or very fine. Coarse ones always conducted, whilst very fine filings or powders acting as insulators, except when strongly compressed. To establish a closer connection with the impulsion cells he tried films of gela- tine and collodion containing metallic powders. Directions for preparing the films are given in the paper. On inserting such a film in circuit with a battery, key, and galvanometer, it acts as an insulator. To render a small portion conducting, the electrodes on the surface of the film are brought very close to- gether, and one of the wires touched with an electrified body (an electric gas-lighter was often used). This caused a current to pass. The electrodes may then be separated a little further, and the process repeated until any desired portion is rendered conducting. The peculiarity of such a film is that if the circuit be broken at the film, the film becomes an insulator ; whereas breaking the circuit at any other point leaves the film conducting. The action of the sparks or charges on the conductivity of the films is attributed to the influence of electric surgings in the wires by the electric discharges. The President read a written communication from Pr.>f. O. J. Lodge, in which the writer suggested that the phenomena of the films, and also of Lord Rayleigh's water-jet experiment (in which water-drops are caused to coalesce by the presence of an electrified body), were due to the range of molecular attraction being increased by electric polarisaiion. Mr. Blakesley said he had tried Mr. Croft's experiments, and found that conductivity could be established in a tube of filings whilst the circuit was unclosed. Breaking the circuit of a transformer or electromagnet would produce conductivity ; hence he concluded that electric surg- ings were not essential. Another curious experiment was to put the discharging knobs of an electric machine on a i hoto- graphic plate at a distance of a few inches. On turning the machine a small spark travels slowly along the plate from the negative to the positive knob. On reversing the polarity of the machine the spark travels back along the same path, but if the polarhy remains unchanged a second spark usually travels along a different path. Prof. C. V. Boys asked Prof. Minchin whether the films themselves, or the contacts between the elec- trode and film is made conducting by the sparks ? Prof. S. P. Thompson wished to know if ordinary photographic dry-plates would serve the purpose ? Mr. Evershed inquired whether the metal used as electrode made any difference ? Prof. Minchin, in his reply, maintained that the phenomena were due to electric impulses. He had not tried photographic plates, and had always used platinum for his electrodes. Chemical Society, November 16. — Dr. Armstrong, Presi- dent, in the chair.— A letter has been addressed to Prof. Mendeleef, congratulating the Russian Chemical Society on the celebration of its twenty-fifth anniversary. The following papers were read : — The normal butylic, heptylic, and octylic ethereal salts of active glyceric acid, by P. Frankland and J. NO. 1258, VOL. 49] MacGregor. The authors have determined the rotatory powers of the homologous series of ethereal salts of active glyceric acid up to octylic glycerate ; the molecular rotations .of the normal and secondary butylic salts are greater than those of any others of the series. This kind of result has been predicted by Guye. — The ethereal salts of diacetylglyceric acid in relation to the connection between optical activity and chemical constitution, by P. Frankland and J. MacGregor. The authors have pre- pared the methylic, ethylic, propylic, isopropylic, and isobutylic salts of active diacetylglyceric acid. In the case of the first two of these salts, two of the atomic groups attached to the assy- metric carbon atom are of equal mass ; according to Guye's theory, these should be almost, or quite, optically inactive. This, the authors find, is not the case, and they therefore again urge that the qualitative nature of the groups attached to the assy- metric carbon atom must be considered, as well as their masses. — The oxidation of paratoluidine, by A. G. Green. The red base obtained by Barsilowsky by oxidising paratoluidine with ferrocyanide is a diparatolylimide of the constitution MeC \ .C: (NC-H-)-CHx CH-C : (NC-Hy)^ >CNH„ On reduction it yields a stable leuco-base. — The action of benzoic chloride on urine in presence of alkali. Formation of benzoic derivatives of urochrome, by J. L. W. Thudichum. By the action of benzoic chloride on alkaline urine, a mixture of benzoic derivatives of urochrome is deposited. — The combination of hydrocarbons with picric acid and other nitro compounds, by \V. A. Tilden and M. O. Forster. Picric acid combines with terpene, giving a compound which forms a peculiar potassium salt, yields picramide and boineol when treated with alcoholic ammonia, and gives borneol when treated with aqueous alkalis. — The formation of pyrrol derivatives from aconitic acid, by S. Ruhemann and F. E. Allhusen. — The conversion of a hydrin- donoxime intohydrocarbostyril, by F. S. Kipping, a-hydrindon- oxime yields hydrocarbostyril when treated with phosphorus pen- tachloride. — The constitution of lapachol and its derivatives. II. The azines of the lapachol group, by S. C. Hooker. The author describes methyllapazire, melhyllapeurhodone, methylhydroxy- lapeurhodone, and several of their halogen derivatives. Geological Society, November 22. — W. H. Hudleston, F. R. S., President, in the chair. — The following communications were read : — The basic eruptive rocks of Gran, by Prof. W. C. Brogger. In previous communications the author has main- tained that the different masses of eruptive rock which occur within the sunken tract of country lying between Lake Mjosen and the Langesundsfjord are genetically connected, and have succeeded each other in regular order. The oldest rocks are the most basic, the youngest (except the unimportant dykes of diabase) are the most acid, and between the two extremes he has found a continuous series. He is now preparing a detailed monograph on this series of eruptive rocks, and in the present communication he gave an account of the results of his work on the oldest members. Several bosses of basic plutonic rock, now forming a series of dome-shaped hills, lie along a northand- south fissure line. The most northerly is that of Brandberget in the parish of Gran, about 50 or 60 kilometres north-north- west of Christiania, and the most southerly occurs at Dignaes on Lake Tyrifjord, about 35 kilometres west-north-west of the same town. The prevailing rock in these bosses is a medium or coarse-grained olivine-gabbro-diabase ; but pyroxenites, hornblendites, camptonites, labrador-porphyrites, and augite- diorites also occur. - Analyses of the typical rocks from three localities on the north and south line were given, and the con- clusion was reached that the average basicity of the rocks form- ing different bosses decreases from north to south. Thecontact- metamorphi-m was referred to ; and the presence of hypersthene in the altered Ogygia-%\\d\&i,, coupled with its absence from the same shales where they have been affected by quartz-syenite, led the author to the conclusion that the chemical nature of the intrusive rock does, in certain cases, produce an influence on the character of the metamorphism. Innumerable dykes and sheets of camptonite and bostonite are associated with the above-mentioned plutonic bosses. These are regarded by the author as having been produced by differentiation from a magma having the composition of the average olivine- gabbro-diabase. Analyses were given, and it was proved that a mixture of nine parts of the average camptonite and two of the average bostonite would produce a magma December 7, 1H93] NA rURE U3 having the composition of the average olivine-gabbro-diabase. The petrographical variations, such as the occurrence of pyroxy- enites and augite-dioriles, in the plutonic masses themselves are described, and attributed to differentiation under physical condi- tions unlike those which gave rise to the camptonites and bostonites. In discussing the general laws of differentiation the author pointed out that it must have taken place before crystallisation to any extent had occurred, because there is a marked difference in mineralogical composition between the rocks occurring as bosses and those occurring as dykes : and, further, that it is dependent on the laws which determine the sequence of crystal-building, in so far as the compounds which, on given conditions, would first crystallise are those which have diffused to the cooling margin, and so produced a contact- stratum, of peculiar chemical composition, before any crystal- lisation had taken place. A discussion followed, in which the President, Prof. Judd, General McMahon, Prof. J. F. Blake, and Mr. W. W. Watts took part. — On the sequence of perlitic and spherulitic structures (a rejoinder to criticism), by Mr. Frank Rutley. This paper related to the order in which the perlitic and spherulitic structures have been developed in a felsitic lava of Ordovician age from Long Sleddale, Westmoreland. The author having described this rock in a paper published in the Quarferly Journal of the Society in 1884, and the accuracy of the views then expressed having been questioned, endeavoured to confirm his original statements, adducing in support fresh observations made upon this and other rocks of a similar kind. Mr. Marr and Dr. J. W. Gregory spoke on the subject of the paper, and the author briefly replied. — Enclosures of quartz in lava of Stromboli, &c. , and the changes in composition pro- duced by them, by Prof. H. J. Johnston-Lavis. The author described the existence of enclosures of quartz in a lava-stream at the Punta Petrazza on the east sile of Stromboli, and also in the rock of the neck of Strombolicchio. He described the effects of the rocks upon the enclosures, concluding that the quartz has undergone fluxion but not fusion, and has supplied silica to the containing lavas, thus causing an increase in the amount of pyroxene and a diminution in the amount of mag- netite in the portions of those lavas that surround the inclusions and raising the percentage of silica. He suggested that such a process at greater depths and higher temperature may, under certain conditions, convert a basic rock into a more acid one, so that possibly the andeshe of Strombolicchio may have been of basaltic character at an earlier period of its progress towards the surface. He offered the sugge>tion that other rocks or minerals once associated with the quartz have been assimilated by the magma. The President and Prof. Judd made a few re- marks upon the paper. Cambridge. Philosophical Society, October 30. — Prof. Hughes, Presi- dent, in the chair. — The following officers were elected for the ensuing session : — Pre>ident, Prof. Hughes ; Vice-Presidents, Prof. C'ayley, Prof. Darwin, Dr. A. Hill ; Treasurer, Mr. Glazebrook ; Secretaries, Mr. Larmor, Mr. Newall, Mr. Bate- son ; New Members of Council, Prof. Sir G. G. Stokes, Dr. Lea, Mr. Shipley, Mr. Seward. — The President (Prof. Hughes) read a paper on the geological evidence for the recurrence of ice ages. Prof. Hughes pointed out that the advocates of the astronomical explanation of glacial ages have urged that there has been a recurrence at rt-gularly varied intervals of combina- tions, the result of which must have been circum polar vicissi- tudes of climate ; and, seeing that the secular recurrence of these conditions formed a necessary part of their theory, they gladly welcomed any confirmation of it, such as was offered by those geologists who saw in the character of the stones in cer- tain conglomerates traces of ice-action in several successive geological periods. The value of this evidence he now criti- cised. He laid before the Society examples of the striated boulders and rock floors supposed to present glaciated surfaces, and with a view to the elimination of sources of error in the identification of the work of ice he exhibited a large series of specimens illustrating the various ways in which results were produced sometimes exactly the same as, and often closely re- sem.bling, the forms, markings, and other characters relied upon as proofs of ice action. By reference to these he showed that the facetted stones from which the extension of the glacial conditions over parts of Southern Germany was inferred, found their exact counterparts among those trimmed by blown sand intii roof-like forms and ridges, and had no parallel among undoubtedly glacially-dressed stones. The scratched stones in the base of the New Red, or so-called Permian of England (with the exception of one single specimen, which he said must have got into the collection in Jermyn Street by mistake,, he compared with those produced by earth movements, in which the included pebbles of the conglomerate were protruded through the softer matrix and scored and indented by harder fragm.ents held in the mass. The supposed glaciation of the boulders in the basement beds of the carbonilerous he explained in the same way, producing examples in which the matrix and in- cluded fragments were scored alike by movements along small fault faces. He exhibited a portion of the solid silurian floor on which these conglomerates rested, which was striated in a manner that might be easily mistaken for glacial action ; but he explained that he had taken this from a thrust plane, and he pointed out the difference in the mineral condition of the surface between these slickensided surfaces and those produced by glacial action. He excluded from the present discussion cases in which ice agency was inferred only from the size and shape of the stones or their isolation in finest material. He admitted the probability of evidence of ice action being found along known axes of recurrent upheaval, such as those in the most ancient rocks along the Scandinavian range, or in the more recent deposits along the Alpine chain, or further south in the carboniferous boulder beds of India, Africa, and Aus- tralia ; but he pointed out that these last, at any rate, could lend no support to the astronomer's contention, seeing that they surrounded a basin whose centre was in equatorial, not in circumpolar regions. He was willing to admit that in the astronomical combinations we might find a vera causa of vicissi- tudes of climate, but he urged that all the evidence from direct observation went to show that extreme glaciation does and did always bear a direct relation to earth movements. Paris. Academy of Sciences, November 27. — M. de Lacaze- Duthiers in the chair. — On the registration of the variable elements of the sun, by M. H. Deslandres. — On equations and implicit functions, by M. Pellet. — On surfaces admitting of gauche cubics for asymptotic lines, by M. Blutel. — On ripples- {clapotis), by M. E. Guyou. Equations are obtained in which elliptic functions are substituted for the circular functions em- ployed by Boussinesq. According to these equations, each molecule oscillates along a straight line of fixed direction which itselt oscillates vertically, and the resultant motion takes place along a parabola whose axis is vertical. For the surface molecules, the first movement is that of the projection upon the minor axis of an ellipse of a point describing the contour of the curve with a constant linear velocity. On examining the photo- graphic tracing obtained by M. Marey it is found that the motion of the surface molecules takes place along a very flat closed curve. This divergence from the theory is easily ex- plained by the oscillations of the cylinder producing in the experimental basin a vertical displacement of the layers which are theoretically at rest. The superposition of this motion upon that indicated by the theory has the effect of separating in a vertical sense the trajectories corresponding to the two inverse phases of an oscillation. — Mutual action of bodies vibrating in fluid media, by MM. Berson and Juppont. Two vertical discs were placed in air with their axes coincident. The one was made of steel, 0033 cm. thick and 12 cm. in diameter, and was kept vibrating by two small electromagnets, excited by currents of intensities, varying according to the amplitudes required. The other w"as of mica, 0'012 cm. thick and 6 cm. in diameter, fixed normally to the bent end of a light bar of aluminium, which, supported by a long silver wire, formed the movable part of a torsion balance. The movement of this disc is due to the surrounding air, thus being analogous to electrostatic induction. The experiments were made inside a cage draped with soft and loose cloth, to prevent resonance. The torsion was measured with a Vernier micrometer to Jt degree. The attractions exhibited between the two discs when vibrating ranged from half a dyne to about 600 dynes. At a distance of I mm. it was 6o2"3 dynes; at 2 mm., gS'o; at 4mm., 14-5, and at 10 mm., 2 '55. To produce the same forces electrostatically, a difference of potential of 600 volts would be required. The authors intend to study the effect of distance and of the medium in the case of pulsating spheres. — Calculation of the forces to which bodies placed in an electro- magnetic field are subjected, by M. Vaschy. — On the variation of the electric state of the high atmospheric regions in good NO. 1258, VOL. 49] 144 jVA ture [December 7, 1893 weather, by M. Ch. Andre. — On the preparation of metallic lithium, by M. Guntz. — Improvement of culinary and lubri- cating oils by an electric treatment, by M. L. A. Levat. — On chloralose, by MM. M. Hanriot and Ch. Richet. — On some facts relating to the effects of injections of organic liquids upon animals, by M. E. Meyer. — On absorption by the urinary ducts, by M. Bazy. — Transpiration and respiration asfunctionsdetermining the habitat of the Batrachians, by M. A. Dissard. — On a ptomaine extracted from urine in influenza, by MM. A. B. Griffiths and R. S. Ladell. This ptomaine is a white substance crystallising in pris- matic needles, soluble in water, and showing a feebly alkaline re- action. Its formula is C,,H3N04. It is a poison producing strong fever and death in eight hours, and is not met with in normal urine. — On a new genus of fishes, related to Fierasfer, by M. Leon Vaillant. — -On the male genital apparatus of the Hymenoptera, by M. Bordas. — Researches on the anatomy and development of the female genital apparatus of the Orthoptera, by M. Feytoureau. — On the localisation of the active principles in the Limnanthere, by M. Guignard. — On the localisation of the active principles in the Cucurbitacese, by M. L. Braemer. — Experiments on the disinfection of mushroom beds, by M. I. Costantin. — On the exchanges of carbonic acid and oxygen between plants and the atmosphere, by M. Th. Schloesing fils. — Subterranean grafting, applied to the preservation of ungrafted French vines, by M. Geneste. — On the requirements of direct or grafted vines, by M. Albert Renault. — Study of a variety of the cider apple in all its life periods, by M. A. Truelle.— Proofs and cause of the actual slow movements of Scandinavia, by M. A. Badoureau. — Observations on the oolitic limestone superior to the gypsum of Villejuif, near Paris, by M. Stanislas Meunier. Amsterdam. Royal Academy of Sciences, October 28. — Prof, vande Sande Bakhuysen in the cliair. — Prof. Behrens treated (i) on the structure of native gold. Several samples of auriferous quartz were examined under the microscope, on the supposition that they would be found to contain agglomerated granules of metal. The gold was found to be crystallised in cubes, and in combinations of the cube with the octahedron, so perfectly as even to present good cleavage planes. It would appear, there- fore, that such gold must have been precipitated and crystallised at the same time and under the same conditions as the sur- rounding quartz. Further evidence for this conclusion was afforded by the presence of microscopical cavities in small nuggets. Like the cavities in quartz, they occur in streaks and small heaps, being partly spherical or oval, and partly of a sub- angular shape. By the distribution of the alloyed silver in concentric layers of rich and poor alloy, the supposition of a molten state is excluded. All these peculiarities were also found in grains of gold washed from an auriferous ochre, enclosed by auriferous quartzite. (2) On the chemical constitution of alloys, (i. ) Lead was found to be a good solvent for crystallising copper and its alloys, a small quantity of lead only being taken up by the latter. If a piece of copper is put into red-hot lead containing a little tin, the surface of the copper is changed to bronze, which does not melt, but will partly dissolve in the lead, and on cooling separate out in crystals. Bronze and common brass will not split up into definite alloys under this treatment. The alloy of copper with 10 per cent, aluminium, which is said to be homogeneous, behaves differently. It will yield red crystals in the upper part of the button, yellow ones in the middle, and white ones near the bottom of the crucible, (ii. ) I> copper in bronze univalent or bivalent? With a view to solving this question, a series of silver-tin alloys was com- pared with corresponding bronzes. The following results were obtained: Regular crystals, Cu^Sn and Ag,;Sn, CujSn and AggSn, CuSn and AgSn, CuSno and AgSno ; other systems (rhombohedric ?) CujSu and Ag^Sn (maximum of hardness), CuoSn and Ag.^Sn (second maximum), CuoSng and AgoSn.j. Now, for Ag4Sn, no other structural formula can be admitted than Ag., = Sn = Ag, hence there is a great probability for the univalent character of copper in its allnys with tin. Several of the other formulse will probably have to be doubled. The formula AggSn cannot be construed here, and the reasoning leads to (he supposition that also in bronzes rich in coiiper the surplus of the predominant metal is simply dissolved in an isomorphous combination. — Prof. Schoute treated on regular seci ions and projections of the ikosat.-trahedron. The author studied the central sections perpendicular to, and the orthogonal projections in, the direction of four lines that join NO. 1256, VOL. 49] the centrum to a vertex, or to the centre of an edge, of a tri- angular face, or of a bounding octahedral three-flat. As to the vertices, the four dimensional being L (24 = number of bound- a ing three-flats, a = length of edge), proves to be the combina- tion of a L (tessaract) and a L , , or of three L 's: as to the ^ ^ V 2 a bounding three-flats it may be considered as the combination of a L ^^ and a L ^^^ or of three L ^^'s. — Prof. Kamerlingh Onnes gave a comparison made by Dr. Zeeman of his measures of polar reflection of light on magnets with the theories of Gold- hammer and Drude. His experiments decide in favour of the first theory. Prof. Onnes communicated also an explanation by Dr. Kuenen of the abnormal phenomena observed in the neighbourhood of the critical temperature by the theory of mixtures. The experiments of Dr. Kuenen agree with the results of Gouy. BOOKS and SERIALS RECEIVED. BfiOKS.— Julius Cssar, with Introduction and Notes, &c. : W. Dent (Blackie). — Heat and the Principles of ThermoHynamics : C. H. Draper (Blackie) — Hydrostatics and Pneumatics: R. H. Pinkerton (Blackie). — The Elements of Hypnotism: R. H. Vincent (K. Paul). — Handbook of British Hepaticas : Dr. M. C. Cooke (Allen). — Helical Gears, a Foreman Pattern Maker (Whittaker).— Choix et Usage des Objectifs Photographiques : E. Wall in (Paris, Gauthier-Villars). — Geologic Atlas of the United States, Hawley Sheet, Massachusetts (Washington). — Jubil(5 de M. Pasteur (Paris, Gauthier Villars). — Marveillesde la Nature, La lerre avant 1' Apparition de r Homme: F. Priem (Paris, Bailliere). — Specola Vaticana, Classificazione delle Nubi (Roma, Tipografia Vaticana). — Celestial < Ibjects for Common Telescopes : Rev. T. W Webb, 5th edition, vol. i (Longmans). Serials. — Zeitschrift fiir Physikalische Chemie, xii. Band, 5 Heft (Leip- zig, Engelmann). — Bulletin of the U.S. National Muse. nn, No. 45, Mono- graph of the North American Proctotrypidse : W. H. Ashmead (\Vashing- ton). — Berichte der Naturforschende GeselUchaft zu Freiburg i. B., Band vii. Heft I and 2 (Williams and Norgate). — Botanical Gazette, November (Bloomington, Ind.) — Journal of the Anthropological Institute, November (K. Paul). — Natural Science, December (Macmillan). — Geological Maga- zine, December (K. Paul). — American Naturalist, November (Philadelphia). — Geographical Magazine, December (Stanford). —Mitteilungen des Vereins fur Erdkunde zu Halle a S. (Halle a S.). — Bulletin of [the New lYork Mathematical Society, November (New York, Macmillan). CONTENTS. PAGE Elementary Practical Science. By Sir Philip Magnus 121 The Pyrenees. By T. G. B 122 Our Book Shelf:— Rodet et Busquet : " Les Courants Polyphases " . . 122 Loney : " Solutions of the Examples in the Elements of Statics and Dynamics" . • 122 Letters to the Editor: — Sir Henry Howorth and "Geology in Nubibus." — R. M. Deeley • 122 The "Zoological Record."— Dr. P. L. Sclater, F.R.S. ; John E. Marr 123 The Proposed Continuous Polar Exploration. — Robert Stein 124 On the Classification of the Tracheate Arthropoda. — A Correction. — R. I. Pocock 124 The Loss of H.M.S. "Victoria." II. By Dr. Francis Elgar 124 Reappearance of the Freshwater Medusa {Lutino- coaium Sowerbii). — Prof. E. Ray Lankester, F.R.S. 127 Death of Prof. Tyndall 128 Notes 129 Our Astronomical Column: — The Variation of Latitude 133 Meteor Shower for December 134 Refraction Tables 134 Geographical Notes 134 The Anniversary Meeting of the Royal Society . . 134 Tne Temperature of Ignition of Explosive Gaseous Mixtures. By A. E. Tutton 138 University and Educational Intelligence 139 Scientific Serials 139 Societies and Academies 140 Books and Serials Received 144 NA TURE 145 THURSDAY, DECEMBER 14, 1893. A BOOK OF PRACTICAL EXAMPLES LV ELECTRICITY. Problt-ines et Calculs Pratiques d^EIectricitc. Par M. Aime Witz. (Paris : Gauthier-Villars et Fils, 1893.) ' I ""HIS is, in the main, a book of fully worked-out -L exercises in electricity and magnetism, designed for the help of practical students. Its idea and arrange- ment are good, and the examples seem to have been chosen with much care, and, as far as possible, from actual cases which have occurred in laboratory and practical work. The aim of the author has not been to furnish a set of examples, like the collection of Walton, in theoretical mechanics, or that of Hall Turner, in heat and electricity. These works illustrate general mathe- matical theories by examples, the solutions of which are in many cases important or interesting particular theorems ; but their interest is, to a great extent, mathe- matical. M. Witz has had in view the wants of students endeavouring to obtain a sound elementary knowledge of electricity, who are not afraid of a piece of calculation involving, when necessary, a little differentiation or integration, when it comes. in its proper place as the simplest and most direct means of attaining the required result. » The work is divided into three parts : (i) containing definitions and formulas, (2) numerical constants, and (3) the greater portion of the book — a collection of illus trative examples. Part i deals first with magnetism, and gives the ordinary relation between magnetic intensity and magnetic induction, introduces the notions of mag- neto-motive force and magnetic resistance, and shortly states the main facts of lamellar and solenoidal magnet- isation. In like manner the next chapter states, merely, some of the principal theorems of electrostatics ; the third deals with phenomena of steady currents ; and the last two with electro-magnetism and induction of currents. In connection with electro-magnetism a paragraph is devoted to the researches of Ewing and " M. Hopkins " on the magnetization of iron. All the latter experimenter (the distinguished inventor of characteristic curves of dynamos appears to be meant !) is credited with is a demonstration that the " travail" (consumed in putting a sample of iron through a magnetic cycle) " exprime en ergs et rapport^ a I'unite de volume, est dgal au produit de la force coercitive de I'echantillon par I'induction maximum, divise par ir." The measure of coercive force assigned by Hopkinson does not seem to be explained in the book, and so a really important idea, rendering definite what was before a perfectly vague expression, is passed over. As to the demonstration referred to, we must confess to never having heard of it. Dr. Hopkinson, we had supposed, simply used the rule stated in the quotation as a rough and ready method of rapidly find- ing the approximate dissipation of energy in a closed magnetic cycle. Ampere's law (" formule classique, connue de tous nos lecteurs") of the action between two current elements is explained, but no hint is given that any number of other laws can be obtained which give for the only cases with which we can without ambiguity deal, NO. 1259, VOL. 49] those of closed circuits, precisely the same result as is given by Ampere's formula, although the latter may have certain advantages in point of simplicity. The word " law " is a good deal misused in electrical science ; we have Kirchhoff's laws, Ohm's law. Joule's law, Lenz's law, and many others ; but we have here a law that we do not remember to have come across before, namely " Pouillet s law, ' which asserts that the quantity of electricity conveyed by a current I in time /is 1/ ! No doubt if the electro-magnetic definition and measure of a current are adopted, it is a proper subject of inves- tigation to settle whether it is simply proportional to the current defined electrostatically as the time rate of flow of electricity ; but the real proof that this is the case, is the consistency with the results of experiment of the great mass of results deduced from this propor- tionality. The chapter on induction is brief, but contains a great deal of information very accurately expressed. The function of the current which multiplied into the speed gives the electromotive force of a dynamo, is referred to as the " fonction caracteristique ' of M. Marcel Depres ; but Hopkinson's extremely important dynamo character- istic curves are merely referred to, without any mention of their author. The so-called law of Jacobi, namely, that " Le travail utile d'un moteur est maximum lorsque sa force contre- electromotrice est egale a la moitie de la force electro- motrice de la generatrice," is no doubt correctly stated^ since by " le travail utile " is meant the electrical work done on the motor in a given time, otherwise than in heating its conductors. But it would be better to say that the elec- trical activity as specified in the motor is a maximum when the condition stated is fulfilled. The phrase " useful work," here used, has caused this result, simple as it is, to be completely misunderstood by many practical electri- cians of high standing. In the present case the tendency to error is obviated by the statement immediately follow- ing, that " Le rendement electrique d'une transformation d'energie, est egal au rapport de la force contre-electro- motrice e de la rdceptrice a la force electromotrice E de la generatrice. Ce rendement peut devenir egal k I'unitd lorsque e devient egal a E ; mais alors le travail produit tombe a zero. C'est la lot de Siemens.''' The late Sir William Siemens objected in 18S3 to the erroneous interpretation put upon Jacobi's result by Verdet and others, and likewise stated the true principle of efficiency ; but the law of maximum efficiency of a circuit containing a motor was given in Lord Kelvin's very important paper on the " Mechanical Theory of Electrolysis," published in 1851 in the Philosophical Magazine. As not only this result, but others, forming practically the whole r,{ the simple but immensely im- portant elementary theory of the electrical efficiency of a generator and motor, are there incidentally given by Lord Kelvin, and are usually stated in practical treatises and lectures as theorems of much later date, we may be allowed to give here a short abridgement of the passage. Denoting by w the angular velocity with which a Faraday disk magneto-electric machine is driven, by .1 the velocity with which the machine would have to be driven to give a back electromotive force equal to that of the generator (a battery in this case), Lord Kelvin H 146 NA TURE [December 14, 1S93 points out that if oi is less than n, the current is opposed to the electromotive force of the disk, and that therefore in this case " the chemical action is the source of the current instead of being an effect of it ; and the disk by its rotation produces mechanical effect as an electro- magnetic engine" (or, as we now call it, a motor) "in- stead of requiring work to be spent upon it to keep it pioving as a magneto-electric machine." If y be the current flowing, F the intensity of the field in which the disk revolves, r the radius of the disk, R the resistance of the circuit, W the rate at which work is done by the current en the engine, M' the rate at which energy is spent by the battery, then the results — 7 = -2^(-"- - '^), or n are given, and it is pointed out that the fraction of the '• entire duty of the consumption which is actually per- formed by the engine is equal to co/n." The ratio w/n is the ratio of the back electromotive force of the motor to the total electromotive force of the generator, and is therefore the law of efficiency stated above in the words of M. Witz. The examples worked out in the book are many of them highly instructive, and, so far as we can judge from the examination of a selected few, seem clearly and correctly dealt with. They are not merely numerical, but include in most cases the deduction from general theorems of formulas for particular cases, which are then illustrated by numerical problems in which results are expressed in C G.S. units. The value of these problems is enhanced by the fact that they are, as we have said for the most part actual problems which have turned up in experimental or practical work. The subjects thus elucidated include magnetism, electrostatics, steady flow of electricity, electro-magnetism, dynamos, motors, and the distribution and transmission of electric energy. There can be no doubt that the book will prove very useful to teachers and students. Its only fault is that it leaves nothing for the student himself to do. A moderate number of unworked examples, on which he might test his grip of the subject, and power of applying principles, would have been very valuable. It is undesirable to spend very much time in solving mere arithmetical or algebraic conundrums, but enough must be done to acquire a fair amount of readiness and expertness of calculation ; and of the great benefit derived from working out numerical examples of physical principles, there can be no doubt. We think, therefore, the author would do well to supply material for this in a future edition. A. Gray. BESANT-S DYNAMICS. A Treatise on Dynamics. By W. H. Besant. (Cam- bridge : Deighton, Bell, and Co., 1893;) 'T^HIS popular text-book has now reached a second J- edition, and contains several additions which have increased its size from 334 to 448 pages. A new chapter has been added on disturbed elliptic motion, which shows how the elements of an elliptic orbit are aftected NO. 1259, VOL. 49] by small disturbances in the same plane. This chapter will serve as a useful introduction to the planetary theory, since the limitation of the problem to two- dimensional motion enables various difficulties, which arise from taking into account the longitude of the node and the inclination of the orbit, to be got rid of. The principle, upon which the method of the variation of the elements is based, is one to which students should be introduced at an early stage ; but unless some simplifica- tion is made, the analysis becomes rather complicated. We are inclined to suggest that this chapter might be extended in a future edition. The last chapter of the first edition has been amplified into two, the first of which deals with motion in three dimensions, whilst the second discusses several im- portant problems relating to the motion of tops, discs, gyroicopes, &c. ; and the book concludes with a new chapter on Lagrange's equations, together with several applications illustrating their use. To discuss any of the higher developments of this branch of the subject, including the Hamiltonian transformation, and the mixed transformation which in 1887 was for the first time given in a complete form by the author of this review, would probably be thought beyond the scope of an ele- mentary work ; but it would be well to bring out more pointedly the fact that the kinetic energy of a dynamical system can be expressed in several different forms, and that when employing Lagrange's equations there is only one form which it is permissible to use, viz. the La- grangian form, in which the kinetic energy is expressed as a homogeneous quadratic function of velocities which are the time-variations of coordinates. Mistakes are frequently made upon this point ; and it is most neces- sary to impress upon the minds of students that La- grange's equations are double-edged tools, which are apt to cut the fingers of those who unskilfully handle them. Dr. Besant has used the word phoroiiomy in the place oi kinematics, and he has stated his reasons for so doing in a letter published in Nature, lAIarch 17, 1892. The word appears to be a good one, and has the merit of being classical, and not Teutonic ; but notwithstanding occasional fiights into the regions of radicalism, the in- grained conservatism of the English mind is so strong that it is by no means certain whether phoronomy will supplant a word which has long held the field. One of the most satisfactory features of the work is that Dr. Besant has drawn marked attention to the principle of momentum. This principle is in some respects a more fundamental one than the principle of the con- servation of mechanical energy ; for the former principle is true in the case of viscous systems in which there is a conversion of mechanical energy into heat, whilst the latter does not hold good when internal friction or vis- cosity exists. The principle of linear momentum can be shown to be a direct consequence of Newton's second and third Laws of Motion ; but doubts have been enter- tained whether the principle of angular momentum can be deduced from Newton's Laws without the aid of an additional hypothesis. The question, however, is far too recondite a one to be discussed in a review. It is possible that some of those whom a recent corre- spondent in Nature has described as "the slug and the bug school '' may object to the large amount of problems December 14, 1893] NATURE 147 and examples which are contained in the text and at the end of the chapters. Persons whose curiosity is limited to finding out 7u/iai electricity docs, and adopt the un- scientific attitude of considering it waste of time to try and ascertain luhat electricity is, and why it is capable of performing so many wondrous feats, may perhaps rebel against a system, one of whose objects is to train the mind to inquire into the causes of natural phenomena. It must be recollected that young men, who are just emerging from the schoolboy stage of existence, invari- ably find that Rigid Dynamics is a very difficult subject to master, and that a thorough knowledge of the principles of the subject, combined with analytical skill in applying ihem to natural phenomena, can only be acquired by working out a large number of problems and examples. It is also an excellent plan for students to work out the same problem (for example, the motion of a top) by various methods, and to study the different results ob- tained by each ; for they will thereby not only obtain analytical skill, but will learn that their symbols, instead of representing mere mathematical quantities, are the embodiment of important scientific facts. A. B. Basset. INSECT PESTS. Our Household Insects : an Account of the Insect Pests found in Dwelling-houses. By Edward A. Butler, B.A., B.Sc.Lond., author of "Pond Life," "Silk- worms," &c. (London and New York: Longmans, Green and Co., 1893.) MR. E. A. BUTLER has done useful service to the cause of popular ento.iiology by reprinting the present series of his contributions to Knowledge in book form. Not very many species are discussed, but these seem to comprise most of the principal insect pests be- longing to the various orders of insects which infest our houses, and attack ourselves or our property. As insects (e.xclusive of insect-parasites) attack all kinds of dead or decaying animal and vegetable matters, and play the part of general scavengers, nothing is exempt from their ravages. Books are particularly sub- ject to their attacks ; and many of their enemies are noticed by Mr. Butler. We remember once being much amused by an account of a book-worm, which was ridi- culed by a writer in a bibliographical magazine, as being evolved from the describer's own consciousness, but which was really fairly recognisable as applicable to Lepisnia sac- charina,\.h.& common silver-fish. But the critic regarded the book-worm as necessarily a small grub or beetle (we forget which), and displayed his own ignorance of ento- mology accordingly. Prof. Westwood once named a minute beetle, which had done much mischief to the ' cover of a book, Hypotheneinus eruditus; and specimens of books damaged by insects may be seen in one of the | cases in the public insect-room at the Natural History -Museum, South Kensington. We believe that Mr. Zaehnsdorf, the well-known book-binder, has also formed a collection of the book-pests which he has met with in the exercise of his vocation. We may add that the Arabs sometimes write the name Kabikaj, said to be that of a genius who presides over insects, on their manuscripts, m order to protect them from the ravages of his subjects. NO. 1259, VOL. 49] I There is no doubt that insects of various kinds get [ mixed with human food from time to time ; but we imagine that the passage which Mr. Butlef quotes from Curtis's "Farm Insects," relating to maggots in cocoa- beans, is somewhat out of place at the end of a chapter on beetles, for we have good reason to believe that the insect to which Curtis alluded was not a beetle, but a moth of the genus Ephestia. The seven plates of magnified insects and their struc- ture, and the numerous woodcuts, add much to the use- fulness of the book. Clear definitions, and accurate demonstration?, are extremely useful in entomology, not merely to beginners, but even to more advanced student?, who often find much difficulty in obtaining the necessary explanations of the characters and terminology, when they take up the study of a group of insects with which they were not previously familiar. The insects which Mr. Butler discusses may be divided into three classes : those which really cause serious de- struction to property, as the clothes-moths and various kinds of small beetles ; those which are rather trouble- some and annoying than destructive, such as the flies and wasps ; and those which attack man himself. Among the latter are the lice, which the increase of cleanliness has fortunately rendered rather unfamiliar objects to the better classes in recent times. Yet they are highly interesting creatures, from many points of view, and several entomologists have not scrupled to make a special study of them ; among others, Denny, who wrote an elaborate monograph on the British species, illustrated with twenty-six coloured plates ; and the old Dutch naturalist. Van Leeuwenhoek, who actually reared a brood in a stocking on his own leg ! We think the figure of the proboscis of a louse, which Mr. Butler copies from the Danish entomologist Schiodte, on p. 332, will be new to most of his readers. But there is a curious omission of a necessary explanation in Mr. Butler's observations, in the following passage : — " Man is not exceptional among mammals in harbour- ing these vermin ; he is but in the same category with the rest, for it seems to be the rule, from elephant to mouse, largest to least, that some member of this group of parasites should be attached to each species ; and even aquatic animals, such as the seal and walrus, do not evade their attacks." Surely Mr. Butler, to avoid being misunderstood, should here have stated that the presence of a true louse on seals is quite an exception as regards marine animals, and that the so-called " whale-louse," and similar para- sites, are not true lice, or even insects at all, but parasitic Crustacea. Our author mentions the fact of colonies of fleas having sometimes been found on sandy sea-shores, and wonders what they can find to eat there. But although certain species of fleas are attached to different species of animals, they are perhaps not so particular about their food as is generally supposed. In all warm countries it is very common to find colonies of fleas camping-out in the open ; and the late Mr. F. Smith once recorded an in- stance of a suburban garden, in which a particular bed was swarming with dog-fleas ; no particular dog being men- tioned as the probable origin of the invasion. In the Western States of America, the " wild fleas," as the late 148 NA TURE [December 14, 189; Frank Rackland would have said, actually feed on the larvae of a white butterrty which abounds in the pine- forests. Some curious stories are related by Mr. Butler re- specting Longicorn beetles, and Sirex gigus perforating sheets of lead. Many years ago, a tin canister was ex- hibited before the Entomological Society, through which a stag-beetle had gnawed its way, and the marks of its jaws were distinctly visible on the tin. In his remarks on the bed-bug, which is almost in- variably, if not always, apterous, Mr. Butler makes some general observations (p. 287) on the use of wings to in- sects. It may be mentioned that the late Mr. Wollaston has observed that most insects inhabiting the Atlantic Islands, are either strongly winged, or practically in- capable of flight. The explanation which he gives is very curious and interesting. Insects living on small islands exposed to gales are very liable to be blown out to sea. Hence it is almost equally beneficial to them either to be gifted with such strong powers of flight that they can make their way back, in case of such an emergency, or else that they should never fly at all, and thus never run the risk of being blown away. There are many interesting subjects touched upon in Mr. Butler's work, and much that would admit of further comment ; but we have perhaps said enough to indicate its general scope and character. Should it reach a second edition, we think it might be made a little more compre- hensive with advantage ; for the subject is a very large one, and those who feel a real interest in it rarely find a book too long or too much detailed. OUR BOOK SHELF. Text-book of Biology. By H. G. Wells, B.Sc.Lond., F.Z.S., Lecturer in Biology at University Tutorial College. With an Introduction by G. B. Howes, F.L.S., F.Z.S., Assistant Professor of Zoology, Royal College of Science, London. Part II. Invertebrates and Plants. (London : W. B. Clive, University Corres- pondence College Press, 1893.) In dealing with a small number of Vertebrate types in Part I. of this book (see Nature, vol. xlvii. 1893, p. 605), the author showed distinct capability and promise ; but we feel that he would have done well to wait and work for a few years before publishing this second volume, which covers a larger field. As the types of plants and invertebrates treated of have already been described in so many text-books, the writer had, at any rate, the oppor- tunity of getting his facts and deductions second hand and fairly correctly stated, even without an extensive acquaintance with biological science. There is, therefore, all the less excuse for the many errors and misstatements which occur in this volume, the preface to which would lead one to expect better things in this respect, as well as in the selection and arrangement of facts. Prof. Howes's introduction appeared in Part I. ; and before inserting his name on the title-page of Part II. it would, we think, have been only just to have at least submitted the proofs to him. The book would certainly have gained by so doing. Apart from the more serious faults, which are so nu- merous that it is not easy to give a short selection of them, awkward terms and misprints abound. Prof. Goebel would probably be surprised to hear that he had written a text-book on botanical " mythology " (p. 94) ! The illustrations are exceedingly crude, and are mostly NO. 1259, VOL. 49] rough copies of well-known figures. '^Itjis, however, only fair to state that the author has purposely made them " as simple and diagrammatic as possible." W.N. P. The New Technical Educator. Vol. ii. (London, Paris, and Melbourne: Cassell and Co., Ltd., 1893.) In a notice of vol. i. of this useful work we pointed out that it filled a want in our general technical literature, and that its contents were of a high order. The present volume is quite equal to its predecessor in this respect, and forms a continuation of all the subjects treated in the previous volume. Under the heading of the "Steam Engine" we find an admirable series of chapters, by Mr. Archibald Sharp, on the subject of valve gear generally, particularly the dia- grammatical treatment of the subject illustrative of the various movements of eccentrics, piston and valve. " Electrical Engineering " is also in good hands, being clearly treated by Mr. Edward A. O'Keefe. The many explanations and descriptions given are of a high order of merit. On the subject of " Cutting Tools " much use- ful information is to be found from the pen of Prof. R. H. Smith, who is an authority on this particular subject. The other subjects embraced in the volume, includmg practical mechanics, plumbing, photography, steel and iron, drawing for engineers and carpentry, are all well written and illustrated, forming a very useful collection of articles on technical subjects. It is to be regretted, however, that the various articles on different subjects continue in this volume to be mixed together, thus causing the reading of one subject to be a matter of frequent reference to the page of contents. Heat, and the Principles of Thermodynamics. By Dr. C. H. Draper. (London : Blackie and Son, 1893.) In these days of innumerable books, it is often a difficult task to correctly appraise the value of a new work, and this is especially the case with books intended for use in classes. The only thing a reviewer can do is to judge whether the volume under his notice differs much from previous volumes on the same subject ; and if the author shows no originality of treatment, it seems to us that his book could very well have been left unwritten. Viewing Dr. Draper's work in this light, we find as follows: ([) Much more attention is paid to the principles of thermo- dynamics than is usual in class-books of its kind ; (2) the examples and exercises distributed throughout the book, and at the end, are more numerous than in most text- books of heat, and cover a wider range of examinations ; (3) the mathematical section of the subject has not been shirked. Little more can be said. The book is as good as any of its class, and to the student who desires to read up for an examination in heat it should be very helpful. LETTERS TO THE EDITOR. [ The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to returti, or to correspond with the writers of, rejected manuscripts intended for this or any other part of Nature. No notice is taken of anonymous communications.^ Systematic Nomenclature. With reference to Prof, Newcomb's suggested nomenclature for radiant energy, which appeared in Nature, November 3c, p. 100, it seems advisable to be rather cautious in adopting new words, or rather terminations to words already more or less in use, for at the present time the student beginning the study of physical science is fairly bewildered wiih the various forms of words used under the present system, or rather want of system, in nomen- clature. If once for all some system of termination was settled upon December 14, 1893] NATURE 149 (as in chemistry, for the increasing oxidation results, &c. ), the coinage of words as fresh needs arose would proceed automxti- cally on rational lines. This might very well form the object of a special committee of the British Association. Mr. Oliver Heaviside's system for electromagnetic matters has much to recommend itself for adoption, also, in general physics. For example, after the plan (i) conduc/ZiJ/^ (2) con^wztance, (3) conduc/zV//)', we would have, in the case of radiant energy, (i) radia//f«, (2) radia/a;/a, (3) radia^/z'/Zr. The first is tor reference in a general way to the phenomenon in question ; the second refers to i's amount in appropriate uniis in any individual case ; while the third is suitable for expressing the piculiar action or factor in the phenomenon possessed by different kinds of bodies. Thus the radiafaiice from a hot kettle would be the total quantity of energy lost per second. The radia/zz'/Aj/ would be the quantity of this ^per square centimetre. With a view of examining the feasibility of this system, the following list is subjoined. Many of the words appear at first as if tliey would prove most awkward in practice, but remembering similar fears (which subsequently proved ground- less) in electromagnetic matters, one is afraid to say they are due to more than unfamiliarity. Phenomenon Amount of Coefficient of Absorption Absorbance Absorbivity Attrition Attritance Attritivity Diffusion Diffusance Diffusivity Emission Emissance Emissivity Expansion Expansance Expansivity Extension Extensance Extensivity Friction Frictance Frictivity Gravitation Gravitance Gravitivity Heat Ileatance Heativity Inertia Inertance Inertivity Polarization Polarizince Polarizivity Reflection Reflectance ReflecLivity Refraction Refractance Refractivity Rotation Rotatance Rotativity Solution Solutance Solutivity Special attention deserves to be called to inertance as a good name for mass, and inertivity for density, to rotatance lor moment of momentum, and rotativity for moment of inertia. Geo. Eras. Fitzgerald. Fred. T. Trouton. Physical Laboratory, Trinity College, Dublin, December 5. On the Nomenclature for Radiant Energy. In connection with this subject there are many things to be considered, and one of the most important is the question of ladialion and absorption, which requires a completely new nomenclature to get over very serious ambiguities that at pre- sent embarrass the subject. It is very necessary to distinguish between what may be called, on Prevost's theory of exchanges, the total radiatance from the actually observed loss of energy by radiation which is, according to this theory, the difference bttween the total radiatance and the total absorbance. This difference per degree of temperature is very commonly called the radiating power, but this same word is used in quite a difi'erent sense when it is attempted to prove, from Prevost's theory of exchanges, that the radiating is equal to the absorbing powers by a consideration of thermal equilibrium. In this latter case the term radiating power means obviously the total radiatance of Prevost's theory. It may also be worth while calling attention to the theory, given at Nottingham by Lord Rayleigh, as to the absorbivity of lough surfaces being equal to unity. The general idea under- lying his investigation is that owing to diffraction the waves amongst the deep corrugations in the surface spread abroad within them, and hardly any of their energy escapes out again. At the time 1 called his attention to the way a similar theory would explain the radiating power of rough surfaces, as I have NO. 1259, VOL. 49] taught here for years back. I am mentioning this now to call attention to an experiment of Magnus' mentioned in Jamin (" Cours de Physique," vol. iii. part 3, p. 113, top line, edition 1881 ; Pog-o-. Ann. vol. cxxiv. p. 476), where I have an old note concerning this theory, and which I had forgotten, to the effect that the radiation from platinised platinum was much greater than that from smooth platinum, but that the increase was chiefly in the ultra-red rays, for that the difference between the two plates was almost completely annulled by a plate of alum. This is what would be expected from the above theory, because corrugations that are small enough to affect the ultra-red radia- tions might still be too large to be anything but a smooth surface for the visible radiations. There is evidently a good deal still to be done on radiativity. Geo. Eras. Fitzgerald. Physical Laboratory, Trinity College, Dublin, December 5. Flame. I TRUST that, in common with otherreaders of Nature, I feel dulychastened by the homily which Dr. Armstrong has addressed to you on the subject of my lecture on " Flame." It is perhaps well that we should be warned from time to time against the sin of dogmatising. The only objection I have to the process is that I should be singled out as a sinner without some good reason being given for the selection. I am charged with forget- ting that certain alleged facts "are but phenomena interpreted by our own limited intelligence," and yet I actually wound up my lecture with a quotation from Carlyle, intended to emphasise that very point. If Dr. Armstrong had said that this was an "appeal to the gallery," I should not have complained. I do not feel equal to the metaphysical discussion to which Dr. Armstrong opens the way. I know only of one kind of fact, namely, " phenomena interpreted by our own limited in- telligence," and it seems better to spell the thing in four letters than to bury it in phrases that smack of the pulpit. Now let us see what I have done. I found on burning a hydrocarbon with a limited supply of oxygen, that in the cooled products of combustion all the carbon was oxidised, and that some of the hydrogen was set free. I had been brought up, like Dr. Armstrong, to cherish certain chemical dogmas, one of which was that the hydrogen of a burning hydrocarbon was oxidised before the carbon. I now asked myself what were the grounds for this dogma ? It seemed to me to spring from the narrowest view of things, probably from the fact — I mean the by- limited-intelligence-interpreted-phenomenon — that hydrogen gas is easier to set on fire than a lump of charcoal. This was obviously an unscientific conclusion, for the carbon of a burning hydr - carbon is part of a gas, and when it is oxidised it has not, like a lump of charcoal, to be virtually gasified in the act of burning, and so to demand a high temperature and an untold amount of heat. I then read with great profit a paper by Dr. Armstrong, which confirmed my opinion that the heat of combustion of an atom of gaseous carbon, in forming carbon monoxide, must be exceedingly high, and so on all grounds I concluded that there was r\o fri?na facie reason for assuming that the hydrogen ot a hydiocarbon would be oxidised in preference to the carbon. Experiment showed the opposite result; the carbon was oxidised, and I adopted the straightforward explanation, and renounced the old dogma. There were alternative explanations. It was conceivable that the hydrogen burnt first and liberated the car- bon, which then acted upon the steam to produce one or both of the oxides of carbon and free hydrogen. We should then have two successive chemical reactions. I pointed out that there was only one piece of indirect evidence in favour of this view, and that has since been contradicted by Prof. Dixon. But Dr. Armstrong appears to suggest the view that the two chemical reactions are simultaneous. Now we know of plenty of chen - ical reactions which are best understood and remembered if we represent them by two simultaneous equations. When, for in- stance, zinc is heated with strong sulphuric acid, and we do not get hydrogen, we may explain the apparent anomaly by saying that hydrogen is liberated, but that it immediately attacks some of the hot sulphuric acid, producing sulphur dioxide and water. Or we may choose another pair of " normal" reactions which, being supposed to happen simultaneously, will explain the " ab- normal " result. But surely no one thinks that the two re- actions do proceed simultaneously. I use this method of expo- sition very largely, but I always tell my students that it is analogous to the treatment of forces in dynamics. We suppose 150 NA TURE [December 14, 1893 a body acted upon by two forces whose direction and intensity may be conveniently represented by the adjacent sides of a parallelogram. The body really moves along the diagonal ; virtually it has a double track, one along each of the adjacent sides of the parallelogram. In like manner, in our hydro- carbon-oxygen system, we may picture two compelling forces, viz. the tendency of oxygen to combine with carbon, and of oxygen to unite with hydrogen. You may, if you please (and this seems a fascinating exercise to Dr. Armsrong), shut your ey^s alternately to each force and say, " first the hydrogen gets ail the oxygen, and then the carbon snatches some from it," or you may just as well put it the other way about. I simply recorded the fact that the carbon got the most of the oxygen, with an explicit reference to the fact that I was dealing with the cooled products. Before my experiments were published Br. Arm- strong thought that hydrogen got most of the oxygen. He had actually tried to persuade Sir G. G. Stokes and many others to this effect. When my paper appeared he sought to discount the facts it contained by flights of polysyllables worthy of a great statesman. 1 Is it not strange that he should now turn to rend the man who relieved him from what he so abhors — a dogma? The assumption that the products which are collected Irom a flime may have totally altered in kind during a minute fraction of a second is perfectly gratuitous, and a similar assumption might be made about nearly every reaction in chemistry. Dr. Armstrong might just as well forbid me to say that zinc and hot sulphuric acid give sulphur dioxide, as to say that when a hydrocarbon burns with limited oxygen, the carbon has the pre- ference. I will not trespass on your space with a discussion of the liberation of carbon in luminous flames. Dr. Armstrong's con- tentions on that matter are of preci-ely the same character as those I have dealt with above. Dr. Frankland has promised us some new evidence in favour of his theory, I trust I have always treated this theory with respect. I am not bigoted on the subject, though I await Dr. Frankland's promised publication with the same sort of feelings as those with which a Neapolitan might look forward to the reawakening of Vesuvius. 1 have now, I hope, given an adequate reply to the question of scientific fact raised by Dr. Armstrong. I will not say much about the imputations he casts upon my scientific honesty. It ought not to be a light thing for a man in Dr. Armstrong's posi- tion to accuse a scientific worker of deluding an audience into unsound opinions by means of dazzling experiments, of playing to the gallery ; of doing, in short, just those things which are most repugnant to the conscience of an earnest investigator. After yeirs of personal friendship. I know Dr. Armstrong's idiosyncrasies very well, and they are, I imagine, pretty well Icnown to the scientific world in general. I feel compelled, none the less, to ask him either to justify or withdraw his aspersions. I make no appeal ad miscricordiam, and seek no comforting eulogy. It is a duty Dr. Armstrong owes no less to the scientific world than to myself to state clearly and precisely how I have departed from the standards of diffidence, deliberation, and exac- titude that are becoming to a man who is honestly seeking to expound the truth. This, at any rate, is a matter the settle- ment of which is not contingent upon the arrival of that chemical millennium when we shall recognise "chemical interchange and electrolysis as interchangeable equivalent terms " ; and I have the right to ask for an immediate and definite reply to my demand. Arthur Smithells. December 2. The Second Law of Thermodynamics. Clausius' supposed deduction of the second law from the ordinary equations of dynamics in the form 30 T = 23 log {lY) has been discussed at length by Messrs. Larmor and Bryan in 1 Here is a quotat'on fro n one of tiis letters to Sir G. G. Stakes : " Re- garding the inieractions in flames as consisting in a series of simultan^aui and consecutive expbsions, of whicti \va can only examine the fi ill s:eady state, it seems to me that the phenoaiena are necessarily of an excessively cjmplex character, and that their appreciati)n ani successful interpretation must tax our powers of mental analysis in a high degree. It will cartainly he unwise at present to infer ihu the oxidation of the hydroca-bo.is, or the separation of carbon anl also of hydrogen from them, takes place entirely in any one way." This seems to me like saying of a fall downstiirs, thit it is -'a series of simultaneous and C)nie:utive" bumps, &c. so diffi :ult ta trace out and presenting so many possible varieties of motion that it is hirdly -afe to call it a f-ill down stairs at all. NO, 1259, VOL. 49J their Report on Thermodynamics for the British Association. They accept the deduction on condition that the system be conservative, that is, that the exterral as well as the internal forces a.cting on it are to be derived from a potential. Now it is admitted that the equation ^ = 29 log (eT) can be proved for a conservative system with the meaning of i given in the report. But in order that this equation, how- ever true, may express the second law, T and « must be inde- pendent variables, or (which is the same thing when there is only one controllable coordinate v) T and v must be independent variables. Now the second law implies comparison of two states, in either of which a substance can exist permanently. So if we seek to prove the law, or an analogous law, for a dynamical system, it is essential that we should compare two states of the system in either of which it is in stationary fnotion. One state may have the variables T and v, and the other may have T -f 3 T and v + d v, but there must be stationary motion with either pair of values. If then K be the virial of all the forces, external as well as internal, the Clausian equation, K = 2 T must hold. But if the system be conservative, as Larmor and Bryan assume, K is a determinate function of v, and the virial equation constitutes a relation between T and v, so that only one of them is independent. For example, a fixed quantity of gas in equilibrium in a vertical cylinder under a piston of mass "w" acted on by gravity. Clearly if T be given, v, the volume, is determinate, or we have only one independent vari- able. If VI be disposable, you may make T and v vary in- dependently, but then the system is not conservative. It seems to me that Larmor and Bryan's equation does not express the second Law. Prof. J. J. Thomson, in his "Application of Dynamics to Physics and Chemistry," pages 95-103, proves the second law on a certain assumption. And Boltzmann, " Uber die Mechan- ischen Analogien des zweiten Ilauptsatzes," has proved it on, I think, the same assuinption. In order to show clearly the nature of the assumption I will begin a proof as follows, treat- ing only the case of T temperature, and v volume. If x denote the potential of all the conservative forces, p the external force necessary to maintain v constant, we have T being the mean kinetic energy of one of N molecules 3Q =N3T -f 3x + P^v. But by the virial equation ^Qy dx pdv = SNT^ 'fdv, iv dx d — in which -1^ is to be distinguished from -;rx ^s explained in Watson's " Kinetic Theory of Gases. Therefore dv' 3Q = N3T |NT3 log e/ -f 3x - '^Sz', dv 3Q T N31ogT-F|\31og now make ('X - ^f^4 (a definite time), then 3 1ogT and therefore 5Q T^ 13 log V = 23 log (jT), ?g = 2N9 1og(^T)-^,L(ax"- J>) Now J. J. Thomson assumes (p. 97) that x, in his notation V, is to be a function of v only, whence it follows that 9x - fj^ o, as he says, and so ?^ =2N3Iog(jT), which I submit as a fo-m o' his result (118). I understand Boltzmann in the treat se above cited to make the same December 14, 1893] NA TURE 151 assumption. J- J- Thomson subsequently condders the case of X being a function of T as well as of & (p. lOo). But he does not in this case make -^ a complete differential. I think that in the general case we must regard x as a func- tion of the unconstrainable coordinates, and as varying from one configuration to another, through which the system passes in the same stationary motion with constant v. When v becomes v ■\- dv we do work in two ways. Firstly, we alter the value of x for each configuration, doing thereby on the whole an amount of work equal to ^—^v. Secondly, we alter dv the comparative frequency of different values of x ii^ the stationary motion. This is essential ; for without this the system would not be in stationary motion with the altered values of T and v. I think J. J. Tnomson had this in his mind when he madex a function of T as well as v (p. lOo). Let, then, fitx^ ... dxn or/da denote the frequency of the con- figuration Xj ... x„, so that f^"" t- and j'i-'" dx = ljdx'^<^ + j xdifda) ddc refciring to variation of the limits of integration = / xd'J'^T) + 'l^^v. and so and ■I Now how to make av J ^^ = 2Na log (.T) + ljxd[fd-o thinkmg. A short article on " Water Bacteriology and Cnolera,'' by Mrs. Percy Frankland, appears in Longinatis' Maga- zine. It deals chiefly with the value of sand filtration as a means of purifying water. The report of the cholera epidemic in Hamburg and Altona has strikingly proved tliat sand-filters offer a remarkable and obstinate barrier to the passage of disease organisms, as well as the ordinary harmless water bacteria. Here is a statement of the facts : — These two cities are both dependent upon the river Elbe for their water supply, but whereas in the case of Hamburg the intake is situated above the city, the supply for Altona is ab- stracted below Hamburg ajter it has received the sewage of a population of close upon ?>oo,ooo persons. The Hamburg water was, therefore, to start with, relatively pure when compared with that destined for the use of Altona. But what was the fate of these two towns as regards cholera ? Situated side by side, absolutely contiguous in fact, with nothing in their surroundings or in the nature of their popul.rtion to especially distinguish them, ill the one cholera swept away thousands, whilst in the other the scourge was scarcely felt ; in Hamburg the deaths NO. [259, VOL 49] from cholera amounted to 1,250 per 100,000, and in Altona to but 221 per 100,000 of the population. So clearly defined, moreover, was the ])aih pursued by the cholera, that although it pu-hed from the Hamburg side right up to the boundary line between the two cities, it there stopped, this being so striking that in one street, which for some distance marks the division between these cities, the Hamburg side 7vas stiicken down with cholera, 'whilst that belonging to Altona remained free. The remarkable fact was brought to light that in those houses sup- plied with the Hamburg water cholera wa-; rampant, whilst in those on the Altona side, and furnished with the Altona water, not one case occurred. We have seen that ihe Hamburg water, to start with, was comparaUvely pure when compared with the foul liquid abstracted from the Elbe by Altona, l)ut whereas in the one case the water was submitted to exhaustive and careful filtration through sand before delivery, in Hamburg the Elbe water was distributed, in its raw condition as drawn from the river. Also in Longmans', Sir John Evans writes on " The Forgery of Antiquities." From his history of ingenious frauds perpetrated in every branch of archeology we select the following :— Of prehistoric antiquities, both in stone and bronze, forgeries are numerous, but it seems needless to enter into all the details of their character, and of the means that may be employed to detect their fraudulent origin. Suffice it to say that in the gravel-pits of the valley of the Somme and of the neighbour- hood of London the manufacture of palDeolithic implements takes rank as one of the fine arts. The chipping of the Eng- lish forgeries is superior to that of the French, but in each case the lanceolate form is the favourite. The appearance of antiquity is usually given by a thin coating of fine clay, but at Amiens a plan of whitening the flint by long boiling in the family kettle has been introduced. ... In some of the bone- caves of the Reindeer period, both in France and Germany, ancient bones have had designs engraved upon them by modern forgers, and ancient flint tools have been inserted in sockets of ancient bone so as together to form a composite falsification. Something of the same kind has been practised with regard to relics from the Swiss lake-dwelling«, many of the bronze objects from which have also been imitated by casting. Of neolithic implements forgeries are equally abundant, and in some instances equally difficult to detect. Large perforated axe heads when made of soft sandstone which could not possibly be used lor cutting purposes, of course betray themselves ; but the modern flint axes and arrowheads are not so easily dis- tinguishable from the ancient. To the experienced eye there is, however, a difference both in the workmanship and the character of the surface, the ancient arrowheads having probably been worked into shape by pressure with a tool of stag's horn, and not by blows of an iron hammer. The grinding of the edges of modern imitations has usually been effected on a revolving grindstone ; in ancient tinaes a fixed stone was always used, on which the surface and edges of axes or hatchets were ground by friction. "A Naturalist's Notes off Mull," by "Nether Loch- aber," in Good IVords^ is a chatty account well worth reading. BlackivoocVs Magazine contains a paper by Prof Andrew Seth on " Man's Place in the Cosmos," being a criticism of Prof Huxley's Romanes lecture on" Evolu- tion and Ethics." Mr. J. Bickerdyke writes on " Suc- cessful Fish-culture in the Highlands." He explains some of the facts and principles which should be under- stood and considered before Highland fish-culture is attempted, and illustrates his subject with an account of some experiinents made by Mr. Stewart at Kinlochmoi- dart. An article on " Anthropometry as Applied to Social and Economic Questions " is contributed by Mr. C. Roberts to the Hit))ianitaria7i. In it we note that the mean height of Fellows of the Royal Society is given as 5 feet 976 inches. We have also received the National Review and the Century, but neither contains any articles of scientific interest. December 14, 1893] NA rURE 157 EXPERIMENTS ON FLYING. T F we imagine the linear dimensions of a bird increased -^ n times, its weight will be increased ;r' times. On the other hand, the work necessary to keep it flying will, as Helmholtz has shown, increase n~ times. ^ Now, we can assume that the power, that is to say, the amount of work that can be done in the unit of time, increases in proportion to the weight, or even less. Helmholtz, there- fore, concluded that large dimensions are a disadvantage, and that there is a limit beyond which the power will become inadequate to the increased weight. This limit, in his opinion, is already attained in the largest birds, whose bodies appear to be constructed with the utmost economy in weight, and whose constitution and food seem adapted to furnish the highest power. And he therefore thought it improbable that man would ever be able to fly by his own power. To these discouraging observations, however, some objections may be raised. First, the work necessary to keep a bird llying horizontally depends largely on its horizontal velocity. It decreases with increasing velocity up to a certain limit, when, on account of the friction, too much work must be spent on the horizontal component of the movement. The air will carry a body moving horizontally better than a stationary one, for the same reason that thin ice will sometimes carry a skater, but break under his dead weight. The moving skater is carried as if he rested on long skates that spread his pressure over a large area. The work which is expended in flying horizontally with a sufficiently high velocity may, in spite of Helmholtz's observations, be quite within the reach of human power. The difficulty, then, would only be to start and to arrive at this velocity, and this difficulty might be met by special contrivances. The size of a flyer might therefore be increased many times without losing the possibility of quick horizontal flight, though birds must be able to do without such contrivances for starting and arriving at the necessary velocity. I Helmholtz, Gesaiiunelte Abhandlungen, bd. i, p. 165. NO. 1259, VOL. 49] A second objection is that we see many birds— and especially the large birds— when soaring, evidently doing an extremely small amount of work, or none at all, but nevertheless moving rapidly, and even rising to great heights. It seems certain 'that the wind must do the work for them. The experiments of O. Lilienthal have shown how this is effected He has made diagrams of the direction of the wind blowing over a plain, and has found it to be on the average three degrees upwards.^ His idea is that the lower regions of the air are retarded by friction against the earth, and that it is therefore heaped up. Of course the rising air or an equal amount would have to come down again somewhere, and this might take place in calm weather. But however this may be, the wind in some way or other does the necessary work for soaring birds. With a bird of linear dimensions increased n times, this work, it is true, would only increase in proportion to the surface of the wings, that is, proportional to ?/-, while the weight increases proportional to ;/^. But for man there would be no difficulty in constructing the wing surface much larger in com- parison than that of a bird. The principal difficulty would lie in the management of the apparatus, in keeping the surface in the right position according to the variations of the wind, and according to the direction that one intends to follow. Perhaps it is not greater than the difficulty a skater meets with in keeping his balance while moving in the direc- tion he pleases ; but the consequences of a wrong move- ment are worse. O. Lilienthal seems to me to have taken a step in the right direction by trying to learn soaring.^ The accompanying illustrations, which are reproductions of instantaneous photographs taken in Steglitz, near Berlin, show the way he slides down a 10. Lilienthal, " Der Vogelfliig," p. 115; see also No. 55 of P^o- jiietheiis, p. 37- * See his article in Nos. 204 and 205 of Prometheus, from which the illustrations are taken. 158 NATURE [December 14, 1893 slight decline of io~ or 15". The shape of the wings is not flat but slightly curved. The experiments recorded in his book, " Der Vogelflug," show that the curved form has decided advantages both as regards the amount and the direction of the resistance. The wing surface is 15 square metres. It is not safe to take a larger surface before having learnt to manage a smaller one. He takes a sharp run of four or five steps against the wind, jumps into the air, and slides down over a distance of about Jjo metres. By shifting his centre of gravity relatively Fig. 3. to the centre of resistance he can give the wing surface any inclination, and thereby can, to a certain extent, either slide down quicker, or slacken the movement, or alter the direction. If the wind is not too strong, and the surface of the apparatus not too large, I think there is very little danger in this kind of practice. If it is taken up by a great many people, improvements of the ap- paratus are sure to follow, and the art of keeping one's balance in the air will be developed. Perhaps this is the road to flying. At any rate it must be fine sport. C. RUNGE. NOTES. The funeral of the late Prof. Tyndall took place on Saturday, in the paiish churchyard at Haslemere. It was the desire of Mrs. Tyndall that the assemblage upon that sad occasion should not be large, so the mourners were chiefly Tyndall's close friends. Among them were the following men of science : — Prof. Huxley, Sir Joseph Hooker, Sir James Crichton Browne, Lord Rayleigh (representing the Royal Institution), Sir John Lubbock, Prof. Michael Foster (representing the Royal Society), Prof. Riicker (representing the Royal College of Science), Prof. Williamson, the Hon. Rollo Russell, Mr. Alex Siemens (repre- senting Sir William Siemens), Dr. Buzzard, and Dr. Atkinson. These mourners are eminent in many different branches of science ; and it is hardly too much to say that their presence not only marked the regard in which Tyndall is held in our best scientific institutions, but also testified to thegrief of all students of natural knowledge at the loss of one of the pioneers of the scientific movement in England. A SPECIAL general meeting of the members of the Royal In- stitution will be held on Friday, December 15, to pass a vote of sympathy and condolence with Mrs. Tyndall oa the occasion of NO. T259, VOL. 49] the death of Dr. Tyndall, who was Honorary Professor of Philosophy of that Institution. The death is announced at Paris of the biologist Dr. Chabry, knovvn for his work in experimental teratology. The Museum d'Histoire Naturelle lost its able con- chologist, M. Paul Fischer, on the 29th ult. He was born at Paris in 1835, and entered the palseontological laboratory of the Museum in 1861, remaining there until his death. The list of his contributions to the literature of science contains no less than three hundred titles, among which may be mentioned his " Histoire des Mollusques du Mexique," and' the "Manuel di Conchylio- logie," written in collaboration with M. Crosse. The friends of Dr. Julius Hann, of Vienna, will be glad to learn that he has received from the Emperor the rare decoration for science and art {Ehrenzeichen fiir Wissenschaft und Kunst). This corresponds to the Order Pour leMeritein Prussia, but is bestowed very charily, the total number of holders of it being only about a dozen. The actual decoration received by Dr. Hann had been set free by the death of Prof. J. Stefan, the physicist. Prof. Riggenbach has been elected a Correspondent of the Paris Academy, in the place of the late Dr. CoUadon, Dr. J. Russell Reynolds, F.R.S., has been elected President of the Royal Col- lege of Physicians, in the place of the late Sir Andrew Clark. The eleventh International Medical Congress will be held in Rome, from March 29 to April 5, 1894. A Reuter's telegram from Berne announces that the Federal Council has decided to introduce the time of Central Europe into the Swiss postal telegraph, railway, and steamship ser- vices on June i, 1894. A PRIZE of 3000 liras is offered by the R. Istiluto Veneto di scienze lettere ed arti, for the most important innavation in Venetian pisciculture. The research for which the prize will be awarded may relate to the artificial hatching of the eggs of any important species of marine fish, the introduction of new species, improvements in methods of ostriculture, or the production of better kinds of fish. For some time negotiations have been in progress for the pur- chase of the Little Barrier Island, with a view to setting it apart as a home for New Zealand fauna. We are glad to learn that the island has now been obtained from its owner, and that there is nDthing to prevent the scheme being carried into effect. The Kew Bulletin (Appendix i. 1894) contains a list of seeds of hardy herbaceous plants and of trees and shrubs available for exchange with colonial, Indian, and foreign Botanic Gardens, as well as with regular correspondents of Kew. No application for seeds can be entertained after the end of next March, except from remote colonial possessions. The Director of the Botanic Garden of Rio de Janeiro has prepared and issued a list of plants cultivated there, and oftered in exchange. A descriptive catalogue will shortly be published containing a description of each separate species in the Garden. December 14, 1893J NA TURE '59 The w eather during the past week has been very unsettled ■over the whole of the British Isles, owing to the approach of several large depressions from the Atlantic. On the 6th a large disturbance passed eastwards to the north of Scotland, causing south-westerly gales in the north and west, and during the night of Thursday, the 7th, another deep depression advanced from the south-westward, attended by serious gales in all parts, but of great severity in Scotland and in Scandinavia. The barometer at Stornoway fell to the exceptionally low reading of 27*97 inches during the afternoon of the 8ih, giving a dilTerence in the pressure of nearly an inch and a half between the extreme north and south of our islands. Further disturbances arrived from the westward both on Sunday and Tuesday, again causing gales from the south-east and south. The storm on the latter day was chiefly restricted to the southern parts of England and the northern parts of France, and has not been exceeded in violence by any that has visited our southern counties this season. Several places reported force 11 of the Beaufort wind scale. Much rainfall and some sleet accompanied these various disturbances ; in the north of Scotland I "2 inch of rain was measured on the morning of the •9th, and the Meteorological Office Reports for the week ended the 9th inst. sho.v that in that district the rainfall greatly exceeded the average, the total amount being 2 '6 inches, while in most of the English districts the fall was less than the average. It is now known that the earthquake which affected Tashkend on November 5, was also felt in other parts of Russian Turkestan. At Samarkand it was felt one minute later than at Tashkend — that is, at 8h. 232T1. a.m., and pretty strong oscillations of the soil lasted for about \\ minutes. Crockery was shattered, and the water in the ponds and irriga- tion canals was set in motion. At Marghelan the strongest shock took place at gh. 35m., and lasted for about five seconds ; it was followed by a feebler o.ie about three minutes later. On November 5, the magnetic instruments at Potsdam were disturbed in a manner which showed that a distinct earthquake had reached the observatory. The supposition that such a cause produced the movements of the needles was afterwards confirmed by the record of the seismometer of the geological laboratory of the Faculty of Sciences at Grenoble. From the magnetic curves at Potsdam it appears that the wave reached the observatory at 5h. 4m. 503. a.m. (Potsdam mean time), and prodaced the greatest effect at 5h. 8m. 55s., a vibration also being recorded at 5h. 7m. 155.. According to Ct?w//i?i A'^wj'/^i' of November 6, the shock was first felt at Grenoble at 4h. 50m. 35s. (Potsdam time), hence the time taken to travel a distance of about 956 kilometres was 8m. 15?. The rate at which the wave was propagated was therefore about i 94 kilometre per second. It is estimated that the time can be read off from the magneto- graph curves with an accuracy of ten seconds. A FEW months ago the President of the Alpine Club invited the co-operation of the Government of India in obtaining a record of observations on the movements of glaciers in the Hima- layan Range, to supplement a similar record maintained of the movements of glaciers in Eurjpe. Believing that such a record would prove of importance to geological and meteorological science, the Government have communicated with officials and others who are stationed in or near the snows, or who may visit from time to tine the glacial regions of the Himalayas. Copies of the Alpine Club's memorandum of instruction in glacier observation have been forwarded to the Foreign and Military Departments of the Government of India, the Governments of the Punjab, North-Western Provinces, and Oudh and Bengal, the Meteorological Reporter, and the Director of the Geological NO. 1259, VOL. 49] Survey, for distribution to suc'.i officers as may be in a p^sition to supply the requisite information. The energetic action of the Indian Government in the matter deserves high praise, and it will doubtless result in some interesting data being obtained. A COPY of the splendid volume published in honour of M. Pasteur's jubilee has been sent to us. It opens with a brief account of the formation of the memorial committee ; this is followed by a reprint of the address delivered by M. C. Dupuy at the jubilee celebration, and of the numerous addresses and telegrams received from ail parts of the world. The volume also includes five beautiful plates, three of which represent medals struck in M. Pasteur's honour, one the invesii^jator himself in his laboratory, and one is a fac-simile of the address presented by the Stockholm School of Medicine. This testimony of the esteem in which Pasteur is held brings to our mind the words, "Wisdom raineth down skill and knowledge of under- standing, and exalteth them to honour that hold her fast." At the Adelaide meeting of the Australasian Association for the Advancement of Science, a lecture was given by Mr. C. W. deVis, on the " Diprotodonandits Times." Popular interest has lately been aroused in this subject owing to an important dis- covery of fossil marsupial bones at Lake Mulligan. Mr. de Vis pointed out the mistake of the current idea that the Diprolodon was a gigantic kangaroo, any great resemblance between the two being confined to the teeth. In general build, Dlprotodon was more like a wombat, but the bones of the ^thigh were even longer in proportion to those of the lower leg than is the case in the wombat, hence it might be concluded that the Dlproto- don was less capable of rapid motion than the wombat. The spongy texture of the bones of the skeleton indicates that it frequented lakes and marches. There were two species of Diprotodon found in Central Australia — D. australis. Owen (circa 6 feet high and 10 feet long), and D. ?>iinor, Huxley (circa 5 feet high and 8 feet long). The arid central plains of the present had been occupied in Diprotodon times by vast ex- tents of luxuriant forest and richly vegetated districts, well- watered by wide rivers. The marsupials were even then the dominant type of life in Australia ; lizards were also numerous, and some were of unusually large proportions, e.g. Megalania, an extinct "guana," 18 to 20 feet in length. Extinct forms of alligators and turtles infested the waters, and amongst the fishes was the still existing Ceratodus. The remains of a varied bird fauna have been well preserved in the same deposits. This fauna included some ancestral forms conaecting, on the one hand, the wingless birds of New Zealand with the Australian emu^, and, on ihe other hand, theAustralian birds with the New Zealand Apteryx. ^Ir. de Vis was inclined to attribute the disappearance of so many of these ancient forms of life from Australia quite as much to senile decay as to altered climatic influences. The slow ascensional movement of Scandinavia, evidenced by the displacement of tide marks, the peculiarities of Scandma- vian lake fauna, and other geographical and geological phenomena, is subjected to mathematical investigation by M. A. Badonrean, who, in the Comp'cs Rendus of last week, treats the subject from the point of view of thermal expansion. At the time of the last glacial epoch, the Scandinavian ice-sheet covered the greater portion of the peninsula, as well as Finland and the Baltic, the area of this sheet being about 1500 km. in diameter. \Yhere the soil touched and partly liquefied the mass of ice, its temperature must have been o^ C. At the present time, the mean temperature of the soil over the area of the ancient ice-sheet is 3^ C. Taking the coefficient of expansion of the rocks as eight-millionths, the elevation of the centre of the ice- cap is calculated at 229 m., and the isoanabatics, or lines of equal i6o NATURE [December 14, 1893 elevation, should be parallel to the contour. De Geer's map of these isoanabatics, traced in 1890, satisfies these conditions, allowance being made for the want of homogeneity in the rocky mass, and the want of lixity of its borders. An interesting account of a fine series of glacial potholes on Cooper's Island, Little Harbour, Cohasset, U.S., is given by Mr. William O. Crosby, in a paper on the "Geology of the Lujton Basin " (Occasional Papers of the Boston Society of Natural History, IV.). It is shown that the potholes were formed by vioulitis, or glacier mills, and Mr. Crosby discusses a question raised in these columns a short time ago, viz. why, as the ice-sheet moves continuously forward, carrying the crevasses and mouliiis with it, the potholes escape elongation in the direction of the movement ? The true explanation of many glacial potholes is found in the fact, that a crevasse closes as it is carried forward by the general movement of the ice, a new one subsequently being formed just where in relation to the land at the margin of the glacier the former one existed. This explanation, however, is not applicable to the Cohasset pot- holes, and in place of it Mr. Crosby makes the suggestion that a moiilin may remain approximately stationary, while the ice moves on, through the backward erosion and melting of its up-stream side ; and that when a pothole is formed at the bottom of a motdin, it is not the direct impact of the water upon the face of the ledge that does the work, nor do the stones carried down by the water wear the ledges appreciably by their direct fall, but the pothole is due to their subsequent move- ment, and especially their rotation, by the water. This rota- tion implies an antecedent depression or hollow to hold the stones, and thus the conditions are seen to be essentially the same as for ordinary river potholes. Since the rotation of stones in a pre-existing hollow appears to be an essential con- dition of glacial as of other potholes, and the moulin simply supplies the power, it would seem to make little or no dif- ference whether the water plunges into the up-stream side, the middle, or the down-stream side of the hollow. The pothole is made where the hollow exist-, and during the progress of a moiiIin across the hollow, there would not, apparently, be any marked tendency to elongate it. In the case of a linear group of potholes on the iceslape of a ledge, concludes Mr. Crosby, it is reasonable to suppose that the upper one, which on Cooper's Island is always the smallest and most indefinite, marks the shifting position of the 7iioiilin, and that the others were formed by the subglacial flow of water from the bottoin of the jnoulin. It has been supposed, say? Mr. A. J. Jukes-Browne, in the Geological Magazine for December, that the total amounts of silica existing in the chalk with flints and the chalk without flints respectively, are very nearly equal ; and this supposition favours the theory that flints have been formed by some process of segregation after the consolidation of the chalk containing them. It is generally conceded that the silica from which such flints were ma'ie was a soluble form like that of sponge spicules, diatoms, or radiolaria ; hence by chemical analyses, aided by microscopical discrimination between crystalline and colloid siliceous particles, it is possible to determine whether flintless chalk always contains soluble silica, and whether chalk with flints contains little or none. Mr. Jukes-Browne has made this investigation, and he finds that there is no definite relation between the occurrence of flints and the absence or presence of soluble silica in the surrounding chalk. He thinks that chalk which is now destitute of any remains of siliceous spicules, has, since it became chalk, always been destitute of such spicules. These conclusions have a very important bearing upon the question of the formation of flints. NO. 1259, VOL. 49] In a recent number of the Comptes Rendns, M. A. Dele- becque gives the results of some observations made la^t summer on water from various depths in inland lakes, which show that the amount of solid matter in solution increases with the depth. Thus in the lakes quoted below the amount of dissolved solid matter in grammes per litre was : — Annecy, surface o'i38, bottom (65 metres) 0'I57 ; Aiguebelette, surface o'li4, bottom (71 metres) o'i6o5 ; Nantua, surface o'i54, bottom (43 metres) o'igo ; Saint-Point, surface 0'I52, botto;ii (40 metres) o'i82 ; Remoray, surface o'i6o5, bottom (27 metres) 0'205 ; Crozet, surface 0'0275, bottom (37 metres) o'0368. The water samples were collected about 3 metres above the bottom, by means of Dr. H. R. Mill's water-bottle. M. Delebscque agrees with Dr. Duparc, of Geneva, that the small amount of dissolved matter in the surface water is due to its removal by the cal- careous organisms which swarm in the upper layers. The Philosopliical Magazine for December contains a paper, by Sidney J. Lochner, on the elongation produced in soft iron by magnetisation. The author undertook the investigaion of this subject in order, if possible, to settle whether the experi- ments of Bidwell or Berget represented what really happens. In order to measure the elongation, what was essentially a Michelson's interferential refractometer was made use of, which was capable of measuring an elongation of a millionth of an inch. The bar of iron, whose elongation was to be measured, was placed inside a long magnetising coil, and carried at one end one of the mirrors of the refractometer. The expansion due to the heating eflect of the coil being slow, while that due to magnetisation was rapid, the two could be distinguished. The author finds that, for a given magnetising field, different elonga- tions are produced according to the manner in which the magne- tising current is applied. Thus different elongations were pro- duced in the cases where the current had been turned on suddenly, or had been applied gradually ; and in the latter case it made a difference whether the current had reached its final value by in- creasing slowly, or by decreasing slowly from a higher value. Another peculiarity observed was that if the current be gradually increased from zero, at a certain point a maximum expansion is reached; after this a further increase of the current will produce a decrease in the elongation ; if, however, instead of increasing the current when the maximum is reached, it is gradually de- creased, it is possible to obtain a still greater elongation. The observations show that the expansion is a function of the ratio between the diameter and length of the bar, and that the elongation varies approximately directly as the square root of this ratio ; also, the expansion varies directly as the permeability. The amount of current required to produce the maximum ex- pansion also depends on the ratio between the diameter and length. The bacterial efficiency of porous cylinders in the filtration of water for domestic purposes is the subject of considerable dis- cussion just now. Kirchner [Zeitschrift f. Hy^s^iene, vol. xiv, p. 307) found in his expeiiments with water purposely infected with typhoid bacilli, that such filters were incapable of arresting these organisms. Large quantities of typhoid infected broth were added to the water before filtration, and the filtrate after 48 hours was found to contain very large numbers of typhoid bacilli. Dr. Schofer, in a recent number of the Centi-alblalt f. Balderiologie, vol. xiv. p. 685, gives the results of his investiga- tions of porous cylinders as regards their retention of typhoid bacilli. In these experiments as small a quantity as possible of nutritive material was added with the typhoid organisms to the water (previously sterilised), and even after 24 days the filtrate was found to be perfectly sterile, al; hough the unfi'.tered water was freshly infected with typhoid bacilli no less than twelve limes during the investigation. Very different results were, December 14, 1893] NA TURF. 161 however, obtained when broth was purposely added to the un- filtered water, an addition of as liltle as 5 c.c. to 6oo c.c. of water so stimulating the growth of the typhoid organisms, that two days later they appeared in the filtrate ; the numbers present, however, gradually decreased, but on again adding 5 c.c. of broth they rose on the following day from 9 to 6,139 per c.c. This large increase was due to the rapid multiplication of the few isolated bacilli still remaining in the pores of the filter in consequence of the supply of food material to the water in the shape of broth, for no fresh infection with typhoid organisms had taken place. Dr. Schiifer is of opinion that typhoid bacilli as present in water, under ordinary circumstances, are not sup- plied with the requisite conditions for their growth and multi- plication, and are, therefore, incapable of growing through these porous filters, and so reaching the filtrate ; but these conditions are, however, undoubtedly furnished when a sufficient supply of food material is contained in or added to the water, under which circumstances the cylinders are unable to retain them. These experiments not only explain the unsatisfactory results obtained by Kirchner, but indicate what precaution? should be taken in the bacteriological investigation of such filters. The last two parts of the well-known "Notes from the Leyden Museum," forming parts 3 and 4 of vol. xv., were pub- lished in July and October. They contain numerous papers describing new or rare species of mammals, birds, reptiles, &c. , added to the museum. Among the articles we notice one which is by F. E. Blaaum, the Secretary of the Z )ological Society of Amsterdam, on a comparative list of the birds of Holland and England. Holland, although so much smaller than the United Kingdom, is the regular abode, at different seasons, of 221 species of birds, whilst the British Islands can only boast of 211. Dr. R. Horst continues his descriptions of earth-worms, giving a list of species found, for the most part by Dr. 11. ten Kate, during his journey in the Malay Archipelago in 1891. A large number of the species belong to the geu'is Perichasta, of which no less than seven species are described as new, bringing the number of the species of this genus already found in the Malay Archipelago to thirty-three. The following note, by Dr. Jentink, will be interesting to others besides book collectors. In the Proceedings of the Ziological Society of Lond)n for i8So (p. 489), Mr. F. II. Waterhouse gives the dates of the publica- tion of the parts of Sir Andrew Smith's "Illustrations of the Zoology of South Africa," and states that as the copy he examined "did not contain plates 18 and 38 (Mammalia), he had examined three or four other copies, and as neither of these pUtes are to be found in any of these, he presumed they do not exist." Now, in the copy in the Leydea Museum's library, plate 3S is present, but plates iS and 37 are wanting, and at the bottom of the page containing an index of the Mammalia, there is the following : " Plates 18 and 37 7iot published." Librarians will call to mind how often the collating of this fine work has perplexed them. The Royal Meteorological Institute of the Netherlands has recently issued its Jaarboek and Onweders in Nederland for the year 1892. The first work has been regularly published for forty-four years, and now contains hourly observations taken at four stations, in addition to those taken at specified hours at a number of other places. It also contains observations taken in Surinam (South America) and French and Upper Congo. The second work is the thirteenth of the series, and contains a dis- cussion of each of the ihunderstorms which have occurred dur- ing the year, with reference to the general weather conditions over Europe. We have received from Mr. John Elliot, the Meteorological Reporter to the Government of India, the daily weather charts of January, 1893, for the Indian sea and land areas. NO. 1259, VOL. 49] MM. J. B. Baillu'cre et Fils, Paris, have issued an ornithological bibliography containing announcements of five or six hundred works on ancient and modern bird-. Herr Moritz, Berlin, has published Nos. 1-4 of his " Anli- quariats-Katalog." The catalogues are of special interest to geographers and anthropologists, and they contain many rare works. Messrs. Friedlander and Son, Berlin, have sent us Nos. 16-21 of their " Naturte Novitates." These bibliographical lists contain works in every branch of science, an 1 are invalu- able to the scientific book-hunter. Another catalogue, recently issued, is one containing the titles of works on geology offered for sale by Messrs. Dulau and Co. The first number of the Psychological Revieiv will be pub- lished early in January, by Messrs. Macmillan and Co., London and New York. It will be edited by Profs. J. Mark Baldwin (Princeton) and J. McKeen Cattell (Columbia). The Revinv is intended to contribute to the advancement of psychology by publishing the results of original research, constructive and critical articles, &c., in connection with the subject. The American Naturalist for November contains several in- teresting articles. Mr. Howard Ayers writes on the genera of the Dipnoi Dipneumones, and Dr. J. Weir gives a number of examples of animal intelligence. A collection of molluscs from North-Western Louisiana is described by Mr. T. Wayland Vaughan, and Mr. H. C. Mercer compares the Trenton and Somme gravel specimens with ancient quarry refuse in America and Europe. Messrs. Newtox and Co. have issued a new catalogue of optical lanterns, microscopes, and polariscopes fir demonstra- tions in science. There are very few class experiments that do not admit of being projected upon a screen by means of the many good lanterns in the market, and certainly there is no better method of demonstrating scientific facts to a large audi- ence. One of the finest lanterns made by Messrs. Newton is the tiiple rotating electric lantern designed by Sir David Salomons. We learn that the Royal Society has just ordered an instrument of this kind. A general method of artificially preparing crystallised anhydrous silicates similar to the naturally occurring pyroxenes, is described by Dr. Hermann Traube in the current Berichte. It consists in precipitating the particular metallic silicate, which it is desired to obtain in anhydrous crystals, by the addition of a solution of sodium silicate to a solution of a s-alt of the metal. The amorphous hydrated silicate thus precipitated is heated to a high temperature with boric acid for some hours. When most of the boric acid has volatilised, the anhydrous metallic silicate is usually left in the form of good crystals. Ebelmen has already succeeded in artificially preparing the magnesium pyroxene MgSiOg by this method ; and Dr. Traube now ex- tends its application. When precipitated silicate of zinc, for instance, obtained by the addition of a solution of sodium sili- cate to one of zinc sulphate, is dried, and then heated with eight times its weight of fused boric acid, in a platinum crucible, for a few days, to the highest temperature of a porcelain manu- facturer's furnace, a large proportion of the boric acid dis- appears by volatilisation, and upon extraction of the remaining portion from the cooled residue with water, beautiful little in- soluble crystals of anhydrous silicate of zinc, ZnSiOj, remain. When examined under the microscope these crystals are observed to be perfectly transparent prisms with domal terminations. Their optical characters indicate that they belong to the rhombic sjstem of symmetry. This artificial silicate of zinc would thus l62 NA TURE [December 14, 189; appear to be isomorplious with the naturally occurring mag- nesium silicate, enstatite, MgSiO;,. The method is also appli- cable to the synthesis of complex mixed silicates, and it is possible by means of it to reproduce almost any of the naturally occurring silicates of this class. At the last meeting of the Southern District Association of Gas Engineers and Managers, Dr. ]>. T. Thorne gave an a'-co'cnt of further experiments with the new process for enriching coal gas by means of oxy-oil gas. Dr. Thorne has been enabled to carry out an exhaustive series of tests at Huddersfield, where the process is now in actual operation. His conclusions are summarised as follows : (l) The addition of oxygen to oil gas, preferably while the latter is still hot, not only increases the illuminating value of the oil gas when employed directly as illuminant, but also when it is used for purposes of enrichment. (2) Oxy-oil gas is a highly permanent gas, and when used as an enricher of coal gas actually increases the stability of that gas. (3) Enrichment of coal gas by oxy oil gas would cost about one- ihird of a penny per candle per thousand cubic feet. Dr. Thorne concludes by expressing the opinion that the experimental results place oxy oil gas at the head of the enriching processes yet known, and fully justify the favourable view of the process which was expressed in an earlier communication. With regard to the actual working of the Huddersfield plant, we learn from London, the organ of the London County Council, of November 30, that the Huddersfield Corporation have now used the new gas continuously for over two months, and have obtained a steady white flame, affording a belter light, while enabling a saving to be effected at the rate of ^10,700 per annum. They are now using 36,000 cubic feet of the new gas per day for enriching the ordinary product. They have been in the habit of enriching their ordinary gas, which is of about six- teen candle power, to the extent of four additional candles, by means of cannel coal. The cost per candle at Huddersfield, using Yorkshire cannel, has been about three-halfpence per cubic foot. With the new plant of the oxy-oil process the actual working cost is at present less than a halfpenny per candle per thousand cubic feet, and will eventually be still less by thirty per cent, or more, as crude petroleum is rapidly becoming cheaper. Moreover, the coke produced from cannel coal is so useless that the Huddersfield Corporation have been unable to dispose of it, even to give it away. Under the new process they find no difficulty in selling all the coke they can produce, for seven shillings and sixpence per ton. The saving due to enrichment amounts to /,7,700 per annum, and the gain from sale of coke to ;^3,ooo, results which will have the practical effect of reducing the price of gas to the consumers at Hudders- field by at least threepence per thousand cubic feet, while supplying them with a more cheerful light which is stable even in winter. Notes from the Marine Biological Station, Plymouth. — There has been little that is novel to record lately, owing to the inability of our small boats to face the stormy seas. Last wetk several specimens of the Teleostean ScicTiia ttinbra were brought in, and the Nemeitine Eiifolia cuita (second capture) and the Crustacean Gebia slcllala were taken in the Sound. The floating fauna is poor as a rule, but there is an increasing number of Annelid trochospheres, Scyfhonatites and Opistho- branch veliger-. There is a noteworthy scarcity of Medusa;. The Anlhozoa Akyonium digitatum and Ccreiis fedunculatits (= Sagartia bellis), and the Crustacea Pandahis anmtlicorms, Crangon Z'/z/far/.f, and one-year-old Carcinusmcenas have begun to breed. The additions to the Zoologicrl Society's Gardens during the past week include a Pale-headed Parrakeet {Platycernis palli- diccps) from North-East Australia, presented by Mr. C. B. NO. 1259, VOL. 49] Lewis; two Common Crossbills [Loxia cinviiosifa), a Song Thrush {Tvroiis ti.uiictis) British, piesented by Mr. H. C. Martin ; two Alligators {Alligator misnssiffiens-s) from the Mississippi, presented by Mr. Austin [E. Harris; a Chacma Baboon {Cyiioc(fhaliisf07caiiiis,'i) frcm South Africa, pre- sented by Mrs. Rowland Tomson ; two Leopards {Felis pardvs) from India, deposited ; thirteen Rufous Tinamous {Rhynchctus rjifescew:) from Biazil, purchased ; a Japanese Deer [Cervus siia, 9 ) born in the Gardens. OUR ASTRONOMICAL COLUMN. New Notation for Lines in Spectrum of Hydrogen. — The application of the photographic plate to that important instrument of physical astronomy, the spectroscope, has brought to our view, in addition to the lour well-known lines of hydro- gen in the visible part of the spectrum, another set of similar lines, the first of which, havirg a wave-length less than that of Hj, coincides with one component of Hj of the broad double line in the solar spectrum which Fraunhofer termed H. The second component, written H^, or K, is wanting in many stars of Vogel's class la ; yet its comcidences with the line Ho or K, where in this class another line in the region of Hj makes its appearance, became established, so that no opportunity offered itself to make a special nomenclature for the two first lines above PL/ outside of the star's spectrum situated in the violet region. The other lines Huggins named with the Greek cha- racters o, y3, 7, &c. A new system of nomenclature, suggested by Prof. Vogel, in the Astronomischcn Nachrichten (No. 3198), has many points in its favour. The four lines in the visible region, C, F, G, and h, retain their old signs of Ha, H/8, Hy, H5, but H or Hj is here changed to Hf, and the a, ;8, 7 lines of Huggins to H^, PI 77, &c., thus makirg the nomenclature thorovghly consecutive. Prof. Vugel says that in future he shall adopt this new notation, and that Dr. Huggins has also agreed to the arrangement, viz. that the hydrogen lines should always have the elen:ent sign H coupled with a Greek letter as index, as shown in the following table, in which aie given the new and old notations with the wave-lengths : — Notation. Wave-lengths. ^ New. Old. 656-3/^ JU Ha HaorC 486-1 Hy3 HyS or F 434-1 117 H7 (written often w rongly with G) 4IQ'2 H5 PI 5 or h 3969 He H or Hi 3889 HC a 383-6 Hr, /3 379-8 He 7 377-1 IL S 375-0 \\k 6 373-4 Ha c 372-2 Hm y\ 371-2 H^ d 370-4 H| I The Spectrum of Nova Norm^.— Prof. Pickeiing, in Astrcnc7nischcn- Nachrichten, No. 3198, gives some details about the discovery of the new star in Noima. The star was found by Mrs. Fleming on October 26 when, examining a photograph of the sfcctra of the stars in this constellation, the negative having been taken by Piof. S. J. Bailey at the Arequipa station ori July 10, 1S93. Comparing the spectrum with that obtained in the case cf Nova Aurigre, nearly the same dispeision having been employed, it seems that they are nearly identical — "about a dozen lines are visible in each, and are identical in wave-length." The line F, although bright in both stars, is more intense in Nova Norma;, and, further, is more intense than any other line, while G was generally strongest in Nova AurigK. With regard to the lime of the outburs; of this new star, photographs indicate that it must have occurred within ihe first ten days of July i. A photograph laken June 21, December 14, 1893] NA TURE 163 1S93, shows no trace of it upon the plate exposed to that region, while charts of the same region taivcn on June 6, June lo, July 21, 1889; May 16, May 16, June 10, June 23, June 23, 1S91 ; May 7, and Mav 27, 1893, also give no indication of a star in that position. The similarity of the spectra of these two new stars is of interest, as Prof. Pickering points out, in that it has proved a means of discovering one of these objects, and that, if confirmed by other new stars, it will indicate that they lielong lo a "distinct class resembling each other in composition and physical condition." The nearest catalogue stars to which the Nova lies are Cord.G. C. 20,940 and Cord.G.C. 20,926 of the 8 and 875 magni'.ude respectively, the Nova being nearly mid- way between them. We may add that the above communica- tion seems to throw some doubt on the accuracy of the note we wrote three weeks ago (November 23), with leference to Prof. Kapteyn's search through his Durchmusterung. Until the exact ]iosilion of Nova Normce is obtained, one cannot of course make any statement, but it seems probable that Prof. Kapteyn's and Mrs. Fleming's stars are not the same. Prof. Rudolf Wolf, of Zlirich. — We are very sorry to have to record this week the death c f Prof. Rudolf Wolf, the well-known director of the Zurich Observatory. He died at midday on November 6, after a short illness, at the age of seventy-eight years. By his death astronomical science has lost one of her most devoted servants. It was through his work, coupled with that of Schwabe, that the existence of the periodicity of the sunspots was without doubt first accepted, and its length determined to be eleven and one-ninth years. The deceased was, among other things, the author of the work on the " Geschichte (ler Aatronomie," and also of a " Tachen-buch Kir Malhematik, Physik, Geodiisie und Astronomie," both of which ran through several editions. The Companion' to the Observatory. — The Companion for •he) ear 1894 follows the same lines as it has done in former years. No additional matter has here been added, unless we mention the ephemeris for the elongations of the satellites of Mars, which planet comes into opposition during next year. We notice that in Mr. Denning's list of meteor showers, instead of November 27, he has this year thought fit to alter it to November 23-27, an alteration justifiable by facts. With regard to eclipses, on March 20-21 a partial eclipse of the moon will take place, but will be invisible at Greenwich. An annular eclipse of the sun, just visible as a partial one in Norway, S^veden, Eastern Europe, and Asia, occurs on April 5, while on September 14 a partial eclipse of the moon will be partly visible at Greenwich. The total eclipse of the sun, on September 28, lasts only for eleven seconds (maximum duration), and as the path of the centre of the shadow lies entirely across the Southern Indian Ocean, the occurrence is of little scientific interest. On November 10 a transit of Mercury across the sun's disc will be partly visible at (Greenwich, the first contact taking place before sunset. Thp times are — Ingress. Egress. h. ni. s. h. m. s. Externa! contact ... 3 55 40 9^3 9 Internal ,, ... 3 57 23 9 n 26 Yox the sun in the zenith at the time of egress, the place of ob- servation lies 63" W. and 17' S. or in Bolivia, South America, that for egress lying 142° W. and 17° S. Solar Observations at Rome. — In the September number of the Mcniorie della Socitta degli Spettroscopisti lialiaiii, Prof. Tacchini csntributes the results of the solar observations made at the Royal Observatory during the second and third trimestre of 1S93. The same number also contains two large diagrams of the limb of the sun, the first showing the observations made a". Catania', Palermo, and Rome, during the second three mouths of the year 1892, and the second indicating observations made at the last-mentioned place during June and Julj'. GEOGRAPHICAL NOTES. Mr. R. D. Oldham, Superintendent of the Geological Sur- vey of India, read a paper at the last meeting of the Royal Geo- graphical Society, on the evolution of the geography of India. He pointed out that the three main divisions of India were natuial regions the individuality of which ha I been marked throughout a long range of geological tin.e. The peninsula NO. 1259. VOL. 49] consists of very ancient land which has not been submerged since the early Palceozoic period, while the continei tal division has been frequently under water until Tertiary times, and the great plain is relatively recent alluvium. There is evidence Irom the close resemblance of fossil forms of a continuous land connection between India and Africa in the Cretaceous period. This former continent has been named Gondwana Land, and must not be confused with the hypothetical continent of Le- muria. It had disappeared by the end of the secondary pt-rioJ. At the close of the Cretaceous period there was an unparalleled outburst of volcanic activity contemporary with a series of great earth-movements which went far to give its present outline to peninsular India, and led to the first appearance of the extra- peninsular mountains. This activity continued during the Tcitiary period. The depression at the base of the Himalaya, now filled up by alluvium, was simultaneously formed. The Indus was the original outlet of drainage from the Himalayan district, the river system splitting up later, and the diversion of the Jumna to the Ganges may even have occurred in hist >rical times. The latter part of the paper gave an able summary of Indian types of scenery. The crossing of the eastern horn of Africa is fast becoming one of the commor places of travel, having been again accom- plished this year by Prince E. Ruspoli, who, starting from Ber- bera in December last year, reached the Jub in March. Tlie last number of the Bulletin of the Italian Geographical S 'ciely contains a letter giving an account of the journey and a sktr-tch- map showing his route. Another Italian expedition, under Captains Bottego and Grixoni, made the journey by a somewhat different route about the same time. The VerhandluMgen of the Berlin Geographical Society states that the Swedish traveller in Persia, Mr. Sven Hedin, has undertaken a serious attempt to reach Lhasa in the disg lise of a Persian merchant. He willstart from Leh,and follow the route of the Pundit Nain Singh to Tengri-Nor. The death is reported of Dr. D. Scott Moncricfif, of Harvard University, who had been making a journey of e Vignon. If a solution of sublimate of i grain to i litre of distilled water is left to itself for a fe* days at the or- dinary temperature, it gives rise, in a period varying from one to three days, to a white precipitate whose quantity grailually increases. Quantitative measurements of the amounts of mer- cury thus precipitated under varying conditions gave the folio a'- NO. 1259, VOL. 49] ing results. When the solution was left in an open vessel, the percentage of mercuiy left in solution after seven days was 0-57, in a closed vessel 0-97, and 0-67 after 220 days. When colouring matters were added to the solutions, the corresponding numbers were, for fuchsine, 067, 0-97, and 077 ; and for indigo carmine, 076, 0-98, and o 80, the latter therefore giving the greatest sta- bility.— Discovery of abrastol in wines, by M. Sangle-Ferricre. This gives a method of finding whether abrastol, a new antiseptic for the preservation of wine, has been used in a given sample. It is the sulphuric ether of /Snaphthol combined with calcium. The method utilises the decomposition ensuing when abrastol is heated with dilute H CI, calcium carbonate, sulphuric acid, and /3-naphthol being formed.— On the sterilisa'ion of bread and biscuit on coming from the oven, by MM. Balland and Masson, This gives an answer to the question whether all dangerous germs which may have been contained in the water used for breadmaking, are destroyed during the process of baking. Experiments show that microbes in general are incap- able of resisting the acidity of the dough and the high tempera- ture of baking. Certain spores notorious for their stability are indeed capable of regaining their activity under favourable circumstances, but all pathogenic bacilli, especially those of typhoid and of cholera, are certainly destroyed. — Some chrono- metric data relating to the regeneration of nerves, by M. C. Vanlair. — On the termination of the motor nerves of striated muscles in the Batrachians, by M. Charles Rouget. — On some points relating to circulation and excretion among the cirrhiped.--, by M. Gruvel. — On phosphaturic albu iiinuria, by M. Albert Robin. The consatution of the group of phosphaturic album'n- urias, shows that the morbid entity known as Brighi's disease, is often nothing but the anatomical complication of an anterior purely functional malady, and that, like a number of similar cases, the cure should begin at this anterior functional disorder. — Parasites in cancer, by M. G. Nepveu. — The shell cavity of the Philinidte, by M. P. Pelseneer. — On a new gregarine of the Algerian Acridians, by M. L. Leger.— On the exchanges of carbonic acid, and oxygen between plants and the atmospher-*, byM. Th. Schlcesing fils. —Observations on the coi stituti^nof the membrane in mushiooms, by M. L. Man.;in.— On the primary strata of Saint-Pons (Herault), by MM. P. de Rouville, Aug. Delage, and J. Mique'. — On the Triassc and Jurassic form i- lions of the Balearian Isles, by M. H. Nolan. Berlin. Physical Society, November 3. — Prof, du Bois Reymond, Piesident, in the chair. — Dr. Rubens discussed the experiments of Righi, who had succeeded in obtaining Hertz's oscillations of much smaller wave length than had hitherto been found po^ sible. Whereas the shortest waves obtained by Hertz were 55 cm. long, and those by Dijppler 20 cm., Righi had produced waves only 7"5 cm. in length, and had repeated all Hertz's experi- ments in a much more convenient form. Rubens hadsomewhu modified Righi's experimental arrangements, and produced waves 10 cm. long, which he intended to submit to further investigation. November 17. — Dr. O. Fro'ilich explained a generalise I form of Wneatstone bridge, and a series of applications of the same for theoretical and technical purposes. Dr. Bllime demonstrated a form of apparatus for showing refraction suitable for use in schools, giving accurate results to the thiid place of decimals with very little practice. Physiological Society, November 10. — Prof, du Bois Reymond, President, in the chair. — Dr. Gumlich gave an account of feeding experiments made on dogs with nucleic acid, which showed an absorption of this substance by the animal organism. The phosphates of the urine were increased, as also the nitrogen of its extractives. There was no increase of uric acid. — Dr. Gold-cheider made further communications on leucocytosis. His experiments, carried on in conjunction with Dr. Jacob, had shown that after the injection of hemialbumose, or extract of spleen, and other substances with similar action, there is a diminution (hypocytosis) in the number of leucocytes, followed by a rapid rise in their number up to the normal and then to a permanent increase above the normal (hypercytosi.-). When the active substance was injected into the jugula', it was found that during the brief period of hypocytosis the capillaries of the lungs were abnormally filled wi:h leucocytes. Later on, there was a still further increase in this region at the time of increase of leucocytes in the blood generally. By using smaller doses of the active substance the stage of hypocytosis could be lessened i68 NATURE [December 14, 1893 or even entirely suppressed, leaving only the stage of hy- percytosis. November 24. — Dr. Katzenstein gave an account of experi- ments on the median pharyngeal nerve. In the rabbit this nerve gives off branches to ihe cricothyroid muscle, whereas in the monkey, dog and cat no such connection can be made out, either anatomically or physiologically. Prof. Munk made some remarks, in connection with these experiments, on Prof. Exner's belief in the existence of a median pharyngeal nerve, which '"ould at most only be admitted in the case of the rabbit. Prof. Zuni^ described a new method of measuring the amount of the circalating blood and the work done by the heart. It depends on the fact that as long as the peripheral resistance is constant, blood-pressure is dependent on the volume of blood driven into the aorta by the left ventricle. When the heart is inhibited by stimulation of the vagus the blood-pressure falls, and if now a volume oi' blood is injected into the aorta sufficient to raise the pressure again to the normal, then this volume must be equal to thai which the heart ordinarily drives into the arterial system. The method had shown itself to be reliable in experiments made on dogs, and had already yielded some interesting results relating to the circulation, which will be further investigated. New South Wales. Linnean Society, October 25.— Prof. David, President, in the chair. — The following papers were read : — On Polycercus : a proliferating Cysticercoid parasitic in certain earthworms, by Prof. Ilaswell and J. P. Hill.— Some points in the anatomy of the monotreme scapula, by Prof. Wilson and W. J. Stewart McKay.— Notes on the family Brachyscelidse, with descriptions of new species, Part III., by W. W. Froggatt. —On some new genera of nematoie worms found in Port Jack- son, by Dr. N. A. Cobb. — On recently observed evidences of extensive glacier action at Mount Kosciusko Plateau, by R. Helms. — Contributions to a revision of the Tasmanian land mollusca, by H. Suter. — Notes on the occurrence of a species of Plecofrema and other species of mollusca in Port Jackson, by Dr. J. C. Cox. — On the distribution of little-known mollusca from Polynesia and Australia, with their synonyms, by |ohn Brazier. — Dr. Cox exhibited a fine specimen of the herring Elops saurus, Linn., purchased in a Sydney fishmonger's shop, and believed to have been captured off Broken Bay ; the species is occasionally taken in Port Jackson, though it is more properly an inhabitant of tropical seas. He also showed a piece of timber in an excellent slate of preservation supposed to be red gum, a portion of a tree encountered in sinking a shaft in the bed of the river during the building of the bridge at Echuca ; the specimen was forwarded to him by Mr. A. P. Stewart, of Hay, N.S. W. Dr. Cox also showed specimens of the shells referred to in his paper, and a very fine example of Vohita vmnilla from Tasmania. — Mr. Froggatt exhibited a fine series of mounted galls and coccids in illustration of his paper, includ- ing a new Brachyscelid collected by Mr. A, Roxburgh at Cobar, and representatives of several new species of Opislhoscelis. — Mr. North exhibited a set of eggs consisting of three eggs of Collyriocicnla hufmonica and an egg of Cacomantis pallida col- lected on the Woolli Cteek on the 19th inst. The cuckoo's egg was deposited on the lyih inst., when the nest contained but two eggs of the Collyriocincla. This is the only occasion he had known the egg of any cuckoo to be found in the nest of the Harmonious Thrush. Mr. North also communicated a note in which he pointed out that the blue wren {Malurus cyaneus) is developing a protective habit against the cuckoos which intrude their eggs upon it, as he had found in several instances that the intruder's eggs wtre covered with a layer of nest material ; a parallel instance has been recorded by Messrs. Sclater and Hudson in their "Argentine Ornithology." — Mr. Mitchell, of Narellan, contributed a note on the occurrence of a fossil at Stockyard Mountain, Jamberoo, bearing a strong resemblance toLepidoslrobusand Halonia ; and of certain scales atGlenlee, referable, in his opinion, to one or other of the genera Lepido- robus or Sigillariostrobus ; also of a species of Pterophyl- lum, at Kenny Hill, near Campbelltown. — Mr. A. M. Lea showed a small collection of insects which inhabit ant and ter- mite nests, including a dipterous insect {Microdot! vaiiegala), one of the Micro-lepidopteraat present undetermined, both from Sydney ; and of coleoptera, two species of Pselaphida; from Tamworth and Inverell, Anthienus sp., from Sydney, Lagria n.sp., from Cootamundra and Queanbeyan, and a fifth species (g. et sp. indet.).— Mr. Brazier exhibited for Mr. T. Steel three NO. 1259, VOL. 49] aboriginal stone axes, one with a groove for hafting, from the Herbert River, said to have been found at a depth of thirty feet in sinking a well ; a second from the Tweed River, being a simple adaptation of a flat water-worn stone by grinding the thinner end ; the third from Harrow, Victoria. — -Mr. Fletcher exhibited for Mr. G. L. Pilcher, of Rockhampton, an undescribed longi- corn, and two of the mud nests of one of the solitary wasps [Etimeiies Latreillei, Sauss. ), together with specimens of the wasp and of a species of Chrysix which, like members of the same family elsewhere, plays the part of cuckoo ; .ind he com- municated a note giving particulars of the mode of construction of the nests exhibited, and of the habits of the maker and of the attendant intruder. BOOKS and SERIALS RECEIVED. Books. — Elementary 'trigonometry : H. S. Hall and S. R. Knight (Mac- millan). — A 1 heory ■ f Devel ■pment and Heredity : H. B. Orr (Macmillan). — Natural Value F. von Wieser, translated (Macmillan) — 1 he Vault of Heaven: R. A. Gregory (Methuen). — A Journey through the 'i'emen : W. B. Harris (Blackwood). — Chinese Central Asia, 2 Vo's. : Dr. H. I.ansdell (Low).— The Dispersal of Shells : H. W. Kew (K. Paul) —A Text-book of Physiological Chemistry : Prof. O. J. Hamraarsten. translated by J. A. Mandel (K. Paul). — Die Hawaiischen Inseln : Dr. A. Marcuse (Berlin, Fried- lander) — Fra 1 Batacchi Indipendenti : E. Modigliani (Roma, Sue Gecg . Iialiani). — A Text-book on Electro-Magnetism and the Construction if Dynamos, Vol. i : Prof D. C. Jackson (Macmillan)— Mining : A. Lupton (Longmans). — Anwendung der Quaternionen auf die Geometr.e : Dr. P. Molenbroek (Leiden, Brill). — Studies from the Physical and Chemical Laboratories of the Owens College, Vol. i, Phys cs and Physical Che-nistry (Manchester). — Schneekrystalle : Dr G. Hellmann (Berlin, P. Miicken- berger). — Darwinianism : Dr. J. H. Stirling (Fdmburgh, T. and T. Clark). — A Catalogue of the Egyptian Collect! jn in the Firzw.lliam Museum, Cam- bridge : Dr. E. A. W. Kudge (Cambridge University Press ■. Serials. — .American Meteorological Journal, November (Boston, Ginn). — Bulletin de I'.Acadiiinie Royale des Sciences de Belgique, 3rd Scrie-;, Tome 26, Nos. q and 10 (Briixelles). — Observatory. December (Taylor and Francis), — Companion to ditto, 1894 (Taylor and Francis). — Mimoires de la .Society d'Anthropol igie de Paris, Tome i, 3rd s^rie, i Fasc (Paris, Masson). — L'Anthrop ilogie. Tome 4, No. 4 (Paris, Masson). — Himinel und lirde, December (Berlin, Paetel). — Engineering Magazine, December (New York). L'Elettricista, December (Roma). — Medical Magazine December (South- wood). — Illustrated Archsoiogist, December (C. J. Clark). — Insect Life, Vol. vi. No. I (Washington). — Z ,e, Vol. iv. No. 3 (San Francisco). — Bulletin de la Soci6t6 Impiiriale des Naturalistes de Moscou, 1^93, N' s 2 and 3 (Moscou). — Bulletin du C' mit6 International Permanent pour rexecuiion photographique de la Carte du Ciel, Tome 2, Deux Fasc (Paris, Gauthier- Villars) CONTENTS. PAGE A Book of Practical Examples in Electricity. By Prof. A. Gray 145 Besant's Dynamics. By A. B. Basset, F. R.S. . . . 146 Insect Pests 147 Our Book Shelf:— Wells: " Text-book of Biology."— W. N. P. . . , 148 " The New Technical Educator " . . . . 148 Draper : " Heat, and the Principles of Thermo- dynamics " 148 Letters to the Editor : — Systematic Nomenclature. — Prof. G. F. Fitz- gerald, F.R.S. ; Fred. T. Trouton 148 On the Nomenclature of Radiant Energy. — Prof. G. F. Fitzgerald, F.R.S . . 149 Flame. — Prof. Arthur Smithells ........ 149 The Second Law of Thermodynamics. — S. H. Bur- bury, F.R.S 150 The Loss of H.M.S. "Victoria." III. By Dr. Francis Elgar 151 The New Laboratories of the Institute of Chemistry 154 Science in the Magazines 155 Experiments on Flying. {Illustrated.) By Prof. C, Runge 157 Notes 158 Our Astronomical Column: — New Notation for Lines in Spectrum of Hydrogen . 162 The Spectrum of Nova Normse 162 Prof. Rudolf Wolf, of Zurich i6j The Companion to the Observatory 163 Solar Observations at R.ome 163 Geographical Notes 163 Unveiling of the Joule Memorial Statue 163 The Ethnological Museum at Leyden. By Dr. H. ten Kate 165 University and Educational Intelligence ■ 166 Societies and Academies 166 Books and Serials Received 168 NA rURE 169 THURSDAY, DECEMBER 21, 1893. THE TOMBS AT BEN I HASAN. Bent Hasan. Part I. (Published under the auspices of the Egypt Exploration Fund.) By P. E. Newberry and G. W. Eraser. (London: Kegan Paul, 1893.) IN the handsome volume which lies before us the Egypt Exploration Fund publishes the first part of an "Archaeological Survey of Egypt," which it proposes to issue under the direction of Mr. F. L. Griffith ; and we believe that it will be generally admitted the site selected for description and illustration in the first part of the projected work could not have been better chosen. We are also very glad to see that the committee has changed the scene of its excavations from Lower to Upper Egypt, for there it is moderately certain that excellent results will accrue to the archaeologist and Egyptologist. It must not be thought for a moment that we wish to underrate the value of the excavations which the Fund has made in the Delta, but it must be said that in the days, now past we hope, when senti- mental Egyptology was more rampant than it is now, too much time and money were spent in the endeavour to bring to light "proofs" of the truth of the Bible narra- tive which could not exist, and in twisting evidence to suit the fancies of enthusiastic dilettanti. We admit that in the Delta these things are " in the air," for the land of Goshen lieth there, and the sites at which the Israel- ites are supposed to have halted must be sought therein, and the yam siiph, or '• sea of reeds," must border it in some part ; but in Upper Egypt we are face to face with the mighty monuments of some of the best periods of Egyptian art and sculpture, and we are free from the influence of the heterogeneous mixture of peoples in the Delta, and in the everlasting hills which fringe the banks of old Nile we have the remains of a nation which could boast of a hoary antiquity, even before Joseph came into Egypt. The spot chosen for the new scene of labour by the Egypt Exploration -Fund is Beni Hasan, probably better known as Jebel Beni Hasan, which forms a link in the long chain of cliffs which bound the eastern side of the Nile valley, and for which we may look on the map between Minyeh and Roda, a little more than 150 miles south of Cairo. Here, high up in the rock, are hewn two ranges of tombs, which are approached by a sloping path, at the top of which is a terrace whereon all the large tombs open. Of the thirty- nine tombs at Beni Hasan, twelve are inscribed, and of these eight are of governors of the nome wherein they are situated ; two are of princes, one is of the son of a prince, and one is of a royal scribe. In one range — the northern — are thirteen tombs, and in the southern are twenty-six. Speaking broadly, it may be said that both ranges were hewn during the twelfth dynasty, or about B.C. 25 o. Of the twelve inscribed tombs six may be dated with a fair amount of accuracy ; one (No. 14) bears the name of Amenemhat I., and another was probably hewn at the end of his reign ; No. 2 belongs to the reign of Usertsen I., and Nos. 3, 4, and 23 we must place in the reign of Usertsen II. Concerning the remaining six, we need have little doubt as to their age, for the NO. 1260, VOL. 49] position of some of them indicates that they belong to the period anterior to the reign of Amenemhat I. Considered historically, the tombs of Ameni-Amenem- hat and Khnemu-hetep are of the greatest importance, for they afford us some insight into the life of high officials in those days, and incidentally record some interesting historical facts. In the reign of Usertsen I. Ameni held the high rank of hereditary prince, and he was chosen by his royal master to make three expedi- tions into Nubia and Ethiopia; on the first occasion he accompanied his king ; on the second he set out with the royal heir at the head of four hundred men, and brought back the appointed tribute ; and on the third, he marched at the head of six hundred men. In quaint, character- istic language this worthy nobleman paints his own character, and says : " I wronged not the daughter of a poor man, I oppressed not the widow woman. I was not hostile to any farmer, I stood not in the way of the cattle-keeper, I levied no men for my works, there was no beggar round about, neither felt any man hunger in my days. In the season of famine I ploughed the land of the nome, north and south, I saved the life of its people, and I provided food, so that there was no man hungry therein. I gave to the widow the same as to the married woman, and in this respect I treated the younger as the eldest son. When, in after years, there were abundant Niles, and wheat and barley were plenti- ful, I did not claim payment for what I had given in the previous years." The most interesting text in the book, however, is that in which Khnemu-hetep, a feudal chief, records the chief events of his life, and the high services which he had rendered to his king. He was the son of Nekhera, and of the daughter of a princess called Baket, and he held the office of governor of the Arabian desert, and utcheb priest of Horus and Pakhet ; the king, Amenemhat II., granted unto him the inheritance of his father and mother in Menat-Khufu, and his property lay on each bank of an arm of the Nile, or of that river itself. As a landowner, he gave great attention to the adjustment of the boundaries of each city in the nome, and his fair and upright dealing in this respect gained him great favour in the sight of all men. The king pro- moted him over the heads of all his nobles, and con- ferred favour after favour upon him ; his sons, Necht and Khnemu-hetep, who had been born to him by the lady Khati, were each raised to the rank of Smer uat. Following the example of his father Nekhera, the son of Sebak-ankh, who from his earliest child- hood had held the highest place in the king's favour, Amenemhat built a tomb, upon which are his own name, and that of his father, and it is to the in- scription which he caused to be engraved upon it, under the direction of the architect Baqet, that we owe our knowledge of the life and times of this trusted official. The hieroglyphic text of the inscription has been pub- lished several times, but Mr. Newberry has succeeded in correcting several errors, one of the most important being in line 12. There is no doubt that this edition of the text is the best hitherto published. But hiero- glyphic texts are, in the main, only useful for Egyptolo- gists, and they form, after all, but a very small part of the book, which owes its chief attraction to the large number of beautiful plates which are in it. In these we I/O NA TURE [December 21, 1893 find depicted representations of all the chief scenes which are found in the first fourteen of the tombs that form the subject of the part before us, and it would be difficult to speak too highly of their excellence. The reader who has seen the originals will have them brought again vividly before his mind, and he who has not seen them may rest content that he has under his eyes faithful copies of the paintings reproduced in soft and pleasing tints. The subjects for the coloured plates are wed chosen, and we believe that they will be generally admired. Altogether, the life of what we might describe as an "Egyptian feudal baron," enjoying high favour with the king, is most thoroughly depicted ; the periodic war waged against the blacks in the gold-producing countries, the chase, to keep the body sound and the limbs supple, and the keen personal superintendence of all agricultural operations, whereby the evil results of " absentee landlordism " was done away with, filled the life of these old lords of the soil, who fondly hoped to live in the next world as they lived in this. When we consider the state and luxury in which they lived, and the large households which they maintained, it is not difficult to understand why Egypt was always an object of plunder by neighbouring nations. Before we end our brief notice of this most interesting book, we must call attention to the hideous system of transliteration which has been adopted throughout ; but we are wrong in calling it "transliteration," for that is intended to help the poor reader, who is not an expert, how to pronounce ; but this is not, and is only meant to indicate what Mr. Griffith imagines to be the proper way of representing Egyptian characters in English letters. Studies in systems of transliterations are excel- lent gymnastics for experts, but the non-expert resents the constant changes which are being thrust upon him ; and no surer plan of alienating the interest of the general public can be found than that of setting out in a work which is paid for by the general public, and is meant for all readers, a system representing hieroglyphics in English letters, which is both unnecessary and diffi- cult; moreover, we submit that the transliteration which Birch and Lepsius formulated is easy, and at the same time sufficiently correct for all practical purposes. A NATURE LOVER'S CORRESPONDENCE. Letters to Marco. By George D. Leslie, author of " Our River." (F.ondon : Macmillan and Co., 1893.) MR. LESLIE has published a good book with an un- promising title. It contains thirty-seven letters written to an old friend, H. Stacy Marks, R.A. The first of these is dated October 4, 1885 ; the last, March 6, 1893. Both the author and his friend have attained to eminence as painters, but there is no word in the book which alludes to their professional careers ; and but for an occasional grumble that a picture is not going smoothly, no one would guess that the letters were written from one artist to another. The interest of the correspondence centres upon mutual associations connected with the banks of the Thames, where they wandered together in days gone by, NO. 1260, VOL. 49] observing nature, sketching her, and nourishing their youth with aspirations, many of which they have lived to realise. That was in very early days, when name and fame were still behind the clouds of morning, and when they used to leave London annually with the expressed in- tention of "improving the quality of the British kit- cat," which was still in an unregenerate condition. As the interest of an artist's career lies in his struggles, and as the annals of success make commonplace read- ing, we can be grateful that all allusion to professional matters has been left out, though we might have been glad to have more artistic observations, such as that of the black rook flying away with a golden walnut in his mouth. One palpable realised ambition is the pretty property which Mr. Leslie has bought at Wallingford, from which he writes to his old friend, describing the condition of their old haunts, and chatting in a desultory way about nature in general. As Mr. Marks is an ornithologist, there is a great deal about birds. He observes their ways, and describes the kingfisher hovering over the water, the terns hawking on the shallows, and the poor swallows during a frost cuddling up together to keep warm ; and what is a great comfort, he kills nothing. He is not a sportsman, and not being a naturalist he does not want specimens for dis- section ; he merely observes with loving watchfulness ; in hard winters he scatters food to mitigate the lot of his feathered friends, and it is absolute grief to him when his children bring a poor fledgling which they have cap- tured. This is the great charm of his book, which probably adds little or nothing to our knowledge of natural history ; indeed, its method is the reverse of scientific, and its originality consists in the persistent way in which the author discerns human attributes in birds. They are to him a little people, whose customs and ways of thinking he studies attentively. The robin comes to him to sing a " conciliating song," the blackbird is " proud, vain, and impudent," and the sparrow is "bold, but he knows that he is only tolerated"; and these things are evidently not stated with any conscious or intentional metaphor, but in perfect good faith. The author, in fact, is an amiable enthusiast, who loves nature with his whole soul ; and when the contemplation of birds, beasts, flowers, and fruit has worked him up to a state of enthusiasm, rushes home and writes to his friend to tell him what he thinks about them. We do not feel in a position to dispute the theories which he occasionally propounds, such as that the young shoots on a hedge are kept in their place and supported by cobwebs, that darkness is favourable to the growth of plants and babies ; on all these matters he speaks with more authority than we can pretend to. All we can ven- ture to say is, that "si non e vero e ben trovato"; and his theory of darkness seems to explain the unfolding of a sycamore shoot, though he gives no instance of its operation in the case of the young of the human species. The contemplation of ail things in nature — birds, beasts, and fishes, reptiles, insects, and molluscs, inflames Mr. Leslie to a rapture of aflection ; and when the fit is on him, he can find extenuation even for snails and sparrows, whereby he soars into a lofty and rarified region of December 21, 1893] NA rURE 171 charity and benevolence, into which we find it impossible to follow him. I There are many amusing descriptions and playful pas- \ sages scattered through the book, such as the friendship I of the donkey and the dirty drake svho disliked cold water; j and the droppings of the reindeer, which the author spread I round his Iceland poppies because he thought it might amuse them ; and it is also very pleasant reading on account of its evident sincerity and absence of affecta- tion, of which the following is a fair example. The author describes the snails in his garden : '' the common 'tabbies,'" he says, "have already begun to hibernate, but the bushes are covered with a small flat kind." A less conscientious and more pretentious writer would inevitably have made a shot at their generic and specific names, and given us the words " Helix aspersa " and "Helix nemoralis" in brackets ; but Mr. Leslie very wisely makes no preten- I sions to be considered a naturalist, though he knows more of the aspect of organic life than many an authority on [Comparative anatomy ; his knowledge is that of Gotz von I Berlichingen, who " knew every pass, pathway, and ford I about the place, before he knew the name of village, ; castle, or river," and he seems thoroughly to sympathise with the sentiments of Shakespeare's " Biron ": — These earthly godfathers of heav'n's lights That give a name to every fixed star. Have no more profit of their shining nights Than those that walk and wot not what they are. The accuracy of Mr. Leslie's observation is shown by the illustrations which he has scattered through the volume ; some of these are extremely beautiful, such as the "Bird's-eye View of a Swallow," "The Fruit of Rosa Rugosa," and " Flight of Starlings and Rooks," as is also the frontispiece, representing his house at Wallingford. This book we can confidently recommend for its tonic properties. To the great world of men and women given over to satiety and boredom it cannot but be salutary^ by pointing out what a world of enjoyment, what a peace- ful and engrossing occupation for leisure, lies open to all of us, outside our own doors, and the only price we have to pay for it is to take the trouble to use our eyes. OUR BOOK SHELF. A Text-book of Heat. The Tutorial Physics, vol. ii (Univ. Corr. Coll. Tutorial Series.) By R. Wallace Stewart. (London : W. B. Clive, 1893.) Not long ago we had occasion to say a few words about the books which have appeared from the pen of this author, and we then stated our belief in him as a writer whose clearness of explanation and concise- ness of language would render him popular among students of physics. In the volume now before us, which is devoted simply to the one branch of this large subject of physics — heat — we may again apply the same remarks to the treatment of the subject, the author stating with all clearness and necessary accuracy the various laws, and showing their practical application by means of appropriate examples. In the descriptions of the experiments, as, for instance, in those for deter- mining the absolute expansion of mercury, the object of I the experiment in question, the end to be obtained, and the different means of attaining it, are especially emphas- ised, and the diagrams aid the reader in grasping a clear NO. 1260, VOL. 49] idea of the arrangement of the apparatus employed. At the end of each chapter, under the heading " calcula- tions," are brought together all the formulated expres- sions of the laws deduced in the one preceding — a very useful arrangement for a short revision of the subject. The concluding chapter deals with the application of graphic methods to the results of experiment, and this part of the subject is one of great importance, although generally omitted in text-books. The work, as will have been noticed from the heading, is published in the Tutorial Series, and is a most useful addition to it. The Industries of Anivials. By Frederic Houssay. (London: Walter Scott, Ltd., 1893.) This — the twenty-third volume of the Contemporary Science Series — is an English edition of a good book. • It is not merely a translation, but a revised and enlarged edition, to which numerous bibliographical references have been added. By this addition the work has gained considerably in value ; for such references are not only useful to the student who desires to increase his know- ledge of any matter broached in the book, but they also furnish a means of estimating the weight of the many stories of animal intelligence and instinct contained in it. The first chapters of the book deal with those industries of animals of which the object is the search for prey. These industries are necessarily connected with protec- tive effects providmg for the immediate safety of the individual. A number of examples are then given, to show that " social species unite for the common security the forces and effects which they can derive from their own organs." The art among animals of collecting pro- visions, of domesticating and exploiting flocks, and of reducing their fellows to slavery, is well described, and, finally, the series of modifications which the dwelling undergoes is investigated. Except in one or two places, the translation reads very well. Forty-four figures illustrate the text, most of them adapted from that great repository of facts in natural history — Brehm's Thierlebcn. Altogether the book is very pleasant reading, and it contains a large amount of matter of interest to all students of animal skill and intelligence. LETTERS TO THE EDITOR. [The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the ivriters of, rejected ?nanuscripts intended for this or any other part of Nature. No notice is taken of anonymous co7nmunications.'\ " Flame." In Nature for November 23, p. 86, under this title, there appears an account of a lecture delivered by Prof. Smithells to the British Association on September 15, in which he brings before the Association those fascinating experiments with which his name has lately become identified. The apparatus by means of which Prof. Smithells draws the "inner cone" of a flame away from the "outer cone," and which he describes as an appliance for dissecting the flame, or the cone- separating appara- tus, is now quite familiar to most. By meins of it a regulated stream of air is admitted along with the burning gas, until a portion of the llame recedes down the tube, and is arrested in its downward movement at the top of an inner tube, where the issuing gases are moving upwards at a slightly greater rate. In all cases Prof. Smithells calls this descending flame the inner cone, and regards the remnant of the flame that remains at the top as the outer cone. It would appear to follow, therefore, that il, fiy means of the "cone-separator," a flame can be io dissected, it must have originally consisted of two cones. Prof. Smithell describes the flames of hydrogen and of car bon monoxide as being of the simplest construction ; it beini; out of the question that any complications can aiise in the com- bustion of hydrogen to water, and of carbon monoxide to 172 NATURE [December 21, 189; carbon dioxide. These flames are therefore described by him as being "simply a hollow conical sheath of pretty uniform char- acter." This is undoubtedly a true description ; neither of these flames presents the appearance of double coned structure which is seen in such flames as cyanogen, carbon disulphide, ammonia, and others ; and it is hardly possible that in a hydro- gen or carbon monoxide flame there can be two distinct areas or cones in which different chemical processes are going on. It occurred to me that it might throw some light upon the real value of this cone-separating apparatus as an appliance for dissecting flames, to try its effect upon the single-coned flames of carbon monoxide and of hydrogen. When air was cautiously admitted into these gases, as they burned at the top of the tube, I found that the flame travelled quickly right down the tube, and did not stop at the narrower tube when the upward rate of movement was greater, and did not appear to leave any remnant at the top of the wider tube. I have no doubt but that Prof. Smithells has made this experiment, and with a similar result. I have found, however, that by a slight modification of the apparatus, it is quite easy to drag down an inner flame from either the flame of carbon monoxide or of hydrogen. In order to do this, all that is necessary is to provide the top of the inner and narrower tube with a cap made of fine wire gauze, either copper or platinum. When this small addition to the original apparatus is made, and the experiment with carbon monoxide is repeated, it will be seen that as air is gradually introduced a portion of the flame descends the tube and sits quietly upon the wire gauze, and, in spite of the flame-extinguishing power of the carbon dioxide^t there generates, a remnant of the original flame remains feebly burning at the top. In the case of hydrogen a similar result is obtained, a portion of the flame descending to the gauze, where it burns with a pale blueish flame, while the remnant burns freely at the top. These experiments show that whatever is the structure of the flame, a part of it can be torn away from the rest by the regulated introduction of air : that in order to divide a flame by this method it is not a neces- sary condition that the flame should consist of more than one "cone," or, in other words, that there should be two distinct areas of combustion. If, therefore, a "simple" flame like that of hydrogen, consisting of a single cone of uniform character, can be divided, the fact that other and more complex flames can also be so divided, does not seem to throw much light upon their structure. As soon as sufficient air has been admitted into a flame, of whatever burning gas, to produce a certain volume of an explosive mixture whose rate of explosion exceeds the rate of efflux of the gases, that exploding mixture will become detached from the remainder of the burning gas, and travel back down the tube. In the case of hydrogen, where a very wide margin exists within which mixtures of this gas and air are rapidly explosive, the admission of a very small quantity of air is sufficent to form such a mixture, and so drag down a comparatively small por- tion of the entire flame. In the space between these two flames there can only be water vapour as the product of combustion, atmospheric nitrogen, and the excess of hydrogen. The lower flame is a burning mixture of air and hydrogen in which an ex- cess of air is taking part in the combustion, and represents a condition of things certainly not far removed from, if not iden- tical with, the old phenomenon of air burning in hydrogen. It is difficult to see in what way the separation of other flames differs from this. I have no doubt that everyone who has read the account of Prof. Smithell's lecture will have been struck, as Dr. Armstrong was, with the manner in which the classical researches of Dr. Frankland are brushed aside, and the difficult question as to the true causes of the luminosity of flame is settled by an appeal to the " opinion of the majority." Without touching the question as to whether or not solid carbon is actually precipitated during the decompositions that are going on in a coal-gas flame, the recent experiments of Prof. Lewes leave no room for doubt that the first stage in the process of decomposition and condensation that goes on, is the produc- tion of acetylene, which is formed during the passage of the gas through the inner dark area of the flame, where no combustion is going on ; that is to say, where the hydrocarbons are being simply strongly heated, tmt are not burning. This fact seems to have an interesting bearing upon some of the peculiarities ex- hibiteii by the well-known flame of air burning in an atmosphere of coal-gas. In this flame the air is in the inside, and the hydro- carbons upon the outside ; it is in effect an ordinary coal-gas flame turned inside out. The formation of acetylene, instead of NO. 1260, VOL. 49] taking place within the flame, as in the usual conditions, in which case it has to pass through the heated area where it is further decomposed with probably the precipitation of carbon, is now produced upon the outer surface or periphery of the flame ; it therefore largely escapes combustion or decomposi- tion, and passes into the coal-gas atmosphere with which the flame is enveloped. Hence the flame is non-luminous, and hence also this constitutes the ready method for obtaining large quantities of acetylene first devised by Prof McLeod. I am not aware that it has ever been noticed that during the combus- tion of this non-luminous flame there are produced, besides acetylene, other hydrocarbons of much greater density. That this is so is evident from the fact that when the flame has been allowed to continue burning for a length of time, the glass vessel in which it is contained becomes coated with a brown tarry film. This non-luminous flame of air burning in coal-gas can be rendered luminous by a simple device. If the vessel employed in which to burn it be an ordinary bulb-shaped paraffin lamp chimney, it will be seen that when the flame is in the middle and wide portion of the chimney it is non-luminous; if, however, it be thrust up into the narrow part, it at once shows signs of luminosity : the acetylene under these circum- stances is reflected back into the flame, which, aided no doubt by the radiated heat from the glass, causes the luminosity. If the supply of air be regulated, the flame may be caused to curl over upon itself, whereby very beautiful vortices are obtained, in which Heumann's floating particles are well seen. There is an old experiment in which two flames of air in coal- gas are placed side by side, and so arranged that at will they can be caused just to impinge upon each other. At the point where they touch a small luminous area is seen to appear, the luminosity being probably due to the same causes. G. S. Newth. I AM unable to understand how Prof. Smithells can in any way suppose that I either have, or possibly could, cast any im- putation on his honesty, "scientific" or otherwise ; and I fail also to understand what has given rise to the impression, unless it be that the opening sentence of my letter — which I intended should convey a compliment — has been turned round and a meaning given to it which I never contemplated, and which it cannot fairly be made to bear. I have always regarded Nature as a journal which is willing, to aftbrd a fair field for the consideration of scientific problems, but the last place in which to raise, let alone discuss, personal questions. By publishing his lecture in Nature, Prof Smithells directly challenged criticism, and the only object and intention of my letter was to challenge the validity of certain of his arguments. That he should have taken the view he has, is to me a matter of deep regret. He has now stated his position very clearly, and the passage that he has been good enough to quote from my letter to Sir G. G. Stokes sufficiently defines mine. I fear that we must agree still to differ ; evidently we look at these matters from very dissimilar standpoints. Henry E. Armstrong. The Postal Transmission of Natural History Specimens, At page lOo, ante, you reproduce a circular letter, sent out by the Academy of Natural Sciences of Philadelphia, on this subject, the object of which is the very laudable one of estab- lishing an international rate of postage for natural history specimens, based on that charged for bona fide trade patterns and samples. It is therein stated that the United States Post Office Department recently proposed to the countries comprised within the Postal Union a modification of the rates in favour of a charge so based, but that the Governments of very many of them declined to consider the proposal, and in the list there given Great Britain is included. No precise date for this refusal on the part of the British postal authorities is given, but presum- ably the date is not precisely recent. Early in 1891, several of our Natural History Societies agreed to approach the British postal authorities on this point, and a letter was addressed to the Secretary of the Post Office (the late Sir S. A. Blackwood) by Lord Walsingham, on March 18, 1891. A reply (which I have before me) to that letter, from Sir S. A. Blackwood, is dated April 13, 1891, and is published in the Proceedings of the Entomological Society of London, 1891, p. 14 (and probably elsewhere). An extract from the letter is to this effect : — " Your December 21, 1893] NATURE "i^lZ lordship will no doubt be glad to learn that so far as this De- partment is concerned, scientific specimens sent by sample post, and addressed to places abroad, will not be stopped in future ; but I must state that this Department cannot guarantee the delivery of such specimens abroad, inasmuch as they do not come within the definition of sample packets as prescribed by the Postal Union. ' I may add that within the last month I have, on two occasions, sent specimens abroad by sample post wiih perfectly satisfactory results. All naturalists will feel grateful to the Academy of Natural Sciences of Philadelphia for agitating in this matter. But it is to be regretted that the United States Postal Department should, in another way, continue to maintain a barrier against cheap transmission and interchange of specimens. The sample post can, in any case, only be used for small packets, but larger packages can now be sent to nearly all foreign countries by parcel post, the introduction of which was an inestimable boon. The United States Government stands almost alone in persist- ently refusing to co-operate in this respect. It is not for scientific men to inquire into what contracts that Government may have entered into with private carrying companies, or how far it may be influenced by hyper-protective susceptibilities ; they can only regret the facts, and deplore the result. Lewi--ham, December 8. R. McLachlan. " Geology in Nubibus.'' — Mr. Deeley and Dr. Wallace. Mr. Deeley will not have anything to say to ice conveying thrust as a solid body, which has been the sheet anchor of glacial geology for many a decade. He also repudiates Dr. Wallace's notion that regelation can in some way act as a compensating element when crushing supervenes in ice, and thus enable it under crushing pressure to convey thrust. So far so good. Mr. Deeley, however, bids me turn to ice acting as a viscous body, a subject on which I have written a great deal in my recent book, which he does not seem to have seen. There are two ways in which we can conceive a viscous body lowing on a flat plain : (i) by pure fluid, or what is commonly •called hydrostatical pressure, in- which the upper layers move up and down, and the lower layers alone have a horizontal motion ; C 2) by its particles rolling over each other. The former ■depends, of course, entirely upon the difference of level of two connected parts of the mass under consideration ; the latter depends upon the slope of the upper surface of the fluid. I contend, as Forbes contended, that in the case of a body so slightly fluid as ice, motion by hydrostatic pressure is practically impossible. The consistency and mutual support of the parts prevent the indefinite transmission of pressure in this way through ice, and nowhere have I seen or heard that in detached masses of a glacier cut off at either end by crevasses the ice rises in one place, and sinks in another, or that the walls of these ice rifts or the perpendicular ice walls in the arctic and antarctic regions or in scarped icebergs bulge out below in the slightest degree, as must happen if ice were to move in this method. Forbes" experiments and measurements and patient examina- tion of the problem proved thst ice as a viscous body moves in fact by its layers rolling over each other, and that this motion is differential, being greatest at the surface and in the middle, and least at the base and sides of a glacier. It is quite true that the rate of this motion on a flat plain would depend theoretically on the slope of the upper surface of the ice. It is established by experiment, however, that such motion is very largely confined to the surface layers, and when we approach the nether layers the motion quickly slackens, owing to the internal friction and drag of the ice particles. Even on inclined beds, glaciers have sometimes been found frozen to the ground. The evidence of a large number of observers is con- clusive, that as glaciers reach the level ground, the motion, even of their upper layers, gradually stops. The masses of ice that collect on the flat Siberian Tundras do not move at all, nor do the thick horizontal ice beds examined by Dall in Alaska. Argument, experiment, and observation are therefore entirely against Mr. Deeley, upon whom the burden of proof Tests. Perhaps he will explain what are the conditions under which he conceives his ice sheets to hav« been formed, to have been maintained, and to have moved. Mr. Wallace confesses that he does not like to face these mechanical issues, which are presupposed in all his reasoning. This is assuredly building on a -quicksand, v^hich is not a profitable experiment. He cannot be serious, either, in arguing that because I believe in Charpentier's view that the Alps were formerly higher, and consequently nursed bigger glaciers, I am therefore committed to Ramsay's extravagant notions, repudiated by nearly all explorers of glaciers, that the lakes of Geneva and Lucerne were dug out by ice. Charpentier's method, in such a case, would have prompted him to first prove the capacity of ice to do the work, and most people will agree that in a scientific argument this method is alone fruitful. H. H. Howorth. 30 Collingham Place, Earls Court. The Viscous Motion of Ice. Is not Sir H. Howorth wrong in assuming that there is no transmission of hydrostatic pressure in ice ? Certainly Forbes was of opinion that such transmission existed, and was necessary to explain the remarkable parallelism between the motion of ice and of vise, us fluids. It is a question of scale. Even a cup of treacle will not flatten out indefinitely ; still less will a barrel of pitch ; but I have no doubt a cubic mile of ice would flatten out, but to what extent is a question for calculation, not for dogmatic assertion. Unfortunately the first requisite of such calculations is w-anting, as no determination of the coefficient of viscosity exists. Canon Moseley's experiments are clearly out of court, and in the interesting experiments of Mr. Coutts Trotter in 1883, the length of the portion of ice which took part in the shearing motion is not given. May I add that the paragraph in Sir H. Howorth's letter of November 23, in answer to Mr. LaTouehe, is distinctly erron- eous so far as our limited evidence goes. If Sir H. Howorth will draw to scale the observations of Prof. Tyndall at the Tacul on the side of the Mer de Glace, or those of Prof Forbes, given on page 554 of his own book, he will see that while the velocity of the ice is greatest at the surface, the viscous yielding or differential motion is greatest at the bottom ; and the curve into which a vertical line in the ice is thrown by the motion, is always convex towards the direction of motion, is relatively flat above, and strongly curved towards the base. This is exactly what we should expect on the viscous hypothesis, and justifies the application of hydrodynamical treatment to the problem, if only the necessary data were to hand. 19 The Boltons, S.W. John Tennant. December 12. Chemistry in Space. It may be of interest to your readers to know that the idea of the arrangement of atoms in space, which is looked upon as quite a modern one, is clearly put forth by Wollaston in his paper entitled "On Super- Acid and Sub- Acid Salts" (Phil. Trans, vol. xcviii. 1808, pp. 96-102). He discusses the constitution of the two oxalates of potash ; and I make the following extracts, but must refer your readers to the original paper for the full context. ..." when our views are sufficiently extended, to enable us to reason with precision concerning the proportions of elementary atoms, we shall find the arithmetical relation alone will not be sufficient to explain their mutual action, and that we shall be obliged to acquire a geometrical conception of their relative arrangement in all the Three dimensions of solid extension. . . . when the number of one set of particles (combined with one particle), exceeds in the proportion of four to one, then, on the contrary, a stable equili- brium may again take place, if the four particles are situated at the angles of the four equilateral triangles composing a regular tetrahedron. ... It is perhaps too much to hope, that the geometrical arrangement of primary particles will ever be per- fectly known. " Thus Wollaston's conception of the combina- tion of four particles with another is exactly the same as our modern idea of the arrangement of four monovalent atoms (or groups) in combination with a carbon atom. The same idea is also developed somewhat later by Ampere in his "Letter to Berthollet" {Annaks de Chimie, 90, p. 43-86, 1814), in which he considers the molecules as forming various geometrical figures dependent on the number of atoms contained therein. JOHX Caxnell Cain. The Owens College, Manchester, December 14. NO. 1260, VOL. 49] 174 NATURE [December 21, 189^ THE MANCEUVRING POWERS OF STEAMSHIPS AND THEIR PRACTICAL APPLICATIONS. IN a recent number of the United Service Magazine, I wrote an article tracing briefly the history of man- oeuvring powers of steamships as ascertained and applied, or as assumed and applied, or as omitted in application, to the purposes of war and navigation. It was chiefly addressed to the Navy as my apology for certain pub- lisaed views on the causes of the loss of the Victoria, but it is suggested that a resume with diagrams would interest the readers of Nature. X b Quite in the early days of steamers it was noticed that when they turned under the influence of their helms, they took a wider and more regular sweep than seamen were accustomed to notice in sailing-ships. There was a limit to their powers ; for when a steamer had put her helm " hard over,'' she had done all she could to turn " sharp," and if the turn was not sharp enough to avoid collision, for instance, it inevitably took place unless she could check her impetus in time by reversing her engines. When steamers began to multiply — I speak of a date before 1854 — collisions with them began to multiply also, and it was necessary to devise "rules of the road" for their prevention, such as sailing vessels had for genera- tions possessed amongst themselves. Admiral Beechey, to whom the matter was confided, could not escape from his knowledge of the sweep that steamers made in turning, but it did not occur to him to make any investigations ii>to its nature. He assumed it. Having done so, it did not occur to him that the application of his assumption could only be made by diagram to scale. He therefore based a proposed law on the assumption that the first 90° of a ship's path was a circular arc, but he did not specify what its radius might be in terms of the ship's length. I reproduce in Fig. i the fundamental diagram of the great " law of port helm " which was set out in Clause 296 of the Merchant Shipping Act, 1854, and was finally condemned by Parliament in August, i860. The fact was that no steamer ever did, or could, turn on the path represented, and that the law could not have been drawn had the Admiral been aware of the real path, and had he applied it by means of diagrams drawn to scale. When the single screw began to supersede the paddle, the characteristics of the turn remained, but constructive difficulties increased the sweep in warships. The late Admiral Sir Cooper Key, being in charge of the Steam Reserve at Devonport, carried out investigations — very incomplete in those days — which culminated, in 1863, in a series of experiments with a gunboat, directed to ascertain the relations between helm-angle, area of rudder, and the length and duration in time, of the path described in turning completely round. It was still assumed that the path was circular from first to last, NO. 1260, VOL. 49] and the results as to helm-angle are shown in Fig. 2. The "diameter" of an assumed "turning circle" was. the comparative space-measurement employed. The result of the experiments was the introduction of the "balanced rudder" into the Navy. Our first ironclad, the Warrior, had been more than a year at sea when these experiments were made. She was 3S0 feet long, much longer than any other man-of- war, except her sister, the Black Prince, and the time she took to turn round, as well as the space she evidently covered, were tremendous. Still assuming that every part of her path in turning was circular, means were devised to measure its " diameter," which was found to be six times her length, or 760 yards ; while, at 12 knots, it took her 7m. 46s. to turn completely round. Every- one was much impressed, but the smallness of the helm- angle — 22°, due to want of power to move the rudder over — was much less noticed than the length of the ship ; and the fact bore remarkable fruit. Great changes of thoughi on the subject of manoeuvring occurred both at home and abroad. Every where the idea of the circular arc was accepted ; no means had been in- vented for discovering the form of the path, and it was not sufficiently plain that only the first 180° of the turn was of any importance, and that knowledge of the nature of the path for the first 90" was the most important of all. Abroad, the idea of the circular arc was made the sub- structure of vast and embracing theories. Admiral Boutakov, of the Russian Navy, based a complete system of tactics on the diagram reproduced in Fig. 3, which he called "tangential arcs." It maybe seen that the path from s to .S' does really embrace the whole question of helm- manoeuvres. But no ship beginning to turn at N, and turning back again, could ever, by any possibility, reach w, or s'. The assumptions were entirely apart from the facts. At home, we contented ourselves with ordering that the time any warship took to turn half-round, and -«gie- A B = 534 feet iS° of helm. I A D = 238 feet 40° of helm'. A C = 318 feet 30' of helm. | A E = 216 feet 45° of helm. Note. — The ship is drawn on twice the scale of the rest of the diagram. Fig. 2. — Scale, J inch = ico feet. completely round, at named speeds, should be recorded, and that the "diameter" of her "turning circle," measured in any way that seemed suitable, should at the same time be ascertained. No advance in the matter could be arrived at by any single experiment of this kind,, but I found in later years that a great fund of knowledge December 21, 1893J NA TURE 175 lay buried, which could be dug up when numbers of the experiments were compared. Meantime the condemnation of Admiral Beechey's law by Parliament had put those concerned on devising a substitute. Discussions over the subject went on from August, i860, to January, 1862, but there is nowhere any sign that the manoeuvring powers of the ships to be dealt with ever came into view at all. A single diagram sur- vi\es, which is reproduced in Fig. 4. It is obviously not to scale, but was intended to show that a movement pro- posed to be prescribed for one of the ships would be a -J^^ Fig. 3. dangerous one. It was not noticed that if scale were applied to the diagram, it would show that no possible movement on the part of either ship could avoid the inevitable collision. The Rules of the Road of 1862 have been continually modified since ; and by some appeal to experiment as applied to diagram, the British delegates at the Washing- ton Conference in 1889 were able to carry material amendments. But the fallacy of the original basis has been perhaps most forcibly brought out by Mr. John <^S> ^ Fig. 4. April 20, 1881. No. 3. — Starboard engine reversed. JDft. of water, 22-5 F. (Wind nearly ahead at start ; light). •7 A. Fig. 6.— To show eflfect of Twin Screws. Scale, J inch = 100 feet. it is but one element out of many. The Edinburgh, for instance, which is 325 feet long, requires a "diameter" 93 yards longer than the Minotaur, which is 400 feet long. beginning to be applied to the rudders, so that any helm- angle provided for, could be obtained at any speed. These changes in the elements of mancEuvring powers demanded especial study ; and, most of all, some more complete and accurate method of measurement. Anticipating, I here show, in Fig. 6, what these developments came to in the case of H.M.S. Thunderer, and how little modification the twin-screw can make in the early part of the turn. The invention of a satisfactory method of measurement is due to Mr. Philip Watts, late of the Admiralty, who, in the year 1877, applied it to the Thunderer for purposes that had nothing to do with manoeuvring. But the experi- ments showed how very far from circular the path really was, and how misleading the idea of a circular path had been. Collisions, unaccountable before, were now easily accounted for, and a terrible opportunity of bringing the new light to bear was offered when, in 1878, the Bywell Castle ran into and sank the Princess Alice, destroying 600 lives. The accident was wholly a question of manoeuvring. Starting, as it was possible to start, with the assumption that the Princess Alice was legally wrong in turning to the left when approaching the Byzuell Castle, disclosing her movement by exhibiting first her red and then her green light in front of the latter ship, the question remained as to what was safe for the Bywell Castle to do .'' She did turn to the right and sink her neighbour. Ought seamen to be instructed that the movement was a right or a wrong one as an answer to the signal received ? The diagram which is reproduced in Fig. 7, was carefully prepared by putting all the facts into line with the best experiments, but it was found im- Princess Alice Green] \Red V 'MO" 20" • f20" Bywell Castle Fig. 7. — Scale, J inch = loo feet. Fig. 8. — Scale, j inch = loo feet. The twin-screw began to make its appearance in the early days of Sir E. Reed's control of our shipbuilding, and he pushed it forward vigorously. Several twin-screw battleships were launched, and others laid down before he left office in 1870. At the same time steam power was NO. 1260, VOL. 49] possible to bring ideas of the manoeuvring powers of the ships, and the causes of the accident, together into the discussion. The form of the accident was common, and it remains common ; but no teaching yet exists- which might help seamen to avoid it. December 21, 1893] NA TURE 177 It was somewhat remarkable that in this same year in the Navy, just, it might be said, when the means of fully applying the experimental method to fleet manoeuvring became available, the tide set strongly against experi- ment. The recommendations for experiment were cur- tailed, and special promptings and means for carrying out experiments, which had been usefully employed for four years, were withdrawn. The feeling grew that what had been done in 1865 was sufficient for all time ; and those who were responsible for errors and shortcomings in 1865, because of the defective means for experiment, found themselves met by the stubborn character of their own mistakes when they desired to amend them. The Navy became too satisfied with the work of 1865, and felt in powers has shown less apparent variation in the move- ment of ships under given conditions ; and when, with any given method, the observers grow skilled, the ap- parent variations of movement become less. The accuracy of movement of all ships at speed when turning is re- markable. The curve traced in Fig. 8 is the mean of three turns of 180'' to the right, made by the Edinburgh, at an original speed of twelve knots, and with a helm- angle of 34°, reached, by means of steam steering gear, in II seconds. The small circles represent the successive positions fixed by observation when the turn had reached 45°) 9°°) 1 35°j ^'^d 1 80°. The figures on each side of the trace represent the total revolutions of each screv/, and the seconds marked denote the time occupied in passing Fig. 9. — Scale, 1 inch everything else disposed to trust to the chances and judgment of the moment when manoeuvring the ships in a fleet. What was lost by failure to pursue the experimental method was not seen, and when I state clearly that if the experimental method could have been persevered in and developed, we should not have lost the Victoria and Sir George Tryon, my views are scarcely ap- prehended by the Navy. I cannot enter upon this matter here, though I shall presently make a remark on it which will then be understood. I must conclude my paper by setting forth some of the results which have been obtained by the experimental method. In the first place it seems made out that every im- provement in the method of measuring manoeuvring NO 1 260. VOL. 49] over each " octant." The accuracy of the turn is apparent to the eye, and while the space measurements in no case vary more than 60 feet from the mean, the time measure- ments do not vary more than five seconds from the mean, and that is out of a total of 220 seconds. To the figure is added a trace of the Edinburgh's powers of reducing the size of her arc and her speed over it, by reversing both engines full speed, as simultaneously as possible with the movement of the helm. Fig. 9 traces a path which is the mean of three turns made by H.M.S. Dreadnought at 10-9 knots speed with 32° of helm, where the apparent variations in tne path seem to be greater. But the space variations here are never more than 74 feet from the mean, while the times 178 NATURE [December 21, 1893 do not vary more than eight seconds from the mean out of a total of 176 seconds. This remarkable precision has been always found. It was equally present in a steam experiment, would make each ship turn towards the other, X turning to the right, and Y turning to the left; in which case it would not be possible for the ships to touch No. I. — 17° Helm."! 55 Revs, 80 to 91 lets. No. 2. — 24^° Helm.! Dft. of water. 25"ioF. 27*4 A. No. 3. — 33J' Helm./ May 12, 18" Fig. 10. — To show effect of Helm-angle. Scale, jl inch = 100 feet. pinnace, and the one experiment made with a very light ship in a high wind failed to disclose any difference due to differing directions of the wind. ' The traces of the Edinburgh and Dreadnought are brought together in order to exhibit the wide differences that exist in the form of the path described by different ships in turning. They show how imperative it is that in fleets, at any rate, these differences of form should be recognised. But the peculiarity of the form of the path remainsnearly the same at all helm-angles, and this makes the necessary equalising of the paths for the purposes of fleet manoeuvr- ing easier. It shows, too, the fallacy of the 1865 idea — still preserved — ^tliat there can be a single '' evolutionary helm-angle " suitable to equalise a large or a small turn. The facts are illustrated by Fig. 10, which shows the effect of varied helm on H.M.S. Thunderer. I have now only to point out how experiment bears on the question of collision between ordinary ships at sea. The ordinary form of approach before collision is given in Fig. II. The law enjoins that Y should keep steadily to her path, and that x should " keep out of her way." In order to do so, she has been for something like thirty years told that she must decide for herself whether to turn to the left or to the right. Needless to say that as she cannot hope to turn " sharper" than the path marked for her, she generally produces collision by turning to the left, but she is never explicitly condemned for that act. Ships often only discover one another when so close that it cannot be certain which has the power of avoid- ing collision. Fig. 12 supposes two Ediitbm-ghs meeting under such conditions, where it is seen that safety can alone lie in knowledge of the general manoeuvring powers of ships and their application to the particular case. Admiral Beechey's law would have caused both these ships turn to the right, and would have made collision inevitable. The existing law — if it were acted on— would compel Y to keep her course, in which case also collision would be inevitable. The natural law, based on 1 I have by me many scores of experiments made with fifteen or .^i-xteen ships and vessels of all sizes and classes. Fig. II. — Scale, (say) i inch = 100 yards. NO. 1260, VOL. 49] The figures denote ^r each ship, eoual intervals of timt. whether iurninq ornot At fZ knots initial speed the interval is equal. Several small inaccuracies to which the method is subject aie mentioned in the paper. Prof. S. P. Thompson inquired if the fishtail-shaped needle of the electrometer was novel. Mr. Blakesley said the author had mentioned the needle previously. He (Mr. Blakesley) thought the name "poten- tiometer " was not very suitable. In effect, the so-called measurement o^ pressures was a comparison of ivio powers. —The Presiilent announced that Mr. Preece's note on the specific re- sistance of sea-water had been temporarily withdrawn. — Prof. G. M. Minchin made a communication on the calculation of the coefficient of sell-induction of a circular current of given aper- ture and cross-section. Instead of assuming the cross-section of the wire small, and the current density constant over the section, as is usually done, the author takes into account the dimensions of the section and the non-uniform distribution of the current. Making use of the expressions for the vector potential (G) of the current given in his previous papers {Phil. Mag, April and August, 1893), the author calculates the total normal flux of force through a surface intersected once in the positive direction by every tube of force emanating from the given cur- rent. This flux, divided by the current, gives the coefficient of self-induction. The surface chosen is the circular aperture of the current and half of the anchor ring formed by the wire. When the current density is inversely proportional to ths dis- tance from the axis of the circular current, the value of the co- efficient of self-induction is found to be '{ 4a(L- 2)-f-2^ \ 4/ 16 ,j2L-fi9)}, where a is the radius of the central filament of the current, c the radius of the cross-section of the wire, and Li? = log — c Clerk-Maxwell's approximate expression agrees with this in the principal term. As an example of the closeness of the approximation, the case of a current in a wire 2 millimetres diameter bent to a circle of 2 centimetres mean diameter bad been taken, the approximate and corrected coefficients being 58"866 and 59'207 absolu'e units respectively. When the cur- rent m the wne is superficial, as in ca>e of alternating currents of high frequency, the Coefficient is somewhat greater, being given by the expression ir|4a(L-2)-t-2/L-f^V-^^ (4L-f ii)j. Incidentally it was pointed out that the function G.r where G is the vector potential at a point distance x from the axis of a circular current was the same as Stoke's current function in hydrod>namics. Another paper, on the magnetic field of a currtnt running in a cylindrical coil, was read by Prof. Minchin. The cylindrical coil is regarded as a series of equal circ e^ lying close together and forming a cylindrical surface. Replacitig each circular current by it.s equivalent magnetic shell, the prol-lcm of nnding the magnetic potential at a point resolves No. 1260. VOL. 49] itself into calculating the gravitational potential due to two circular plates of attracting matter, one positive and the other negative, situated respectively at opposite ends of the cylinder. The magnetic potential due to one plate is then deduced in terms of elliptic integrals of the first, second, and third kinds. The President had pointed out that the expressions given in the printed proof of the paper, only applied when the perpen- dicular from the point to the plate fell within the circle ; the author had therefore modified the formula so as to be true generally. From this formula the equipotential curves can be constructed. The same system of curves serve for the plate at the other end of the cylinder by changing the signs of the numerals representing the potentials and giving the curves a motion of translation equal to the length of the cylinder in the direction of its axis. The equipotential curves for the coil can then be deduced by drawing through the points of intersection of the two sets of curves whose numerical values have a constant sum. In determining the curves the author had to calculate tables of elliptic integrals of the third kind, and these he hoped to complete before the paper was published. In reply to a question on the first paper, which had been brought before him by Prof. Perry, the author said that as the diameter of the wire diminished indefinitely, both the self-induction and resistance became infinite, but the ratio L/R became zero. It was inter- esting to examine what relation betwen the aperture and cross- section gave minimum impedance. If the ordinary expression for it be taken the problem was impossible, but the corrected form admitted of a solution. Prof. Perry hoped the work Prof. Minchin had done so well for circles and cylinders would be extended to cylindrical coils of rectangular cross-section. It was most important to be able to find the shape of the field produced by such coils. Prof. S. P. Thompson inquired if there was any way of deducing the expression for the magnetic force at a point other than that given in the paper on the magnetic field of a circular current {Phil. Mag. April, 1893). In reply Prof. Minchin explained how the formula followed at once from the fundamental theorem that magnetic force is the curl of the vector potential. This was based on Laplace's expression for the force between a magnetic pole and an element of current which had been proved experimentally. Zoological Society, December 5. — W. T. Blanford, F.R.S., Vice-President, in the chair. — The secretary read a report on the additions that had been made to the Society's menagerie during the month of November. Among these special attention was called to a Cunning Bassaris {Bassaris asttila), obtained by purchase, to two Jerboas presented by Capt. R. A. Ogilby, and to a fine adult female of the Caucasian Wild Goat {Capra caucasica), presented by H. H. P. Deasy. — Prof. G. B. Howes exhibited and made remarks on some specimens of abnormal Marsipobranch Fishes. These were two heads of the Lamprey with the first pair of gills only imperfectly developed, and a Hag {Myxine glutinosa) with a supernumerary gill on one side. — Mr. F. E. Beddard, F. R. S. , gave an account of the general geographical distribution of Earthworms^ as treated of in a work on the subject which he had in preparation. Mr. Beddard recognised sixty-nine genera of this order, divided into six families ; and after some preliminary remarks on the artificial introduction of earthworms into districts colonised from Europe, called attention to a series of tables in which the genera found in the six generally recognised regions of the earth's surface were shown. In addition to these six regions Mr. Beddard was dis- posed to recognise, in the case of earthworms, the existence of an Antarctic region, to embrace New Zealand and most of the Antarctic Islands. — A communication was read from Mr. C. J. Gahan, containing an account of a collection of Coleopiera sent by Mr. H. H. Johnston, C. B., from British Central Africa. Amongst these were examples of eight species new to science. — A communication was read from Capt. F. W. Hutton, F. R.S., containing a report on a collection of Petrels from the Kermadec Islands. Amongst them was an example of a new species proposed to be called CEstrelata leucophrys. — Mr, G. A. Boulenger gave an account of Vipera rcnardi, a newly recognised European Viper from Southern Russia and I urkestan. Entomological Society, December 6. — Henry John Elwe.s President, in the chair. — Mr. W. F. Kirby exhibiied, for Dr. Livelt, specimens of a moth taken at Wells, which Dr. Livett considered to be varieties of Dasycampa rubiginea, but which many entomologists present thought were varieties of Cerastts vaccina. Mr. Kirby stated that specimens similar in appearance I December 21, 1893] NATURE 191 to those exhibited had been taken rather freely during the past autumn in Berkshire, and it was susjgested that they might be hybrids between D. i-itbigi)ica and C. vxccinii. — Mr L)vell- Keays exhibited a series of Lyciena alexis, with coafluent spots on the under sides of the front wings. He drew attention to the fact that the insects were all taken within a short radius, and probably were in the ratio of about one in forty with reference to the ordinary form. All the examples, with one exception, were females. Mr. Lovell-Keays remarked that he had some years ago met with a similar brood near Weymouth, in which the confluent spots were entirely confined to females. Prof. S. H. Scudder, of Cambridge, Mass., U.S.A., stated that he had observed the occurrence of broods of allied species with suffused spots in America. — -Mr. C. O. Waterhouse exhibited the type specimen of Coptomia opalina of Gory, from the Hope Collection at Oxford, and pointed out that it was quite distinct from C. mutabilis, W. Mr. Water- house also called attention to Silpha atoniaria of Linnsus (Syst. Nat., ed. xii., i., p. 574), a Swedish species which appeared to have escaped notice, and was not included in any catalogue. The type is still extant in the Linnean cabinet, and he said he was of opinion that it was Olibrns geminiis of our collections, but he had not had an opportunity of making a critical examination. He also exhibited male and female specimens of a Helopeltis (the Tea- Bug), which he con- sidered a distinct species, occurring only in Assam. — Mr. M. Jacoby exhibited certain species and varieties of the genus Ceroglossiis from Chili, and Dr. D. Sharp, Mr. J. J. Walker, and Mr. Champion made remarks on their geo- graphical distribution. — Prof. Scudder exhibited the type spe- cimen of a fossil butterfly, Pyodryas persephone, found in beds of Tertiary Age at Florissant, Colorado. He said the species belonged to the Nymphalida:, and the specimen was remark- able as being in more perfect condition than any of those from the European Tertiaries. He also stated that he had found a bed near the White River on the borders of Utah, in which insects were even more abundant than in the Florissant beds. Dr. Sharp, Mr. Kirby, Mr. H. Goss, and the President took part in the discussion which ensued. — Mr. Goss exhibited hybernating larvse of Spilothyrus alcea:, which had been sent to him by Mr. F. Bromilow from St. Maurice, Nice. Mr. W. F. H. Blandford read a paper entitled "The Rhyncho- phorous Coleoptera of Japan." The President, Dr. Sharp. Mr. Champion, Mr. iNIcLachlan, and Mr. J. J. Walker took part in the discussion which ensued concerning the distribution of the group and the admixture of Palsearctic and Oriental forms. — Mr. G. T. Bethune-Baker read a paper entitled " Notes on some Lepidoptera received from the neighbourhood of Alexandria," and exhibited the specimens described. Mr. McLachlan suggested that the scarcity of insects in Egypt was possibly to be accounted for by the fact that much of the country was under water for a considerable portion of the year ; and Dr. Sharp said that another cause of the scarcity was the culti- vation of every available piece of land for centuries past. — Mr. C. O. Waterhouse rf ad a paper entitled " Further Observations on the Tea- Bugs {Helopeltis) of India." — Dr. F. A. Dixey communicated a paper entitled " On the Phylogeny of the PierincE, as illustrated by their wing-markings and geographical distribution." Geological Society, -December 6. — W. H. Hudleston, F. R. S., President, in the chair. The following communica- tions were read : — Ttie Purbeck beds of the Vale of Wardour, by the Rev. W. R. Andrews and Mr. A. J. Jukes- Browne. The authors have obtained better evidence than previously existed for calculating the thicknesses of the several parts of the Purbeck series in the Vale of Wardour, and compared the different sub- divisions as developed in that vale with those exposed in other • localities. The average thickness of the Lower Purbeck strata was given as 70 feet, of the Middle Purbeck beds about 32 feet, and of Upper Purbeck strata at least 66 feet. A compari- son was instituted between the Purbeck beds of the Vale of Wardour and those of the Dorset coast, &c., and some remarks were made upon the physical conditions under which the beds were deposited A discussion followed, in which the President, Prof J. F. Blake, Prof. T. Rupert Jones, and Mr. H. B. Woodward to )k part. The Rev. W. R. Andrews briefly re- plied.— On a picrite and other associated rocks at Birmon, near Edinburgh, by Mr. Horace W. Monckton. The object of this paper was to describe a cutting on a new railway in Birnton Park, where there is an excellent exposure of picrite. It con- NO. I -60. VOL. 49J sisls of serpentinised olivine, augite, mica, iron oxide, and a little plagioclase-felspar, with a variable amount of insterstitial matter. In many respects it comes very near to the picrite of Inchcolm, which island is 4}, miles north of Barnton cutting It differs from the picrite of Bathgate, and the probability is that the Barnton rock is an offshoot from the same magma as that which supplied the Inchcolm rock. Besides the picrite other igneous rocks from the same cutting were described — in par- ticular, a rock with porphyritic crystals of a green mineral re- placing olivine, or more probably augite, and a great quantity uf brown mica in small flakes and crystals. It was suggested that the name of niica-porphyrite might be given to this rock. Sir James Maitland made some remarks upon the paper. — On a variety of Ammonites (Stephaiioceras) subai-matits, young, from the Upper Lias of Whitby, by the same author. The author described an ammonite found by himself in 1874 near Sandsend, three miles north-west of Whitby. He thought it was not actually in situ, but lying with a number of nodules on the floor of an old alum-pit, although he had no doubt that it was from the alum shale of the Upper Lias. A peculiar arrangement of the costs as they cross the siphonal area dis- tinguishes the specimen from other Whitby ammonites known to the author. It bears a strong resemblance to a shell figured ^s A. stibarmatiis by D'Orbigny (" Terr. Jurass." pi. Ixxvii.), but is unlike the figures of that species given by other authors. Linnean Society, December 7. — Prof Stewart, President, in the chair. — Mr. C. T. Druery exhibited and made remarks upon a new example of apospory in Scolopendrium vulgare, and Prof. Bower brought forward a similar case in Trichoinanei Kaidfussii. Mr. George Brebner exhibited some new and rare British Algse, including Haplospora globosa, Tilopteris IlTer- tensii, Eciocarpus tornenlosoides, and Polysiphonia spinulosa var. tnajo): Mr. F. Enoch, with the aid of the oxyhydrogen lantern, exhibited the various stages of development of the black currant mite, Phytopttis ribis, and gave an interesting account of its life history. — Mr. Thomas Christy exhibited a gigantic reed-like leaf froui the Zambesi, with drawings of sec- tions. Ilappearedto bedAWedtoSaiisevieri icylindrica, butdiffered conspicuously in the greater size of the leaves, which measured about 9 feet in length, instead of from 18 inches to 3 feet. The remarkably tough and strong fibre which it produces is con- sidered to be of great commercial value, being equal to the best Sansevieria hemp.-^Mr. W. F. Kirby read a poper on the dragon-flies of Ceylon, with descriptions of some new species. The paper was based chiefly upon a collection made by Colonel Yerbury, which he had presented to the British Museum. Seventy-five species were enumerated, of which fifty-five had been collected by Colonel Yerbury. Another collection, made in Ceylon by Mr. E. Green, had been dealt with in a previous paper [Proc. Zool. Soc. 1891, pp. 203-206), — On behalf of Signor Martelli, the secretary read a paper on the cause of the fall of the corolla in Verbasctim, which gave rise to an in- teresting discussion. The meeting adjourned to December 21. Paris. Academy of Sciences, December 11. — M. de Lacaze- Duthiers in the chair. — On the sublimation of the red and yellow iodides of mercury, by M. Berthelot. — Research on the struc- ture of feathers, by M. C. Sappey. — The densities of saturated vapours, and their relation to the laws of condensation and vaporisation of the solvents, by M. F. M. Raoult. — On the burning of moor and forest lands in Gironde, and the excep- tional drought during the spring and summer of this year, by MM. G. Rayet and G. Clavel. The long drought of the spring and summer of this year has favoured the production and extension of fires in the pine woods of the department of Gironde. In the 184 days between March I and September I, 132 (ires happened in the woods of Gironde, destroying 35,589 hectares of forest land, and doing damige to the extent of six million francs. Similar disasters occurred in 1870, and they have led the authors to look up the rainfall observations for the last 122 years for purposes of comparison. Among other points brought out by the investigation is that only two springs, 1716 and 1768, were drier than that of 1893. The summer of this year, however, only ranked thirteenth in order of dryness. — Solar observations made during the --econd and third quarters of 1893, by Prof. Tacchini (see Our Astronomical Column). — On the surfaces of which the lines of curvature of a system are plane and equal, by R. T. Caronnet. — On the characters of convergence of series, by M. Hadamard. — Low wave-length 192 NA TURE [December 21, 1893 spectrura of fluorine, by M. G. Carvallo. — On the diurnal variation of pressure on the summit of Mont Blanc, by M. A. Angot. — On the transformation of iron, by M. G. Charpy. Osmond's investigations of the transformations of iron led him to conclude that this metal exists in two allotropic forms, o and /3, having very different mechanical properties, and, according to him, it is to the transformation of o into yS that we must attribute the greater part of the modification undergone by steel during the process of tempering. M. rharpyhas investigated the matter, and he finds that permanent defoi mation by cooling produces in iron and steel of different qualities an allotropic modification of iron. This transforma- tion can be shown by means of curves of extension-tests. In the case of annealed iron and steel the curve showing the stress and strain has a step in it which does not appear when other varieties are tested. The curves thus furnish a simple method of studying the transformation of iron, its influence on me- chanical properties, and its role in tempering. — On the velocities of etherification of hydrofluoric acid, by M. M. Meslans. — Analysis of butters, by M. C. Viollette. — On the buccal armature and a new digestive gland of Cirripedes, by M. A. Giuvel. — On the localisation of the active principles in resedas, by M. L. Guignard. — On the olivine of MaiUargues, near Ailanche (Cantal), by M. F. Gonnard. — Eruption of the Cal- buco volcano, by M. A. E. Nogues (see Notes).— On Benettiies Morie?-ei, a fossil fruit presenting a new type of gymnosperm inflorescence, by M. O. Lignier. — Employment of artificial cultures of pathogenic microbes in the destruction of trouble- some rodents , by M. J. Dampz. Amsterdam. Royal Academy of Sciences, November 25. — Prof, van de Sande Bakhuyzen in the chair. — Prof. J. A. C. Oudemans read a paper on the accuracy of the divisions of the altazimuth made by Pistor and Martin, and that by Repsold, for the triangu- lation of Java. In Pistor and Martin's circles, divided into 5', the intervals were alternatively larger and smaller in one instance, the difference in an instrument constructed in 1856 being almost = 6" ; in the other instruments it was much smaller. In Repsold's circles, divided into 4', no difference was found. The discovery of this imperfection led to a severe examination of all the circles, and the result was that, taking into account this dif- ference, and measuring the intervals of seven degrees of each circle from three to five times, it was found that Pistor and Martin's divisions had grown better and better, so that ivithin one degree, the mean error of each line, in the instruments of 1S65 and 1867, in linear measure, was only ^/« = TnrrnTTTT of ^n inch. Two altazimuths of Repsold gave ^rV/* — ts Trinnr of an inch. Account was taken of the errors in the measurement of the intervals by the micrometers of the microscopes. The periodic and irregular errors were, of course, larger. — Prof. Zaaijer read a paper on the sutura condylo squamosa of the occipital bone of man and mammalia. For the first time in 1S78 attention was directed to this suture (only part of which remained, and that very rarely, with man) by Dr. W. Dominicus who had found this anomaly on some skulls in the collection of the Anatomical Museum at Leyden. However, this observation remained buried in the dissertation of Dr. Dominicus ("Ontleed kundige aanteekeningen betreffende het achterhoofdsbeen." Leiden, 1878). Last winter Prof. Zaaijer quite accidentally lighted on a human skull (from a grave on the island Disko, Greenland) of which the above-mentioned suture was not obliterated. This induced him to examine the state of the sutura condylo-squamosa of mammalia. By the kindness of the Director of the Museum of Natural History at Leyden, about 1900 skulls of mammalia were examined. The chief result of the examination of the skulls of full-grown animals indicated that the suture was found in its entire state with Marsupialia in S'6 per cent, of the examined skulls (35 in number), Rodentia 3*9 per cent. (155), Pachydermaia l6'5 per cent. (85), Ruminantia lO'5 per cent. (210), Simire i per cent. (202). With the skulls of the adult anmials from the other classes the suture was never found in its entire state, no more than with man. Before com- municating these results Prof. Zaaijer gave a short description of the normal development of the occipital bone in man. A minute and close investigation of a great number ol human skulls raises the question as to whether the entire obliteration of this suture may not be found more frequently with the so- called lower races. NO. 1260, VOL. 49] BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books. — Dynamos. Alternator?, and Transformers: G. Kapp (Biggs). — Electric Traction on Railways and Tramways : A. Reckenzaun (Biggs). — Poriative Electricity: J. l'. Niblett (Biggs). — The Design of Alternate- Current Transformers : R. W. Weekes (Biggs). — Electrical Distribution, its Theory and Pra^ tice, Part i, M H. Kilgour ; Part 2, H. Swan and C. H. W. Biggs (Biggs). — Town Councillor's Hand-book to Electric Lighting : N. S. Russell (Biggs). — First Principles of Electrical Engineering, new edition : C. H W. Biggs (Biggs). — Descriptive Catalogue of the Anatomical and Pathological Specimens in the Museum of the Royal College of Surgeons of Edinburgh, Vol. 1, the Skeleton and Organs of Motion : C W. Cathcart (Edinburgh, Thin). — Romance of the Insect World : L. N. Badenoch (Mac- iiiillan). — tlemeniary Lessons in Steam Machinery and the Marine Steam Engine, new edition: J. Langmaid and H. Gaisfurd (Macmillan). — A Text- book of the Physiological Chemistry of the Animal Body, Vol. 2, the Physio- logical Chemistry of Design : Dr. A. Garagee (Macmillan). — Meteorology: H N. IJickson ( Methuen). — Le Cuivre : P. Weiss (Paris, Baillicre).— Key to Lock's Shilling Arithmetic : H. Carr (Macmillan). — About Orchids : F. Boyle (Chapman and Hall). — Annals of British Geology, 1892 : J. F. Blake (Dulau). — The Flora of the Assyrian Monuments and its Outcomes : Dr. E. Bonavia (Constable). — The Cliff Dwellers of the Mesa Verde, South- Western Colorado : G. Nordenskiold, translated by D. Lloyd Morgan (Stockholm, Norstedtl. — Index Kewensis, Part 2 : J. D Hooker and B. D. Jackson (Oxtord, Clarendon Press).— The Royal Natural History, edited by R. Lydekker, Vol. i. Part 2 (Warne). — Random Recollections of Woodland. Fen, and Hill : J. W. Tutt (Sonnenschein). — Imperial University of Japan, Calendar for the Year 1892-3 (Tokyo). — Les Emules de Darwin, 2 vols. : A. de Quatrefages (Paris, Alcan). Pamphlets. — Report of a Conference on Secondary Education in England (Oxford, Clarendon Press).— Official Catalogue of Exhibits and Descriptive Catalogue World's Columbian Exposition, Department M, Anthropological Building (Chicago).— Memoranda of the (Origin, Plan, and Results of the Field and other Experiments at Rothamsted. — Report of an Investigation on the Gases enclosed in Coal and Coal Dust : W. McConnell. oERiALS.— Journal of the Chemical Society, December (Gurney and Jackson). — American Meteorological Journal, December (Ginn/. — Bulletin from the Laboratories of Natural History of the State University of Iowa, Vol. 2, No 4 (Iowa). — M6moires de la Soci^t^ de Physique et d'Histoire Naturelle de Geneve, Tome xxxi . Seconde Partie (Geneve). — American Journal of Science, December (New Haven).— Miner logical Magazine, November (Simpkin). — Matt-rials for a Flora of ihe Malayan Peninsula. No. 5, Dr. J. King (Calcutta).— Materials for a Flora of the Malayan Peninsula. Index and Title Page to the Tha'amiflora: (Nos. i to 5 of the Series) : Dr. G. King (Calcutta;.— Johns Hopkins University, Studies in Historical and Political Science, b-leventh Series, xi.-xii. (Baltimore). — Beitriige zur Biologie der Pflanzen, vi. Band, iii. Heft (Williams and Norgate).— Morphologisches Jahrbuch, 20 Band, 4 Heft (Williams and Norgate). CONTENTS. PAGF The Tombs at Beni Hasan 169 A Nature Lover's Correspondence 170 Our Book Shelf:— Wallace Stewart : " A Text-book of Heat " .... 171 Houssay : " The Industries of Animals " 171 Letters to the Editor : — Flame.— G. S. Newth ; Prof. Henry E. Arm- strong, F.R.S .• '71 The Postal Transmission of Natural History Speci- mens.—R. McLachlan, F. R.S 172 "Geology in Nubibus" — Mr. Deeley and Dr. Wal- lace.—Sir H. H. Howorth, K.C.I.E., M.P., F.R.S ....... 173 The Viscous Motion of Ice.— John Tennant ... 173 Chemistry in Space. — Dr. John Cannell Cain . -'73 The Manoeuvring Powt-rs of Steamships and their Practical Applications. {With Diagrams.) By Vice-Admiral P. H. Colomb, R.N I74 The Tunicate, By R. M i79 Notes 179 Our Astronomical Column: — Colour- Aberration of Refracting Telescopes .... 18^ Stars with Remarkable Spectra 183 " Himmel und Erde " for December 184 A New Variable 184 Geographical Notes 184 A New Process for the Preparation of Ethers. By A. E. Tutton 184 The Progress of Technical Education. By R. A. Gregory 185 Scientific Serials 188 Societies and Academies 189 Books, Pamphlets, and Serials Received 192 NA TURE 193 QUATERNIONS AS AN INSTRUMENT IN PHYSICAL RESEARCH. Utility of Quaternions in Physics. By A. McAulay, M.A. (London : Macmillan and Co., 1893.) T UST as " one shove of the bayonet " was truly said to J be more effective than any number of learned discussions on the art of war : — this really practical work, giving genuine quaternion solutions of new pro- blems as well as largely extended developments of old ones, is of incomparably greater interest and usefulness than the recently renewed, but necessarily futile, attempts to prove that a unit vector cannot possibly be a quad- rantal versor : — nay, that a Calculus of Vectors must limit itself to the beggarly elements of addition and sub- traction, commonly called "composition." It is much to be regretted that Mr. McAulay has not determined simply to let his Essay speak for itself. His Preface, though extremely interesting as the perfervid outburst of an enthusiast, assumes here and there a character of undignified querulousness or of dark insinu- ation, which is not calculated to win sympathy. It has too much of the," Rends-toi, coquin " to make willing converts ; and in some passages it runs a-muck at Institutions, Customs and Dignities. Nothing seems safe. It is a study in monochrome : — the lights dazzlingly vivid, and the shades dark as Erebus ! We gladly pass rom it to the main contents of the book. There can be no doubt whatever of its value from the scientific point of view. It is the work of a man of genuine power and originality. Many parts of it are, no doubt, laboured and somewhat heavy, others very crude ; and in some places the obscurity is almost repulsive. [Curiously, these obscurities occur chiefly where more than usual pains have been taken to make things plain !] But faults like these are well-nigh inevitable in a first effort ; and they should, perhaps, be regarded as enhancing by contrast the merits of the novel processes and results to which they act as a foil. It is positively exhilarating to dip into the pages of a book like this after toiling through the arid wastes pre- sented to us as wholesome pasture in the writings of Prof. Willard Gibbs, Dr. Oliver Heaviside, and others of a similar complexion. Here, at last, we exclaim, is a man who has caught the full spirit of the Quaternion system : — " the real csstiis, the awen of the Welsh bards, the divinus afflatus that transports the poet beyond the limits of sublunary things"! No doubt, to a man like this, the restrictions imposed, in view of the prospective ordeal of the Senate-House, by the passionless worldly- wisdom of a " Coach," must have been gall and bitter- ness. Intuitively recognising its power, he snatches up the magnificent weapon which Hamilton tenders to all, and at once dashes off to the jungle on the quest of big game. Others, more cautious or perhaps more captious, meanwhile sit pondering gravely on the fancied imper- fections of the arm; and endeavour to convince a bewildered public (if they cannot convince themselves) that, like the Highlander's musket, it requires to be treated to a brand-new stock, lock, and barrel, of their NO. 1 261, VOL. 49] own devising, before it can be safely regarded as fit for service. " Non //zi' juventas orta parentibus . . ." What could be looked for from the pupils of a School like that? Mr. McAulay himself has introduced one or two rather startling innovations. But, unlike the would-be patchers or underpinners to whom we have referred, he retains intact all the exquisitely-designed Hamiltonian ma- chinery, while sedulously oiling it, and here and there substituting a rolling for a sliding contact, or introducing a lignum vitce bearing. To borrow an analogy from current electricity, he endeavours to add facilities, while his concurrents are busy adding resistances, sometimes indeed breaking the circuit altogether ! Among the additions to which Mr. McAulay calls attention, some are certainly not novel, they were per- fectly well known to Hamilton himself. Thus the use of suffixes, to show which factor of a product (say) is to be acted on by an operator, is at least as old as Herschel's Appendix to the translation of Lacroix : — and is an essential part of the notation required for what is cor- rectly called "Hamilton's Theorem." Mr. McAulay refers to this as a process of his own, which was found "necessary somewhat to expand the meaning'' of a symbol. Another instance is the use of a vector, which may have an infinite nu?nber of values, for the purpose of condensing three independent scalar equations into one common expression, &c. This is purely and entirely Hamiltonian. The "startling innovations," however, as we called them above, are unquestionably Mr. McAulay's own — and he has certainly gone far to justify their introduc- tion. He has employed the sure tests of ready applica- bility and extreme utility, and these have been well borne. Objections based upon mere unwontedriess or even awkwardness of appearance must of course yield when such important advantages as these (if they be otherwise unattainable) are secured ; but it certainly requires a considerable mental wrench to accustom our- selves to the use of d Xi dx-j^ as an equivalent for the familiar expression dx. If this be conceded, however, it is virtually all that Mr. McAulay demands of us, and we are free to adopt his system. It is to be carefully observed that there is no interference with ihe. principles of quaternions to which, as was remarked above, Mr. McAulay strictly adheres. The quantities and operators, to which the dislocation applies, are all scalars, and the wrench referred to is therefore an algebraic, not a specially quaternion, one. Its introduc- tion is made necessary by the determination to adhere to the non-commutative property of quaternion multiplica- tion, while endeavouring to effect certain desirable trans- formations. Mr. McAulay likens this dislocation of the usual arrangement of operator and subject to the occasional disarrangement of relative position of adjec- tive and substantive in a Latin sentence : — the nexus between them being the common case-ending, which is the analogue of the common suffix. A single example, K 194 NA TURE [December 28, 1893 of a very simple character, must suffice. Thus in the strain of a homogeneous isotropic solid, due to external potential u, we have for the strain-function v + Vti = o, which is the vector equation required. Here it is obvious that, in the usual order of writing, 4)V = — ^i + --. Has the attention of zoologists been called to this story before? Heidelberg, Germany, C. R. Osten Sacken. December 5. On an Undescribed Rudimentary Organ in Human Attire. Lecturers who are tired of the cockade hat-ribbon and tail buttons, may be glad to know of the following rudiment. The old-fashioned double eye-glass was a folder, with a knob at the cuter side of the distal glass ; and this on folding locked against a pin on the outer side of the proximal glass. The double eye- glass of the present day does not fold ; but, none the less, is the knob outside the distal glass retained for it, though there is no pin to lock with on the proximal glass. How long will it take be- fore this useless rudiment disappears ? What will be the cause of its disappearance? As panmixia is out of the question, we may prophesy that it will be economy of material. Cork, December 12. Marcus Hartog. EARLY ASTERISMS} III. The Constellations referred to in the Myth 0/ Marduk and Tiuinat. WE are indebted to the myth, then, for the knowledge that when it was invented the constellations Bull, Scorpion, Goat, and Fishes had been established. This argument is strengthened by the following con- siderations suggested by Jansen : — " We look in vain among the retinue of Tiamat for an animal corresponding to the constellations of the zodiac to the east of the vernal equinox. This cannot be accidental. If therefore we contended that the cos- mogonic legends of the Babylonians stood in close relationship to the phenomena of sunrise on the one hand and the entrance of the sun into the vernal equinox on the other ; that, in fact, the creation legends in general reflect these events, there could not be a more convincing proof of our view than the fact just mentioned. The three monsters of Tiamat, which Marduk overcomes, are located in the ' water-region ' of the Heavens, which the Spring Sun Marduk 'overcomes' before entering the (ancient) Bull. If, as cannot be doubted, the signs of the zodiac are to be regarded as symbols, and especially if a monster like the goat-fish, whose form it is difficult to recognise in the corresponding constellation, can only be regarded as a symbol, then we may assume without hesitation that at the time when the Scorpion, the Goat-Fish, and the Fish were located as signs of the zodiac in the water-region of the sky, they already played their parts as the animals of Tifimat in the creation legends. Of course they were not taken out of a com- plete story and placed in the sky, but conceptions of a more general kind gave the first occasion. It does not follow that all the ancient myths now known to us must have been available, but certainly the root-stock of them, perhaps in the form of unsystematic and unconnected single stories and concepts." There is still further evidence for the constellation of the Scorpion. Jensen remarks : — 1 Continued rom vol. xlviii. p. 520. NO. 1261, VOL. 49] " A Scorpion-Man plays also another part in the cosinology of the Babylonians. The Scorpion-Man and his wife guard the gate leading to the Masu mountain(s), and watch the sun at rising and setting. Their upper part reaches to the sky, and their irtti (breast?) to the lower regions (Epic of Gistubar 60,9). After Gistubarhas traversed the Masu Mountain, he reaches the sea. This sea lies in the east or south-east. However obscure these conceptions may be, and however they may render a general idea impossible, one thing is clear, that the Scorpion-Men are to be imagined at the boundary between land and sea, upper and lower world, and in such a way that the upper or human portion belongs to the upper region, and the lower, the Scorpion body, to the lower. Hence the Scorpion-Man represents the boundary between light and darkness, between the firm land and the water region of the world. Marduk, the god of light and vanquisher of Tiamat, i.e. the ocean, has for a symbol the Bull = Taurus, into which he entered in spring. This leads almost necessarily to the supposition that both the Bull and the Scorpion were located in the Heavens at a time when the sun had its vernal equinox in Taurus and its antumnal equinox in Scorpio, and that in their principal parts or most conspicuous star groups ; hence probably in the vicinity of Aldebaran and Antares, or at an epoch when the principal parts of Taurus and Scorpio appeared before the sun at the equinoxes." If my suggestion be admitted that the Babylonians dealt not with the daily fight but with the yearly fight between light and darkness — that is, the antithesis between day and night was expanded into the antithesis between the summer and winter halves of the year ; then it is clear that at the vernal equinox Scorpio setting in the west would be watching the sunrise ; at the autumnal equinox rising in the east, it would be v/atching the sun- set ; one part would be visible in the sky, one below the horizon in the celestial waters. If this be so all obscurity disappears, and we have merely a very beautiful state- ment of a fact, from which we learn that the time to which the fact applied was about 3000 B.C., if the sun were then near the Pleiades. Jensen in the above-quoted passages by implication, and in a subsequent one directly, suggests that not all the zodiacal constellations were established at the same time. The Babylonians apparently began with the easier problem of having six constellations instead of twelve. For instance, we have already found that to complete the present number, between Scorpio. Capricornus. Pisces. we must interpolate Sagittarius. Aquarius. Aries and Libra seem also to be late additions accord- ing to Jensen, who writes : — " We have already above (p. 90), attempted to explain the striking phenomenon that the Bull and Pegasus, both with half bodies only, rifj.iTOfj.oi, enclose the Ram be- tween them, by the assumption that the latter was in- terposed later on, when the sun at the time of the vernal equinox stood in the hind parts of the Bull, so that this point was no longer sufficiently marked in the sky. Another matter susceptible of a like explanation may be noted in the region of the sky opposite to the Ram and the Bull. Although we cannot doubt the existence of an eastern balance, still, as already remarked (p. 68), the Greeks have often called it ^rj^al ' claws ' (of the Scor- pion), and according to what has been said above (p. 312), the sign for a constellation in the neigh- bourhood of our Libra reads in the Arsacid inscription ' claw(s) ' of the Scorpion. These facts are very simply explained on the supposition that the Scorpion originally extended into the region of the Balance, and that originally a and ,3 Librse represented the ' horns ' 200 NA TURE [December 28, 1893 of the Scorpion, but later on, when the autumnal equinox coincided with them, the term Balance was applied to them. Although this was used as an additional name, it was only natural that the old term should still be used as an equivalent. But it also indicates the great age of a portion of the zodiac." Let us suppose that what happened in the case of Aries and Libra happened with six constellations out of the twelve, in other words, that the original zodiac consisted u.ily of six constellations. We should have — u list not only classifies an unbroken The upper manner the Fish-Man, the Goat-Fish, the Scorpion-Man and Marduk of the Babylonians, but we pick up all or nearly all of the ecliptic stars or constellations met with in early Egyptian mythology, Apis, the Tortoise,^ Min, Selk, Chnemu as represented by appropriate symbols. Further, the remarkable suppression or small represen- tation of the Lion in both the more ancient Babylonian and Egyptian mythology is explained. I have shown before how the Babylonians with an equinoctial year would take slight account of the solstice, while it also follows that the Egyptians, who were wise enough not to use zodiacal stars for their warnings of sunrise for the reason that stars in the brighter light of dawn near the sun are more difficult to see, might easily neglect the con- stellation of the Lion as first Phact and then Sirius, both southern stars, marked for them the advent of the summer solstice ; on different grounds, then the Lion might well have been at first omitted in both countries. Since there is a doubt as to the existence of the Lion among the first Babylonian constellations,- the argument in the following paragraph would appear to refer to observations made at a later time when totemism was less prevalent : — "The Lion in the heavens must represent the heat of the summer. He does this most effectually when the summer solstice coincides with the constellation, that is, when its principal stars appear before the sun at the summer solstice. This happened at the time when the vernal equinox lay in Taurus, and when the principal star-group of the Bull appeared before the sun at the time of the vernal equinox. The water- jug (Amphora) — Aquarius must represent symbolically the watery season of winter. It does this most effectu- ally when the winter solstice coincides with it, or its principal star-group appears before the sun at the winter solstice. This happened about the time when the vernal equinox lay in Taurus, and its principal star-group rose before the sun at the time of the vernal equinox." The above suggested basis of the Babylonian mytho- logy, regarding the demons of Tiamat, established when the sun was in Taurus at the spring equinox, enables us to understand clearly the much later (though similar) imagery employed when the sun at the equinox had passed from Taurus to Aries — when the Zend Avesta was written, and after the twelve zodiacal constellations had - 1 I think I am riglit about the Tortoise, for I find the following passage in Jensen, p. 65, where he notes the absence of the Crab; — " Ganz absehend davon, ob dasselbe fiir unsere Frage von Wichtigkeit werden wird oder n.cht, muss ich daran erinnern, das unter den Emblemen, welche die sogenannten "Deeds of Sale" haufigbagleiten, verschiedene Male wie der Scorpion S3 die Schildkrote abgebildet gefunden wird. . . ." - Jensen, p. 314. NO. 1 26 I, VOL. 49] been established. We find them divided equally into the kingdoms of Ormuzd and Ahriman. Here I quote Dupuis : ^ " L'agneau est aux portes de I'empire du bien et de la lumiere, et la balance a celles du mal et des tenebres ; I'un est le premier des signes superieurs, et I'autre des signes inferieurs. " Les six signes superieurs comprennent lessix millede Dieu, et les six signes inferieurs les six mille du diable. Le bonheur de I'homme dure sous les premiers signes, et son malheur commence au septieme, et dure sous les six signes affectes a Ahriman, ou au chef des tenebres. " Sous les six signes du regne du bien et de la lumiere qui sont agneau, taureau, gemaux, cancer, lion et vierge ou epi nous avons marque les etats varies de I'air et de la terre, qui sont le resultat de Taction du bon prin- cipe. Ainsi on lit sous l'agneau ou sous le premier mille ces mots, printemps, zephyr, verdure ; sous le taureau, seve et fleur ; sous les gemeaux, chaleurs et longs jours ; sous le cancer, ete, beaux temps ; sous le lion, epis et moissons ; et sous la vierge, vendages. " On passant a la balance, on trouve les fruits ; la com- mence le regne du mal aussitot que I'homme vient a cueiller les pommes. La nature quitte sa parure ; aussi nous avons ecrit ces mots. Depouillement de la nature, sous le scorpion on lit froid ; sous le sagittaire, neiges j sous le capricorne, glace et brouillard, siege des tene- bres et de long nuits ; sous le verseau, pluies et frimas ; sous les poissons, vents impetueux." We now return for a moment to la. Associated with la was an la-star, which Jensen con- cludes may be r) Argus. This we must consider. Jensen concluded that the la-star is rj Argus, on the ground that many of the texts suggest a darkening of it now and again ; he next proceeds to point out that a varia- bility in the star is the only point worth considering in this connection, and by this argument he is driven to ?/, which is one of the most striking variables in the heavens, outshining Canopus at its maximum. Speaking gener- ally, everybody would agree that observation by clouds, &c., would not be recorded, but if the star were observed just rising above the southern horizon only, then its absence, due to such causes, would, I should fancy, be chronicled, and it must not be forgotten that this is pre- cisely the place where it would be observed, for in the first place it was to the south of the heavens, what Bi) was to the north, and the temple sacred to it at Babylon was oriented to the south. But J? Argus never rose or set anywhere near the south. I have ascertained that its declination was approximately 33^"" S. in 6000 B.C., and increased to 40" S. by about 2000 B.C. Hence between these dates at Eridu its amplitude varied between 38^ and 47° S. of E. or W. Now here we are far away from the S. point, though very near the S.E. or S.W. point, to which it is stated the Babylonian structures had their sides oriented. The question arises whether there was a star which answers the other conditions. There was a series of such stars. First, beginning with the most recent; we have Canopus. 6000 B.C. its declination was 62.3^, it would then have been below the horizon of Eridu, first making its appearance with a declination of 59' nearly at the south point in 4700 B.C. Phact would follow in 5400 B.C. Achenar would make a similar appearance for the first time about 8000 B.C. It may be here mentioned gener- ally that the precessional movement must, after certain intervals, cause this phenomenon to be repeated con- stantly with one star after another. May this explain the "other animals" who subsequently appeared like la (Cannes) ? The whole myth is, I think, clearly one re- lating to men coming (from the south ':) to Eridu in ships. The boat is turned into a " fish man," and the " Origine des Cultes," vol. vii. p. 82. December 28, 1893] NA TURE 201 star to which they pointed to show whence they came or made a god.^ It will have been gathered that the constellations of the Bull and the Scorpion were recognised as such at the same early date both in Babylonia and Egypt, and this of course implies intercommunication. The ecliptic stars in use in Babylonia in later times are as follows - : — I. 1) Piscium. 15- 0 Leonis. 2. ^ Arietis. 16. p Leonis. 3- a Arietis. 17- ^ Leonis. 4- r\ Tauri. 18. & Virginius. 5- a Tauri. 19. 7 Virginius. 6. ^ Tauri. 20. a Virginius. 7- ^ Tauri. 21, a Liliae. 8. 7j Geminorum. 22. i3 Liliae. 9- yi Geminorum. 23- 5 Scorpionis. 10. II. 12. 7 Geminorum. a Geminorum. yS Geminorum. 24. 25- 26. a Scorpionis. S Ophiuchi. 0 Capricornis. 13- 14. 5 Cancri. 6 Leonis. 27. 2b. 7 Capricornis f\ Capricornis. With regard to the complete ecliptic, the information seems meagre both from Babylonia and from Egypt in early times. As to later times in Babylonia — say i ooo B.C. — the follow- ing list represents the results of Jensen's investigations : — (i) Perhaps Aries (= " leading sheep "). (2) A "Bull (of the Heavens)" = Aldebaran or (and) = our Taurus. (3) Gemini. (4) ? (5) Perhaps Leo. (6) The constellation of the "corn in ears " = the ear of corn. [Spica.] (7) Pi-obably Libra, whose stars are, however, at least in general, called "the claw(s) " {Le. of the Scorpion). (8) The Scorpion. (9) Perhaps Sagittarius. (10) The "goat fish" — caper. (II)? (12) The "Fish" with the "Fish band." In Egypt we find no such sharp references as the above to either the poles or the great circles, but dating from the twentieth dynasty (iioo B.C.), and therefore almost con- temporaneous, is a series of star tables which have puzzled Egyptologists from Champollion and Biot downwards. Looking at them they seem to be observations of stars made during the twelve hours of the night on the ist and i6th of every month. The chief stars seem to be twenty-four in number, and it looked at first as if we had really here a list of priceless value of twenty-four either ecliptic or equatorial stars. Unfortunately, however, the list has resisted all efforts to completely understand it. Whether it is a list of risings or meridian passages even is still in dispute. Quite recently, indeed, one of the investigators, Herr Gustav Bilfinger,^has not hesitated to consider it not a list of ob- servations at all, but a compilation for a special purpose. " The star-table is intended to carry the principle of time into the rigid world of the grave, and represents over the sepulchral vault, ' the eternal horizon ' as the ancient Egyptians so aptly styled the grave, an imitation of the sky, a compensation for the sky of the upper world with its time-measuring motion ; yet the idea here is bolder, the execution is more artificial and complicated, since the sculptor endeavoured to combine the daily and the annual motion of the celestial vault in one picture ; wanted to transfer into the grave the temporal frames in which all human life is enacted. This endeavour to re- present by one configuration both motions and both 1 For the story as told by Beroasas, see Sayce, p. 131. - " Astronomisches aus Babylon," pp. 117-133. 3 "Die Sterntafein in den iigyptischen Konigsgriibern von Biban el Molflk " . — von Gustav Bilfinger (p. 69). NO. T261, VOL. 49] chronological units explains all the peculiarities and im- perfections of our star-table. "The simplest means of representing both motions was found in the stars, which circle the earth in the course of a day and indicate the year by the successive appearance of new stars in the morning twilight. If the same stars were to serve both purposes in one repre- sentation, it was necessary to take twenty-four stars which rose at intervals of fifteen days, since only such followed each other at an average distance of 15^, and were there- fore useful for showing the hours." "If the calendar-maker really possessed a list of the twenty-four principal (zodiacal) stars, the course of the year was indicated thereby ; but since he also wanted to represent the daily motion, he might with some justice have composed each night out of eleven of these stars, since the stars' risings are only visible during the ten middle hours of the night. But ten hours would not have adequately represented the night, since this was thought of as a twelve hours' interval. " There was a way out of it, viz. to call hora o ' sun- set,' hora 12 ' sunrise,' which would have been a simple and correct solution if the division of the night into twelve parts for practical purposes had been aimed at. But this expedient he could not adopt, because he could or would only operate with stars, and the notions of sun- rise and sunset found no place in his tables. Thus he was forced to falsify the customary division of the hours, by squeezing the twelve hours of the night into the time during which star risings are visible, viz. the dark night exclusive of twilight. On the other hand he could not, with his principal stars at intervals of 15", divide his night, shortened as it was by two hours^ into twelve parts, and thus he was obliged to make use of two or three auxiliary stars, as we have proved in detail above, and thus yet more to disfigure the hour-division, since thereby the lengths of the hours were made very vari- able. These are then two things which we must not re- gard as peculiarities of ancient Egyptian reckoning, but as a consequence of the leading idea of our table, which did not intend to facilitate the division of the night into twelve parts by star observations, but was calculated by the connection of thirteen stars with thirteen successive moments to create the idea of the circling host of stars and thence the course of the night." I give an abstract of the list of the twenty-four principal stars and the constellations in which they occur : — 1. Sahu = Orion. 2. Gothis = Sirius. 3. The two stars. 4. The stars of the water. 5. The lion. 6. The many stars. 7. Mena's herald. 8. Mena. 9. Mena's followers. \l\ . 12. ; Hippopotamus. 13-1 14.; 15- 16. 17- 18. 19- 20. 21. Ari. 22. 23- . 24. Sahu = Head of Orion. It will be seen that this Egyptian star list is very in- determinate, but there are other lists, which are much more definite, represented by the Indian Nakshatras, the Arab Manazil al-Kamar, and the Chinese Sieu. Necht. Goose. 202 NA TURE [December 28, 1893 Hindu Asterism. 1. A9vini (The two gods) 3 and 7 Arietis 2. Bharani (Carrying away) 35. 39) and 41 Arietis 3. Krttika (Has been explained as matting doubtful) 17 Tauri, &c. (Pleiades) 4. Rohini (Red) «» ^> 7> 5, € Tauri 5. Mrgaciras (Head of deer) A, <^, (j)" Orionis •6, Ardra (Damp) a Orionis 7. Punarvasu (Twice bright) fi, a Geminorum 8. Pushya (Auspicious) 9, 5, 7 Cancri 9. Acleshii (Embracing, serpents) €, 5, (T, v> p Hydrse 10. Magha (The strong ?) 0. V, 7, C) 1") * Leonis 11. Purva Phalguni (Grey) 5, 6 Leonis 12. Uttara Phalguni j3, 93 Leonis 13. Hasta (Hard) 8, y, e, a, /3 Corvi 14. Citra (Beautiful) o Virginis 15. Svati a Bootis 16. Vicakha (Fork) 1, 7, $, a Librae 17. Anuradha (Blissful) 5, 0, IT Scorpionis 18. Jyeshtha (The best) a, (X, T Scorpionis 19. Mula (Root) A, V, K, I, 0, V, C> M. e Scorpionis 20. Purva- Ash adha (Unconquered) 5, € Sagittarii 21. Uttara- Ashadha (Unconquered) a, C Sagittarii 22. Abhijit (Victorious) a, 6, C Lyrae 23. Qravana (Lame) a, /3, 7 Aquilas 24. Qravishtha (Most glorious) 0, a, 7, 5 Delphini 25. (^atabhishaj (?) A Aquarii, &c. 26. Purva Bhadrapada (Having ox feet) o, 0 Pegasi 27. Uttara-Bhadrapada (Having ox feet) 7 Pegasi, a Andromedse 28. Revati (The rich) C Piscium, &c. NO, I 261. VOL. 49] Arab Manzil. 1. ash-Sharatan (The two signs) $ and 7 Arietis 2. al-Butain (The little belly) 35) 39) and 4' Arietis 3. ath-Thuraiya (Probably " the cluster") V Tauri, &c. (Pleiades) 4. ad-Dabaran("The follower" of the Plei- ades) a, 0, 7, 5, € Tauri 5. al-Hak'ah (The circle of hairs) A, (j)^, I Geminorum 7. adh-Dhira' (The arm) 0, a Geminorum 8. an-Nathrah ("The point between lip and nostrils " of Leo) 7, S Cancri, and Praesepe 9. at -Tarf ("The eyes" of Leo) I Cancri, A Leonis 10. aj-Jabhah (The forehead) ") Vt 7> C Leonis 11. az-Zubrah (The shoulder) S, d Leonis 12. as-Sarfah ("The change" of weather) fi Leonis 13. al-Auwa ("The howler," sometimes con- ceived as a dog barking round Virgo) fi, Vt 7) 5, 6 Virginis 14. as-Simak (The prop) a Virginis 15. al-Ghafr (Of uncertain sense) *, K, A Virginis 16. az-Zubanan ("The two claws" of the scorpion) a, j8 Librse 17. al-Iklil (The crown) j3, S, 7r Scorpionis 18. al-Kalb (The heart) a Scorpionis 19. ash-Shaulah (" The sting " of the scorpion) A, V Scorpionis 20. an-Na'aim (The ostriches) 7^ S, €, 7j, (j>, or, T, f Sagittarii 21. al-Baldah (The hairless space between the eyebrows) N of TT Sagittarii 22. Sa'd adh-Dhabih (Sa'd (luck) the sacrificer) a, j8 Capricorni 23. Sa'd Bula' ("Greedy Sa'd," because the larger star seems 10 swallow the smaller) e, fi, V Aquarii 24. Sa'd as-Suud (" The luck of lucks " = spe- cially lucky star 0, I Aquarii 25. Sa'd al-Akhbiyah (" Sa'd with the tents") *) 7) C) '? Aquarii 26. al-Fargh al-Mukdim (The front lip of the bucket) o, 0 Pegasi 27. al-Fargh al-Mukhir (The hinder lip of the bucket) 7 Pegasi, a Andromedse 28. Batn al-Hut (The fish's belly) 0 Andromedae, &c. Chinese Sieu. Mao 7j Tauri 2. Pi e Tauri Tse A Orionis Tsan 5 Orionis Tsing (A well) H- Geminorum Kuei 0 Cancri Lieu (The willow) 5 Hydrae Sing (A star) a Hydrae Chang j*^ Hydras 10. Y a Crateris 11. Chin 7 Corvi 12. Kio (A horn) a, Virginis 13. Kang (Overbearing,strong) aminaticn of the plates. The advantage of photography for obtaining cometary photographs, and especially for making analyses of the tails, will be at once grasped when one con'-iders that Prof. Barnard, with the 12 in., could not trace the tail even to a distance of 1°, while the photo- graphs taken with the Willard lens (6 in. aperture, 31 in. focus) showed it fully for 10^. Hydrogen Envelope of the Star D.M. +30^3639. — Prof. W. VV. Campbell, in the December number of .-^i/rdJ^owj ■and Astrophysics, communicates a very important observation with regard to the spectrum of one of the Wolf-Rayet stars. The star in question is of the 93 magnitude, D.M. +30^3639, and its spectrum is very rich in bright lines. The most striking features of the visual spectrum have been noted as the bright line A 5694, the bright blue band at A 4652, and the very bright hydrogen line Hy3. By arranging the spectroscope so that each of these different parts of the spectrum is in focus, the line A 5694 is seen as " a very small image of the star. " The band at A 4652 is " broad and lies wholly upon the narrow continuous spectrum," the H/8 line observed with a narrow slit "is along line extending to a very appreciable distance on each side of the continuous spectrum," and with an open slit is " a large circular disc 5" in diameter." Other hydrogen lines H7 and Ha also exhibit the same peculiarities. The explanation of this appearance is that the star in question must be surrounded by an envelope of incandescent hydrogen, for other lines in the same spectrum are not so changed. It is remarked also that in other stars of the same type no such image has been observed. " L'Astronomie" for December. — The December number of this journal commences with a most interesting article by Dr. Tanssen on the Observatory at Mont Blanc. The article itself contains nothing of which our readers have not been informed in the previous columns of Nature unless it be the illustration showing the summit of the mountain with the observatory "in winter." Two good illustrations of the appearance of the sun during the last total eclipse of the sun (April 16, 1893), the cliches of which were obtained by M. Schreberle and Prof. Des- landres. "Around the world of Jupiter in ten hours" is the title of a series of observations made at the observatory of Juvisy by M. Eugene Antoniadi. The writer gives twelve drawings of this planet, as made during this period, showing the various surface markings which were brought to view by rotation. Amateurs and others who at this time are observing this planet will find these drawings a most useful help in recognising many markings. The red spot is described as excessively pale: " Elle est coloree en rose; ses regions centrales sont claires, ses bords plus sombres ; elle est entouree d'une aureole blanchatre." GEOGRAPHICAL NOTES. The death of Dr. H. Rink, on December 15, removes the greatest authority on Greenland and the Eskimo. His life-long devotion to the problems of the Arctic people gained for him the esteem of all geographers. Reuter's Ac.ency announces that information has been re- ceived from Baron Toll to the effect that up to October 25 Dr. Nansen had not called at the Olenek river. This is practically decisive news that Dr. Nansen found the sea so open that he NO. 1261, VOL. 49] determined to push northward without delaying to call any- where ; and it is improbable that we shall hear more of the in- trepid traveller until we receive his own report of success or failure. Dr. Murray's paper on the renewal ot Antarctic explora- tion will be published in the January number of the Geographi- cal younial, which commences the third volume. It will be accompanied by a series of letters from distinguished foreign oceanographers and naturalists, strongly urging the importance of " resuming systematic exploration in Antarctic seas. Dr. Hillier has recently communicated a paper to the Vienna Academy of Sciences on the geography of the Pindus range, one of the few mountain systems of any extent in Europe which has never yet been adequately explored. He finds that the system consists of three parallel ranges, and he has unravelled the geological structure of each. A communication to the Royal Geographical Society states that Mr. Crawshay, a Government official in British Central Africa, has recently visited the Angoni country near Lake Nyasa. He found the Nyika Plateau, which was traversed on the way, a magnificent country, inhabited by a scattered population of Anyika, living in huts built on narrow terraces on the mountain-side or in caves, and cultivating peas as an almost exclusive crop. In this district there are some fine mountains, exceeding 8,000 feet in height, the principal town of the Anyika, on the slope of Kantorongondo, being nearly 6,000 feet above the sea. EPIDEMIC INFLUENZAE 'X'HE present report, a welcome supplement to the epoch- -'- making report on the epidemic of 1889-90, is divided into eight parts, the first seven by Dr. Parsons, and the last one by Dr. Klein. It includes statistical studies of the epidemic of 1890, an account of the recent epidemics in England and Wales, a history of influenza abroad in 1891 and 1892, considerations respecting the retiology of the disease, notes on some clinical features of the later epidemics, reports on outbreaks in institu- tions, &c., remarks on the prophylaxis of the disease, and, in Dr. Klein's department, a report on influenza in its clinical and pathological aspects, to which photographic plates are appended exhibiting influenza bacilli. Among the conclusions confirmed by the present report are the small influence of locality, or environment, and the invariably potent factors of exposure or proximity to the sick, and bad ventilation. Over and over again serious epidemics in a town or island have been traced to the arrival of one or two persons from an infected place. With regard to the later epidemics, it would appear that the contagion of the disease, scattered broadcast, had "retained its vitality, but in a suspended or inconspicuous form, perhaps by transmission from one human being to another in a succession of mild sporadic cases, perhaps in some medium external to the human body." Recrudesence has taken place chiefly in early spring and in autumn. Observers in various parts of the world have contributed their experience that the progress of influenza in a country is gradual. The most remarkable instances of rapid and wide diffusion were in the United States, especially in the Western States and to settle- ments far apart. A good example of the usual manner of spread is given in Part IV. A teacher of music visited two relatives ill with influenza on April 6, and returned to his own locality, which had been hitherto unaffected. On April 9 he was attacked, but struggled through his work, and gave lessons to pupils at several houses. On April 11, ten of his pupils, and on April 12, the people with whom he lodged, developed the disease. One medical officer states that he recollects no instance of the disease spreading from one member of a household to others where strict precautions for isolation and disinfection were taken. Unfortunately, however, it often happens that the first member attacked was not the only one who had been previously exposed to infection. Dr. Newsholme, medical officer for Brighton, states that the borough sanatorium, being very strictly isolated in every respect, escaped during the first two outbreaks, and in the third until a servant who had been absent « Fuither report and papers on Epidemic Influenza, 18S9-92. With an introduction by the Medical Officer of the Local Government Board. 1893. December 28. 1893] NA TURE 211 returned and fell ill with influenza ; strict isolation was even then successful in preventing its spread to the inmates. Dr. Caldwell Smith's evidence as to retiology is valuable and interesting. "It is to the life history of Pfeiffer's bacillus that we must direct our attention if we wish to understand the seemingly strange vagaries of the disease. An individual is infected by breathing at once the expired air from a person suffering from the disease, and I believe this to be the only method of infection." The concourse of people is favourable to the spread of influenza in two ways, according to Dr. Parsons : firstly, by bringing the affected and the healthy near together ; and secondly, by the poison being present in a more concentrated form in confined and vitiated air. Among the discussions which throw light on the character of the disease, and bear upon the means of preveniion, the following may be mentioned : on the degree of protection afforded to individuals and to communities by previous attacks, on the influence of occupation and of unsanitary conditions, on the connection with pneumonia, on the period of infectiousness, on the clinical features of the later epidemics, and on relapses. The researches of Dr. Klein, in respect to the eftect of inocula- tion upon animals, gave results for the most part negative. His affirmative results, however, were " in full agreement with the results obtained by Pfeiffer and Kitasato. " The bacillus was always abundantly present in the bronchial secretion of patients suff"ering from influenza, diminishing in number as the disease abated. " It is to be feared," wrote Dr. Parsons, " that the contagion of influenza is still domiciled among us, and that a renewal of its epidemic activity within the next few years is by no means improbable." The expected revival is now only too apparent. A certain proverb declares, with the rashness of its class, that the man once bit is twice shy. In a literal sense, the saying may contain a good deal of truth, but to nations, or aggregations of individuals, it is quite inapplicable. The development of common sense for common action against these evils has still to take place. This country has now passed through three severe epidemics of influenza within four years, each outbreak drawing many sad maladies in its train, prostrating hundreds of thousands of breadwinners, cutting short many illustrious lives, and crippling many for years to come, and we are now running into a fourth epidemic in London, without any great organised attempt being made to counteract it. The provisional memorandum of the Local Government Board, issued on January 23, 1892, impressed upon the public the fact that in its epidemic form influenza is an eminently infectious complaint, communicable in the ordinary personal relations of individuals with each other, that separation of the sick from the healthy should as far as practicable be carried out, that rooms, &c. should be disinfected, and that ventilation should receive special attention. It would be some defence against a serious recrudescence of the pest if this memorandum, or an abstract of it, were supplied to every householder on the first thre.'itenings of an outbreak in any locality. In his article on prophylaxis, Dr. Parsons remarks on the difficulties which would frustrate any measures of notification and isolation on a large scale, but suggests that notification, with fees for early cases only, might be tried in certain districts, and that such a measure should be adopted '• in the interval before another epidemic." So much experience has been gained in distinguishing the symptoms of influenza from those of other ailments, that the difficulty of diagnosis cannot now be an insuperable bar to attempts at prevention. It is well to remember that the pecuniary cost of prevention cannot be compared with the loss to the country by an epidemic, for this has been proved to amount to millions. Among places and means of infection which may cause much mischief, but are not noticed in this volume, are bakers' shops, in which the baker or attendant suff"ers from influenza or severe cold ; booking offices, post offices, banks, &c. in which the mouth and the ledger, &c, are in multiple communication ; letters written and fastened by patients ; and, most of all, railway carriages packed full and with windows closed, daily conveying vast numbers of people to and from the city, and containing perhaps the most organically polluted air which can easily be found in a civilised country. The report closes with an interesting statement respecting the immunity of animals, including monkeys, at the Zoological Gardens. R. Russell. NO. I 261. VOL. 49] f ON A METHOD OF SEPARATING THE MINERAL COMPONENTS OF A ROCK. TT is told of a famous German petrographer, that whenever appealed to by a student in difficulties over a problematical mineral in a rock-slice, his invariable advice was "Get it out." It is hard dispassionately to reflect on the sufferings to which this simple process of "getting it out " have given rise, AH we petrographers have passed through the vale ! May we now indulge the pious hope that the following simple apparatus may bring some mitigation to the ordeal ? It will certainly save a good deal of time and trouble when only small quantities of a particular mineral are required ; enough, that is, for a blow- pipe analysis, a flame test, and microscopical examination. A large test-tube (see Fig.), conveniently six inches in length by three-quarters in diameter, is filled with heavy solution, graded from specific gravity 3'3 to 2*5, so as to form after standing a diffusion column, as already described in Nature, vol. xliii. p. 404, 1891. It is not necessary to wait till the change in density of the column is uniform from top to bottom ; by introducing a sufficient number of specific gravity indexes the column is mapped out into a succession of lengths, within the limits of each of which the change of density is practically uniform, certainly sufficiently so for mineral determinations. A fragment of the rock to be examined, about the size of a hazel-nut, is powdered in the usual way, sifted and washed, dried and then introduced into the diffusion column. Separation of the constituent minerals at once begins to take place, and in the course of a few hours is com- plete. Each species of mineral is then floating in liquid of its own specific gravity ; the next problem is to get it out. A pipette as commonly used is not suffi- cient, for as it is introduced grains of minerals from other zones than that sought for, adhere to its sides ; on removing the finger, the sudden inrush of fluid carries with it grains from surrounding zones, and finally on drawing up the pipette, fluids of zones lying above that to which it has descended displace the heavier fluid it already contains, carrying with them suspended grains, and thus bringing about the mixture which it is our desire to prevent. With very little trouble these difficulties may be completely overcome. To prevent the sudden inrush of fluid the pipette, which should be of small calibre (in my experiments it measures i*5mm.), is fitted with a piston {p). This may be very simply made by winding a little unravelled cotton thread round the end of a stem of Esparto grass, such as is sold for cleaning tobacco- pipes. The piston is pushed down to the bottom of the pipette, which is then ready for use. To extract grains from any zone the pipette is slid down into the diff^usion column till its lower end is just immersed in the zone ; a gentle shake given to it as it passes through the solution will serve to detach adhering particles ; the piston is then slowly raised, and the fluid with its floating mineral grains quietly follows it, the other zones remaining undisturbed. To prevent the fluid of higher zones entering the pipette as it is with- drawn, it is necessary to plug its lower end ; no very tight closure is necessary, since the piston, which now lies at the upper end of the pipette, by excluding the air ensures the retention of the contained column of fluid ; all that is needed is a stopper, which will exclude solid particles. A very thin glass rod is rounded off" at one end, which is then bent upwards into the form of a crook (r). The crook is let down into the diffusion column till its upward pointing lower end lies beneath the open ex- tremity of the pipette, which it completely blocks up on being \J) A test-tube con- taining a diffusion column. The figures at the side indicate corresponding specific gravities : t, pipette fitted with a piston / ; c, crook by which the lower end of the pipette may be plugged. 212 NA TURE [December 28, 1893 raised into position. The pipette with the crook is then taken out of the fluid, and inverted. The crook is laid aside, and the outside of the pipette cleaned with blotting-paper, by which all adhering foreign grains are removed. The pipette now con- tains a pure gathering of the mineral required, and it only remains to discharge its contents, and this is of course accom- plished by pushing down the piston. Minerals may thus be removed from every zone of a diffusion ..jlumn ; and all the species which enter into the composition of a reck, except of course the very heaviest, may be separately obtained, with their specific gravity determined as an incident of the process. In this absurdly simple fashion "getting it out" ceases to be a penance, and becomes a pleasure. W. J. Sollas. THE CLOUDY CONDENSATION OF STEAMS 'T^HE air, as every one knows, is composed almost entirely of the two gases, oxygen and nitrogen. It also contains small quantities of other substances, of which the chief are car- bonic acid gas and water vapour, and it is the latter of these constituents, water vapour, or "steam," as it is sometimes called, that will principally concern us this evening. The quantity of invisible water vapour which the air can at any time take up depends upon the temperature ; the higher the temperature of the air the more water it can contain. The pro- portion, however, never exceeds a few grains' weight of water to a cubic foot of air. Air at any temperature, containing as much water as it can possibly hold, is said to be " saturated," while the temperature at which air containing a certain propor- tion of water becomes saturated is called the " dew point." The large glass globe, upon which the beam from the electric lantern is now directed, contains ordinary air, kept in a state of saturation, or nearly so, by the presence of a little water. Vou will observe that although heavily laden with water vapour the air is perfectly transparent. If, now, we turn a tap, and so con- nect the globe with an exhausted receiver, the air expands and becomes colder ; the space inside the globe is no longer able to hold the same quantity of water as before in the form of vapour, and the excess is precipitated as very finely divided liquid water, which fills the globe and is perfectly visible as a cloud or mist. In a few minutes ihe cloud disappears, partly, no doubt, because some of the particles of water have fallen to the bottom of the vessel, but chiefly because the air becomes in time warmed up to its original temperature (that of the room), and the suspended water is converted back again into invisible vapour. I once more rarefy the air, and admit a fresh supply while holding the flame of a spirit lamp near the orifice of the inlet pipe, so that some of the burnt air is carried into the interior of the globe. When the air is again expanded a cloud is formed which is far more dense than the others were. It appears on examination that the increased density of this cloud is not due to the condensation of a greater quantity of water. Little, if any, more water is precipitated than before. But the water particles are now much more numerous, their increased number being compeasated for by diminished size. Within certain limits, the greater the number of particles into which a given quantity of water is condensed, the greater will be the apparent thickness of the mist produced. A few large drops will not impede and scatter light to the same extent as a great number of small ones, though the actual quantity of condensed water may be the same in each case. Then comes the question, why should the burnt air from the flame so greatly increase the number of the condensed drops? An answer, though perhaps not quite a complete one, is fur- nished by some remarkable experiments made by M. Coulier, a French pro fessor, nearly twenty years ago. He believed his ex- periments showed that water vapour would not condense at all, even at temperatures far bilow the dew point, unless there were present in the air a number of material particles to serve as nuclei around which the condensation would take place. All air, he says, contains dust ; and anything that increases the number of dust particles in the air increases the density of the condensation by affording a greater number of nuclei. Air in which a flame had been burnt he supposed to be very highly charged with finely divided matter, the products of combustion, 1 Extracted from a lecture on " Fogs, Clouds, and Lightning," delivered at the Royal Institution on May 5. NO. I 26 I, VOL. 49] ard thus rendered extraordinarily *' active " in bringing about condensation. And that, according to Coulier's view, is the reason why such a dense fog was formed when air which had been contaminated by the spirit flame was admitted to our globe. On the other hand, air, even burnt air, which has been fil- tered through tightly packed cotton woo), is found to be per- fectly inactive. No cloud or mist will form in it, however highly it may be supersaturated. Coulier explained this fact by supposing that the process of filtration completely removed all dust particles from the air. The experiments of Coulier were repeated and confirmed by Mascart. The latter also made one additional observation which may very probably turn out to be of great importance. He found that ozone, or rather, strongly ozonised air, was a very aclive mist producer, and that unlike ordinary air, it was not deprived of its activity by filtration. Four or five years later, all the facts which had been noticed by Coulier, and others of an allied nature, were independently discovered by Mr. Aitken, who has devoted much time and study to them, and made them a foundation of an entirely new branch of meteorology. Later, perhaps, we may see reason to doubt whether all the conclusions of Coulier and Aitken are quite accurate, especially as regards the action of so-called products of combustion. Every one has noticed how dense and dark a thundercloud is. It shuts out daylight almost as if it were a solid substance, and the glimmer that penetrates it is often imbued with a lurid or copper-coloured tint. I had always found it rather difficult to believe that these peculiarities were due simply to the unusual extent and thick- ness of the clonds, as is commonly supposed to be the case, and it occurred to me about three years ago, that perhaps some clue to the explanation might be aff'orded by the electrification of a jet of steam. On making the experiment I found that the density and opacity of the jet were greatly increased when an electrical discharge was directed upon it, while its shadow, if cast upon a white screen by a sufficiently strong light, was of a decidedly reddish-brown tint. As a possible explanation of the effect I suggested that there might occur some action among the little particles of water of a similar nature to that observed by Lord Rayleigh in his experi- ments upon water jets. A jet of water two or three feet long is made to issue in a nearly vertical direction from a small nozzle. At a certain distance above the nozzle the continuous stream is found to break up into separate drops, which collide with one another, and again rebounding, become scattered over a con- siderable space. But when the jet is exposed to the influence of an electrified substance, such as a rubbed stick of sealing-wax, the drops no longer rebound after collision, but coalesce, and the entire stream of water, both ascending and descending, becomes nearly continuous. There is one other point to which I wish to direct your par- ticular attention. If the sealing-wax, or better, the knob of a charged Leyden jar, is held very close to the jet, so that the electrical influence is stronger, the separate drops do not coalesce as before, but become scattered even more widely than when no electrical influence was operating. They become similarly electrified and, in accordance with the well-known law, repel one another. We will now remove the water jet, and in its place put a little apparatus for producing a jet of steam. It consists of a half- pint tin bottle, through the cork of which passes a glass tube terminating in a nozzle. When the water in the bottle is made to boil, a jet of steam issues from the nozzle, and if we observe the shadow of the steam jet upon the screen we shall see that it is of feeble intensity and of a neutral lint, unaccompanied by any trace of decided colour. A bundle of needles connected by a wire with the electrical machine is placed near the base of the jet, and when the machine is worked electricity is discharged into the steam. A very striking effect instantly follows. The cloud of condensed steam is rendered dense and dark, its shadow at the same time assuming the suggestive yellowish- brown colour. I at first believed that we had here a repetition, upon a smaller scale, of the phenomenon which occurs in the water jet. The little particles of condensed water must frequently come into collision with one another, and it seemed natural to suppose that, like Lord Rayleigh's larger particles, they rebounded under ordinary circumstances, and coalesced when under the influence December 28, 1893] NATURE 213 of electricity. The great maiority of the small particles or- dinarily formed consisted, I thought, of perhaps only a few molecules, which were dispersed in the air, and again converted into vapour without ever having become visible, while the larger particles formed by their coalescence under electrical action were of such dimensions as to impede the more refrangible waves of light. Hence the brownish-yellow colour. Other explanations have been proposed. There is the mole- cular shock theory of the late R. Helmholtz(who, as it turned out, had studied electrified steam jets before I made my own .experiments). I shall refer to his speculation later. And there is the dust-nucleus theory, which no doubt appears a very obvious one. Though I knew that my own hypothesis was not quite free from objection, neither of these alternative ones commended itself to me as preferable ; and so the matter rested until a few months ago, when the steam jet phenomenon was discussed anew in a paper communicated to the Royal Society by Mr. Aitken. Mr. Aitken said that he did not agree with my con- jecture as to the nature of the effect. This led me to investi- gate the matter again, and to make some further experiments, the results of which have convinced me that I was clearly in error. At the same time it seems to me that the explanation which Mr. Aitken puts forward is little less controvertible than my own. Mr. Aitken's explanation of the phenomenon is, like mine, based upon Lord Rayleigh's work in connection with water-jets, but, unlike mine, it depends upon the experiment which shows that water particles when strongly electrified are scattered even more widely than when unelectrified. He believes, in short, that electrification produces the effect, not by pro- moting coalescence of small water particles, but by preventing such coalescence as would naturally occur in the absence of electrical influence. In the electrified jet, he says, the water particles are smaller, but at the same time more numerous ; thus its apparent density is increased. The chief flaw in my hypothesis lies in the fact that the mere presence of an electrified body like a rubbed stick of sealing- wax, which is quite sufficient to cause coalescence of the drops in the water jet, has no action whatever upon the condensation of the steam jet. There must be an actual discharge of electricity. But it is by no means essential, as Mr. Aitken assumes, that this discharge should be of such a nature as to electrify, posi- tively or negatively, the particles of water in the jet. If, instead of using a single electrode, we employ two, one positive and the other negative, and let them spark into each other across the jet, dense condensation at once occurs. So it does if the two discharging points are removed quite outside the jet. A small in- duction coil giving sparks an eighth of an inch in length causes dense condensation when the electrodes are more than an inch distant from the nozzle and on the same level. In one experiment a brass tube two feet long was fixed in an inclined position with its upper end near the steam jet, and its lower end above the elec- trodes of the induction coil. In about three seconds after the spark was started dense condensation ensued, and it ceased about three seconds after the sparking was stopped. No test was needed, though in point of fact one was made, to show that the steam was not electrified to a potential of a single volt by this operation. And the time required for the influence to take effect showed that whatever this influence might be it was not induction. The inference clearly is that in some way or other the action is brought about by the air in which an electrical discharge has taken place, and not directly by the electricity itself. The idea has no doubt already occurred to many of you that it is a dust effect. Minute particles of matter may be torn off the electrodes by the dis,';harge, and form nuclei upon which the steam may condense. The experiments of Liveing and Dewar have indeed shown that small particles are certainly thrown off by electrical discharge, and the idea that such particles promote condensation appears to be supported by the fact that if a piece of burning material, such as touch-paper, is held near the jet so that the products of combustion can pass into it, thick condensation is produced. From a recent paper by Prof. Barus, published in the American Meteorological J ournaliox March, it appears that he also is of opinion that such condensation is in all cases due to the action of minute dust particles. Yet it is remarkable that Mr. Aitken, the high priest and chief apostle of the philosophy of dust, gives no countenance to the nucleus theory. He doss not even advert to its possibility. I imagine that his experi- NO. I 26 I, VOL. 49] ments have led him, as mine have led me, to the conclusion that it is untenable. And this not only in the case of electrical dis- charge, but also in the case of burning matter. If we cause an electrical discharge to take place for some minutes inside a suitably arranged glass bottle, and then, ten or fifteen seconds after the discharge has ceased, blow the air from, the bottle into the steam jet, the condensation is not in anyway affected. Yet the dust could not have subsided in that time. And again, if we fill another large bottle with dense clouds of : smoke by holding a bundle of burning touch-paper inside it, and almost immediately after the touch-paper is withdrawn, force out the smoke-laden air, through a nozzle, upon the jet — ! you can all see the black shadow of the smoke upon the screen — nothing whatever happens to the jet. Yet a mere scrap of the paper which is actually burning, though the ignited portion may not be larger than a pin's head, at once darkens the jet. Dead smoke (it I may u.se the term) exerts little or no influence by I itself: there must bj incandescent matter behind it. The question naturally arises, whether incandescent matter may not [ be sufficient of itself, without any smoke at all. \Ve can test j this by making a piece of platinum wire red-hot and then holding j it near the jet. It is seen to be quite as effective as the burning touch-paper. Yet here there can be no nuclei formed of pro- ducts of combustion, for there is no combustion ; there is simply \ ignition or incandescence. One other point I may mention. It is stated by Barus, in the ! paper above referred to, that the fumes given off by a piece of phosphorus constitute a most efficient cause of dense conden- sation. This is true if they come directly from a piece of phos- phorus ; but if phosphorus fumes are collected in a bottle and then directed upon the jet, all traces of unoxidised phosphorus being first carefully removed, they are found to be absolutely inoperative. Phosphorus in air can hardly be said to be incan- descent, though it is luminous in the dark ; but it appears to act in the same manner as if its temperature were high. All these facts seem to indicate that the several causes men- tioned, electrical, chemical, and thermal, confer upon the air in which they act some temporary property — certainly not due to mere inert dust — in virtue of which it acquires an abnormal power of promoting aqueous condensation. I thought that possibly some clue as to the nature of this property might be obtained by observing how some other gases and vapours behaved ; but though the experiments I made perhaps tend to narrow the dimensions of the mystery, I cannot say that they have completely solved it. Indeed some of the results only introduce additional perplexities. One of the most natural things to try is hydrochloric acid, which is known to have a strong affinity for water. If we heat a little of the acid solution in a test tube, closed with a cork, through which a glass tube is passed, and direct the issuing stream of gas upon the jet, the densest condensation results. The vapours of sulphuric and nitric acids also cause dense condensation, and I suppose both of these have an affinity for water. But so also, and in an equally powerful degree, does the vapour of acetic acid ; yet the aflinity of this acid for water, as indicated by the heat evolved when the two are mixed, is very small. Ammonia gas, when dissolved in water, causes the evolution of much heat. Yet a stream of this gas directed upon the jet has no action. Ozonised air, which Mascarl found so effective in his experi- ments with the closed vessel, is quite inoperative with the steam jet. Equally so is the vapour of boiling formic acid, which I believe is chemically a much more active acid than acetic, and has a lower electrical resistance. (See Table.) Condensation of Steam Jet. Active. Air, oxygen, or nitrogen, in which electrical discharge is occurring. Burning and incandescent substances. Fumes from phosphorus. Hydrochloric acid. Sulphuric acid vapour. Nitric acid vapour. Acetic acid vapour. 14 NATURE [December 28, 1893 Inactive. Air, &c., in which electrical discharge has ceased for about ten seconds. Smoke without fire. Bottled phosphorus fumes. Ammonia. Ozone. Steam. Alcohol vapour. Formic acid vapour. Sulphurous acid. It seems that we have here a pretty little problem which might, perhaps, be solved without much difficulty by a com- petent chemist, but which quite baffles me.^ Is it possible that the condensing vapours may contain dissociated atoms? To return to the electrical effect. There are only two kinds of chemical change that I know of which could be brought about in air by an electrical discharge. Either some of the oxygen might be converted into ozone, or the oxygen and nitrogen of the air might be caused to combine, forming nitric acid or some such compound. The former of these would not account for the action of the air upon the jet, because, as we have seen, ozone is inoperative ; the latter migbt. But if the activity of the air is due to the presence in it of a compound of oxygen and nitrogen, then it is clear that an electrical discharge in either nitrogen or oxygen separately would fail to render those gases active. I arranged a spark bottle, inside which an induction-coil dis- charge could be made to take place ; two bent tubes were passed through the cork, one reaching nearly to the bottom for the ingress of the gas to be tested, the other, a shorter one, for its egress. The open end of the egress tube was fixed near the steam jel, and first common air, then oxygen and then nitrogen were successively forced through the bottle while the coil dis- charge was going on. All produced dense condensation, but I thought that oxygen appeared to be a little more efficient than common air, and nitrogen a little less. This last experiment points to a conclusion to which at pre- sent I see no alternative. It is that the action on the jet of an electrical discharge is due in some way or other to dissociated atoms of oxygen and nitrogen. There is nothing else left to which it can be due. So far as Robert Holmholtz's explanation coincides with this conclusion, I think it must be accepted as correct. As to the precise manner in which he supposed the dissociated atoms to act upon the jet, it is more difficult to agree with him. He thought that the abnormal condensation was a consequence of the molecular shock caused by the violent recombination of the dissociated atoms in the supersaturated air of the jet, the action being analogous to that which occurs when a supersaturated solu- tion of sulphate of soda, for example, is instantly crystallised by a mechanical shock. To me this hypothesis, ingenious as it is, seems to be more fanciful than probable, but I can only hint very diffidently at an alternative one. To many chemical processes the presence of water is favourable or even essential. Is it possible that the recombination of free atoms may be assisted by water ? And is it possible that dissociated atoms in an atmosphere of aqueous vapour may obtain the water needed for their union by condensing it from the vapour ? According to Holmholtz, flames and incandescent substances generally cause dissociation of the molecules of oxygen and nitrogen in the surrounding air. This, I believe, is generally admitted. I do not know whether slowly oxidising phosphorus has the same effect. If it is conceded that the atmospheric gases are dissociated by electrical discharges, and that the presence of such dissociated gases somehow brings about the dense condensation of water vapour, we may still regard the electrified steam jet as affording an illustration of the abnormal darkness of thunder-clouds. Perhaps another source of dissociated atoms is to be found in the ozone which is generated by lightning flashes. A molecule of ozone consists of three atoms of atomic oxygen, while one of ordinary oxygen contains only two. Ozone is an unstable kind of material, and gradually relapses into ordinary oxygen, the process being that one atom is dropped from the three-atom molecules of ozone, these detached atoms in course of time Two chemists of the highest eminence have been good enough to con- sider the problem for me, but they are unable to throw any light upon it. NO. 1 261, VOL. 49J uniting with one another to form pairs. Thus two molecules of ozone are transformed into three of oxygen. A body of ozone is therefore always attended by a number of dissociated atoms which are looking for partners. In the steam jet experiment there is not time for the dis- engagement of a sufficient number of isolated atom.s from a blast of ozone to produce any sensible effect. But the case is otherwise when the vapour is confined in a closed vessel, as in Mascart's experiment, or when it occurs in the clouds, where the movement of air and vapour is comparatively slow. Ozone, it will be remembered, was found by Mascart to pro- duce dense condensation in a closed vessel even after being filtered through cotton wool. Similar filtration seems to entirely deprive the so-called products of combustion of their active property, a fact which has been adduced as affording over- whelming evidence in favour of the dust nucleus theory. Coulier himself, however, detected a weak point in this argument. He produced a flame which could not possibly have contained any products of combustion except steam, by burning pure filtered hydrogen in filtered air ; yet this product was found to be per- fectly capable of causing dense condensation, and, as in his former experiments, filtration through cotton wool deprived it of its activity. These anomalies may, I think, be to a great extent cleared up if we assume that the effect of the cotton wool depends, not upon the mere mechanical obstruction it offers to the passage of particles of matter, but upon the moisture which it certainly contains, and which may act by attracting and facilitating the reunion of dissociated atoms before they reach the air inside the vessel. According to this view ozone would remain an active condenser in spite of its filtration, because free atoms would continue to be given off by it after it had passed the cotton wool. The filtration experiment should be tried with perfectly dry cotton wool, which, however, will not be easily procured, and if my suggestion is right, dry wool will be found not to deprive ordinary products of combustion of their condensing power. To sum up. I think my recent experiments show conclusively that the dense condensation of the steam jet is not due directly either to electrical action or to dust nuclei. The immediate cause is probably to be found in dissociated atoms of atmospheric gases, though as to how these act we can only form a vague guess. ShELFORD BlDWELL. SCIENTIFIC SERIALS. American journal of Science, December. — An apparent time- break between the eocene and Chattahoochee miocene in south- western Georgia, by Raphael Pumpelly. The Red Clay Hill region, a plateau extending through the south-western part of Georgia and adjacent northern Florida, has a maximum altitude of 300 feet, is sharply limited on the north by a declivity facing the eocene flat-land country, and consists of miocence deposits resting on eocene, both of which dip about 13 feet per mile to the south. The base of the plateau is formed by the white calcareous beds of the Chattahoochee group. A time-break between the latter and the eocene is evidenced by the almost general presence of a limestone conglomerate at the base of the Chattahoochee, immediately overlying eocene fossils, and the irregularity of the surface of demarcation. It seems possible that during miocene time the present plateau of southern Georgia was outlined by submerged islands of the eocene limestone. The Gulf Stream, after the creation of the central American barrier, found its way back to the Atlantic sweeping over southern Georgia and northern Florida, and supplying the food needed to build up the great organic beds of the Chat- tahoochee and Chipola. The lower flat-land country of central Georgia may represent the contemporaneous course of the cold current carrying less pure water and less nutriment. — The rise of the mammalia in North America, by H. F. Osborn. This second part deals with ancient and modern pla- cental differentiation, the succession of the perissodactyls and the ariiodactyls, a discussion of the factors of evolution, and a diagram illustrating the supposed descent of the mammalia from their Jurassic prototypes. — On the thoracic legs of Triarthrus, by C. E. Beecher. Some very perfect specimens of Triarthrus Becki, Green, in which nearly the entire calcareous and chitinous portions are represented by a thin film of iron pyrites, show, besides the antennae already noticed, a complete series of thor- December 28, 1893J NA rURE 215 acic legs becoming shorter towards the pygridium, but without any essential differences amongst each other. Each limb con- sists of two nearly equal members, one of which was evidently used for crawling, and the other for swimming. These two members and their joints maybe correlated with certain typical forms of Crustacean legs among the Schizopoda, Cttmacca, and Decapoda, and may be described in the same terms. — On the diamond in the Caiion Diablo meteoric iron and on the hardness of carborundum, by George F. Kunz and Oliver W. Huntingdon. The carborundum made by Mr. Acheson, of Pittsburg, is capable of scratching most varieties of corundum, but not the diamond. SOCIETIES AND ACADEMIES. London. Anthropological Institute, December 12. — Prof. A. Mac- alister, F.R.S., Presidenr, in the chair. — Mr. Cuthhert E. Peek exhibited some specimens of fishing-line made of human hair, some needles constructed from ribs of feather, and two message-sticks from the extreme north of Queensland. — Mr. W. L. Duckworth read a paper on the collection of skulls of Aboriginal Australians in the Cambridge University Museum, and the following papers were also read :— On an unusual form of rush basket from the northern territory of South Australia, by Mr. R. Etheridge, jun. — On a modifi- cation of the Australian Aboriginal weapon, termed the leonile, langeel, bendi or buccan, by Mr. R. Etheridge, jun. — An Austra- lian Aboriginal musical instrument, by Mr. R. Etheridge, jun. — The Aborigines of North-West Australia, by Mr. P. W. Bassett-Smith. — Rites and customs of Australian Aborigines, by Mr. H. B. Purcell. — Japanese onoraatopes and the origin of language, by Mr. W. G. Aston. Mathematical Society, December 14. — A. B. Kempe, F.R.S., President, in the chair. — On the stability of a deformed elastic wire, by A. B. Basset, F. R. S. — This paper commences with a discussion of the different. methods of determining the stability of a deformed elastic wire which is in equilibrium, and then proceeds to discuss two special problems. When a naturally straight wire is deformed into a helix having m convo- lutions, the helical form is unstable unless its pitch is greater than sec"i 2 m. This result shows that it is impossible to de- form the wire into a helix of small pitch and having a great many convolutions, such as the spring of an ordinary spring- balance, unless the wire is given a permanent set. The two special cases in which the terminal stresses consist, (i) of a thrust and a fiexural couple, (2) of a couple alone, are also noticed ; and in the latter case the helix is unstable when the length of the wire exceeds_half a convolution. When the natural form of the wire is a circular coil, which is unrolled and the ends joined together without twist, so that the wire forms a circular ring, the ring will be unstable when the length of the wire is greater than about one and a half convolutions. The ring is stable from displacements in its plane, and consequently will not collapse like a boiler flue ; but it is unstable for displace- ments perpendicular to its plane, which involve torsion as well as flexion. The stable figure will consequently consist of a closed tortuous curve. — Papers were also read by R. J. Dallas, on the linear autcmorphic transformations of certain quantics ; and by Dr. Hobson, F. R. S., on Bessel's functions and relations connecting them with spherical and hyperspherical harmonics. — -Messrs. Love, Greenhill, Macmahon, and the President spoke on the subject of the communications.- — The following papers were taken as read : — A theorem of Liouville's, by Prof. G. B. Mathews ; note on non Euclidian geometry, by H. F. Baker ; note on an identity in elliptic functions, by Prof. L. J. Rogers ; and note on a variable seven-points circle analogous to the Brocard circle of a plane triangle, by T. Griffiths. Royal Meteorological Society, December 20.— Dr. C. Theodore Williams, President, in the chair. — Mr. C. Harding gave an account of the great storm of November 16 to 20, 1893. This storm was the most violent of recent years, and, so far as anemometrical records are concerned, the wind attained a greater velocity than has previously been recorded in the British Islands. The velocity of the wind was 96 miles in the hour from 8.30 to 9.30 p.m. on November 16 in the Orkneys, NO. I 26 I, VOL. 49] where the hurricane burst with such suddenness that it is de- scribed as like the shot of a gun, and the wind afterwards attained the very high rate of 90 miles and upwards, in the hour, for 5 consecutive hours. At Holyhead the storm was terrific ; the anemometer recorded a wind velocity of 89 miles in the hour, and it was 80 miles or above for 11 hours, while the force of a whole gale, 65 miles an hour and upwards, was maintained for 31 hours, and for 4i days the mean hourly velocity was 54 miles. Many of the gusts were at the rate of 115 miles an hour, and at Fleetwood a squall occurred with the wind at the rate of 120 miles in the hour. The storm was felt over the entire area of the United Kingdom, and the wreck returns show that disasters occurred with almost equal frequency on all coasts. Four weeks after the storm the official records gave the total loss of life on our coasts as 335, while there were 140 vessels which had been abandoned, or had foundered, stranded, or met with other severe casualty, involving either loss of life, or saving of life by some extraneous assistance. There were 600 lives saved on our coasts by aid of the Lifeboat Institution and other means. The author has tracked the storm from the neigh- bourhood of the Bahamas on November 7, acress the Atlantic and over the British Islands to Central Europe on November 20. — The other papers read were on rainfuU and evaporation observations at the Bombay Waterworks, by Mr. S. Tomlin- son ; and on changes in the character of certain months, by Mr. A. E. Watson. Dublin. Royal Dublin Society, November 22. — Prof. W. N. Hartley, F.R.S., in the chair. — Prof. T. Johnson communicated a paper on the systematic position of the Bangiacese. The author, with Berthold and others, regards the group as true Floridea;, and discusses in his paper the views expressed by Schmitz, in a recent number of La Nuova Notarisia, against their Floridean nature — Mr. Thomas Preston gave an ele- mentary explanation of the system of waves attending a bullet moving at a high speed through the atmosphere. — Mr. W. E. Adeney read a note on the present condition of the water in the Vartry reservoir at Roundwood, co. Wicklow, and Mr. Richard J. Moss gave the results of an examination of the Vartry water as at present supplied to Dublin. Paris. Academy of Sciences, Annual Public Meeting, December 18. — M. de Lacaze-Duthiers in the chair. — After some com- memorative words on the deaths of Sir Richard Owen, Kummer, and de Candolle, Foreign Associates, and those of Chambrelent, Admiral Paris and Charcot, Members of the Academy, by the President, M. Bertrand, one of the Secre- taries, announced the names of those to whom prizes had been awarded. In Geometry, the Prix Francceur was awarded to M. G. Robin for mathematical physics, and the Prix Poncelet to M. G. Kcenigs, for geometrical and mechanical work. — Mechanics: The extraordinary prize of 6ooo francs offered by the Departement de la Marine for contrivances increasing the efficiency of the Navy, was distributed among M. Bourdelles (for lighthouse illumination), M. Lephay (compass with luminous index), and M. de Fraysseix (system of optical point- ing) ; the Prix Montyon of 700 francs to M. Flamant (hydrau- lics), the Prix Plumey of 2500 francs to M. Lebasteur (steam engine appliances) ; the Prix Fourneyron of 500 francs, to M. Brousset (fly-wheels). — Astronomy : The Prix Lalande of 540 francs, to M. Schulhof (Comets) ; the Prix Valz of 460 francs, to N. Berberich (Minor Planets). The Prix Janssen of a gold medal, to Mr. Samuel Langley (Astronomical Physics). — Physics : The Prix La Caze ot 10,000 fr., to M. E. H. Amagat (gases and liquids). — Statistics : The Prix Montyon of 500 fr., to Dr. Marvand (diseases of soldiers). — Chemistry : The Prix Jeckerof 10,000 fr., to M. D. Forcrand and M. Griner in equal parts, with a special prize to M. Gautier. — The Prix La Caze of 10,000 fr., to M. Lemoine (Phosphorus Compounds). — Mineralogie and Geology : The Grand Prix, to M. Marcellin Boule (Tlie Central Plateau of France). The Prix Bordin of 3000 fr. was distributed amongst MM. Bourgeois, Gorgen, Michel, and Duboin for their researches in mineral synthesis. The PrixDelesse of 1400 fr., to M. Fayol (Commentry Strata). The Prix Fontannes of 2000 fr., to M. R. Zeiller (Palason- tology). —Botatty : The Prix Desmazieres of 1600 fr., to M. C. Sauvageau (Algae). The Prix Montagne, to MM. Cardot (Mosses) and Gaillard (Fungi). — Agriculture: The Prix 2l6 NATURE [December 28, 1893 Morogues, to M. Millardet \^\\A.&^).—A7tatomy and Zoology. The Prix Thore, to M. Corbiere (Muscinese) — Medicine ajid Surgery: The Prix Montyon was distributed between MM. Huchard (Heart Diseases), Delorme (Army Surgery;, and Pinard and Varnier (Pathological Atlas). The Prix Barbier, 500 fr. each to MM. Sanson (Heredity) and Dr. Mauclaire (Osteo- Arthritis). The Prix Breant, being the interest on a sum of 100,000 francs offered for a cure for cholera, was distributed amongst MM. 2.'etter and Thoinot (French Cholera, 1892) and MM. Grimbert and Burlureaux (Treatment of Tuberculosis by Creosote In- jections). The Prix Godard of 1,000 francs, to Dr. Tourneux (Physiological Atlas). The Prix Serres of 7500 francs, to M. Pizon (Blastogenesis), with small portions to MM. Sabatier (Sperui;i!.ogenesis) and Letulle (Inflammation). The Prix Bellioii of 1400 francs, to Dr. C. Chabrie (Physiology of the Kidney) and Dr. Coustan (Fatigue). The Prix Mege to Dr. Herrgott (History of Obstetrics). The Prix Lallemand of 1800 francs, to M. Trolard (Venous System). — Physiology: The Prix Montyon of 750 francs, to M. Laulanie (Respiration) and MM. Abelous and Langlois (Renal Capsules). The Prix La Caze, of 10,000 francs, to M. d'Arsonval (Physiological Effects of Electricity). The Prix Pourat to M. E. Meyer (Renal Secretion). The Prix Martin-Damourette, of 1400 francs, to Dr. Geraud (Albuminuria). — General Prices: The Arago Medal to Mr. Asaph Hall (Satellites of Mars) and Mr. E. E. Barnard (Jupiter's First Satellite). The Prix Montyon, for improvements in unhealthy industries, was divided between MM. Garros (Porcelain Manufacture) and Coquillon (Fire-damp Meter). The Prix Tremont, of iioo francs, to M. Jules Morin for his useful hydrostatic and other inventions. The Prix Gegner of 4000 francs to M. Serret. The Prix Petit d'Ormoz of 10,000 francs, to M. Stieltjes (Mathematics), and another of the same amount to M. Marcel Bertrand (Physics of the Globe). The Prix Tchihatchef of 10,000 francs, to M. Gregoire Groum- Grschimailo (The Pamirs). The Prix Gaston Plante, of 3,000 francs, to M. Blondlot (Electric Interference), Mme. de Laplace's Prize, consisting of Laplace's works, to M. Bes de Berc, of the Ecole Nationale des Mines. Berlin. Physical Society, December i.— Prof. Schwalbe, Presi- dent, in the chair. — Prof. Neesen demonstrated a method of coating aluminium with other metals. This consists in dipping the aluminium in a solution of caustic potash or soda, or of hy- drochloric acid, until bubbles of gas make their appearance on its surface, whereupon it is dipped into a solution of corrosive sublimate to amalgamate its surface. After a second dipping into caustic potash until bubbles of gas are evolved, the metal is placed in a solution of a salt of the desired metal. A film of the latter is rapidly formed, and is so firmly adherent that, in the case of silver, gold, or copper, the plate can be rolled out or polished. When coating with gold or copper, it is well to first apply a layer of silver. When thus treated the aluminium may be soldered with ordinary zinc solder. — Dr. Wien spoke on the entropy of radiation. Meteorological Society, November 7.— Prof, von Bezold, President, in the chair. — Dr. Arendt spoke on the transport of heat by means of aerial currents on the earth's surface, based on calculations derived from material provided by the Hamburg station. He first determined for each month of the year the direction and rate of the wind, from which he calculated the resultant volume of air transported over Hamburg. From the temperature and speed of the winds he obtained, under certain assumptions, numerical values for the amount of heat carried towards Hamburg during each month of the year. December 5. — Dr. Vettin, President, in the chair. — Prof. Hellmann presented a book on "Snow-crystals," and gave an account of its contents, during which he discussed fully the structure and classification of snow-crystals. All the crystals belong to the hexagonal system, and are either flat or columnar. The radiating stars, the plates, and mixed forms belong to the first category ; while the prisms and much more rare pyramids belong to the second.— Dr. H. Meyer communicated the results of his observations, made in conjunction with Prof. Koppen, on the cloud-conditions of various climates. They had rejected as valueless mean values based on determinations which are largely influenced by the personal opinion of the observer, and had in preference calculated the frequency of the occurrence of clouds. They had in this, for simplicity's sake, distinguished between three groups : (i) Complete absence of clouds ; cloudiness zero. (2) NO. I 26 1, VOL. 49] Intermittent occurrence of clouds ; cloudiness i tog. (3) Total cloudiness represented by 10. Taking a series of stations in various climates, they had calculated and graphically represented the frequency of the three groups for the morning, midday, and evening for each month. It appeared that for Hamburg and the whole of middle and north Europe, in passing from the cold to the warm periods of both the day and year, the intermittent cloudiness increases ; while complete cloudiness, which is most frequent in winter, and in the morning and evening, diminishes. Complete cloudlessness is always the most rare condition. The above characters change gradually towards the Mediterranean, even at Lesina, and more markedly at Alexandria. In mid- Asia, East Siberia, China, Batavia, and Rio Janeiro, and on the elevated station of Pike's Peak, and also on the Atlantic Ocean, the change in cloudiness in passing from winter to sum- mer is reversed. BOOKS and SERIALS RECEIVED. Books. — A Text-Book on Gas, Oil, and Air-Ergines : B. Donkin, Jun. (Griffin). — An Elementary Treatise on Fourier's Series : Dr. W. E. Byerly (Boston, Ginn). — Uniplanar Algebra: Dr. J. Stringham (San Francisco, Berkeley Press). — Science and Hebrew Tradition: T. H. Huxley (Mac- millan). — Dictionary of the Active Principles of Plants : C. E. Sohn (Bail- liere). — The Country and Church of the Cheeryble Brothers : Rev. W. H. Elliot (Selkirk, Lewis).— Hints to Travellers, 7th edition (Royal Geo- graphical Society). — The Story of the Sun : Sir R. Ball (Cassell). Serials. — Insect Life, Vol. 6, No. 2 (Washington). — Cabinet Portrait Gallerj', Part 52 (Cassell). — Astronomy and Astro-Physics, December (Wesley). — Eccnomic Journal, December (Macmillan). — Journal of the Franklin Institute, December (Philadelphia). — Internationales Archiv fiir Ethnographie, Band vi. Heft6(Kegan Paul). — Journal of the Royal Micro- scopical Society, December (Williams and Norgate). — Royal Geographical Society, Supplementary Papers, Vol. III. Part 5 (Murray). CONTENTS. PAGE Quaternions as an Instrument in Physical Research. Prof. P. G. Tait 193 The Manufacture of Painter's Colours and Var- nishes 194 British Fungus Flora. By Dr. M. C. Cooke .... 195 Our Book Shelf:— Dawson : " Some Salient Points in the Science of the Earth." 196 Cvijic : " Das Karstphanomen." — T. G. B 197 Letters to the Editor : — The Origin of Lake Basins.— R. D. Oldham, Dr. A. R. Wallace, F.R.S 197 The Second Law of Thermodynamics. — G. H. Bryan 197 Flame.— Prof. Arthur Smithells . . 198 The "Zoological Record."— R. I. Pocock; F. A. Bather 198 On the Bugonia-Superstition of the Ancients — Baron C. R. Osten Sacken 198 The Earliest Mention of the Kangaroo in Literature. — Baron C. R. Osten Sacken . 198 On an Unde.^cribed Rudimentary Organ in Human Attire. — Prof. Marcus Hartog 199 Early Asterisms. III. By J. Norman Lockyer, F.R.S • 199 The Secondary Education Movement. By Sir H. E. Roscoe. M. P., F.R.S 203 The Sonnblick Mountain Observatory {Illustrated.) 204 Notes . . 205 Our Astronomical Column : — Small Distances Measured with the Heliometer . . . 209 The Tail of Comet Brooks {c 1893) 210 Hydrogen Envelope of the Star D.M. -h 30°3639 . . 210 L'Aslroiiomie for December 210 Geographical Notes 210 Epidemic Influenza. By the Hon. R. Russell . . . 210 On a Method of Separating the Mineral Com- ponents of a Rock. {Illustrated.) By Prof. W. J. Sollas, F.R.S ... 211 The Cloudy Condensation of Steam. By Shelford Bidwell, F.R.S 212 Scientific Serials 214 Societies and Academies 215 Books and Serials Received 216 NA TURE 2 iy THURSDAY, JANUARY 4, i! RECENT CONTRIBUTIONS TO METEOROLOGY. Report on the Present State of our Kno-wledge respecting the General Circulation of the Atmosphere. By L. Teisserenc deBort. (London: Stanford, 1893.) On Hail. By the Hon. Rollo Russell, F.R.Met.Soc. (London: Stanford, 1893.) Weather Lore : a Collection of Proverbs, Sayings, and Rules concerning the Weather. Compiled and arranged by Richard Inwards, F.R.A.S. (London : Elliot Stock, 1893.) WHILE meteorologists are generally prepared to admit the salient points of the theory of the atmospheric motions as outlined by Ferrel, there are to be met discussions by various authors, accentuating not only differences in the details of the scheme, but also defects in the theory on which the general circulation of the atmosphere is based. The latest contribution to the literature of the subject illustrating these points, is from M. Teisserenc de Bort, Meteorologist to the Central Bureau, and General Secretary of the Meteorological Society of France; for this authority cannot accept, in its entirety at least, either Ferrel's deductions or his method of conducting the inquiry, Ferrel, it is well known, having deduced the equations for the horizontal motion of the atmosphere, relative to the earth's surface, applied, with effect, the condition of continuity and the law of conservation of areas, or, what would possibly be a better term, the preservation of the moment of rotation, and demonstrated the existence of an easterly motion of the atmosphere in the higher latitudes, and a westerly motion in the lower. To define the limits of these zones, Ferrel remarked that the sum of the moments with reference to the axis of the earth, of the air forming the easterly winds, ought to be equal to that of the westerly winds, and that this condition was fulfilled on a hemisphere, if the easterly winds prevailed up to 30' latitude, and westerly winds to the pole. This line of argument receives some support from the suggestion, that otherwise there would be a residual unexpended force, tending to change the velocity of the earth's rotation. But M. de Bort replies, with some force, that this argument is inadequate, because there is no evidence that the earth's rotation is uniform ; and, indeed, the action of the tides and the diurnal variation of the barometric pressure, point, pretty con- clusively, in an opposite direction. If the effects of friction are omitted, the author seems prepared to admit the validity of Ferrel's argument, and it would be very unjust to deny that Ferrel neglected friction altogether, or failed to modify his original result, obtained without friction. Further, Oberbeck especially has considered the effects of friction, and he has assigned a lower limit to the zone of change of direction not greatly different from Ferrel's value. Apart, however, from this point of theory, the author differs from Ferrel as to the cause of the belts of maximum pressure, north and south of the equator, and adds an explanation of the low pressure zone in latitude 55'' and of the polar maximum. NO. T262, VOL, 49] But the most interesting, and possibly the most valuable portion of the paper, is the insistance on the connection traced between temperature and distribution of pressure, and the effort to explain the observed vari. ation of pressure along parallels of latitude by the presence of thermic anomalies. The author sees in the variation of temperature over continents and seas in the same latitude, and the consequent changes in the density of the lower strata of the atmosphere, the origin of many of the irregularities that mark the isobaric curves, and a cause not inferior in its effects to the rotation of the earth in establishing the prominent features of the general circulation. M. de Bort has also made an ingenious attempt to compute from theory the mean isobars of January and July, and to compare the results with actual observa- tions. This is a step in advance, but the measure of suc- cess that has attended the effort must be left to the de- cision of individual judgment. Two approximations, or two distinct attempts, have been made. In the first, it has been assumed that at an altitude of 16,000 feet the irregularities in the distribution of the isobars disappear, and only the influence of latitude remains. Consequently the observed barometric pressure at the surface should be given by adding to the mean pressure, corresponding to the latitude, the weight of the column of air of variable density e.xtending from the surface to this altitude. When this operation is effected, a comparison with the observed quantity discloses the fact that the computed pressures are too great, and further shows a tendency to exaggerate the barometric minimum over the North Atlantic, while it exhibits a maximum of pressure over North America which does not really exist. There is therefore, admit- tedly, a more marked difference in the computed isobars over continents and seas than is actually observed. Two causes are assigned for the failure to reproduce actual facts, both of which are probably operative. The one is that the density of the column of air does not diminish uniformly with the temperature, which hypothesis, for the purpose of computation, it is necessary to assume. The other is that probably the slope of the surfaces of equal pressure from the equator towards the poles is greater where the temperature is already low, than where the temperatures are high, in the upper regions of the atmosphere. The second attempt to reproduce the observed pressure is arranged to take into account the influence of the un- equal distribution of temperature upon the form of the upper isobars, and it is contended that the computed values of the surface pressure " show close analogy with those representing the isobars deduced from direct observation.'' Not content with surveying the conditions of our atmospheric circulation, the author proceeds to discuss those that obtain on the planets, and submits two ideal pictures of the earth with its surrounding cloud as seen from space. These are compared with a photograph of Jupiter, but we strongly doubt whether the author gleans any additional facts in support of his views. The red spot is a conspicuous feature in this photograph, and whatever may be the true explanation of that phenomenon, the tolerable permanence of its character forbids us to ascribe it to atmospheric circumstances. But M. de Bort 2l8 NA TURE [January 4, 1894 is disposed to regard the dark raarkings, in which the red spot would be included, probably, as the real surface of Jupiter, seen through an unobscured atmosphere, and the position of the belts on Jupiter is thought to support the suggestions of the author. But we doubt whether astronomers are agreed that the dark markings represent clear sky, and the lighter portions cloudy vapour. Mars would seem to be the one planet in which we might ex- pect i-O find atmospheric conditions similar to those here prevalent ; but we are told that there are " probabili- ties based upon scientific reasons, that the clouds upon Mars are not distributed in the same manner as upon the earth." Though when we consider what a presumably comparatively unimportant factor the solar heat is upon Jupiter, and that, moreover, the axis of rotation is nearly perpendicular to the plane of the orbit, on a superficial view, this observation seems to be more applicable to Jupiter than to Mars, From the remark with which the paper closes, we gather that the author intends to pro- secute this subject of investigation on the planets. We wish him success. Of the second work mentioned at the head of this notice, it is rather difficult to speak. Although the author has not sketched the plan and scope of the work in any introductory chapter, it is easy to understand the prin- ciple that has guided him in the construction of the book. He has evidently been at great pains to bring together all that is valuable, or that he thought valuable, in the descriptions that have been given of hailstorms in the past, not only in the accompaniments of the hailstorms, or of the characteristics of the hailstones themselves, but also of the theories that various authorities have suggested to explain their occurrence. When we con- sider that in the case of nearly every hailstorm, some one is found to describe it, it is evident that the materials from which Mr. Russell can draw his information are very widely scattered. The list of authors quoted is a long one, and could no doubt have been made much longer, did not the reiteration of the same facts become weari- some. Having collected his information, the author has attempted to digest it, and has given us a summary of the characteristics of hailstones with a graphic descrip- tion of the development of a hailstorm. One consequence of this method of dealing with the subject is that about three-fourths of the book consist of extracts from various authors, and only the remainder is original matter. This class of work, if not very brilliant, is, no doubt, valuable ; and inasmuch as most of the extracts are given in the words of the author, with distinct references to the sources from which they are taken, this book may save much searching of original authorities, and a proportionate saving of time. Whether the materials are arranged in the most advantageous manner, is a question about which some doubt may be entertained. It would seem some- times as though the extracts had been printed in the order in which they had been encountered, without any attempt at arrangement at all. To take the first chapter, " descriptions of hailstorms and hailstones," at first sight it would look as though some chronological order was to be maintained, for we begin in 1680, and pass next to the early years of this century ; but when we get into the middle of the century, we flounder about from 1890 to 1870, and back again, without any guide. Neither is NO. 1262, VOL. 49] locality any rule, for we are taken all over the world, without method or system. Nor is it easy to trace any gradual scientific progress in the descriptions. We have simply more or less complete descriptions of some fifty hailstorms, or of the salient features that distinguished them. The second chapter gives us observations of tempera- ture, clouds, and winds at great altitudes, principally confined to the accounts of balloon ascents. In this chapter, which is very short, there might have been found room to discuss in more detail the observations made at some of the meteorological stations at considerable alti- tudes. The results obtained at Pike's Peak, Colorado, would seem to be of the highest importance in this con- nection ; but the author prefers to drop this topic, though apparently germane to his subject, in order to discuss, or rather to collect, the opinions and observations of those meteorologists who have noticed the connection of elec- tricity with the occurrence and formation of hail. The chapter on theories of hail is interesting. In it is given the opinions of most of those whose opinions are worth recording, but in the popular and not the scientific language which some of the authorities quoted would have used. Von Bezold especially suffers from inadequate description, and, if we are not mistaken. Hertz's name is not mentioned. It would seem almost as though the author were not acquainted with much of the hydro- dynamical analysis that has been applied to the atmo- sphere, or being acquainted with it, disapproves of its application to the present inquiry. In the chapter on the development of a hailstorm, objection will probably be taken to the insistance and stress that is laid upon the part played in the mixture of air of different temperatures, as a primary cause in pro- ducing precipitation, whether it be of hail or any other form of moisture. The numerical example worked out to illustrate the author's point is not very clearly ex- pressed ; and even granting the figures of the author, he is obliged to fortify his case by a continual mixture- But the continual mixture would tend to produce uni- formity of temperature, and disturb the accuracy of the original calculations. Undoubtedly we have present, in what it is usual to call the hail stadium, an ainount of dry air which it is convenient to separate, in theory at least, from the saturated vapour also present, the drops of water, and the particles of ice or snow which probably constitute the germ of the large hailstones, and then, if the conditions are favourable, we get hail ; and it is diffi- cult to see that our author has carried the explanation much further. Nor possibly does the application of the mechanical theory of heat, however legitimate its methods may be, advance our knowledge very materially, at least in a practical direction. The local, and often confined, area over which hailstorms occur, is a marked feature of their occurrence, and is likely, for a long time to come, to baffle the applications of a general theory, and prevent any sufficient precautions being taken against the damage they produce, which it maybe supposed is the practical outcome that sufferers hope to derive from the studies and inquiries of meteorological observers. In the final chapter, headed " Conclusions." there is an attempt to gather up the results of the observations recorded in the previous chapters. It is a pretty fair January 4, 1894] NATURE 2 19 record of our general knowledge of the subject, exhibit- ing a tolerably complete grip of all the circumstances attending these phenomena. It does not show much originality, perhaps, but it does show very extensive reading, accurate observation, and power of condensa- tion. The third book mentioned is scarcely of the kind that compels one to sit down and read off-hand. It is pre- cisely what it professes to be— a collection of the many weather proverbs which possibly the wit of one, rather than the wisdom of many, has perpetuated.- If these adages did contain the results of long-sustained and well- directed observation of the habits of birds, animals, and insects, they would possess a distinct value, though it is difficult to see how the information so gleaned could indicate the severity or the mildness of the coming season ; but it is to be feared they too frequently record the opinion of one who is capable of a jingling rhyme, or of one whom his comrades consider to be wise in such matters. There are also quotations from the poets, ancient as well as modern, and all bearing on the subject of weather prediction. The hope of the author is that the perusal of such a collection may induce students to take more in- telligent notice of meteorological conditions, and to avail themselves of accurate instrumental means, rather than to rely upon hackneyed quotations. A somewhat similar collection of " wise saws" was published by the United States Signal Service, but we fail to see any reference to this work in Mr. Inwards's introduction. A study of these sayings would probably furnish some additional quota- tions, and as the compiler aims at greater completeness in the next edition, we would refer him to this source. The book is well printed and admirably " got up," and will no doubt be welcome to many interested in folk and weather lore. PH YSICO- CHE MICA L MEASUREMENTS. Hand- unci Hi If sb itch ziir Aus/iihrun^ physiko-chemis- cher Messungen. Von W. Ostwald. (Leipzig : W. Engelmann, 1893.) THIS manual must be regarded as the only guide to measurements in physical chemistry which has yet been published. The book is not intended to com- pletely cover this field of investigation, but has evidently been devised with the primary object of assisting Prof. Ostwald in his course of instruction at Leipzig. It is not an introduction to the subject, as the detail supplied, both in connection with apparatus and methods, is insuffi- cient for the requirements of the beginner ; nor is it a treatise wherein a representative collection of methods may be consulted. The book is rather to be viewed as an aid to the teacher, or as indicating to the chemist or the physicist methods which for the most part the author has found to be of service in his own laboratory. The information contained in the opening portion of the volume is of the kind usually met with in a physical text-book : modes of calculating results, the influence of errors, the use of corrections, the measurement of length, the balance and weighing, and the measurement and regulation of temperature. Succeeding chapters NO. 1262, VOL. 49] take up the more common operations in glass-working, the measurement of pressure, the measurement of the volume and density of solids and liquids, and the ordinary methods of measuring vapour density. Here it may be noted that Perkin's modification of Sprengel's pyknometer, which is perhaps the most useful of all the various patterns, is not included among those de- scribed. Kopp's pyknometer also is rendered more serviceable if a short mm. scale instead of a single mark be etched on the neck. The thermal properties of liquids are next briefly con- sidered. Modes of determining expansion and mole- cular volume at the boding-point are given with a moderate amount of detail. The determination of the boiling-point itself is, however, described in the most meagre way. Of the various methods of measuring vapour pressure the dynamical process introduced by Ramsay and Young alone finds a place. Critical tem- perature and critical pressure are determined in separate pieces of apparatus in the manner recently described by Altschul. No general method is indicated whereby the relation between pressure and volume maybe determined under varying conditions of temperature, and no practical method can thus be given for estimating critical volume, although the principle of the new method due to Mathias is mentioned. Calorimetry is now dealt with, and short accounts are given of the simpler methods of estimating specific heat and the thermal changes accompanying vaporisa- tion, dissolution, combustion, and reactions in dilute solution. Descriptions of optical measurements relating to refrac- tive indices, spectroscopy including spectrum photometry, calorimetry, and rotatory polarisation are now introduced, and are followed by a chapter on viscosity and surface tension. In connection with viscosity, the apparatus repre- sented is only adapted for obtaining relative values, and is quite unsuited for investigating the effect of temperature. What appears to be the correct value of the kinetic energy correction used in calculating viscosity co- efficients is ascribed to Finkener and Wilberforce, whereas the first published account of the mode of deduc- ing it is due to Couette. None of the methods given for measuring surface tension are free from the objection that air is in contact with the liquid surface. The remaining chapters are devoted to measurements on solutions. Methods of estimating the solubility of solids, liquids, and gases, and of determining molecular weights from the freezing-points and boiling- points of solutions are given at considerable length. At still greater length, and thus in marked contrast with the treatment elsewhere, electrical measure- ments are next set out. Here are found accounts of the methods of measuring electromotive force and con- ductivity, dissociation constants, the basicity of acids, &c. The last chapter takes up elementary problems in chemical dynamics relating to the velocity of chemical change, the catalysis of methyl acetate and the inversion of cane-sugar by ddute acids being given as examples. From whit has been said it is evident that the operations dealt with in the book are only such as are frequently perlormed, or which at the present time are considered to be of importance. Some of these even are 220 NA TURE [January 4, 1894 occasionally omitted ; no mention is made, for example, of the ordinary methods of obtaining melting-points. It is noteworthy also that processes relating to the purification of substances for physical study are not touched upon. Accounts of the best systems of fraction- ation, either by distillation or crystallisation, or of dis- tillation under reduced pressure, &c., have, it seems to us, a better right to a place in a book of this kind than, say, the chapter on glass-blowing. Again, no particular notice is taken of methods which have to be used when only a small quantity of material is available. It fre- quently happens that a substance can only be obtained sufficiency pure in but small quantity, and if methods of obtainmg boiling-point, density, refractive index, &c. in such cases were more widely known, physical constants would no doubt be more generally estimated in the course of ordinary chemical investigations. It is needless to state that the book is full of useful hints both on methods and apparatus, and will be indis- pensable to those for whom it is specially designed. It is also worthy of special recognition as being yet another effort on the part of Prof. Ostwald to place physical che- mistry on a level with other departments of experimental investigation. J. W. Rodger. OUR BOOK SHELF. Handbook of British Hepatica. By M. C. Cooke, M.A., LL.D. I vol. 8vo. 310 pp. 7 plates. 200 woodcuts. (London : W. H. Allen and Co., 1894.) Probably no group in the British flora has received so little attention as the HepaticcE. This is due partly to the ordinary botanical text-books describing merely the life history of the ubiquitous Ma?-cha7itia polymorpha, and ignoring or passing over with but scanty reference the foliaceous group. But chiefly is it due to the want of a handbook by which beginners could identify their plants and obtain references to the literature of the sub- ject. Sir W. J. Hooker's magnificent monograph, which appeared in 1816, contained plates with copious descrip- tions of all the British species then known ; but it is now scarce, costly, and having all the species described under one generic ndime, Jiiuge?vna?inia, it becomes necessary, after identifying a plant by it, to refer to some other source to ascertain the now accepted name. Hooker's " English Flora," vol. v., in dealing with the same group, divides the frondose group into several genera, but re- tains the generic name oi Jiaigermannia for the whole of the foliaceous group. In 1865 Dr. M. C. Cooke published, as a supplement to Science Gossip, a catalogue with outline figures of all the British species. This is now out of print. Since then notes scattered through various journals have formed the whole of the British literature upon the subject, except the commencement of a monograph by the late Dr. B. Carrington. Dr. M. C. Cooke has now filled up the gap by produc- ing a " Handbook of the British Hepaticae," containing full descriptions of all the species, about two hundred in number, known to inhabit the British Islands. The volume opens with an introduction of 20 pp., describing the position, structure, reproduction, and subdivisions of the group. This is followed by a detailed account of the spacies, each arranged upon the same plan. First come the diagnostic characters, followed by copious synonymy, then the habitat, and finally a full description. Each species is also represented by an outline figure, either in the text or in one of the seven plates at the end of the oiO. 1 262, VOL. 49] volume. A bibliography and index complete the work. The size and clearness of the type will be appreciated by those who use the book, as it should be, in conjunction with microscopical examination of specimens. Altogether a very useful work has been produced, which ought to fill a gap already too long vacant. C. H. W. Edited by Richard (London : Frederick The Royal Natural History. Lydekker. Parts i and 2. Warne and Co., 1893.) Yet another "Natural History." There is certainly a demand for such, and without doubt there is a supply. The work" is to be in six volumes, and the parts, pub- lished monthly, will complete the series in three years. The paper and typography leave nothing to be desired. The illustrations are in almost every instance, so far as our knowledge of the published paits goes, excellent ; many of them are as artistic as they are accurate ; and when we add that the editor of the series is an able and well-known zoologist, there can be no doubt but that the reader or purchaser will get full value for their expenditure of time or money. In noticing a work of this nature, when the facts are as above stated, there is but little room for criticism, and despite the shock which the first blazing sound of its advent conveyed to our senses, despite the fact that "it is not compiled or translated from foreign sources," and that " the co-operation of the Bibliographic Institutes of Leipsic and Vienna" has been secured so as to obtain " all that is best and newest among the productions of the greatest natural history publishers of Europe," we yet most heartily recommend the work to all our readers,, and we anticipate that most of those who take any interest in zoology will place it on their book shelves. Of the six volumes, as was to be expected in a work of this kind, the larger number (five) is to be devoted to the backboned animals, and but one to the boneless crew ; and of the first five volumes, two and a half will relate to the mammals, one and a half to the birds, and but one to the reptiles,, amphibians, and fish. It is not at all a fair division, but then the mammals are thought to be the most generally interesting class, and we are promised a lot of informa- tion about " the larger game." The first two parts are devoted to the monkeys, and we have an account of nearly all the known species, accompanied with an im- mense number of illustrations. One suggestion occurred to us while reading over the account of the habits of the baboons ; that when plants are referred to they should,, when their scientific names are used, be quoted speci- fically as well as generically ; thus a " very remarkable kind of West African plant" is mentioned as the " wel- witschia," but the editor would never think of quoting the Anubis baboon as the " cynocephalus." We hope it will be a long time before WclivitscJiia niirabilis will be exterminated by the baboons. From a natural history stand-point there is really no such plant as an "/avVz," but there are several species of the genus Ixia, upon the bulbous stems of which it would appear these baboons feed. LETTERS TO THE EDITOR. [ The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to .return, or to correspond with the writers of, rejected manuscripts intended for this or any other part <7/Naturk. No notice is taken of anonymous communications.^ The Origin of Lake Basins. I WELCOME the criticism of my article on the glacial origin of a certain class of lakes by an experienced geologist like Mr. Oldham, because it probably embodies the strongest argument that can be adduced on the other side— at all events as regards January 4, 1894] NATURE 221 the one aspect of the problem which he alone touches upon. He urge* that my paper contains a fallacy and a misrepresenta- tion. The alleged fallacy is, that because the lakes in question are found in glaciated and not in otherwise similar non- glaciated regions, "therefore the rock-basins in which the lakes lie were excavated by glaciers." But this is not my argument, and therefore not my fallacy, What I say is — "there must be iomc causal connection between glaciation and these special types of lakes. What the connection is we shall enquire later on." That there is a "causal connection " Mr. Oldham asserts as strongly as I do myself, though it is a different, and as I have endeavoured to show, an untenable one. This brings us to the alleged misrepresentation, which is, that I have imputed to the opponents of the ice-erosion theory, the view that the earth movements which, as they allege, produced the lakes, occurred in the period just before the ice-age came on. Mr. Oldham says, this is an unreasonable and unfounded limi- tation, since the movements in question probably occurred throughout the glacial period itself, I quite admit the validity of this criticism, and that I should have added, "or during the glacial period itself," to, "immediately before" it. I cer- tainly had this probability in my mind, and the reason I did not express it was twofold. In the first place, all the advocates of the earth-movement theory appeared to assume, either directly or implicitly, the preglacial origin of the lakes; and secondly, this assumption gave them the strongest argument against my views, and I therefore gave them the benefit of it. Mr. Oldham appears to have overlooked this. Yet it is clear that the shorter you make the time since the formation of lake basins by earth- movements the more difficulty there is in explaining the total absence of valley-lakes from all the non-glaciated mountain regions of the world, since there is less time for them to have been all silted up. When arguing this point I said — in the pas- sage evidently referred to by Mr. Oldham — "The only way to get over the difficulty is to suppose that earth-movements of this nature occurred only at that one period, just before the ice-age came on, and the lakes produced by them in all other regions have since been filled up." I thus gave my opponents the benefit of an extreme supposition which was all against myself ; while the more reasonable view, that earth-movements are just as likely to have occurred during and since the glacial epoch as before it, renders my argument from the geographical distribution of lakes much stronger, since it is impossible to believe that, if lake basins as large and as deep as those of •Geneva, Maggiore, Como, Constance, and Garda, were formed ■in non-glaciated regions as recently as the middle or latter part of the glacial epoch, a considerable number of them would not 'be still in existence. Of course, if it can be shown that filled up lake-basins exist in tropical and subtropical regions, corresponding in number, po- sition, size, and depth, with those of glaciated areas, the argument from geographical distribution will break down. At present I am not aware of any evidence that such is the case. But even if it were so, there remains the singular correlation between the size and depth of lake basins and the known size of the glaciers that occupied these valleys ; together with the surface and bottom contours of the lakes themselves, so strongly opposed to their production by any form of valley-subsidence or €arth-movements. A friend has pointed out an unsound argument in my article on the above subject in the Fortnightly Revitio, and I therefore ask to be allowed to state what it is, and thus avoid its being possibly made the subject of discussion in the pages of Nature. As a proof of the very great erosive power of ice I have adduced Dr. Helland's estimate of the quantity of Scandinavian debris in Northern Europe. But it is evident that this only proves the great carrying power of the ice, since the rock and gravel would be mostly of sub-aerial origin. It, however, indicates a very long period during which the ice-sheet was at work, while the clayey element in it would be due to erosion. The larger part of this, however, would certainly have been carried away into the North Sea during the passage of the ice-sheet across the Baltic. The enormous quantity of boulder-clay in North America, which I have also referred to, is a better indication of true ice-erosion. Alfred R. Wallace. The question you have allowed me to raise is too important and far reaching to justify its dissipation upon personal issues. It cannot be thought unreasonable that those geologists who propound transcendental theories should justify the mechanical NO. 1262, VOL. 49] postulates on which they claim to base them. This is all I have asked. Dr. Wallace asks me to explain what will happen when suffi- cient pressure is applied to ice not only to crush it, but to in- duce retfelation. I have already explained in my work, that the notion of fracture and regelation taking place in glaciers is at issue with the details of their differential motion as tested by experiment. There is no evidence that ice which on pressure being applied to it has ample room to move, will undergo regelation at all. The pressure when crushing ensues will be dissipated in the direction of least resistance, and most probably upwards. This emphasise'-; Mr. Deeley's statement, and he wrote as a champion of Dr. Wallace, that " fracture and regelation have little to do with the question." Dr. Wallace then returns to his charge against me that I have in some way committed myself in my work to a position incon- sistent with the one I am now maintaining. I can assure him that if he has read this meaning into my words, it was not what they were meant to convey. In giving the history of the "Glacial Nightmare," I entered largely into the views of Charpentier, and in so far as he championed glaciers as against ice sheets I agree with him. I have said that his views " are for the most part soitnd and tmanswerable, since they finally established for the Alpine country and for Switzerland the fact that glaciers ivere formerly much more extensive" &c. Beyond this I could not go, since my work was written to prove the unscientific character of the extravagant conclusions of the later glacialists, including Charpentier himself after he became a follower of Agassiz. Apart from this, however, what your readers I am sure would welcome would bean argumenturn ad rem, and not one ad hominem. In demanding that the advocates of the glacial theory in its extravagant form should justify their premises and postulates, I must not be understood to decline to meet the geological case against the glacial excavation of lobes. I have met it at great length already in my recent work, but not so ably and not so thoroughly as Mr. Spencer met it in his elaborate and crushing examination of the critical case of the North American lakes, which I commend most heartily to the study of enthusiastic champions of omnipotent ice. The geological question, however, is necessarily contingent upon the mechanical question, and no amount of ingenuity will in the long run enable those who invoke ice as the author of all kinds of geological work to evade the duty of proving its capacity to do that work, and notably to explain how it can travel over hundreds of miles of level country, or suddenly begin to excavate deep and extensive lake basins after it has been moving gently over its own bed of soft materials for many miles, or, indeed, how it can excavate on level ground at all. The first step is to show that ice can convey thrust in a way to compass these ends ; the second one is to show whence this thrust is to be derived. Your readers who are committed to no theories unsupported by facts, will not quarrel with the reasonable demand that these first steps should be surmounted before we advance any further. Those who like to traverse cloud-land on the wings of fancy may be otherwise satisfied. To them I would only say that the result cannot be science ; it must remain nothing more than poetry. Henry H. Howorth. 30 Collingham Place, Earls Court, December 30, 1893. Hindoo Dwarfs. In your issue of November 9, 1893, is a notice of some photographs, by Colonel A. T. Eraser, of two dwarfs, taken in the Kurnool district of the Madras Presidency, near Bellary. Erom the account given of these dwarfs — the hereditary nature of the deformity, its limitation to the males of the family, the inability to walk, the normal bodily growth up to six years of age^it seems possible, if not probable, that the family is afiflicted with the disease known as pseudo-hypertrophic paralysis (Duchenne's paralysis). Any physician could settle the question immediately on seeing one of the subjects in question ; and very probably a study of the photographs would be sufficient. I have had cases of this disease in my wards at the General Hospital, sent from Bellary. Perhaps Colonel Eraser would kindly send me a copy of one of the photographs, or show them to another medical officer, and tell us his opinion. Madras, December 2, 1893. A. E. Grant. :22 NATURE [January 4, 1894 EWART'S INVESTIGATIONS ON ELECTRIC FISHES} THIS is a magnificent memoir containing the very in- teresting observations of Prof. Ewart concerning some of the most important chapters of comparative anatomy. Everyone who has an idea of the enormous difficulties connected with these investigations will ad- mire the great skill and successful perseverance with v> hich the author has followed up many dark problems anc thrown light upon a number of the most obscure questions. My studies have been in the same direction for nearly twenty years, and I congratulate my companion in work upon liis great success. It might appear a bold attempt for a foreigner to debate the complicated problems treated in the work ; but, on the other hand, there is apparently a strong in- terest attached to the endeavour to enlarge the field of international intercourse, and this will serve as an excuse for any awkwardness of language. There is no doubt that science is the chapter of know- ledge most entitled to international treatment, and Prof. Ewart himself has done his best to acknowledge the merits of foreign authors. Still, I wonder whether he is aware of the fact that in many places his deductions bear a more or less national character. The proof of that fact cannot be compressed in a few notes, but it may suffice to point out the places where the differences of treating these matters between British and continental writers seem to be most apparent. Everybody will probably agree that the whole of Prof. Ewart's work deserves very high praise. The plates, which have been accurately drawn by the author himself, are beautifully printed, and yield very ample and useful instruction to anyone who wants anatomical and histo- logical information about these interesting, and yet very imperfectly known, organs. They give a clear account of the immense work the author had to accomplish before he could give so exact and complete representations of the electric organs as well as the cranial nerves and the sense organs. It will remain to Ewart's undisputed credit that he has brought before the public a large amount of information on the anatomy and histology concerned. The explanation of the plates facilitates the understanding of them, and forms the connecting link between the figures and the tenourof the deductions. It is proved by comparing a great number of organs in different species of Raja, that there are two distinct kinds of electric organs, viz. " cup-shaped," which occurred in R. circularis, radiata and fiillonica of the British seas, in R. eglanteria from abroad, and, on the other hand, " disc-shaped," which he found in R. bails, macrorhynchus, alba, oxychynchiis, tnaailata, clavata, and microocellata. Everywhere Ewart confirms the statement of former writers, that the electric organs were derived from muscles of the tail which became changed into electric tissue. With great care and skill he has followed the develop- ment of these organs in the embryo, and showed how the muscles gave up their firm hold on the sinews, and shrivelled up to discs or cups. There remains yet one difficulty to be overcome, which the author has not considered ; that is to say, he finds the termination of the nerves for each element at the proximal ^«^ of each muscular club, and compares them (as other authors do) to the motor end plates of common muscles, which are fixed alongside the striped fibres, and not at the end. That is. of course, a subordinate question, and I am very glad to repeat here what I have stated in former publica- tions of mine, that the muscular origin of the electric 1 " Electrical and Lateral Sense Organs, and on the Cranial Nerves ol Elasmobranchs." By Prof. J. C. Ewart. (Edinbui-gh, 1893.) NO. 1262, VOL. 49] organ in the skate also appears beyond doubt, and that I thoroughly agree with Prof. Ewart, not only in that principal question, but also in his deductions regarding the phylogenetic development. One of the general deductions appears rather strange, not only to me, but to most authors on the continent interested in the matter. How is it possible to consider the electric organs of the skate as such of " vestigial char- acter" before any evidence is given in favour of a retrograde development, which takes place at any period of life ? Are not all the statements of Ewart, as well as of former authors, clear proofs that the development is progressive, or at least resting at a certain degree of perfection, after having left the starting-point (muscular tissue) only for a comparatively short distance .'' The organs might still advance to further perfection (which I presume they do), or they might become rudi- mentary again ; but so long as there is only progressive and no retrograde motion in the development, it is hardly worth while to argue about the probability of their vestigial character. I differ only so far from Ewart, as he does not convince me that the electric organs of the skate are as equally perfect as the organs of the Torpedo. In the skate, and up to a certain degree also in Mormyrus, the striated layer of the organ is histologically and optically (in pol- arised light) proved to be the rest of the original muscular tissue. If there is so much left of the former state of things, it proves, in my opinion, that the process of transformation going on is not so far perfected as in another case (Torpedo), where nothing of the muscular character is left. I may be permitted to quote here a suggestion I made in a former number of this journal (January 19, 1893) regarding the probable way of phylogenetic de- velopment in these organs. It seems to me possible that a kind of physiological alteration changes certain muscles so gradually into electric tissue that a compara- tively still imperfect element under favourable circum- stances might give an electric shock, which proves useful to the skate for maiming small animals upon which it preys ; and so the fish might continue to improve the organ by using it. Ewart {R. circularis, p. 546) argues exactly in the same way as I did, but hesitates to assume that weak electric shocks might be of any use to the skate. It should be kept in mind that small aquatic animals are often extremely sensitive to electricity, and that an un- expected weak electric shock startles even a human individual. At another place, where the author treats the same theory, and grants the possibility of all the other presumptions, he holds back from the universally accepted principle, that constant use makes an organ increase. (Skate, p. 41 1). Of course, up to a certain degree, the phylogenetic de- velopment of the electric organs contains still a good deal of mystery, and will, I fear, always lack the scientific proof so eagerly looked for ; but I must repeat my conviction, that it is easier to imagine the trans- formation of striped muscle in electric tissue, than to explain by natural selection the development of any distinct, lively-coloured pattern on the wing of an insect. The cautiousness of the author is, however, to be praised, and it is very interesting to follow his argu- ments about the pro et cofitra in these complicated matters. I cannot admire as much another chapter of his paper, where Prof. Ewart does not seem to be quite up to the international mark ; it is that in which he compares the number of electric elements in the different electric fishes. (Skate, p. 397). The total of electric elements for each organ in Torpedo marinorata he gives as 250,000, and in spite of the great difference of this number with the sum found by other writers before Ewart, he does not say one January 4, 1894] NA TURE 223 ^vord about that divergence. I spent much time in count ing the elements in the organ of Torpedo, and confirmed rny results by counting also the ganglionic cells belong- ing to the plates. My total comes very near to that of Valentin, but amounts only to 179,625 in each organ. Prof. Ewart cannot expect me to give up my number in favour of his, published much later, before he proves that I made a wrong estimate. He speaks also of the large Torpedo of America, and calls it Torpedo giganiea. It seems he is not aware of the fact that the name of Torpedo gignntca is given to the petrified species from the Monte Bolca, whilst the American species got the name of T. oca'deniaiis {Stoxer). He ignores, or neglects, at the same time, the fact that a near related species, which has about the same number of electric elements, generally named T. iwbiliajia (Bonap.), occurs also in the British seas. If it is difficult to explain such want of harmony with other authors ; it amounts to an impossibility for a foreigner to give a clear account of the following papers concerning the cranial nerves of Elasmobranch fishes. Not that I mean to blame my learned colleague for this ; on the contrary, I admire the papers very much, and re- commend them with all my heart to everyone who wants instruction about the finer details of these nerves ; but with regard to the nomenclature employed. I am afraid very few continental authors will agree with the homologies stated by Ewart. When he in a certain place says against Sappey, " that nerve is all but uni- versally acknowledged to be a part of the facial,'' Sappey will most decidedly state " that nerve is all but universally acknowledged to be a part of the trigeminal." Considering it of little use to discuss the confusion of names in the papers quoted by Ewart, I wish it to be borne in mind that the leading principle of the author to prove his homologies is the equality of distribution of the ner\-es in the peripheric organs. If that holds good, as I am convinced it does, how can he at the same time give the name of a true motor nerve (A', facialis) to a cephalic nerve of a true sensitive character .' Perhaps he will answer, " All, or at least most, of the other authors do, why shouldn't I do the same.'" Putting aside the protest many continental authors (myself included) make against such nomenclature, at any rate his principle of innervation is given up, and I am firmly convinced that the comedy of errors in the nomination of cranial nerves in comparative anatomy will not cease until quite new names or, perhaps still better, only numbers are applied to them according to the place of origin in the substance of the central nervous system. Motor and sensitive nerves must be kept separated by all means, segmental and not segmental nerves may be designated at tlie same time in any proper way. It is in this respect that the want of an international understanding is most severely felt, and we must hope that the future may provide an advancement of science also in the matter ; for before a firm and clear base for these homologies of nerves is given, we might just as well talk Chinese toge her. Professor Ewart's investigations about the cranial nerves had for their chief purpose a clearer insight into the innervation of certain organs of sense, treated in another paper annexed to the same volume. I am very glad to state that the impossibility of accepting his homologies does not interfere with his results as regards the innervation of these sense organs. The anatomical skill of the author is best shown in the treatment of the structure of these organs. So far as my own experience in these matters goes, I am led to ask, Are his statements and figures of the sensory canals and the nerves belonging to them very correct and com- plete ? He overreaches the previous writers treating the same objects by the adm.irable finish of his papers NO. 1262, VOL. 4q] which, as far as I see, ought to be followed by another concerning the ampullaiy canals. In this chapter I have also to object to his way of treating the literature and of stating homologies in spite of his own principles. The sense organs 1 discovered on the skin of Raja, and called " .Spaltpapillen," named " pit-organs " by Ewart, were not found by any other author before. It is not true that Merkel saw them on the back of Mustelus and at the mouth of Spatina ; he described only " freie Ner- venhugel" {free nervous collines) in these places. The name itself proves that the sense organs described by Merkel belong to another group altogether, and so does their position. How Ewart, who places such importance in the distri- bution of the nerves, can find that the " Spaltpapillen" probably correspond to organs of Squatina placed at the mouth of a very different make and different innervation, he may know himself, but the reader finds it impossible to follow such argument. The figure he gives of the pit-organ (sensory canals, pi. 3, Fig. 10) does not show such an organ fully deve- loped. Otherwise the split would be narrow and straight, the cells by which it is lined flattened and columnar, not rounded, the papilla itself much higher raised above the surface of the epithelium, and pigment cells frequently found between the epithelial ceils. (Comp. my paper: " Uber Bau und Bedeutung der Canalsysteme unter der Haut der Selachier." Sitz. Ber. d. Berlin Akad. d. Wischenss^ 1888, s. 291.) The papilla is, in the adult, a good deal raised above the level of the skin, so that even the sense organ at the bottom of the split in the papilla has still a somewhat ele- vated position. This position prevents me from admir- ing the name of "pit-organs," as a pit ought to mark a depression below the main level. Continental writers will also shake their heads in reading that a differen- tiated group of epithelial cells forming a sense organ, and resting between them, is called a " follicle," which by all means wants a kind of stronger envelope enclosing the cells. But I quite agree that in England Latin words might be admitted, which would not do on the continent. Before Prof. Ewart proceeds to describe the am- pullary canals, I recommend him once more to study the paper of Savi concerning these canals. He places the French author amongst those who take also the am- pullary canals for sense organs, which is a great mis- take, as Savi affirms in most decided terms the excretoric function of the ampullary canals. (Mateucci et Savi, " Etudes Anatomiques sur le Systeme Nerveux et sur rOrgane Electrique de la Torpille," p. 331.) But such objections very slightly detract from the great merit of the author. They only prove the strong interest which the perusal of Prof. Ewart's papers has aroused in me, as it will do in all other readers. I cannot conclude my remarks without acknowledging once more, with all my heart, the magnificent results ob- tained by him, and I trust that he may succeed further in the same direction. Gustav Fritsch. NAVIGATION BY SEMI-AZIMUTHS} THE year 1893 should be an interesting one to nautical men. A new Daniel has come to judg- ment in the person of Mr. Ernest Wentworth Buller, M.R.A.I., M.R.U.S.I.,M.I.E.E., the inventor of the semi- azimuth system of navigation, who is equally earnest in denouncing the shortcomings of the existing systems of 1 "Semi-Azimuths. New Method of Navigation, being a combination of Spherical Trigonometry and Mercator's Sailing." (London: Norie and Wilson, 1893.) 224 NATURE [January 4, 1894 navigation, and in advocating the merits of his own. For the precise object of the new method let our author speak for himself In page iv. of the preface we read : " It is here claimed for the semi-azimuth method that it renders double altitudes unnecessary ; that a better result than they have been supposed to yield can be obtained from either observation singly, and this also with a great saving of time and trouble." Again on page 27 : " The range of the General Method exlepds, either from the meridian, or from the limit at which the direct method becomes uncertain, viz., three points from the meridian, up to an azimuth of seven points, or more, that is to say to within less than one point from the prime vertical, which may be considered the practical limit of the semi-azimuth method. ... It may safely be affirmed that nothing like this extent of range in the computation of latitude has ever been attained by the current systems of navigation." The feats which our new teacher claims to have ac- complished are two in number. (i) The discovery of anew formula for reduction to the meridian. (2) By a somewhat tedious system of approximations to obtain by the semi-azimuth method from either of two observations for double altitude the same or a better re- sult than would under the usual double altitude method be derived from the two combined, subject only to the limitation that the body must not be within a point of azimuth from the prime vertical. Let us consider (i) and (2) in detail. First with regard to (i), the formula obtained is this : Reduction = h cos / x arc i azimuth. The formula is a simple one, and now that hour angle is so easily converted into azimuth by the Burdwood and Davis' tables, there seems no objection to its adoption by those who prefer to work out their correction rather than to take it direct from the tables. Mr. BuUer deduces the formula from a somewhat ela- borate construction on the Mercator's chart. It is, how- ever, merely an old friend masquerading in a new dress, and he might, if he pleased, have easily obtained it from the expression in ordinary use. Thus in the formula sin - = sm / sin 2 cosec z sin -h where 0 is the correction,/ the polar distance, c the co- latitude, r the zenith distance, and h the hour angle, if we assume that 2 sin h sin s sin A 2 sin A sin/ A is the azimuth, we obtain . e sin - = 2 . h . A sin c sin - sin - , 2 2 0 = i sin c . A . A . sin i', the BuUer formula in a logarithmic shape. The use of this formula is first exemplified by its application to examples from Jeans' " Navigation," and so long as the azimuth is small it answers well enough. But our author is tempted further afield, and so soon as he gets well away from the meridian his formula begins to give trouble, and he is only able to obtain an accurate result by a process of approximation so cumbrous as to be quite useless for practical purposes. As an instance of this, witness the example of which the results, but not the full work, are shown on p. 14. Were the work to be shown in full, it would occupy more nearly two pages than one page of the text. Now let us suppose it had not been given to Mr. Duller NO. 1262, VOL. 49J to discover the methods lately presented to the nautical world, and that he had been content to follow mere ordinary processes. Imagine, for instance, that he had selected the well- known furmula vers Mer Zen Dist = vers z - sin / sin c vers k in order to work out example § 16, p. 12. Then, upon his own assumption that the latitude was 51°, or 12' in error, he would obtain as a first result lat. 50 49' 42". Repeating the process with this new latitude, a second approximation would be 50' 48' 16", while a third repetition would result in 50" 48' 3", the true value and this with less than one-third of the trouble. The semi-azimuth had better, therefore, be confined to observations within a point or so of the meridian. We pass on to the second and more important part of the task which Mr. Buller has set himself, namely, to show that the latitude within certain wide limits of azimuth may be obtained with accuracy from a single altitude without waiting for a second. And this may be at once conceded, that by making the necessary adjustments for change of azimuth, and by successive approximations, an altitude may be reduced to the meridian, even when the azimuth is considerable. But the same result may be obtained from the versine formula given above with far less trouble but greater accuracy. The question, then, narrows itself to this : Why should we not in all cases of observation within seven points of the meridian, reduce the altitude to the meridian at once, by one method or another, and so obtain the latitude without waiting for hours to take a second altitude, and then making lengthy calculations? Why have Robertson, and Raper, and Inman,and the other giants failed to hit the bull's-eye, while it is left to Mr. Buller to put his finger on the "blind spot".? The answer is easily stated. The " blind spot " is to be found not in the accepted custom of mariners, but in the author himself. Mr. Buller in arriving at his conclusions leaves out of consideration the real vital point which attaches to every observa- tion taken ashore or at sea, but especially to the latter class, namely, what is well defined by Raper as the " Degree of dependence" to be placed on the observation. In every observation off the meridian we have to deal in one form or another with a spherical triangle, in which three elements being given we have to find a fourth. Now the three given elements are in general known only approximately, and it behoves us to find under what conditions an observation should be taken that the smallest possible error maybe produced in the final result. In the problem under consideration, treated by the Buller process, the data are the polar distance, the approximate colatitude, and the zenith distance. Of these the polar distance may fairly be regarded as accurately known, since the difference can only be at most but a few seconds. The latitude is required to be known only approxi- mately, the object of the observation being to find the amount it is in error, and it has already been admitted that the new process will suffice to obtain the correct latitude, always supposing that the observed altitude is correct. What reason is there then to consider that the altitude is correct, and what will be the effect if it is incorrect ? When we take into account the haziness and uncer- tainty of the horizon, the difficulty of accurate observation on board a rolling ship, the varying effects of refraction, the imperfections of the sextant, and the personal error of the observer, it is probable that an average error of 2' is a very moderate estimate. Taking 2', therefore, as an average value, let us see January 4, 1894] NA TURE 225 what will be its effect upon the typical examples in the text, worked first by the new process, and secondly by the old method of double altitude. On page 30 an example (§ 32) is taken from Lecky, which will answer the purpose. The data are as follows. Lat DR 32 15' N. Bearing. March 7, 1880. Altitude. S. 25 E. S. 57 W. Times by chron. h. m. s. o ' " ilh. a.m. ... I II 3'S ••• 5° o o 3h. p.m. ... 5 II 1-2 ... 33 17 45 Sun's declination, 4' 59 15' S. for first observation; 4- 55' 30" S. for second observation. Let us suppose that an error of 2' occurs in the second altitude, the one treated for reduction to the meridian. The error in latitude {dl) produced by an error in alti- tude {(iz) is given approximately by the formula dl — sec A^ . ci'z, where Aj is the azimuth of the body. Thus (// = sec 57° X 2', or 3' 40" nearly. But if treated, so as to take in both observations, by the double altitude process, sin A. di = dz, sin (Ai + Aj) where A^ = 57", A2 = 25"", the azimuths being reckoned from south in each case. Thus sin 82° ^ So that in one case a reasonable error in altitude gives an error in latitude of nearly 4', in the other of less than i'. One other instance will perhaps suffice. On page 36 an example from Riddle is worked out, wherein an error of 2' in altitude would produce an error of 18' upwards in latitude. Such a result at once condemns the observation. Indeed, for the purpose of accurate determination of latitude, the double altitude stands out among the various methods a very king. In other cases, as in the meridian altitude, we are satisfied if the latitude is no more in error than the original observation. In a double altitude, taken under advantageous conditions, only a fraction of the error in altitude appears in the final result. It is somewhat remarkable that Mr. BuUer's evident appreciation of Sumner methods has not made him more familiar with the main principles which apply equally to all classes of observations. Every observation furnishes the observer with a circle upon the globe, a straight line upon the Mercator's chart, on which to place his position. The circle has the sun's projection on the earth for its centre. The line has the sun's line of bearing perpendicular to it. If this line of position is inclined at a very acute angle to the meridian, that is, if the body observed is near the prime vertical, it is evident that a very small increase in the perpendicular drawn from the sun to the line of position, that is, a very small increase of zenith distance, will produce relatively a very large difference of latitude. And thiscondition,coupled with the impossibility of obtain- ing accurate altitudes at sea, is sufficient to account for the restriction of ex-meridian observations to a point or two in azimuth from the meridian. The British seaman, therefore, had better pause before he throws overboard his Norie or his Raper, and takes to his heart the new Buller methods. The greatest self-confidence, the most implicit belief in the reality of the mission to which he has been called, will not enable Mr. Buller to find the latitude accurately by a single altitude near the prime vertical, for the very simple reason that the error (even when supposed small) which must be expected NO. 1262, VOL. 49] in the altitude produces a large error in the latitude, and thus vitiates the result. If he would make the ex-meridian method available as he proposes to do, at almost any time of day, the author must supplement his treatise by the invention of some appliance for measuring altitudes very much superior to any now in use. Pending its production the very pertinent question asked in page 36, "We have known long enough how to get a fairly correct A. T. S. from an observation near the Prime \'ertical and the latitude D. R., but who has yet shown how to obtain the True Latitude" t must re- main unanswered. There is indeed freshness in the " New Method of Navigation," Part I., but no light. That perhaps will be supplied by Part II. G. VOICES FROM ABROAD. THE following literal translation of parts of an article recently published in the Chemiker Zeitung (Nos. 85 and 86, 1893) is an appropriate addendum to a recent article of mine in this j ournal. It must be sorrowfully admitted that in essential particulars the picture is a true one. Henry E. Armstrong. " Notwithstanding the enormous industrial develop- ment of England, the appreciation of science by technical v.'orkers is inconceivably slight, the main cause being deficient comprehension. The Englishman is conser- vative in all his customs, in his way of living, and not less in his methods of manufacturing, so that there are still very many manufacturers who would be as little prepared to place the control of their works in the hands of a scientific chemist as to convert them into philanthropic institutions. At present great efforts are certainly being made to alter this condition of affairs by the aid of technical schools modelled on German lines, but opinions as to the value of these schools are as yet much divided ; and, indeed, for various reasons their ultimate success is doubted. In the first place, it is to be borne in mind that these institutions are not under State control, but are governed and con- trolled by local boards. Moreover, the preliminary training which their students have received is not to be compared with that of students in the German institu- tions, as an education such as is given in the German Realschulen and Gymnasiums— of the character given in England at most by the grammar schools— is only pro- curable by those who are well off, owing to the enor- mously high school fees (about ^20 or 400 marks a year). The possibility of consolidating and widening the tech- nical training by a short subsequent course of scientific study at the University is absolutely out of the question in most cases, owing to its extreme costliness. It is therefore probable that these schools will but produce a number of half-educated persons who will take up posi- tions as chemists and will thereby but bring the chemist proper into discredit. " It is clear that under these circumstances there is but very little prospect that a chemist coming to England will find a suitable position. I cannot sufficiently strongly caution ' young chemists ' against coming to England on the chance of picking up something good, even when provided with good introductions. So few analysts are in demand here that the chance of securing such a post is most uncertain. Works and laboratories in which scientific work is systematically carried on scarcely exist, not one even of the English aniline colour works having a scientific laboratory worthy of the name. The ' young chemist' has therefore very little chance of securing an appointment, as he does not possess the necessary qualification for a works post, that is to say experience, 226' NATURE [January 4, 1894 and the volunteer nuisance is scarcely known here even by name. I can therefore only repeat that it is a very risky enterprise for a young, inexperienced chemist to come to England without a definite engagement, as so often happens. The result, with very few exceptions, is disillusionment, and many get into most unfortunate positions through financial pressure. The outlook is somewhat better for a chemist who has had experience and practice in works. But even such will find it infinitely more difficult to find posts in England than it is either in Germany or Austria, and will do well to go to England only when offered a definite appoint- ment. The thorough scientific training and business capacity of the German chemist is unreservedly recog- nised by all unprejudiced judges in contradistinction to that of his Enj^lish colleague. In carr>ing on routine operations, the English chemist is doubtless as compe- tent as the German chemist, even if he be not his supe- rior, but in conducting and developing chemical indus- tries on a scientific basis the latter is far in advance of the former. " I need refer but briefly to the great chemical indus- tries, as they are well enough known. Of these the first to be mentioned is the soda industry, including that of sulphuric acid and chlorine ; furthermore, tar-distilling, dyeing, calico-printing, the manufacture of iron, steel, copper, tin, and antimony, glass-making, the utilisation of fatty matters, the Scotch parafifin industry, and the manufacture of bichromate. These industries, excepting glass-making, employ a considerable number of chemists, although, in proportion to their output, not nearly so many as the German works. This is especially the case in dye works, calico-printing works, and in those dealing with fatty matters, many of which carry on their manu- facture without chemists, or only with the aid of very imperfectly trained chemists, as every one here regards himself as a full-blown chemist who, after a most elementary preliminary training, has attended a technical course during one, or at most, two years. At least 80 per cent, of the chemists engaged in the industries mentioned are Englishmen, the remainder being either Germans or Swiss. I have never met a French chemist here. With few exceptions the condition of these industries during recent years must be characterised as dull and even as bad in some cases ; they therefore offer the chemist little prospect of employment, and foreign capital is certainly not to be invested in them with advantage. Only dye-v/orks and those utilising fatty matters offer a prospect to the e.x- perienced chemist, as these are both distinctly capable of being improved in position. The helpless condition of the English aniline colour works is peculiar, these having been simply stifled by the German works, which have developed vvith such giant strides. The English works eke out a miserable existence, and altogether do not employ as many chemists as are to be found in a similar German works of the fifth or sixth rank. Fuchsine, soluble blue, chrysoidine, Bismarck brown, and the few naphthol colours unprotected by patents, are almost the onlycolours manufactured. Not a singledyestuft"of import- ance is made by any English firm alone, as scientific la- boratories such as are a matter of course in every German works exist here only in the most rudimentary form. Most of the chemists engaged in English aniline colour works are German (? ?), but the demand for chemists in these works is very small. The erection of such a works in England on the German model could only be achieved by the large German firms engaged in this industry ; it is another question whether it would pay. But the manu- facture of pigments— of mineral coloursfjand lakes— is certainly capable of development here. It is true there are a number of such works, but these rarely employ a chemist, and still more rarely one who has had a thorough scientific training. Consequently, enormous quantities NO. 1262, VOL. 49] of lakes are imported, especially for printing oil-cloths and carpets, which might equally well be manufactured on the spot. The necessary capital would be not an inconsiderable one, and may be estimated at, at least, 150,000 marks. Competent chemists in this branch can probably count on easily finding employment here. " The manufacture of fine chemicals, which at present are almost entirely imported from Germany and France, is certainly capable of considerable development here. Of these may be mentioned especially, tannin, tartar emetic, pyrog^llol, oxalic acid, cyanide of potassium, and most of the almost innumerable chemicals and prepara- tions which are made use of in trade, and which are either not made here at all, or in altogether insufficient quantity and of poor quality. With reference to such articles, in the case of which wages form a considerable item in the cost of production, it is to be borne in mind that English wages are on the average considerably higher than German." THE EFFECTS OF LIGHT ON THE ELECTRICAL DISCHARGE, "X^^HILE engaged on his classical experiments Hertz ^ * noticed that the appearance of the discharge be- tween the two terminals of the oscillator was greatly changed upon the spark gap being illuminated by the light coming from another spark. This change was not due to an electrical action of the sparks, for it was equally well produced by other sources of light, such as the electric arc and burning magnesium, while all effect im- mediately ceased on interposing a plate of glass. Since the time when the above observations were made many ex- perimentalists have investigated this subject and have ob- tained rather divergent results. In most cases the source of light employed has been the electric arc formed be- tween carbon rods, though, with a view to increase the proportion of ultra-violet rays emitted, Bi hat and Blondlot used carbon rods with aluminium cores, while Righi used a zinc rod for one terminal. Other observers have used the spark of an induction coil passing between terminals of copper, zinc, or aluminium. While Hertz had only noticed that the illumination of the discharging knobs increased the facility with which sparks passed, Wiedemann, Ebert and Hallwachs found that it was only when the negative terminal was illuminated that this effect took place. More recent observations by Branly have led to this view being modified, for he finds that on illuminating a piece of zinc by the sparks of a large induction coil produced between aluminium terminals, if the source of light is sufficiently near to the plate, the loss of charge is nearly as rapid for a positive as for a negative charge. On increasing the distance between the spark and the charged plate, the decrease in the rate of loss of charge is much more rapid for positive than for negative charges, and thus at some distance from the source of light the negative charge is the only one which is ap- preciably affected. Hence radiation of certain kinds in- creases the rate at which a positively charged body loses its charge, just as in the case of a negative charge, but the rays which are active in the case of positive electricity are absorbed by even a small thickness of air, while those rays which are unabsorbed are still able to accelerate the discharge of a negatively charged body. After having made a series of experiments in air at ordinary pressures, Stoletow on the one hand, and Righi on the other, have investigated the influence of pressure on the phenomenon, and have both found that the effect increases with a decrease of pressure, while Stoletow has shown that if the rarefaction is carried to the extreme limit there exists a pressure, after which the effect de- creases as the pressure is further diminished. An experiment of Bichat's seems to show that the loss January 4, 1894] NATURE 227 of electricity is due to convection currents, and this view has been further strengthened by Righi, who placed a plate of ebonite covered with tin foil on its upper side above a brass plate on which some figure, such as a cross, had been traced with varnish so that theplatewasprotected at these points from the effect of the illumination, the active rays being absorbed by the varnish. The negative pole of an electric machine was connected to this plate, the positive pole being connected to the tin foil, and the light of an electric arc allowed to fall on the under plate for a few seconds. The plate of ebonite being removed and powdered over with a mixture of sulphur and red lead a yellow cross on a red background was obtained of the same size as the one traced on the brass plate. As the sulphur attaches itself to those parts of the plate which are positively, and the red lead to those which are negatively charged, it follows that the parts of the lower plate which were not protected by the varnish have lost some of their negative charge, which has been carried on to the ebonite plate, and that this displace- ment has followed the lines of force of the electric field between the plates, which are in this case perpendicular to the two plates. This conclusion is further strengthened by observing that, if the electrified particles which escape from the lower plate are prevented, by means of a screen, from reaching the ebonite, a shadow of the screen is obtained. The explanation that this convection is caused by the molecules of gas which, after being in contact with the body, become charged and are repelled, is hardly satis- factory, and the experiments of MM. Lenard and Wolf seem to show that it is particles of dust which carry the charge, for they suspended an insulated plate of metal in a box filled with air which had been carefully freed from dust. A plate of quartz fixed in one side of this box allowed the light from an electric arc to fall on the metal plate, while a stream of some vapour could be introduced through a side tube. Under these circumstances the vapour was condensed on allowing the light to fall on the plate if It was uncharged or negatively charged, while if the plate was positively charged no condensation took place. As it is known that a given space can become supersaturated with vapour when no dust is present, but that the introduction of the least trace of dust causes an immediate condensation, it appears that when a body either uncharged or negatively charged is illuminated it gives off some dust, and that the loss of charge is due to this dust. Further particulars of the work which has been done in this subject are given in a paper by M. Blondm in Electricitc, p. 313, 1893. W. W. AEOLITHIC DISCO VERIES IN BELGIUM. 'T^HE fact that in Belgium flint was in certain districts -*■ largely worked durmg Neolithic times, for the manu- facture of hatchets and other implements, has long been well known. The mines in the chalk near Mons, from which the rough blocks of flint were procured by the ancient flint-workers, have frequently been described, and bear a close analogy with the old workings at Grimes' Graves, near Brandon, and with the pits near that place, still being sunk by the flint-knappers of the present day. The fields in the neighbourhood of Mons have their sur- face strewn with roughly-chipped hatchets, and in other districts the occurrence of worked flints has been not unfrequently noted. In a memoir, recently published in the Bulletin de la Souetc d'Anthropologie de Bruxelles (Tome xi. 1892-93), M. G. Cumont has placed on record his discovery of two important Neolithic stations at Verrewinckel and Rhode-Saint-Gencse, neither of which places is far from the main road from Brussels to Charleroi, while both lie at but a short distance from the field of Waterloo. The forest of Soignes extended in early NO. 1262, VOL. 49] times over the whole district, and though both stations are on promontories of high land, there are or were, in the neighbourhood of each, springs or ponds from which to obtain a supply of water and, possibly, of fish. The principal of the two was that at Rhode-Saint- Genese, whence, including flakes and scrapers, M. Cumont has obtained no less than 3591 worked flints, a few implements made of other kinds of stone being reckoned among them ; while Verrewinckel is credited with 815 specimens. Of all the forms a good summary account is given, and characteristic examples are figured in five plates. A detailed map of the district is also given. That the manufacture was carried on at the stations is proved by the presence of upwards of 240 nuclei from which flakes have been dislodged ; but few of these appear to have rivalled in size those of specimens near Mons. It is indeed suggested that the hatchets and larger implements were rough-hewn at Spiennes, and finished where they were found. That this was the case is further shown by the fact that some twenty polissoirs were collected by M. Cumont, who also regards the flint which forms the material of the implements as having been derived from Spiennes, dbourg, or the neighbour- hood of Mons. Over a hundred arrow-heads figure in the lists, and some of these, as shown in the plates, exhibit skilful workmanship. A few quaternary or palaeolithic implements from the same region have been' described by M. Cumont in another paper. He is to be congratulated on the rich harvest that he has reaped by his labours, which have now extended over a period of eight years. J. E. THE LATE SIR SAMUEL BAKER. NOTHING impresses more vividly upon one the rapid unfolding of our knowledge of Africa than the fact that the pioneers who forced the first paths into the unknown interior have survived to see generation after generation of younger men, who followed in their footsteps, fall victims to the fatal fascination of that continent. Burton, Grant, and Oswell, the companion of Livingstone's earliest journeys, have died so recently that we realise with a feeling of sorrowful surprise that the last of the first great group of explorers has passed away in the person of Sir Samuel White Baker, on December 30, 1893. He was born in London in 1821, and after his school education turned his attention to engineering, but his professional work never took so thorough a hold upon his mind as the love for travel and sport, which his private means fortunately enabled him to gratify to his heart's content. Baker first went to Ceylon for elephant shooting in 1845, ^rid saw a great deal of the island in subsequent years. Two books resulted from this experience — " The Rifle and Hound in Ceylon," published in 1854, and " Eight Years' Wanderings in Ceylon," in 1855. The study which he made of the climate of the elevated part of Ceylon led him to estabhsh a colony of English agri- culturists, fully equipped with a stock of cattle and sheep, at Nowera Eliya, over 6,000 feet above the sea, which is now a noted health resort. On the death of his wife, in i855,he went tothe Crimea, and carried out some railway work subsequently on the Black Sea coast. In i860 he married a Hungarian lady, who surviveshim, after beinghis devoted companion through the trying years of .African ad- ventures, and in the pleasanter wanderings of his later life. In 1861 he went to Egypt, resolved to carry on an ex- tensive scheme of exploration at his own expense. With this object he spent a year in Abyssinia, working out the complete hydrography of the Atbara and its tributaries, and then started from Khartum to follow up the White Nile itself. In February, 1863, he met Speke and Grant at Gondokoro, returning from their great journey to the 228 NATURE [January 4, 1894 Victoria Nyanza, and a year later Baker was able to sup- plement their discovery by arriving on the shores of the Albert Nyanza, the size of which he considerably over-esti- mated. He did not return to London until 1866, and found his fame as a traveller established. He received many honours, including that of knighthood and the gold medals of the Royal Geographical Society and the Paris Geographical Society ; but in the following year, again accompanied by Lady Baker, he returned to Africa. The story of his first journey is recorded in two fascinat- ing books — "The Albert Nyanza Great Basin of the Nile," in 1866, and "The Nile Tributaries of Abyssinia," in 1867. In 1 869 he commenced the occupation of the upper White Nile provinces for the Egyptian Government, at the head of a body of Egyptian troops, and for five years laboured at the heavy task of restraining the slave-deal- ing Arabs and keeping in order his apathetic and often disaffected Egyptian subordinates. He established steam navigation on the Nile to the equator, and in his " Ismailia," published in 1874, told the story of the ex- tension of Egypt. This completed his career as a pioneer and explorer ; but a traveller he remained to the very end of life, and until last year he spent almost every winter either in Egypt or in India. He took a keen interest in the geography of Africa, and at critical m.o- ments in the course of recent developments in that continent he did not fail to give the benefit of his advice for the guidance of the country. In 1879 he visited every part of the island of Cyprus, recording his impressions in " Cyprus as I saw it in 1879." The many reminiscences of his hunting adven- tures in every continent made his last book, " Wild Beasts and their Ways," a most valuable contribution to that liberal form of natural history which studies the lower animals as mankind is studied by the sociologist or historian rather than by the anatomist or physiologist. Baker was elected a Fellow of the Royal Society in 1869, and received the official recognition of several govern- ments and innumerable learned societies in all countries for his services to geography and to humanity. His health kept up to within a month of his death, and to the last he remained a keen sportsman. He died in his residence at Sandford Orleigh, Newton Abbot, in Devon- shire, and his funeral takes place at Woking to-day. NOTES. The list of New Year honours contains the names of two men of science in the public service — Mr. Norman Lockyer, F. R. S. , Professor of Astronomy in the Royal College of Science, and Mr. W. H. Preece, F.R.S., Engineer-in-chief to the General Post Office — upon both of whom have been conferred Companionships of the Bath. "We note with much regret that Prof. Milnes Marshall, F.R. S., of the Owens College, Manchester, met with a fatal accident while ascending Scawfell, on Sunday, December 31. A notice of his life and work will appear in our next issue. We have to record the death of Mr. R. Bentley, Emeritus Professor of Botany in King's College, on December 24, at the age of seventy-two. Mr. Bentley became botanical lecturer at King's College in 1859, and three years later he was appointed professor of botany at the London Institute. He was twice — in 1866 and 1867 — elected president of the Pharmaceutical Conference, and was well known for his works on pharma- ceutical botany. The death is announced of Mr. R. Spruce, the well-known botanist and explorer, in his 67th year. Rather more than forty years ago Mr. Spruce visited South America on behalf of the Royal Gardens at Kew, and successfully carried out some very Important scientific investigations. He explored the river NO. 1262, VOL. 49] Amazon, and crossed the continent from the Atlantic to the Pacific. The introduction of the cultivation of cinchona into India was very largely the result of Mr. Spruce's work, and his fine collection of plants have done good service to commerce and to botanical science. The chair of Agricultural Chemistry in the University of Tokio has been accepted by Prof. Loew, of Munich. Mr. Smith Hill has been appointed Principal of the Aspatria Agriculture College, in succession to the late Dr. Webb. We understand that the Queensland Government, in pursu. ance of their policy of retrenchment, have abolished the post of Government botanist hitherto held by Mr. F. M. Bailey. ^ Prof. W. H. Corfield has been appointed President, and Dr. P. F. Moline secretary, of the English committee of the International Congress of Hygiene and Demography to be held at Budapest this year. Dalziel's correspondent at Copenhagen states that the time of Central Europe was adopted throughout Denmark on the first day of this year. A prize of 1250 francs is offered by the Natural History Society of Dantzic for the best means of destroying the poisonous insects in the forests of Western Prussia. We learn from the Times that the sum of ;!^6oo a year has been bequeathed to the trustees of the Mason College, Birming- ham, by the late Mr. Aubrey Bowen, of Melbourne. In making the bequest the testator stipulates that the trustees shall apply the sum in founding six scholarships of ,^100 a year each in con- nection with the college, to be called respectively the first, second, and third Bowen scholarships, for the promotion of the study of metallurgy, and civil, mechanical, and electrical en- gineering ; and the rest Priestley scholarships, for the promotion of the study of chemistry. The refusal of the S.P.C.K. to withdraw a book by Prof. Percy Frankland because in it experiments on living animals were approved, has led Lord Coleridge to address a letter to the secretary of the Society, in which he says : " I have learned from what seems unquestionable authority that those who ad- minister the affairs of the Society for Promoting Christian Knowledge have finally determined to range the society in the number of those favouring the practice of vivisection and advo- cating its horrors. It is my duty, as I regard it, to separate myself at once from such a body, and I have accordingly directed Messrs. Childs not to pay any further subscription to the society. As I informed you of what I should feel bound to do in the events which have happened, I shall not occasion the society any inconvenience." The following officers'of sections have been appointed for the meeting of the Australasian Association for the Advancement of Science, to be held at Brisbane this year : — Section A — Astronomy, Mathematics, and Physics : Vice-presidents, Mr. Clement Wragge and Mr. John Tebbutt ; secretary, Mr. J. P. Thomson. Section B — Chemistry : Vice-president, Mr. J. B, Henderson ; secretary, Mr. G. Watkins. Section C — Geology and Mineralogy : Vice-president, Mr. W. H. Rands ; secretary, Mr. Hargreaves. Section D — Biology : Vice-presidents, Dr. A. Dendy, Mr. F. M. Bailey, and Mr. J. J. Fletcher ; secretary, Mr. J. H. Simmonds. Section E — Geography: Vice-presi- dent, Mr. D. S. Thistlethwayte, C.E. ; secretary, Major A. J. Boyd. Section F — Ethnology and Anthropology : Vice-presi. dents. Rev. James Chalmers and Mr. F. M. Curr ; secretary, Mr. Archibald Meston. Section G — Economic Science and Agriculture : Vice-presidents, Mr. G. A. Coghlan and Mr. January 4, 1894] NATURE 229 James Tolson ; secretary, Mr. Wm. Soutter. Section J— Mental Science and Education : Vice-presidents, his Grace Archbishop Dunne, Mr. G. J. Anderson, M.A., and Mr. D. Cameron. An earthquake shock was felt in Shepton Mallet, Somerset, and neighbourhood on December 30, about 11.30 p.m., and another shortly after midnight. The direction of motion of the waves was apparently from north to south. Prof. F. J. Allen sends us the following description of what was noticed by some friends of his. " At about 11.20 p.m. a shock was felt by three persons in one house ; and about an hour later a second and more severe shock was observed by two of these persons. In another house, a quarter of a mile distant, three distinct shocks were felt by several persons. Both these houses are situated on the south side of the valley, whereas the reports published in the papers refer more particularly to movements observed on the north side. For those who are not acquainted with the district, I would mention that the strata (Carboniferous limestone, with overlying Trias, Lias, and Oolite) are very much disturbed, and present many interesting studies of horizontal as well as vertical faulting. It is just the kind of spot in which one might e.xpect to have superficial movements occurring from time to time." A LETTER fromiProf. S. J. Bailey, of the Harvard College Observatory, to the editor ol La Bolsa, published at Arequipa, Peru, gives an a'-count of the establishment of the meteorological station on the summit of the Misti, in the Peruvian Andes, at an altitude of 19,300 feet above sea level, this being at present the highest observatory in existence. The fatigues undergone by observers ascending the conical peak from Arequipa are such as to render exact observations impossible, and it was therefore found necessary to construct a nuile-path to the summit from a stone hut erected at an elevation of about 16,000 feet. This hut was erected on the north-east slope, being the most accessible side of this peak, which maintains its aspect of an isolated symmetrical cone from all points of view. On September 27 the summit was reached by Prof. Bailey, his assistant, several Indians, and two mules. The latter could hardly be made to go more than twenty paces without a rest. On October 12 the summit was revisited with two members of the Arequipa observatory, twelve Indians, and thirteen mules carrying materials for erecting two huts, and the registering meteorological instruments, comprising a barograph, a thermograph, several mercury thermometers, an hygrometer and anemometers. Each of the registering instruments works for ten days, and a member of the observatory will visit the station three times a month. A store of provisions is kept at the stone hut, and of the wooden huts at the top, one, provided with double wooden walls, is intended for the observer, the other for the instruments. With regard to meteorological work in Australia, Sir Charles Todd remarked at the last meeting of the Australasian Association for the Advancement of Science, that in New South Wales there were 175 meteorological stations and 1063 rail-, gauges; in Victoria, 31 meteorological stations and 515 rain gauges ; in South Australia, 22 meteorological stations and 370 rain gauges. In Australia there were 385 meteoro- logical stations and 2580 rain gauges. During the last four years the forecasts issued in South Australia have been justified to the extent of 73 per cent., partially justified 20 per cent., and wholly wrong 7 per cent. The radius of curvature of the cornea, together with the in- dices of refraction of the various refractive media of the eye, constitute the experimental data for determining the most im- portant points a.bout the eye. Drs. H. C. Chapman and A. P. Brubaker have measured this radius in fifty individuals by means NO. 1262, VOL. 49] of the ophthalometer (Proc. Acad. Nat. Sci., Philadelphia, 1893, p. 349), and they have found that in the average young man it amounts in the horizontal meridian to 7 '797 mm., and in the vertical meridian to 7 '552. The Director of the Central Meteorological Observatory of Mexico, Seiior M. Barcena, has published an interesting pam- phlet on the climate of the city of Mexico, based on the hourly observations of sixteen years 1877-92. Mexico, from its position of 7431 feet above the sea, and latitude 19°, might be supposed to be subject to great extremes of temperature, but as one geographical element neutralises the other, the result is a temperate and agreeable climate. The mean annual temperature is 59'7) and the monthly means vary from 53°'6 in December to 64°"6in May. The absolute maxima in the shade vary from 73°'4 in December to88°"9 in April, while the absolute minima vary from 28° '9 in December to 46° "8 in August and September. The greatest daily range amounted to 41^ in the month of March. The mean annual rainfall amounted to 23 '8 inches, the wettest months being June to September ; the greatest fall in one day was 2'5 inches in August 1888. The prevalent wind is north-west, which blows during most part of the year, and is the coldest and wettest quarter. The strongest wind blows from the north east ; the greatest hourly velocity observed during the sixteen years was about 56 miles per hour. A DETAILED investigation of the properties of mirror silver chemically precipitated on glass is published by Herr H. Llidtke in Jl'iedemann's Annalen. The three modifications of silver obtained in the wet way, termed by H. Vogel the arbor- escent, the powdery, and the niirror variety respectively, have been recently enriched by Mr. Carey Lea through his discovery of colloid silve . Herr Llidtke thinks that this last variety and mirror silver are closely allied ; that the latter, when newly formed, is indeed identical with the former. The electrical resistance of several varieties of mirror silver decreases con- siderably with their age. No such decrease was, however, ob- served in the case of mirrors produced by Martin's process or by that of Liebig, i.e. reduction by means of milk-sugar. On in- troducing a pole of ordinary silver and one of allotropic miiror silver into a weak acid or salt solution, and closing the circuit, a current was obtained indicating a difference of potential of about O'l volt between the two varieties, the allotropic variety being the positive pole. These conditions were reversed if the solution was one of silver nitrate, but the difference of poten. tial was less. Lehmann's surmise that the precipitation of the mirror on the glass is due to a thin layer of sodium silicate, was invalidated by precipitating it on mica, porcelain, quartz, and platinum by the same methods. The Philosophical Magazine for the present month contains a paper, by H. Nagaoka, on the hysteresis attending the change in length produced by magnetisation in nickel and iron. The author at first used the interference fringes produced between a plano-convex lens and a plate of plane glass attached to the end of the rod under examination to measure change in length. He found, however, that it was impossible to keep the temperature of the apparatus constant during the time necessary to make an observation, and also that there was considerable difficulty in counting the number of fringes displaced. To overcome the lemperature difficulty the author has made use of the principle of the gridiron-pendulum, and has by this means succeeded in almost entirely overcoming this difficulty. In place of the interference bands he uses an optical lever, that is, a mirror fixed to a small base, to which are attached three needle points, two of these rest in a grove on the base-plate of the in- strument, while the third rests on a small glass plate fixed to the end of the iron or nickel rod. The rod was placed along the axis of a solenoid which lay in a horizontal position pointing 2XO NATURE [January 4, 1894 magnetic east and west. The deflection of the mirror was measured by means of a microscope with a micrometer eyepiece, such that one division of the scale corresponded to a deflection of the mirror of o"'295 of arc, or to an elongation of 0805 ;< 10" cm. Experiments were made on wires of iron and nickel of different lengths, and he finds in every case that the elongation in iron and the contraction in nickel by magnetisation is accom- panied by marked hysteresis. The curve of hysteresis is syir-metrical with respect to the line of zero magnetising force, so that the elongation or contraction during cyclic changes is an even function of the magnetising force. When a wire has been magnetised it cannot be brought to its original length by simply reversing the magnetic field. In a note communicated to the same number of the Philo- sophical Magazine, Prof. Knott calls attention to the similarity between the effects observed by Mr. Nagaoka, and those which he has himself observed in the case of magnetic-twist cycles for iron and nickel. A steady current was passed along the wire under observation, and the longitudinal field acting on the wire was gradually altered between the limits itl, and at suitable intervals observations of the twist made. It was found that with a small range of field the hysteresis curve obtained by plot- ting twist against field was very similar to the 1 well-known hysteresis curve of magnetisation. With limiting fields, how- ever, stronger than the field which produces the maximum twist, the hysteresis curve crossed itself twice and formed three loops. In the magneto-elongation cycle the change of sign of the magnetising force does not produce a change of sign in the elongation. On the other hand, in the magnetic-twist cycle, as the magnetic force passes through zero from positive to nega- tive, the twist tends to do the same, though with a lag. The author considers that the twist, under a given combination of circular and longitudinal magnetising forces, depends not only upon the elongations but also upon some function of these forces which changes sign wuh each, and to which the existence of the maximum twist is largely if not entirely due. An entertaining chapter on minerals, and the popular super- stitions connected with them in Germany, is contributed to Die I^atur by Friedrich Klinkhardt. The fact that variety among minerals is less easily perceived than that among plants and animals, is emphasised by the great influence that "a stone" pure and simple, without further specification, is capable of exerting in the popular estimation. Children un Jer the age of one may not play with stones, otherwise bread will be scarce. An ill omen may be made innocuous by throwing a stone into the road before taking the next breath. Chalk is credited with many virtues, and is used both for its own efficacy and for making signs with. Cows marked all down the spine with chalk consecrated at Epiphany, remain healthy, and always find their way home. Alabaster in water is used for curing sick children in Bohemia. A flmt pebble from the brook, if thrown over the roof into the poultry yard, encourages the hens to lay eggs. The beliefs connected with " thunderbolts," which are sometimes flint instruments, or quartz crystals, or lightning tubes, are exceedingly numerous. In the Palatinate it is believed that thunderbolts, after penetrating seven yards into the ground, rise a yard every year ; this reminds one of Miolnir, Thor's hammer, which returned to his hand. We read an interesting paper "On the Kulm District of Lenzkirch in the Black Forest," by Dr. Rafael Herimann. A geological map of the district is given, scale i : 5o>oo3 {Berichte der Naturforschenden Gesellschajl zii Freiburg i. B., June, 1893). In the Black Forest, just as in the Hartz and in Thiiringia, two main series of carboniferous rocks are recognisable, an older group of dark shales, and a younger formation of conglomeratic rock. During the intermediate epoch, the upraising and folding NO. 1262, VOL. 49] of the rocks took place, associated with intrusions of crystalline rock. The eruptive rocks of the district are granite, coarse and fine grained, granitite, granitic dykes, quartz porpyhry, porphy- ritic dykes, and porphyritic breccias. Herrmann does not agree witk Vogelgesang that the granite and granitite are petrogra- phical varieties of one and the same rock united by a complete transitional series, but regards them as two independent masses of rock, differing in composition and structure. All the granitic rocks have been intensely affected by pressure, whereas the younger porphyry shows no appearance of it. Herrmann de- duces, therefore, that the intrusion of porphyry marks what was probably the last phase of folding and overthrusting of rocks Id the Black Forest during the Carboniferous period. The region watered by the upper part of the Yenisei (which is known to the Mongols under the name of Ulu-Khem, and is made up by the confluence of the Bei-khem and the Kha-khem) belonged until lately to the least known parts of north-west Mongolia. The opinion expressed in the " General Sketch of the Orography ot East Siberia " {Zapiski of the Russian Geographical Society, vol. v. 1874), to the effect that it must be a high plateau, and that the so-called circular chain Erghik-targak-taiga is ^nothing but a border ridge, or often but the steep slope of the ph-xteau, had been contested. Now it finds its full confirmation in the recent exploration of the region by Mr. Kryloff, published, with a map, in the Izveslia of the Russian Geographical Society (vol. xxix. 4, 1893). The whole region really has the above-menioned character. After having left the valley of the main river, which has, even at the junction of the two Khems, an altitude of 1873 feet, Mr. Kryloff had to travel all the time on the level of the high plateau, never finding altitudes less than 3000 feet, till he returned to the Russian dominions in the basin of the Tuba. Mr. Kryloff's journey having been performed for the St. Petersburg Botanical Garden, special attention has been paid by the explorer to the flora of the region; and he found that the vegetation on the plateau assumes in many places the character of a Steppe vegetation, namely, in the flat but high valleys of the rivers, which are dotted by numerous small lakes. At the sources of the Bei-khem, the flat surface of the water parting, as well as large portions of the plateau itself, raise above the level of the tree-vegetation, usually marked by the cedar, and are covered with Alpine meadows. As to the ridges which rise above the surface of the plateau, they attain heights of over 7000 feet, and over 8000 feet in the Tannu-ola ridge in the north of Lake Ubsa-nor. The same number of the Izvestia contains a paper by M. M. Pomortseff, on hisextremely valuable observations on the direc- j tions and angular speed of motion of clouds. The method I resorted to for these observations is described at length, and the instrument which was used for this purpose is figured on a plate. The chief results are given on 94 separate small maps. The author himself sums up his results as follows : — (i) The middle of the cumulus clouds moves almost in the direction of the isobar which passes through the place of the observer. (2) The cirrus, cirro-cumulus, and cirro-stratus clouds move on a pretty long distance as a broad and nearly straight-line current — the direction of the stream being almost parallel to the part of the 760 mm. isobar which stands on the line con- nectingtogetherthe centres of two nearestand contiguous regions of high and low pressure. (3) There is doubtless a connection between the distribution of atmospheric pressure and the march of the barometer on the earth, and the vertical circulation of the atmosphere ; but this connection does not extend farther than the height of the upper, i.e. cirrus clouds. In a letter addressed to the Russian Geographical Society from Lan-chou, in March last {Izvestia, vol. xxix. 4), Mr. January 4, 1894] NA TURE 231 Obrucheflf wrote that while crossing the plateau of Shan-si, he was enabled to supplement to some extent the observations of Richthofen ; namely, he has discovered some fossil plants in the middle parts of the series of deposits which cover in China the carboniferous formation, and which Richthofen had de- scribed under the names of Ueberkohlen-sandsteine or Plateau- sandsteine. The plants unearthed by Mr. Obrucheff would indicate that the middle portions of this formation belong to the Mesozoic age, and are Tiiassic or Liassic. This formation spreads from Shan-si into the Shensi, the Alashan, andGan-su, without losing in thickness, and probably represents an unin- terrupted series of deposits from both the Mesozoic and the first half of the Cainozoic times. We notice in the Memoirs ( Trudy) of the Kazan Society of Naturalists (vol. xxvi. No. 2) a very interesting work by N. Wnukow, on the bacilli of leprosy. In addition to his own experimental researches, the author has carefully studied the West European and Russian literature of the subject, and has •divided his memoir into three parts : the localisation of leprosy bacilli in the tissues of the human body ; the inoculation of the bacilli to animals ; and the artificial culture of the bacilli. The paper is accompanied by a coloured plate. The author's conclusions are : — The Bacillus leprce is motile, and is found both within and outside the cells ; but it has never been dis •covered in the cells of the epithelial layers of the skin or the mucous mem.hranes. In the wounds the bacilli are brought to the surface, and undoubtedly may be transported on the skin of other individuals, thus becoming a cause of infection. Neither the injection of the pu5 containing leprosy bacilli, nor the graft- ing of pieces of skin taken from leprous patients to rabbits, could provoke leprosy in these animals. The bacilli intro- duced from man into rabbits and fishes, diminish in numbers after a time, and ultimately disappear. Most inoculated rabbits contract tuberculosis, but the illness must be ascribed in such cases to other causes than infection proper. As to the arti- ficial culture of the Bacillus lepra, it has failed with all culture media experimented upon by the author ; the culture of B. Uffreduzzi, described by Eisenberg as leprosic, cannot be re- cognised as such. An elaborate paper, entitled " Les Vibrions des Eaux et I'Etiologie du Cholera," by Dr. Sanarelli, has recently appeared in the Annates de V Instilut Pasteur, vol. vii. Numerous bacteriological examinations were made of the river Seine water above and below Paris, as well as of drain water, and the effluent of sewage after irrigation. In all no less than thirty- two vibrios were isolated, morphologically distinct, four of which gave the indol reaction, and in their pathogenic action on guinea-pigs could not be distinguished from the cholera-bacillus. Dr. Sanarelli is of opinion that there exist many varieties of vibrios, morphologically distinguishable, but capable of exciting in man and animils a disease in its morbid and clinical aspects identical with those regarded as typical of cholera, and that the conception of a restricted monomorphism is no longer tenable in the diagnosis of the cholera-vibrio. In all the more or less contaminated waters which were examined vibrios were present, finding in these surroundings conditions highly favour- able to their existence and multiplication. It is possible that although the larger number of such vibrios may exist in the saprophytic or harmless state, yet probably pathogenic vibrios are more frequently present in such waters than has hitherto been suspected. Dr. Sanarelli points out that the saprophytic condition of some at least of these vibrios is, in all probability, due to the modification in and attenuation of their biological i functions which residence in such media has produced. Thus I an extremely virulent vibrio was reduced to a harmless sapro- phyte deprived of its pathogenic properties and power of NO. 1262, VOL. 49] producing the indol reaction, by being kept in boiled Seine water for a month, whilst even after three months it had under- gone no change in its morphological condition. In the same manner that pathogenic organisms may be deprived of their virulence, it is conceivable that circumstances may ari^e under which they may recover their toxic character ; so far, however, bacteriology has been unable to establish the correctness of this hypothesis, either in the laboratory or in actual experience. For several years the State of Massachusetts has been attempting to exterminate the Gipsy Moth, and a Bill has recently been introduced into the House of Representatives to appropriate 100,000 dollars to rid the State of that troublesome insect. The American Naturalist points out, however, that the desired end can never be attained by merely hunting the moths in trees, hedgerows, and garden patches. In its future work, the Gipsy Moth Commission of Massachusetts should employ at its head a trained entomologist who should devote his time to finding and introducing some natural enemy to the pest. Moths, eggs, larvae, and cocoons will escape the most careful of field agents, whereas insect parasites will keep the pest in con- tinual check. Messrs. T. D. A. Cockerell and Walter E. Collinge have published " A Check-list of the Slugs." It is a reprint from the Conchologlst, vol. ii., 1893. The authority for the list is the first-named author ; Mr. Collinge adds an appendix and notes ; 628 species are recorded with very numerous varieties. There would appear to be a very'^ardent discussion as to the respective value of morphological and anatomical characters for the due determination of the species and varieties among these molluscs; but surely here, as elsewhere, the rational method would be to employ all such points of difference, whether ex- ternal or internal, as may be found constant. The Association for the Promotion of Home and Foreign Travel has issued a programme of tours arranged for this winter. The December number o^ Insect Life is almost entirely taken up with the proceedings of the meeting of the Association of Economic Entomologists, held at Madison in August last. Mr. C. Meldrum, the Director of the Royal Alfred Obser- vatory, Mauritius, has issued his report for the year iSgr. and also the results ot meteorological observations made at the Observatory during 1892. A paper on " Technical Education in Glasgow and the West of Scotland : a Retrospect and a Prospect " read before the Philosophical Society of Glasgow in November last, by Dr. Henry Dyer, has been issued in pamphlet form. It is of interest to all concerned with matters of technical instruction. Mr. W. Warde Fowler, a disciple of Gilbert White, has put on record his observations of the Marsh Warbler {Aero- cephalus palustris) in Oxfordshire and Switzerland, and the differences between it and the Reed Warbler. His paper (issued by Simpkin, Marshall, & Co.) will be read with pleasure by all lovers of nature. The number just issued of the Journal of the Royal Agri- cultural Society (vol. iv. part 4) contains several important articles. Mr. Carruthers describes the ''Cross-fertilisation of Cereals," and his paper is given additional interest by means of seven good illustrations. " Water in Relation to Health and Disease " is treated by Prof. J. Wortley Axe, and under the title " Peat and its Products," Dr. Fream gives an account of the occurrence and utilisation of peat in various peat-producing countries of Europe. Messrs. BailliI-'RE and Son have recently added to their series of works on chemical industries a volume entitled " Le 232 NATURE [January 4, 1894 Cuivre," by M. Paul Weiss, in which the origin, mode of occurrence, properties, metallurgy, applications, and alloys of copper are fully treated. The author has visited the chief copper mines and works in Europe, and his book is a very use- ful resume o{ \.\\Q. fundamental principles of the copper industry. The ninety-six figures inserted in the text include twelve excel- lent sections illustrating the molecular structure of various metals and alloys. The structure of snow-cryslals photographed by G. Norden- skiold formed the subject of an article in our last volume. Another important contribution to the subject has recently been published, namely. Prof. G. Helimann's " Schneekrystalle " (Rudolf Miickenberger, Berlin). The work begins with a brief history of the study of snow-crystals, illustrated by reproduc- tions of the various forms observed and drawn by different observers, from the spikes, crescents, and daggers of Magnus in the sixteenth century, to the elaborate and perfectly symmetrical stars designed by Glaisher. But in meteorology as in astronomy, photography is rapidly taking the place of the observer ; so much, indeed, is this the case that the modern meteorologist and physical astronomer views visual observations with more or less sus- picion. At any rate, the remarkably fine series of micro- photographs of snow-crystals obtained by Dr. Neuhauss during the winter 1892-3, and reproduced in Prof. Helimann's work, indicates that eye-observations of their forms are no longer necessary. After discussing the structure of snow-crystals. Prof. Hellmann proposes a classification into tabular and columnar crystals, the former class being subdivided into radiating stars, plates, and a combination of the two, and the latter into prisms and pyramids. A descriptive bibliography is given, thus increasing the value of a work upon a subject of which much more can yet be said. The cause of the violent explosion which usually occurs when any considerable quantity of metallic sodium is brought in contact with water in a more or less confined space, forms the subject of a communication to the journal filr praktisclie CJiemie, by Prof. Rosenfeld. It has been hitherto supposed to be due to the formation of a quantity of sodium peroxide, by the decomposition of which oxygen is liberated, which mixes with the hydrogen produced in the main reaction, thus forming an explosive mixture. Prof. Rosenfeld has fully investigated the question experimentally. It was first established that steam may with impuoity be passed over sodium contained in a slightly bent iron tube, no explosion ever occurring under these con- ditions. This would be quite compatible with the above explanation of the cause of the explosions, for any explosive mixture would be rapidly carried from the seat of the reaction by the escaping hydrogen or the excess of water vapour. No oxygen, however, was ever detected in the gas thus liberated. In all the experiments in which explosion was brought about by the action of water, whether in open vessels or in vessels closed by a water column, it was invariably observed that the sodium was blown to powder from the centre outwards — that is to say, the seat of the explosion was the interior of the piece of metal experimented with. Prof. Rosenfeld comes to the conclusion, from the whole of the phenomena observed, that the explosion is brought about by the sudden dissociation of a hydride of sodium which is formed in the first stage of the reaction. As such a compound can only be produced in an atmosphere of hydrogen, the only safe mode of decomposing water by metallic sodium is considered to be that previously mentioned, of passing a rapid current of steam over the metal ; for the hydrogen is then removed from the sodium as quickly as it is produced, and the formation of hydride, and therefore all risk of explosion, is NO. 1262, VOL. 49] consequently avoided. In order 'to carry out this reaction an iron crucible is best employed which is capable of being closed in a gas-tight manner by means of an iron plate, which can be pressed firmly down against a flange on the edge of the crucible by means of a screw threading through a suitably sup- ported nut. Steam is blown into the body of the crucible con- taining the sodium by means of a side tube, and the escaping hydrogen is led away by a similar tubulus upon the other side. , If the supply of steam is arrested the moment hydrogen ceases to escape, solid caustic soda is obtained, mixed in a curious manner with more or less finely divided iron, probably owing to the formation of a quantity of an alloy of iron and sodium, which is subsequently decomposed with liberation of iron. Silver is likewise attacked in a similar manner. The method may also be employed to prepare solutions of soda of known strength. Thus, if twenty-three grams of sodium are employed, and the escaping hydrogen is washed through a little water, an exactly normal solution of soda can at once be obtained by dis- solving the product in water, adding the wash water, and making up to a litre. An interesting investigation of the amount and nature of the gases occluded in the coal derived from several collieries in the Durham coal field has been carried out by Mr. W. McConnell, of the Durham College of Science. The collieries from which samples were taken are situate at different points along the same seam, known in Durham as the Hutton seam. It is bituminous coal used as gas-coal and as steam-coal. The coal or coal-dust was placed in an apparatus constructed entirely of glass, and which was capable of continuous exhaustion while heated in baths to known temperatures varying from 100' to 180° ; the gas previously occluded by the coal was delivered by the pump into a receiving gas-holder, and subsequently measured and analysed. The coals from the Ryhope colliery were found to contain as combustible gases considerable quantities of occluded free hydrogen, marsh gas, ethane, and other members of the paraffin series of hydrocarbons as far as pentane. More- over, a portion of the gas, consisting chiefly of the higher members of the paraffins and smaller quantities of olefines, is so firmly retained that crushing to fine powder and heating to 180° under reduced pressure is insufficient to remove it. It is also singular that the coal retains a remarkably high proportion of free oxygen in the occluded form, even after heating to 180°. In the case of the Hebburn colliery, a notably " gassy " mine, in which frequent "blowers" are met with, the results are especially interesting. The "blowers" deliver such large quantities of gas that some of it is actually " piped " up to the bank and burnt under the boilers. The combustible constituent of the gas thus utilised is found to be entirely marsh gas. The coal itself is found to contain a relatively very large volume of occluded gas, the combustible constituents being mainly marsh gas and ethane ; and the ground coal and coal-dust yield in addition considerable quantities of higher members of the paraffin series. From the whole of the results derived from the various collieries, there can be no doubt that the coal-dust largely owes its sensitiveness to ignition to the denser occluded gaseous hydrocarbons which it retains so tenaciously. The additions to the Zoological Society's Gardens during the past week include a Leopard [Felts pardus, 6 , black variety), from India, pre.'iented by the Duke of Newcastle ; a Her- ring Gull {Lams argentatus) from Jersey, presented by Mr. John Stanton ; an Alligator {Alligator mississippiaisis) from the Mississippi, presented by Mr. C. Knox Shaw ; a Diamond Snake {Morelia spilotes) from Australia, presented by Com- mander A. Burgess, R.N.R. ; a Diamond Snake {Morelia spilotes) from Australia, purchased. January 4, 1894] NATURE 23: OUR ASTRONOMICAL COLUMN. Prizes at the Paris Academy. — Among the numerous prizes presented by the Paris Academy {Coniptes Roichis, No. 25, Dec. iS), those devoted to the science of astronomy were as follows : — M. Schulhof, the Lalande Prize, for his magni- ficent researches on comets ; Dr. Berberich, the Valz Prize, for his well-known connection with the calculations of cometary and ^minor) planetary orbits ; and Prof. Langley, the Janssen Prize, for the work he has done relating to the distribution of the heat in the normal solar spectrum, and to the influence exerted on this distribution by both the solar and terrestrial atmospheres. Among the general prizes we notice that the Arago medal has been awarded to two American astronomers, Profs. Asaph Hall and Barnard. The former receives this medal as he was the discoverer of the two satellites of Mars, although on a former occasion he was the recipient of the Lalande prize for the same reason. The latter, it is needless to say, owes this honour to the fine use he made of the great 36-inch telescope of the Lick Observatory, in searching out the fifth, or, as it should be named, the first satellite of Jupiter. The Tail of Comet Brooks (<: 1S93). — Last week, under this heading, we referred to Prof Barnard's remark that the fall of this comet had encountered some outside or obstructive medium. It is interesting, in the face of this, to look at the drawmgs of the great comet of 18S2, and to notice the frag- ments and their relative positions and forms. With the draw- ing before us (Young's " Astronomy," 1888, p. 427) the follow- ing description is given : — " Besides this " (referring to that curious phenomenon called the sheath) "at different times, three or four irregularshreds of cometary matter were detected by Schmidt, of Athens, and other observers, accompanying the comet at a distance of three or four degrees when first seen, but gradually receding from it, and at the same time growing fainter. Possibly they may have been fragments of the tail which belonged to the comet before passing perihelion, or of the matter repelled from the comet when near perihelion. Since the comet, in passing the perihelion, changed the direction of its motion by nearly 180° in less than three hours, it was, of course, physically im- possible that the tail it had before the perihelion passage could have made the circuit of the sun in that time. . . . Visible or invisible, the particles of the old train must have kept on their way under the combined action of the sun's gravitation and repulsion. ..." Would not a more simple explanation in this case be that these fragments were the result of collisions near perihelion passage, for here most certainly we should ex- pect to be in the presence of meteoritic matter in abundance, and these travelling at high speed ? The Planet Venus. — This planet, which forms such a bril- liant object in the evening sky, will during this month become brighter, reaching its maximum brilliancy on the loth of January. For observers in northern latitudes its position is becoming more favourable for observation, owing to its move- ment northward in declination. A conjunction with the moon takes place on the loth of January, so that about the day before and after that date these two bodies will form a striking pair. GEOGRAPHICAL NOTES. With the first of January the weekly South German geographical paper, Das Aiislaiul, edited by Dr. Sigimund Giinther, of Munich, and established as long ago as 1827, comes to an end, having sunk its identity by amalgamating with Globus, which for thirty-two years has been its North German contemporary and rival. Globus will continue to be published, with numerous illustrations, as heretofore, and with the additional attraction of Roman type being substituted for the old German character. It is somewhat remarkable that weekly papers of this kind, entirely devoted to geography and travel, with no political purpose, should be so thoroughly established in Germany and France, while no successful attempt has ever been made in an English-speaking country to start a similar publication. The Russian geologist, W. A. Obrucheff, who started in the early part of 1893 for a journey into the little known region of Ordos, lying in the great bend of the Hoang-ho, has (says Globus) been able to make many new observations. Leaving Tai-Yuen-fu, the farthest point reached by Richthofen in this NO. T262, VOL. 49] direction, on January 18, and crossing the Hoang-ho on the ice on the 28th, he selected the route to Ning-hsia, across the south-western edge of Ordos, as the least known, with the in- tention of proceeding to study the mountains of Alashan and the left bank of the Hoang-ho, up to the Nan-shan range. On his way Obrucheff was able to throw some light on the hills between the plateau of Shan-si and Kansu, and the plain of Ordos, which he found to be only the denuded edge of the plateau, and in no sense a range. The portion of Ordos which he intended to cross is a blank on all maps, and the whole dis- trict in the great bend of the Hoang-ho north of the Great Wall is practically unknown territory. The last number of the VerluDidlungen of the Berlin Geographical Society contains a short note on a journey to Hadramaut undertaken last year by a German explorer named Hirsch, whose experience gives some clue to the difficulties now being encountered by Mr. and Mrs. Bent. At the outset Herr Hirsch met with opposition from the British Resident at Aden, but overcoming this he reached Makalla and started for the interior, with two camels and a small party, on July I. He ascended the Wadi Howere to the great plateau, and crossed the watershed at an elevation exceedmg 6,000 feet. From the barren plateau Hirsch descended to the fruitful and populous Hadramaut valley, several of the towns of which were visited. At Terim he was very badly received, subjected to insults, and compelled to leave at very short notice, returning to Makalla through the scarcely known Wadis Bin Ali and Odym. Alto- gether the journey in the interior only lasted forty days, but observations of considerable value were made, which are now being prepared for publication. A remarkakle discovery has been announced by the Austrian Institute for Historical Research, in the formof acopy of a map by Columbus, drawn on a letter written from Jamaica in July, 1503. This, although only a rough pen-and-ink sketch, shows exactly the opinion of Columbus himself as to the part of the world he had reached, which he believed to be the east coast of Asia. The original map, drawn by Columbus and his brother Bartholomew, was presented to Frate Hieronymo, who gave the map and a description to Alexander Strozzi, a noted collector of early voyages. He is supposed to have copied the original map on the margin of the letter of Columbus, which he had bound in a volume with other documents, and this volume is now in the National Library at Florence, where the existence of the map was discovered by Dr. R. v. Wieser, the Professor of Geography at Innsbruck.; NE W FRENCH LA W FOR THE PRE VENTION OF FOREST FIRES} 'T'HE wooded tract of country comprising the hill ranges of Les Maures and I'Esterel in the departments of Le Var and Les Alpesmaritimes, in the south-east of France, has been annually ravaged by forest fires from time immemorial. It is stocked with conifers, Pinus Halepeusis, and P. Pinaster ; the cork oak, and the pubescent variety of Qucrcus sessiliflora, and there is a dense undergrowth of Erica arborea, the roots of which are used for briar {brtiycre) pipes, also of Erica scoparia, lavender, juniper, broom, dwarf palms, wild olive, and Arbutus, &c. During the months of June, July, August, and September, the drought, high temperature, and the violent mistral wind which prevail, increase the danger from forest fires and their severity. Owing to the great destruction of property which these fires cause, a law was enacted in 1870, to be in force for twenty years, and has given excellent results, the frequency and extent of forest fires in the region having diminished by half during the period 1S70-90. This law was renewed up to the present time, in order to allow Government to draw up a permanent law on the subject. The Minister of Agriculture accordingly drafted a bill, which, after consideration by a Committee of the Chamber of Deputies, and some unimportant amendments, was passed by the legislature, and received the consent of the President of the Republic, as a law, on August 19, 1893. The principal clauses of the Act deal with methods of preven- tion and extinction of fires : thus the first clause prohibits, during the dangerous season above mentioned, all fires in forests J The text of this Law is given in the Revue dcs Eatt.x et FcrCts, vo .\ix. part 18, for September 25, 1893. 234 NATURE [January 4, 1894 or shrubby waste lands, or within a distance of 200 metres from their boundaries. The period during which these fires were declared illegal by the former Act of 1870, was fixed annually by the prefects, but experience has shown that it can now be fixed once for all by the law. As exceptions to this law, Clause 2 also authorises the prefects to allow charcoal-makers and other woodmen to liiiht fires at their own risk, in case of damage arising, and subject to certain rules made by the prefects. Among the fires prohibited during the close season is the so- oalled petit feu,^ by which strips of undergrowth were care- fully burned every six or seven years in the cork forests, to save the valuable cork oak trees from more dangerous uncontrolled fires. This system costs only 3.?. dd. an acre, as compared with £df an acre for uprooting the dangerous undergrowth. It is evidently more hariful to the forest than the other method, as the fire occasionally gets out of control, and, in any case, the burning diminishes the fertility of the soil. The ninth clause directs that all landed proprietors, whose land has not been entirely cleared of all woody growth, may be compelled by an adjoining proprietor to keep a strip of land between the two estates entirely free from shrubs or conifers. The breadth of this strip will vary, according to circumstances, between 20 and 50 metres. It is further enacted in Clause il that similar bare strips 20 metres broad shall be kept up along all lines of railway through a wooded area, and that these strips in adj .ining property shall be kept clear at the expense of the railway companies. As it may not always be necessary to keep up these fire lines along the railways, a committee, consisting of a departmental councillor {comeiller ghierat), a forest officer, and a railway engineer, shall decide when they may be omitted. All pro- prietors, whose woods are cut down in clearing these strips, are to obtain indemnities. This is a new provision, and called for owing to the extension of railways. The Act looks to the future in a clause exempting railway companies from this liability if they should use electric motors, or other inventions which cannot cause a forest fire. In case any fire should break out, and it may appear advis- able to light a counter fire, the two fires meeting and extinguish- ing one another for want of inflammable material, the local mayor, or his deputy, or failing these the most senior forest officer present, is to take charge of all measures to extinguish the fire, and no indemnity arises for woods burned under such circumstances. As in India, it is found in the south-east of France that fire is frequently caused by sportsmen, or poachers during the dry season, and the prefect is therefore authorised to delay the commencement of the shooting season until the commencement of the rains, which generally happens before the end of September. As it is found that the construction of a network of roads greatly facilitates fire protection, by giving more value to forest produce, and rendering it possible to transport the material cleared from fire lines, and as roads serve as lines from which counter fires may be started, the State offers a subvention of 3000 francs per kilometre {;^200 per mile) for roads constructed in the district, up to a total outlay of 600,000 francs (;i^24,coo). It appears that since 1870, 479,000 francs (^19,160) have been spent by the State on new roads in the State forests of the Esterel. The penalties attached to the breach of the first clause of this law are one to five days' imprisonment, or fine of 20 to 500 francs, and both fine and imprisonment can be inflicted, so that magistrates can make the penalty proportional to the gravity of the offence, and all police, forest guards, whether belonging to the State or to private properties, are directed to carry out the law by reporting offences, their written statements being received as evidence in cases which may arise. If the railway companies do not clear the fire lines along the railways, these lines will be cleared at their expense by the French Forest Department. Although much land which might otherwise be planted is wasted in England owing to heather fires, and not only is a large area of pine forest destroyed annually by fire, but also the increase of destructive pine beetles is thus greatly favoured, there is little hope of our Legislature interfering ; but the matttris more serious in North America, and along the Northern Pacific Railway about 1000 miles of treeless country exists, where the forests have been destroyed by fires, whilst the immensely valu- "^ Vide "A Forest Tour in Provence and the Cevennes," by Colonel Bailey, R.E., in Transactions of the Botanical Society of Edinburgh, vol. xvi. part 3, 18S6. able pitch-pine forests of the Southern States are rapidly dis- appearing from the same cause. Matters have been dealt with in British India much more prudently, and regulations against forest fires have been enacted for the last twenty years at least in all the provinces under our control, and also to a certain extent within the native States. As a result of these regulations, and the careful management of the Indian Forest Department, 23,144 square miles of State forest in India were protected from fire in 1891 at a cost of Q rupees per square mile, and this in addition to large areas of evergreen forest where no danger from forest fires exists. W. R. Fisher. PRIZE SUBJECTS OF THE PARIS ACADEMY OF SCIENCES. "T^HE following are the subjects for which prizes will be awarded by the Paris Academy in the years 1894, 1895, 1896, and 1898 : — 1894. Grand Friz for Mathematical Sciences — The develop- men, of an imiiortant point in connection with the deformation of surfaces. Friz Bordin — The study of problems in analytical mechanics admitting of algebraic integrals with regard to velo- c ties, and especially quadratic integrals. Friz Francoeur — Discoveries or useful works on the progress of pure and applied mathematical sciences. Friz Foncelet — To the author of the most useful work on the progress of pure and applied mathe- matical sciences, Extraorainary Prize of six thousand francs — For any work tending to increase the efficacy of French naval forces. Friz Montyon — Mechanics. Friz Pinmey — To the author of an improvement of steam engines or any other invention which promotes the advance of steam navigation. Friz Dalmont — To the engineer of bridges and highways who presents the best work to the Academy. Fi-iz Lalande — Astronomy. Friz Danioiseaii — Improvement of the method of calculating the perturbations of minor planets so as to give their positions within a few minutes of arc for an interval ol fifty years ; also the construction of tables which allow the principal parts of the perturbations to be rapidly determined. Friz Valz — Astronomy. Ptiz jfanssen — Astronomical physics. Friz Mo'ityon — Statistics. Priz Jecker^Oizz.r\\c:. chemistry. Friz Vaillant — Study of the physical and chemical causes de- terminmg the existence of rotatory power in transparent bodies, especially from the experimental point of view. Friz Desma- zieres — -To the author of the most u'^eful work on all or part of the cryptogams. Priz Montagne — To the authors of important works having for their subject the anatomy, physiology, develop- ment, or description of the lower cryptogams. Priz Thore — Awarded alternately to works on the cellular cryptogams of Europe, and to researches on the habits or anatomy of a species of European insect. Friz Savigtiy — To young zoological explorers. Priz da Gama Machado — On the coloured parts of the integumentary system of animals, and on the fertilising matter of living things. Friz Mtintyoji — Medicine and surgery. Priz Brcant — For a means of ciiring Asiatic cholera. Friz Godard — The anatomy, physiology, and pathology of genito-urinary organs. Priz Parkin — Researches on the curative effects of carbon in its various forms, and more especially in the gaseous form of carbon dioxide, in cholera, different kinds of fever, and other ailments. Priz Earlier — For a useful discovery in surgery, medicine, pharmacy, or botany in connection with the art of healing. Friz Lallemand — For the recompensation or encourage ment of works relating to the nervous system, accei'ting the widest meaning of these words. Priz Beliion — To the writers of works or discoverers of facts of special importance to the health of human beings or the improvement of mankind. Priz Mlge — For the completion of Dr. Mege's essay on the causes that have retarded or favoured the progress of medicine. Priz Montyon — Experimental physiology. Pi'iz Potiiat — On the influence exercised by the pancreas and suprarenal capsules on the nervous system, and reciprocally, on the influence that the nervous system exercises on these glands, studied especially from a physiological point of view. Frt~ Gay — The study of subterranean waters ; their origin, diiection, the strata they traverse, their composition, and the animal and vegetable life that live in them. Priz Montyon — Unhealthy occupations. Priz Cuvier — For the most remarkable work on the animal kingdom, or on NO. 1262, VOL. 49] January 4, 1894] NA rURE 235 geology. Priz Tremont — To the savant, artist, or mechanic requiring assistance to attain an object of use or benefit to France. Priz Gegncr — For the assistance of the savant dis- tinguished for his contributions to the positive sciences. Priz Delalande-Gturineau—To the young French explorer, or the man of science, who shall have rendered the greatest service to France or science. Priz Jerome Ponti — To the author of scientific work of which the continuation or development is important to science. Priz Tchihatchen — To the naturalist of any nationality who shall have pursued explorations in the .\siatic continent or neighbouring islands, having for their object the advancement of any branch of natural, physical, or mathemaiical science. Priz HouUevigue — Awarded in rotation by the Academy of Sciences, and by the Academy of Fine Arts. Priz Cahoiirs — For the encouragement of young workers known for their interesting re-earches, and more especially for researches in chemistry. Priz Alberto-Levy — For a means of preventing or curing diphtheria. Priz Laplace — To the head student of the Ecole Polytechnique. 1895. For the improvement of the theory of the relation between the flywheel and the regulator. JViz Gay — For a study of the regime of rain and snow over the whole surface of the earth. Priz L. La Gaze — To the authors of the be-t work on physics, cheiiiistry, and physiology. Priz Deles^e — To the author of a work dealing with geology or mineralogy. Priz Bordin — For the memoir that adds most to the knowledge of natural history (zoology, botany, or geology) of Tonkin or one of the French possessions in Central Africa. Grand Priz des Sciences Physiques — For the work that contributes most to the advancement ol French paleontology by dealing in a thorough manner with the vertebrata of the coal measures, and those of the secondary epoch, and comparing them with existing types. Priz Chuussii'r — For important works in legal or in practical medicine. Priz Petit d'Ort>ioy — Pure and applied mathematics or natural science. Priz Leconle — To be awarded (i) to the authors of new and important discoveries in mathematics, physics, chemistry, natural history, or medical sciences ; (2) to the authors of new applications in these sciences. Priz Gaston Piantd — To the French author of a discovery, invention, or important work in the domain of electricity. 1896. Priz yanssen — Astronomical physics. Priz Sevres — On general embryology, apulied as far as possible to physiology and medicine. Priz Jean Pcnaud— For the best work published during the preceding five years, 1898. Priz Damoiseau -For a development of the theory of the pertur'aiions of Hyperion, the satellite of Saturn dis- covered simultaneously by I3ond and Lassell in 1848, principally taking into account the action of Titan. Also to compare observation with theory, and thence deduce the mass of Titan. SCIENCE IN THE MAGAZINES. pROF. J. W. JUDD contributes to the Fortnightly zx).z.x\.\z\t ■*• on " The Chemical Action of Marine Organisms," dealing with the nature of the ocean-floor, and showing that the opera- tions going on there are similar to those described by Darwin in his work on vegetable mould and earthworms. Prof. Judd favours the organic view of the origin of manganese nodules, and believes that the chemical theory is improbable. He says : — "All the facts collected by the deep-sea exploring expedi- tions point to the conclusion that accumulation of material is going on with the most extreme slowness at these abysmal depths where the manganese nodules are found in greatest abundance, and it may well be that these slowly accumulating muds have been passed through the bodies of marine worms or other organisms an almost infinite number of times. At each passage of the clay through the organism a small addition of mangane>e and iron oxides would be made to the mass by the action of ihe living strucure on the sea water, and thus in the course of time these oxides might be sufficienily concentrated to build up, by concretionary action, the remarkable nodules on the ocean-bed. ''Such action would be in complete analogy with processes going on both in fresh and salt water, by which calcareous, silicious, phosphatic, and ferruginous deposits are being every- where formed in the waters of the ocean, while all theories of the direct separation of the manganese and rarer metals from their state ol excessively dilute solution in sea-water by chemical NO. 1262, VOL. 49] reactions appear to me to be beset with the greatest difficulty. All the observations that have been made in recent years upon the deposits of the ocean-floor point to one conclusion, namely, that where materials have once passed into a state of solution in the waters of the sea they can only be separated from it in the open ocean by the wonderful action of living organisms." Prof. Buechner discusses "The Origin of Mankind," his article being more or less a review of a pamphlet by Abel Hovelacque, entitled " Les debuts de Thumanite," in which the results derived from archaeological researches are compared with the observations of travellers as to the lowest types of the human family that can exist. Captain Gambier, R.N., writes on " The True Discovery of America." He shows that Jean Cousin, a sea-captain of Dieppe, discovered the River Amazon in 1488, that is, four years before Columbus discovered San Salvador. There is clear evidence that Cousin was thoroughly conversant with all that was known of geography, hydrography, and nautical astronomy in his day, and that he sailed up the Maragnon, which was his name for the River Amazon as he heard it from the natives. On board Cousin's ship, as second in command, was a man named Vincent Pincon, and Captain Gambler's contention is that this Pincon was the same man as the Vincent Pinc^on who i> known to have commanded one of the ships under Columbus. The Pincon that sailed with Cousin was tried by court-martial for insubordination when the ship returned to Dieppe, and was condemned to perpetual banishment from the soil of France. He went to Genoa, and from there to Palos, in Andalusia, where his two brothers carried on the business of shipowners and traders, making occasional voyages themselves. It is not too much to suppose that Columbus met the Pinions, and was indebted to them for informal ion about Cousin's voyajje. Jealousy and human self- interest will explain why Cousin's name was carefully omitted from all writings referring to the discovery that was afterwards made by Columbus and the three Pincons who accompanied him on the celebrated voyage. In addition to these articles, the Fortnightly contains one in which Dr. Thin comments upon the most important points brought out in the Report of the Leprosy Commission in India. The Neiv Peviezv, which appears for the first time this month as an illustrated review, contains an article on the late Prof. Tyndall, by Mr. P. Chalmers Mitchell. Sir William Flower contritiutcs to Good Words an excellent description of the structure and action of " Birds' Wings." "The Vanishing Moose and their Extermination in the Adirondacks " is the title of a well-illustrated article by Mr. Madisson Grant in the Century. Mr. Grant says that the last moose in New York State was killed on the east inlet of Raquette Lake, in the autumn of 1861. In the Century also is related the circum- stances that led to the first employment of chloroform, in 1847, by Sir James Simpson, the scribe being his daughter, Miss E. B. Simpson. Since chloroform may soon be superseded by some newer anaesthetic, it is well that the events which estab- lished it as the great alleviator of animal suffering have been recorded. Other magazines received by us are the Hu?>ianitarian, which reprints the address on "Biology and Ethics," recently delivered by Sir James Crichion Browne at Sheffield, Scribner, the National Review, Contemporary, the Modern Review, and Longman's, but none of these contain any articles of scientific interest. THE RISE OF THE MAMMALIA IN NORTH AMERICA. I. TN a remarkable address delivered before the Zoological sec- ^ tion of the American Association for the Advancement of Science, at the Madison meeting, in August, Prof. H. F. Osborn gave an account of the recent achievements of explora- tion and research in connection with the rise of the mammalia in North America, and suggested the lines along which further advances were desirable. The length of the address precludes its complete publication here, but the most important features will be found in the following extracts. Among the omitted por- tions are sections dealing with the origin and evolution of Trituberculism, the succession of the Perissodactyls, and that of the Artiodactyls, and the relation of the Ancyclopoda (Cope) to the law of correlation. 2^6 NA TURE [January 4, 1894 Twenty years ago an era opened in the mammalian palae- ontology of Europe and America. Partly inspired by the Odontogi-aphie of Kutimeyer, Kowalevsky completed and pub- lished in 1873 his four remarkable memoirs upon the hoofed mammals. He wrote these four hundred and fifty quarto pages in three languages not his own, in French upon Anchithcrium and the ancestry of the horses, in English upon the Hyopo- tamidogenesis, the more widespread heterodontism is — all modern homodontism proving to be secondary. The simple conic teeth of the porpoise, for example, bear a mislead- ing resemblance to those of a reptile. Flower, Weber, Julin, and Kiikenthal agree that the ancestral whales and edentates were heterodont and had a smaller number of teeth than the existing forms. Heterodontism is the second problem. Did the differenti- ation of the teeth into incisors, premolars, and molars occur before or after the Monotremes, Marsupials, and Pla- centals separated ^ It i> well settled that the canine was the first maxillary tooth, and developed from the most anterior bi-fanged premolar ; also, from the discovery of complete succession, we must now define the first molar as the most anterior specialised or triconid tooth, not as the most anterior permanent tooth. It seems to me we now find strong evidence that the stem mammals had a uniform number of each kind of teeth ; in other words, a uniform dental formula. The Monotremes are most doubtful as the existing forms point only to primitive heterodontism. It will be a great step forward when we learn whether or not the Multituberculates are Mono- tremes— the resemblance of their molars to those of the duck- bill is very superficial, for the duckbill upper molars lack the intermediate row of tubercles universally seen in the Multitu- berculates, and look to me rather like degenerate Trituberculate teeth. Cope has recently found in the cretaceous rocks a re- markable Trituberculate, which he names ThLcodoti ; the jaw of this animal is neither Placental nor Marsupial ; it is like that of the Multituberculates — and both resemble remotely the de- generate modern Monotreme jaw. All we can say, therefore, is that the Multituberculates are an archaic group, highly specialised even in the Trias, that they were probably Mono- tremes, and neither structurally nor functionally akin to the Diprotodont Marsupials (Owen), nor to the Microbiotheridas (Ameghino). With a dental mechanism and a condyle exactly like that of the rodents, they show no trace of canines, and the mode of evolution of their peculiar molars was probably paralleled later in the rodents. They present vestiges of a primitive dental formula like this : 73. C?. P^. JI/4 + . Thlceodon shows Ci. P^. M^. .Thus, so far as this doubtful palaeonto- logical evidence goes, the Monotremes had a typical formula. Our next step is to unify the typical 5. i. 3. 4 of recent Mar- supials with the 3. I. 4. 3 of higher Placentals. Thomas has shown in his studies of recent Marsupials that they have pro- bably lost one of the four typical premolars (pm. 2) ; this obser- vation, fortunately, is partly confirmed by Rose's finding an em- bryonic germ of this tooth. Ignoring the incisors of the Jurassic Marsupi lis, Thomas raised the number of ancestral incisors to five, the highest number known among recent Marsupials ; Rose therefore made another step towards uniformity when he showed that the Marsupial 2.5 is probably a member of the second series of incisors, and should not be reckoned with the first. Nov\, if we suppose that the Placentals have lost one incisor, and one molar, abundant evidence of which is found in Otocyon, Cenietes and Homo, we derive as the ancestral formula of both orders : I^. C &^ P^- ^M- The aberrant placental Cetacea point in the same direction, as we read in the conclusion of Weber's fine memoir : " All the NO. 1262, VOL. 49] 238 NATURE [January 4, iJ^94 Cetacea sprang from a stem with a heterodont, but only partly specialised dentition (something like that of Zeuglodon, 73. Ci. P&'M). . . . not direct from Carnivores or Ungulatts, but from a generalised mammalian type of the Me^ozoic period, with some affinities with the Carnivora. . . . Zeuglodon itself branched off extremely early from the primitive line, and the heterodont Squalodon" (mark its formula, 3. i.\i\. 7.) " branched olf later from the toothed whale line, after the teeth had begun to increase in number and before homodontism had st-t in." It would be easier for us while speculating to take Squalodon and the OJontocetes directly from the Jurassic mammalian formula (3. I. 4.8.). As for the multiplication of this formula, we have found the way, says Kiikenthal, by which numerous homodont '^tth have arisen from a few heterodont molars, namely, l>y the splitting tip of each of the molai's of the Jurassic ancestors into three. He substitutes this hypothesis for the one advocated by Baume, Julin, Weber, and Winge, that the multiple cetacean teeth represent the intercalation or joint appearance of both the first and second series of teeth, owing to the elongation of the i/(/(/(/ vuuuUUUij'-^ ^-mmfmwmmr-- Ritahons nf the First and Second Series of Teeth, I. Reptiles. //. Marsupials. ///. Insectivores (Erinaceus> /K. Higher Placer.tals. /'. Edentates. VI. Cetacea, Odoiitocetes jaw — a view which is now disproved by Kiikenthal's discovery of the second row beneath the first. Since even by Kiikenthal's hypothesis the typical Mesozoic mammals could not furnish as many teeth as are found in some of the dolphins, a likelier ex- planation than his S' ems to be that as the jaws were elongated the dental fold was carried back and the dental caps multiplied. •^ The Edentates, like the Cetaceans, point back to diphyo- donti'im, and somewhat less clearly to a typical dental formula. We are here indebted to Flower, Rheinhardt, Thomas, Kiiken- thal, and Rose. It is their rudimental and useless first series whjch gives the evidence of heterodontism, while the second series has become adaptively rootless and homodont. The especially aberrant feature is that a double succession exists in the typical "true molar " region. The adult nine-banded Armadillo presents only eight maxillary teeth, seven of NO. 1262, VOL. 49] which are preceded by two-rooted milk teeth (Tomes) ; in the embryro Leche finds fifteen dental caps, of which onlv thirteen are calcified ; this number probably includes the four rudimentary incisors f>bserved by Rheinhardt. In the aberrant Orycteropus (Aard-Vark), with ten adult teeth, Thomas finds seven milk teeth behind the maxillary suture (thus taking us into the molar region of the typical heterodonts). The last of these milk teeth is large, and two-rooted; behind this are three large permanent posterior teeth, apparently belonging to the first series. The large lateral tooth of Bradypus is suggestive of a canine. From this rapidly accumulating evidence it appears prohable that the ancestral Edentates had four incisors, a canine and eight or more teeth behind it, the double succession extend- ing well back, so that the first series did not become permanent at the fifth tooth behind the canine, as in the Marsupials and higher Placentals. If these are primitive conditions, as seems probable fiom comparison with fossil Edentates, they carry the divergence of the Edentates, like that of the Cetaceans, back into the Mesozoic period. Comparative anatomy and embry- ology thus point back to highly varied branches of a generalised placental heterodont stem in the Mesozoic, and a much earlier divergence than we formerly imagined. Now let us see to what the early Mesozoic mammals point. There are three distinct and contemporary Jurassic types, the Muliituberculates, the Triconodonts, and the Trituberculates. Are not these the representatives of the Prototheria, Metatheria, and Eutheria? In the archaic Multituberculates we have seen a monotreme type of jaw and vestiges of a typical ancestral formula. The Triconodonts are a newer group, pei haps derived from the Domotheriidte (incipient Triconodont^) of the Trias, although these appear to be aberrant ; the typical forms extend from Amphilestes to Triconodon, and exhibit the first stages of development of the inflected Marsupial jaw. The Trituber- culates include the Amphitheriidae and Amblotheriidse with true tuberculo-sectorial lower molars, like those of modern Insectivores; they alone exhibit the typical angular placental jaw — no reason can be assigned for calling them Marsupials, excepting the traditional reverence for the Marsupial stem theory. Now, it is very significant that the avi rage dentition of these old hut highly diverse forms, namely, Multituberculates, 3. ?4. 6., Triconoin' ^ Ainmlen dei Physik tmd Chcmie, No. 12.— On the change of in-ensity of light polarised parallel to the plane of incidence by reflection on glass, by Paul Glan. The light reflected from a glass prism was compared with that of a petroleum flime by means of a polarisint; arrangement consist- ing of a doubly-refracting prism and a Nicoll, between which a Hofmann prism was placed in order to obtain a spectrum of the reflected light. For crown glass, the ratio of the intensity of the reflected to that of the incident light polarised in the plane of incidence ranged from 0^055 at 30° to 0293 at 70", the corresponding values for flint glass being 0070 and 0-327. — Hydrodynamico acoustical investigations, by W. Konig. The turning moment exerted by a moving column of a fluid upon a disc suspended in it was subjected to experimenialinvestigation, the torsion being balanced by a magnet. For very small velo- cities of the column of air employed the form of flow was uniform, but it was found impossible to keep it so in the case of any considerable velocities. The contemplated determination of all the dynamical conditions of Rayleigh's disc swinging in an organ pipe, and its application to the absolute measurement of sound intensities has not yet succeeded. — Experimental in- vestigations concerning elastic longitudinal and torsional fatigue in metals, by Louis Austin. The wires experimented upon were 23 m. long, and were suspended in the tower of the Strassburg Physical Institute. It was found that longitudinal and torsional fatigue phenomena are subject to similar laws. The fatigue effects in copper, silver, and brass were, for torsion, as 7 : 3 : 2, and for tension, as 4 : 3 : 2 approximately.— On the properties of various modifications of silver, by H. Liidtke. — On thermo- piles made of electrolytes and unpolarisable electrodes, by A. Gockel. — On the magnetism of iron cylinders, by O. Groirian. — On the pissage of electric waves through layers of electrolyte, by G. Udny Yule. — On some modifications of the Thomson quadrant electrometer, by F. Himstedt.— A calibrated electro- dynamometer, by J. \V. Giltay. — A new method of measuring self-potentials and induction coefficients of induction, by L. Gr£Etz. SOCIETIES AND ACADEMIES. London. Chemical Society, December 7, 1893. — Dr. Armstrong, President, in the chair. — The following papers were read : — An apparatus for the extraction and estimation of the gases dissolved in water, by E. B. Traman. — The magnetic rotation of hydrogen chloride in different solvents, and also of sodium chloride and of chlorine, by VV. H. Perkin. The author con- firms his previous observations on this subject, and also shows that isoamylic oxide and hydrogen chloride do not appreciably interact. The magnetic rotation of hydrogen chloride in isoamylic oxide solution is 2'245, in alcoholic solution 3'324, and in aqueous solution 4 300. The magnetic rotations of sodium chloride and of chlorine were also determined. — Analysis of water from the Zem-Zem well in Mecca, by C. A. Mitchell. The author gives analyses of waterolitained by the late Sir R. Button from the holy «ell in Mecca. — The preparation and properties of bromolapachol, by S. C. Hooker. Bromolapachol is obtained by reducing dibromolapachone ; when dissolved in sulphuric acid it yields bromo-/3-.apachone. The latter is con- verted into bromo-a-lapachone by the action of hydrobromic acid, whilst the reverse change occurs on dissolving the a-iso- meride in sulphuric acid. — Studies on citrazinic acid (Part ii.), by T. H. Easterfield and W. J. Sell. — The oxides of the elements and the periodic law, by R. M. Deeley. The author obtains a new periodic diagram by plotting the atomic weights of the elements against the numbers obtained on dividing the densities of the oxides by the atomic weights of the corre- sponding elements. — The freezing p >ints of alloys in which the solvent is thallium, by C. T. Heycock and F. \\. Neville. The uiean depression of the freezing point by the addiiion of one atomic proportion of gold, sdver, or platinum to one hundred atomic proportions of thallium is 6 '31 ; the addition of lead to thallium, however, raises the freezing point. Geological Society, December 20, 1893. — W. H. Hudle- ston, F. R.S., President, in the chair. — The following com- munications were read : — On the stratigraphical, lilhological, and palaeontological features of the Gosau beds of the Gosau district, in the Austrian Salzkammergut, by Herbert Kynasion. The author, after referring to the previous literature of the subject, treated of the situation and physical aspects of the Go-au valley, the distribution of the Gosau beds, their stratigraphy, palaeontology, and geological horizon, and the physical conditions under which they were deposited, and a comparison was instituted between the Gosau beds and the equivalent beds of other areas. He showed that Hippurites occur at two horizons in the Gosau beds — a hippurite-limeslone immediately above the basement- conglomerate being characterised essentially by Hippurites cornuvacciiiuin, which is overlain by Acl^roiidla- and Nerin,,:a- limestones and an estuarine series, and above these was a second hippurite-limestone characterised essentially by Hippurites organisans. It was p linted out that Toucas similarly dis- tinguishes two hippurite zones in Southern France, the lower, characterised essentially by H. corniruacciniim, being placed by him at the top of the Turonian system, whilst the second, with H. orgatiisans, is refeired to the summit of the Scnonian ; and the auihor gave reasons for regarding the Gosau zones as the equivalents of those of the South of France, in which case the Gosau beds will represent the uppermost Turonian and the whole of the Senonian, i.e. the zones of Holaster planus, Micraster, Marsupites, and Bdemnitella nnuronata in Eng- land, whilst the upper unfossiliferous beds may be the equiva- lents of the Danian beds. The strata are, on the whole, of shallow-water origin, and were deposited in shallow bays in the L^pper Cretaceous sea of Southern and Central Europe, on the northern flanks of the Eastern Alp.=. Probably towards the close of Upper Cretaceous times the southern area of the Gosau district was cut off from the sea to form a lake-basin in which the upper unfossiliferous series was deposited. Mr. W. Whitaker, Sir John Evans, and Prof. J. F. Blake spoke on the subject of the paper, and the author briefly replied. — Artesian boring; at New Lodge, near Windsor Forest, Berks, by Prof. Edward Hull, F.R. S. The boring described in this paper was carried down from a level of about 220 feet above Ordnance datum through the following beds : — London Clay and Lower London Tertiaries, 214 feet ; Chalk, 725 feet ; Upper Greensand, 31 feet ; Gault, 264 feet ; Lower Greensand, 7 feet. The chalk was hard, and contained very little water ; but on reaching the Lower Green- sand the water rose in the borehole to a height of 7 feet from the surface. The author discussed the probability f the Lower Greensand yielding a plentiful water supply in the Windsor district. In the discussion that followed, the President said it was satisfactory to learn that there was an area near West London in which the Lower Greensand was full of water. He thought that the section exhibited by the author explained why It was full in that particular locality, for the rainfall about the extensive area of Hindbead, which lay nearly due south, must be considerable. Mr. W. J. Lewis Abbott and Mr. W. Whitaker also spoke, and the author replied. — Boring on the Booysen Estate, Witwatersrand, by D. Telford Edwards. An account was given of a boring on the Booysen estate, situated about two miles from Johannesburg, and about 5000 feet south of the nearest point of outcrop of the "Main Reef" of the Witwatersrand. The "Bird-Reefs" crop out generally at a distance of 4000 feet south of the Main Reef The borehole, 1020 feet deep, passed through sandstones (often micaceous), quartzites, and conglomerates, the last-named having a col- lective thickness ot 91 feet 7 inches, the two thickest reefs being respectively 26 and 22 feet thick. The dip of the beds was 35'. Traces of gold were obtained. All the reefs were highly mineralised, principally with iron pyrites, and belonged to the " Bird- Reef " series which overlies the Main Reef. Paris. Academy of Sciences, December 26. — M. de Lacaze- Duthiersin the chair. — On the motion of Jupiter's fifth satellite, by M. F. Tisserand. A calculation of the displacement of the "perijove" of the fifth satellite due to the polar depression of Jupiter shows that it would amount to 882' per annum, or one revolution in nearly five months. It is hoped that powerful instruments will enable observers to verify this. — On the pro- paga'ion of electricity, by M. H. Poincarc. Starting from the " telegraphists' equation," the author shows that when an elec- trical disturbance proceeds along a wire, the head of the dis- turbance moves with a velocity such that, in front of this head, the disturbance is nil, as in the case of light and of plane sound waves, with the difference, however, that the electric disturbance leaves behind a residue of finite magnitude. — Numerical verifi- cations relating to the focal properties of plane diffraction NO. 1262, VOL. 49] 240 NA TURE [January 4., 1894 qralings, by M. A. Cornu. The verification of the theory of focal anomalies in gratings already published, by testing actual gratings showing such anomalies, was based upon the following theorem : When the observed pencils make a constant angle with the incident beam remaining fixed, half the sum of the azimuths of the grating corresponding to spectra of symmetric orders is constant, and equal to the azimuth corresponding to the reflected beam. — Remarks on the spontaneous heating and ignition of hay, by M. Berlhelot. Hay dried and stacked under norma! circumstances loses moisture and oxidises slowly, with- out being sensibly heated. The initial heating, where it takes place, is due to the action of ferments, but not the higher stages of the process. When the ferments are no longer capable of further raising the temperature without endangering their own existence, it often happens that purely chemical action steps in, and leads up to the ignition of the haystack. The temperature of ignition for these materials is far below red heat. — On the composition of winter drainage waters from bare and from culti- vated soils, by M. P. P. Deherain. — Observations of the minor planets 371 and 372 (1893) made with the great equatorial of the Bordeaux Observatory, by MM. G. Rayet and L. Picart. — The analysis of comm.ercial butters, by M. C. Viollette. — On the approximate development of the disturbing function in the case of inequalities of higher orders, by M. M. Hamy. — Investi- gation of that part of the coronal atmosphere of the sun which is projected upon the disc, by M. H. Deslandres. — Is there oxygen in the sun's atmosphere? by H. Duner. — New applications of the tables of increasing latitudes to navigation, by M. E. Guyon. — On the successive radii of curvature of certain curves, by H. R. Godefroy. — Calculation of electro-magnetic forces, according to Maxwell's theory, by M.Vaschy. — On the diurnal variation of the tension of aqueous vapour, by M. Alfred Angot. The observations made at the top of the EifYel Tower since the end of 1889 have shown that at the height of 300 m. the change of vapour tension during winter does not exceed a few hundredths of a mm. During the eight months beginning with March, a single maximum was observed during the day at 9 a.m., and a minimum at 5 p.m., while in the adjacent Pare SaintMaur, there were two maxima, at 9 a.m. and 8 p.m., and two minima, at 4 a.m. and 4 p.m. It appears that the variation of vapour tension, as observed in ordinary meteorological stations, is a local phenomenon, limited to the lower strata of the atmosphere. — On the diurnal variation of atmospheric electricity, observed near the summit of the Eiffel Tower, by M. A. B. Chauveau. The indications of an electrometer registering photographically the potential of the air, lead to conclusions similar to those of the preceding paper. The two sets of maxima and minima observed on the ground are replaced by one set only, con- sisting of a maximum at about 6.30 p.m. and a minimum at 4 a.m. The potential, which sometimes exceeded 10,000 volts, was reduced to a convenient amount by the interposition of con- densers in cascade. — On the weight of a li>re of normal air, and the density of gases, by M. A. Leduc. — Skeich of a system of atomic weights of precision, founded unon the diamond as standard substance, by iVI. G. Hmrichs. — General method for the volumetric e timation of silver under any form, by M. G. Deniges. — On the stability in air of a O'ooi solution of corrosive sublimate, by M. Tanret. — Remarks on the critical pressures in the homologous series of organic chemistry, by M. E. Mathias. — On caseineand the organic phosphorus of caseine, by M. A. Bechamp. — On a new source of rhodimil, by MM. P. Monnet and Ph. Barbier. — Presence of camphene in essence of aspic, by M. G. Bouchardat. — On the volatile carbides of the essence of valerian, by M. Oliverio. —Contribution to the study of the ptomaines, by M. CEchsner de Coninck. —Influence of certain causes upon receptivity ; bactenan associations, by M. V. Gattier. — Toxicity of the binod of the viper ( Viperaaspis L). — Modifications of the emissive powt-r of the skin unner the in- fluence of the electric brush di-charge, by M. Lecercle. — In- fluence of iron upon ihe vetjetation of barley, by M. P. Petit. — Influence of I'aik-strippirg upon the mechanical propr-rties of wood, by M. E. Mer. — On ihe natural dessication of grains, by M. II, Coupin. — On the oolitic strata of the Paris Tertiary, by M. G. F. DolHus. Berlin. Physiological Society, December 8. — Prof. Munk, Presi- dent, in the chair. — Prof. A. K'>s el gave an account of his further researches on nucleic acid, carried on in conjunction with Dr, Neumann. I he acid, as obtained from the thymus, differs from that obtained from other sources, in that during its decomposition it yields only adenin ; it has hence been dis- ' NO. 1 262, VOL. 49] tinguished as adenylic acid. It occurs in two forms : one readily soluble, the other soluble with difficulty. When boiled with water, this acid yielded a paranucleic acid, which con- tained no adenin. By boiling with dilute hydrochloric acid a fourth acid (ihyminic) was obtained, from which crystalline thymin could be obtained. All the above well-characterised sub- stances possess, when analysed, an extremely complex constitu- tion ; thus the molecule of adenylic acid contains 75 atoms of carbon, and that of paranucleic acid 90 atoms. Dr. H. Kossel had studied the action of nucleic acid on bacteria, and found that cholera-germs and streptococci are readily killed by small quantities of the acid ; whereas anthrax germs are much more resistent. He therefore considered that the bactericidal action of lymph-cells was attributable, in part at least, to this action . of nucleic acid. — Dr. Rawitz spoke on spermatogenesis in Hydromedusre. Unlike all other animals, the spermatozoa in this animal are developed in the outer layer of the bell, and are discharged direct into the surrounding fluid. The same speaker further described curious large branching villi in the jejunum of Macacus, not met with in the intestine of other species of monkey. BOOKS PAMPHLETS, and SERIALS RECEIVED. Books. — The Canadian Ice Age: Sir J. W. Dawson (Montreal). — The Genus Salpa. 2 Vols., Text and Plates : Prof. W. K. Brooks (Baltimore). — The Butterflies and Moths of Teneriffe : A. E. H. White (L. Reeve) — Journal of Microscopy and Natural Science, Vol. 3, Third Series (Baillicre). — Linnean Society of New South Wales, the Macleay Memorial Volume : edited by J. J Fletcher (Dulau). P.\MPHUETS. — Origin of the Pennsylvania Anthracite : J. J. Stevenson (Rochester). — On the Use of the Name "Catskill": J. J. Stevenson (Rochester).— The Marsh Warbler, &c. : W. W. Fowler (Oxford, Black- well). — On Technical Education in Glasgow and the West of Scotland : H. Dyer (Glasgow). — Imperial Institute Series, Handbooks of Commercial Products, Indian Section, Nos. 1-22, 24-25, 27-29 (Calcutta). — Guides to Commercial Collections, Indian Section, No. i (Calcutta). — Agricultural Ledger Series, Nos. 1-13 (Simla). Serials. — Bulletin de 1' Academic Royale des Sciences de Belgique, '' ; Annee, No. 11 (Bruxelles). — Journal de Physique, December(Paris). — Zeit- schrift fiir Physikalische < hemie, xii. Band, 6 Heft (Leipzig). — Zeitschrift fiir Wissenschaftliche Zoologie, Ivii. Band, i Htft (Leipzig) — Bulletins de la Soci6tc d'AnthropoIogie de Paris, December 15 (Paris). — Verhandlungen des Gesellschaft fiir Erdkunde zu Berlin, Band xx. Nos. 8 and 9 (Berlin).^ Verhandlungen der Gesellschaft fur Erdkunde zu Berlin, Bandxxviii. No. 4 (Berlin) — American Naturalist. December (Philadelphia). — Journal of the : Royal Agticultural Society of England, Third Series, vol. iv. part 4 (Murray), i — L' Astronomic, January (Paris). — 1 he Asclepiad, No. 39, vol. x. (Long- mans).— Geological Magazine, January (K. Paul). — Seances de la Socictc- Francaise de Physique, April-July, 1893 (Paris). ~ CONTENTS. PAGE Recent Contributions to Meteorology 217 Physico-chemical Measurements. By J. W. Rodger 219 Our Book Shelf:— Cooke : " Handbook of British Hepaticre." — C. H. W 220 Lydekker: " The Royal Natural History " .... 220 Letters to the Editor : — The Origin of Lake Basins.— Dr. Alfred R. Wal- lace.F.R.S.; Sir Henry H. Howorth, K.C.I. E., M.P., F.R.S 220j Hindoo Dwarfs.— Surgeon-Captain A. E. Grant . 221 i Ewart's Investigations on Electric Fishes. By Prof. Gustav Fritsch 222 Navigation by Semi-Azimuths. By G 223 Voices from Abroad. By Prof. Henry E, Armstrong, F.R.S 225 The Effects of Light on Electrical Discharge. By W. W 226 Neolithic Discoveries in Belgium. By J. E. ... 227^ The Late Sir bamuel Baker 227! Notes 228| Our Astronomical Column : — Prizes at the Paris Academy 233 [ The Tail of Comet Brooks (^ 1893) 2331 The Planet Venus 233! Geographical Notes 233 New French Law for the Prevention of Forest Fires. By Prof. W. R. Fisher . . .... 2 Prize Subjects of the Paris Academy of Sciences . 234 Science in the Magazines 235 The Rise of the Mammalia in North America. I. ( Wifh Diagram.) By Prof. H. F. Osborn 235 Scientific Serials 238 Societies and Academies 235 Books, Pamphlets, and Serials Received 24c NA TURE 241 THURSDAY, JANUARY 11, 1894. THE KEW INDEX OF PLANT-NAMES. Index Keiveitsis plantarum phanerogamarum nomina et synonyma otimitan generujn et specieriun a linnaeo usque ad annuvi mdccclxxxv complectens nomine recepto auctore patria ujiicuique plantae subjectis. Sumptibus Caroli Robert! Darwin, ductu et consilio Joseph! D. Hooker, confecit B. D. Jackson. Fasciculi II. (Oxonii : E prelo Clarendoniano, mdcccxciii.) THE appearance in rapid succession of the first two fasciculi forming the first volume of this splendid work, to be fittingly known to all time as the " Index Kewensis," is an event of supreme importance not only to the widely limited section of the scientific world which is professedly botanical, but also to the much wider circle of those who are interested in plants, whether this be from their more strictly technical side as the source of economic products, or from their more general and popular one, as objects of pleasure in cultivation and decoration. With the completion of the work in the second volume, which we are glad to know is not likely to be delayed beyond the current year, everyone will have within reach a book of reference in which may be found the correct name, the synonymy, the authority for the name, and the title of the work in which it is first published, along with an indication of the native country of any flowering plant described before the end of the year 1885. It is to Charles Darwin we owe primarily this valu- able work. In a short preface to the first fasciculus. Sir Joseph Hooker gives the following concise narrative of its origin : " Shortly before his death Mr. Darwin informed me of his intention to devote a considerable sum in aid or furtherance of some work of utility to biological science ; and to provide for its completion, should this not be accomplished during his lifetime. He further informed me that the difficulties he had experienced in accurately designating the many plants which he had studied, and ascertaining their native countries, had suggested to him the compilation of an index to the names and authorities of all known flowering plants and their countries, as a work of supreme importance to students of systematic and geographical botany, and to horticulturists, and as a fitting object of the fulfilment of his intentions. " I have only to add that, at his request, I undertook to direct and supervise such a work ; and that it is being carried out at the herbarium of the Royal Gardens, Kew, with the aid of the staff of that establishment." Everyone who has had dealings with plants will have realised the difficulties referred to by Mr. Darwin, and will welcome the issue of the " Index Kewensis " to which his munificence has given birth, and will congratulate Sir Joseph Hooker and Mr. Daydon Jackson on the result of their fifteen years' labour as the instruments through which the practical wish of Mr. Darwin is in process of being carried out. In passing, it is not uninteresting, from the point of view of history, to note the association of the name of Darwin with this Index. The biological sciences, whilst owing an eternal debt of gratitude to Linnaeus for the order which he brought out of their pre- ceding chaos, and for the binomial nomenclature his NO. T263, V^T,. 49] genius so deftly constructed as an alphabet of system, have reason to regret the retarding influence on their progressive development of the dogma of constancy of species which his scholasticism tacked on to his nomen- clature, and which the nomenclature served to per- petuate. From the trammels of this dogma the genius and work of Darwin gave to biology final emancipation, and now by his forethought and munificence this enumeration of genera and species is being provided, the foundation of which rests on the enduring portion of the work of the great Swedish naturalist. It is impossible to emphasise too strongly the value of the book before us. The most recent work of similar kind is the " Nomenclator Botanicus" of Steudel. But this was completed in 1841, and since that date the activity of botanists and the exploration of the world's surface has added so enormously to the known plants, that for practical purposes Steudel's Nomenclator has been for long out of date. The "Index Kewensis " is not, however, cast on quite the same lines as Steudel's work, and possesses valuable features absent from it. The Nomenclator was confessedly a critical botanical book, expressing the views of the limitation and relationship of genera and species held by the author, and conse- quently new names on the authority of Steudel occur throughout. The " Index Kewensis" makes no such pro- fession. It takes the literature as it existed at the end of the year 1885, and from it is compiled, in conformity with certain definite guiding principles of plant-naming, the correct nomenclature, based, so far as the limitation of genera and species is concerned, upon the work of the most competent and trustworthy writers. The " Genera Plantarum" of Bentham and Hooker gives the standard of limitation of genera, and for species the conclusions of monographers and recognised authorities in the different groups supply the basis for the synonymy. The Index is therefore essentially a literary work carried out under effective botanical supervision, and the circum- stances surrounding its production are most favourable. No one more qualified for this detailed work than Mr. Daydon Jackson, by his extensive knowledge of botanical literature and critical judgment, could have been found; in Sir Joseph Hooker the work has the supervision of the most experienced systematic botanist of the day ; and Kew, the natural birthplace of a British book dealing with all flowering plants, affords unrivalled facilities for the investigation involved in such a work. We have said the " Index Kewensis "gives the correct name of all plants described before the end of the year 1885. This brings up the much-discussed question of what is the correct name of a plant.? Under what rules is it to be fixed.'' In its bearing on this question the Index appears most opportunely, and it may be regarded as the manifesto of the working British systematic botanists upon the vexed subject of plant-nomenclature ; and a thoroughly practical one it is. Briefly the guiding rules of the Index are these :— The starting point for genera is the first edition of the " Systema " of Linnaeus, published in 1735 ! *^he starting point for species is the first edition of the " Species Plantarum "of Linnsus, pub- lished in 1753 ; the correct name is that given by the author who first placed the plant in its proper genus. There is a soundness in these principles which should M 242 NATURE [January ii, 1894 appeal to any unprejudiced mind. If nomenclature dates from Linnsus, who founded the system, naturally the first editions of his works dealing satisfactorily with genera and with species, are respective points of de- parture for the names of these, and in dealing with the species described by subsequent authors a similar course must be pursued. This code has been the tradition of the representative British botanists, and to it the former leaders of American botany also subscribed. It is the simple rule that priority determines the name. But, as with other rules framed by frail humanity for its guidance, this, if applied with rigorous inflexibility, would defeat the object it is designed to serve. To drop a name which has become generally accepted as the designation of a plant, and with which it is always associated, and take up for it some unknown name, simply because some one has discovered that this one preceded that by a few months in publication, or because it occurs a few lines earlier on the page of the same work, may mean logical adherence to the rule of priority, but is subversive of the purpose of nomenclature. Conformity with the code has therefore on the part of the botanists mentioned been governed by circumstances of practical expediency. They have kept in mind that nomenclature is only an aid to, not the aim of, the study of plants, and that a theoretically perfect nomenclature is inconsequent by the side of one which in practice ad- mits of the ready recognition of the plants named; they have thought more of the identity of the plant and of its relationships than of the technical accuracy of the name under generally guiding principles, and have not therefore hesitated to cite older and obscure names as synonyms, and to ignore them if their use would replace others which had come to be generally and widely known. This principle of expediency and con- venience, it has been said, is an unstable one, and to workers in fields of science in which it is not admitted may appear to be a mistake. But in the past of botany, in the hands of men really endeavouring to increase the general store of knowledge of plant-life, it has worked well. No doubt inconsistencies and mistakes may be found in the works of botanical writers who have acted upon it, traceable to a laxity which it introduces ; but it has been a strong conservative element in nomenclature, whereas the application of the rule of strict priority has been most unsettling. For there are, unfortunately, men endowed with antiquarian zeal mated with sentiment which deems the naming of a species honour, and of a genus glory, who ferret through the pages of forgotten or unknown tracts or obscure journals, which perchance may contain a name, given by an author whose work has perhaps had no effect whatever upon the progress of the science, with which, under strict priority rules, they may supplant one custom has made part of popular language ; or who rake out of correspond- ence (alas, that its preservation should serve such end) the history of private quarrels and jealousies of men who^e names, as the roil of time has handed them down to us, carry only the attribute of scientific distinction, with the object of showing that one may have ignored the work of another, preceding it by a ^^"^ days or weeks, and that consequently firmly established names must give place to those which strict priority demands. It is MO. I ^63. VOL. 49J through such work, revelling in the overturning of authorities, which does not contribute to the progress of botany, and is essentially non-botanical, that many of the difficulties in nomenclature arise, and it merits the censure of all true botanists. Such work proves the wisdom of the botanists who have held aloof from binding agreement to strict priority rules, and against the load of synonymy and the confusion the strict priority rule would in these ways inflict upon plant-nomenclature, expediency and convenience are the protection to which appeal can be made. We are glad to note that in the " Index Kewensis " discretion has been exercised, and familiar and generally known names have not been sunk, although under the strict priority rule they should have been replaced by other and obscure ones. That the procedure in the Index will meet with the universal acceptance of botanists may be hoped for ; it cannot be expected immediately, when we have regard to the existing divergencies upon fundamental points. The laws of nomenclature formulated by the Paris Botanical Congress of 1867, made strict priority the basis of nomenclature, and were so generally adopted by syste- matic botanists out of England, that little was heard of the subject in subsequent years until a revolt of the younger American botanists against the practice of their former leaders — adherents to the line of expediency — brought it so prominently under notice a few years ago, that it has since been a staple of discussion in some botanical journals. Strict priority was the cry of the Americans, and some of them, with a zeal tinged with pedantry rather than bred of thought for the good of the science, endeavoured, in the application of the rule, to carry back to Virgil, Catullus, and other classical writers the scientific nomenclature of plants. But the event which most roused the attention of European botanists was the publication, in 1891, by Otto Kuntze, of his " Revisio generum plantarum " — a book remarkable no less for the industry and linguistic powers it exhibits than for its audacity and unconscious humour. Having assumed the role of a reformer of nomenclature, the author begins business by changing the names of some thousand genera and thirty thousand species, the new ones being only certified by the coincidently significant initials O. K. ! As a curiosity of botanical literature the book will be historical ; meanwhile its menace to syste- matic botany has had the effect of drawing from the Berlin school of systematists, which in recent years has shown so much activity, a statement'of views v/hich, after circulation, was submitted to the meeting of botanists at Genoa in 1892. If the result of all the discussion and conference that has taken place has not been the establishment of a common agreement, they have at least served to bring out the points of divergence of view. We cannot, of course, discuss here the various issues upon which botanists are disagreed on this subject, but we may point out that the differences are mainly upon the starting point of nomenclature and the import of the specific name. The German school, which appears to carry with it a considerable bulk of continental opinion, pre- fers 1753 as the starting point for both genera and species to the date adopted in the Index, but makes an im- portant declaration of adhesion to the principle of January 1 1, 1894J NATURE 24; expediency as qualifying the strict priority rule. The Americans have come round to fix 1753 as the starting point of nomenclature, but unfortunately tack on to the priority rule a rider compelling the use of the earliest specific apellation wherever the genus is changed — a proper enough rule if botanists would only follow it, but which, if carried out retrospectively, as they propose, would involve a changing of plant names appalling to contemplate. We have said sufficient to show the importance of the " Index Kewensis," and to make clear that its issue at this time is most opportune. The professed desire of all systematic botanists — although there is a wide gulf often betwixt their profession and their practice — is the estab- lishing of a stable nomenclature. To this end the "Index Kewensis" is the most important contribution that has appeared since the "Genera Plantarum" of Bentham and Hooker was completed, and it supple- ments that work. What effect it will have in bringing about a modification of the views now held by continental and American botanists time will show. In the various discussions and conferences through which it has been attempted to settle questions of nomenclature, the Kew botanists have not taken active part ; they have done better, and in the " Genera Plantarum," and now in this " Index Kewensis," we have practical expression of their views, and systematic botanical literature is enriched with what may be fairly termed the most valuable and important additions of the century. The "Index Kewensis" provides a book of reference which every library must possess, and there need be little doubt its nomenclature will take firm hold in this country at least. For the detail and workmanship in the book we have nothing but praise. They- are of a kind we are in the habit of associating with the race which has given us "the sausage for food and the encyclopaedia for know- ledge," but the book shows there is no monopoly in this sort of work. It is a lasting tribute to the painstaking industry, skill, and knowledge of Mr. Daydon Jackson. The citation of the place of first publication of a species is a most valuable feature in the book, supplying at once a clue through which its history may be followed, and the mention of the native country, necessarily general and brief in most instances, is a further helpful feature. We could have wished for a more extensive citation of the garden names of plants ; in every-day life these are constantly turning up, and of no names is the history more difficult to run down. In a work such as this, the preparation of which has taken so many years, and the separate items of which are so multitudinous, slips, omissions, and inconsistencies must occur; but the number of these, so far as use has enabled us to judge, is remark- ably small. " Menda non commemorata lector benevolens ipse corriget," says Mr. Daydon Jackson, as a preface to a list of " addenda et corrigenda " in each fasciculus ; let us hope readers will also send them to Mr. Daydon Jackson, who may incorporate them in succeeding fasciculi. It only remains to add, regarding the style and printing of the book, that the best work of the Clarendon Press is displayed in it. NO. 1263. VOL. 4q] ASTRONOMY FOR THE PUBLIC. In the High Heave?ts. By Sir Robert S. Ball, F.R.S. (London: Isbister and Co., 1893.) IT is not too much to say that at the present time Sir Robert Ball is the fashionable interpreter of astro- nomical science. He retails to the general public, by voice and by pen, the facts accumulated by astronomers who love their science for her own sake, the practical observer and the eloquent expositor thus mutually benefiting one another. The book before us contains a collection of heteroge- neous articles, several of which have appeared in the Con- tevtporary and Fortjiightly, and all of which are written in the style that pertains to magazines. To the student of science this, diffuse method of expounding facts is distasteful. As Ruskin has remarked, " A downright fact may be told in a plain way ; and we want downright facts at present more than anything else." The chapter on " The ' Heat Wave ' of 1892 " furnishes an example of what can be done in the way of connecting facts between which there is apparently no relation. The chapter begins with a description of the temperature observations in different parts of the world in July and August, 1892 ; it then passes to the movements of the moon, transits of Venus, and meteor-showers, in illustra- tion of the accuracy of astronomical predictions as against the prediction of weather. The work of Lord Kelvin and Prof. G. H. Darwin on tidal prediction is next considered, and the tide-predicting machine of the former is described. Fourier's theorem is discussed, and some of the causes affecting the heights of tides mentioned, the chapter finally concluding with an account of Prof Hale's photographs of a luminous eruption on the sun in July, 1892. The different scraps of infor- mation in this omnium gatheru7n are joined together with an ingenuity that is only acquired after long practice ; but in spite of this, the article gives one the impression that the author has spun out his subject in order to provide copy. The star 1 830 Groombridge is a " King Charles' Head " to Sir Robert Ball, the reason being its large proper motion. We doubt whether he has ever written a book in which the number of miles per second, per minute, per hour, per day, per annum, &c. through which 1830 Groombridge travels, is not enlarged upon ; and in the volume under review this runaway star is twice inflicted upon the reader. So persistently, indeed, does 1830 Goombridge appear, that we begin to wonder whether it is hurrying through space at a great rate in order to afford subject-matter for popular lecturers and writers on astronomy. Another subject that has often given Sir Robert Ball an opportunity of exercising his descriptive faculty is the correlation between solar and terrestrial phenomena. But in view of the facts recently brought out in these columns and elsewhere, he may find it necessary to modify or substantiate the statement that "great out- bursts on the sun have been immediately followed, I might almost say accompanied, by remarkable magnetic disturbances on the earth." For the sake of historical accuracy, it may be well to 244 NATURE [January ii, 1894 point out that Prof. Rowland first made the striking re- mark that " were the whole earth heated to the tempera- ture of the sun, its spectrum would probably resemble that of the sun very closely " {Johns Hopkins University Circular, No. 85, February, 1891). In referring to Prof. Rowland's work in August, 1891, at the British Associa- tion meeting of that year. Dr. Huggins made practically the same remark, and Sir Robert Ball (p. 169) quotes his words, and gives him the credit for the idea they contain. r-.vo of the chapters in the book refer to shooting- stars, meteors, and meteorites ; and in them the authoj- discusses the origin of meteorites and the relation be- tween meteorites and comets. In his opinion, meteorites are masses of matter ejected from terrestrial volcanoes in a primeval condition of the earth ; but we fancy that the analyses of most meteorites do not favour this origin. How, for instance, is the absence of quartz accounted for? But, as a matter of fact. Sir Robert Ball is almost the only astronomer who holds the volcanic view, and the same can be said with regard to his denial of the con- nection between comets and meteorites, and between meteorites and shooting-stars. The work of Schiaparelli and Newton, Tisserand, and Schulhoff, not to mention many others, considerably outweighs all that Sir Robert Ball has ever said upon the matter. The spectroscopic evi- dence upon the connection is dismissed in half a dozen lines, while page upon page is devoted to a description of what might happen to masses of matter projected from the moon or a minor planet. In fact, by discussing and judging these theories in a volume designed for the general reader, Sir Robert Ball has made a mistake. Though he has done some excellent mathematical work, astronomers are not at all ready to recognise him as a judge on matters of astronomical physics. His function is to expound and popularise discoveries in celestial science, and when he is exercising it he is at his best. There are some good points about the book, and any- one desirous of obtaining information upon a few of the recent important discoveries in astronomy will profit by reading it. The illustrations are not so numerous as they ought to be, but what are included are mostly very good, though the illustration on p. 156, of the region of the Milky Way about /3 Cygni, should have been a posi- tive instead of a negative, for in its present form it looks more like a pathological section than anything else. It would be an advantage if, in a future edition, the author would give the name of the observer of the solar eruptions figured on pp. 271, 273, 338, and 339. We fancy that Father Fenyi was the original draughtsman of the prominence forms there illustrated, but cannot find his name mentioned in the text relating to them. R. A. Gregory. OUR BOOK SHELF. Practical Agricultural Chemistry for Elementary Students. By J. Bernard Coleman, A.R.C.Sc, F.I.C., and Frank T. Addyman, B.Sc, F.I.C. (London : Longmans, Green, and Co., 1893.) " The course of instruction described in this book has been in use for some years at University College. \ Nottingham." After a few instructions as to the use of apparatus, there follows a short course of experiments on NO. 1263, VOL. 49] oxygen, air, carbonic acid, water, and hydrogen. The third section treats experimentally of soils, manures, feed- ing materials, and dairy produce, and gives a number of simple experiments that serve to show many of the most important properties of these substances. For example, the differences between the sulphur present in gas-lime and in gypsum respectively, and the various conditions in which phosphoric acid occurs in superphosphates, bone phosphates, reverted phosphate, and slag phosphates are made the subjects of experiment, Tests are given for the various constituents of manures. Oilcakes, grass and hay, roots, flour, milk, butter and cheese, are dealt with in a similar manner. The fourth section of the volume gives a few reactions of a select number of metals (viz. seven) and acids, with a few other matters, and tables for the qualitative analysis of substances containing them. We would remark in reference to this, that to allow students to fuse insoluble substances in porcelain crucibles, in order to test for silica, is, to say the least of it, un- desirable. Regarding the volume as a whole, it forms an excellent addition to an ordinary student's course of agriculture, whether this is, as is too often the case, only a matter of listening to a few lectures, or whether practical agri- culture forms an essential part of it. Perhaps it is hardly possible for a teacher to take much account of the danger that is proverbially inseparable from a little knowledge ; but in cases where this is particularly liable to manifest itself, it may be his duty to do what he can to obviate the evil. Speaking from e.xperience, we fear there are students who, after having worked through these seventy-one pages, would not hesitate to state that they had studied inorganic and organic practical chemistry at whatever college they might have done the work. In this way it is at least possible for grave discredit to be brought un- deservedly upon the usual course in chemistry at such a college ; for there are many people with no technical knowledge of these matters, who attach considerable value to the mere fact that a specific routine of study has been gone through at a well-known educational establishment. It appears, therefore, to be highly desirable to do what- ever may be possible to prevent such a chemical course as that in this volume from being in any way confused with even the most elementary course that is arranged to impart a knowledge of chemistry itself. A similar danger doubtless exists in many other cases, but it may probably be said with truth, that there is in none other likely to be so great a temptation to misrepresent facts by an incomplete statement of the truth. C. J. Bionomie des Meeres. Von Johannes Walther. Erster Theil einer Einleitung in die Geologie als historische Wissenschaft. (Jena : Gustav Fischer, 1893.) Prof. Walther has set before himself an ambitious programme, which, if carried out, should result in a geo- logical treatise of great interest ; we fear also of porten- tous length. The first instalment is a modest little book of 200 pages, with a preface summarising the travels and researches which the author made for ten years with a view to fit himself for the task, and a separately paged introduction defining the scope of the contemplated work, and enunciating the ontological method in geology. Bionomy is the study of the life-habits of organisms in relation to their environment, and it is obvious that the bionomy of the ocean at the present time must be the clue to all deductions from the character of marine fossils regarding the physical conditions in which they were produced. Prof. Walther is extremely systematic, and in twenty numbered sections he summarises a vast amount of recent work on the relation between marine organisms and physical conditions. His numerous references to original memoirs might be profitably increased by the inclusion of more British, French, and American work, and espe- January i i, 1894J NA TURE 245 cially by some indication of such piles of raw material for discussion as have been accumulated by the Fishery Departments of many governments. A compilation of this sort depends for its value on its completeness, as the reason for adopting one theory or classification rather than another must be the outcome of an attempt to weigh evidence. After a brief discussion of the conditions of life, there follow sections on the life-districts of the ocean, Hajckel's classification of marine organisms, a concise discussion of the influence of light, temperature, salinity, tides, waves, and currents on marine life, and a short statement of the flora and fauna of the littoral, shallow water, estuarine, open sea, deep sea, and oceanic archipelago divisions, concluding with a few pages on the geological changes of ocean basins. It would be premature to express an opinion of Prof. Walther's contemplated work. The sketch he gives of its plan stimulates interest and curiosity, and we can heartily congratulate him on the orderly way in which he has collected and laid down the building-material, while we wish him success in his labours. LETTERS TO THE EDITOR. { The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to returft, or to correspond with the writers of, rejected manuscripts intended for this or any other part tf/ Nature. No notice is taken of anonymous communications. '[ Correlation of Solar and Magnetic Phenomena. The opinion of Mr. Whipple, quoted at p. 2 of Nature for November 2, to the effect that the solar outburst observed by Messrs. Carrington and Hodgson on September i, 1859, was not the cause of the coincident magnetic perturbations, cor- responds to tny own conclusion in regard to the matter based upon evidence of an altogether different character. There was a recurrence of strong magnetic perturbations and auroras twenty-seven days later than the great magnetic storms of August 28 and September i, 1859, thus following the general rule which is found to apply in such cases, there being a well- marked periodicity of such outbreaks at this precise interval corresponding to the time of a synodic rotation of the sun. Such recurrence manifestly could not exist if outbreaks upon the sun were able to produce terrestrial magnetic effects indifferently in all locations. In order that there may be recurrence at the synodic period the magnetic effects must proceed from the sun at some particular angle exclusively, and fortuitous outbursts elsewhere, no matter how violent, must fail to have any per- ceptible effect. In the estimation of the writer there is no point more important in connection with solar physics than the determination of this period and this angle with the greatest accuracy possible. M. A. Veeder, Lyons, N.Y., December 26, 1893. My letter in Nature (vol. xlix. page 30), amongst other interesting communications, has brought one from Mr. Law- rance (vol. xlix. page loi) and the accompanying letter from Dr. Veeder. Mr. Lawrance's graphic account well describes the circumstances attending the manifestation of 1882 (Novem- ber 17). The magnetic disturbance which broke out at 10 a.m. on that day set us all on the look-out for aurora in the evening. Neither were we disappointed ; the display was remarkable. But the question in this case, as with the Carrington-Hodgson and Young instances, is still whether the solar and magnetic phenomena were directly related or simply coincident. This cannot be said to be determined, and nothing less than proof, in so important a matter, will serve. Better to advance surely if slowly towards truth, rather than accept too hastily evidence that is incomplete. We must remember that on the occasion of the solar disturbance seen by Trouvelot, the magnets were especially quiet, not only at the time but also before and after. But any explanation of these phenomena must include all cases. Theposition ofthings, as stated in my first letter, referred to above, still I consider holds, qualified only by the circumstance that instead of one presumed case of direct relation, three are now adduced, with a fourth case (the Trouvelot observation), which unquestionably was not accompanied by magnetic disturbance. NO. 1263, VOL. 49] If we further consider that, since the year 1859, when attention became distinctly drawn to this question, there has occurred mag- netic movement, equal to and in very many cases far exceeding that accompanying the Carrington-Hodgson observation, on some 400 different days, we see on how slight a foundation the presumption for direct relation, that is of a nature more or less instantaneous in action, exists, although the general relation between the two classes of phenomena remains undoubted. Dr. Veeder, from his own point of view, supports the con- tention that the 1859 solar outburst cannot be taken as causing the accompanying moderate magnetic movement ; indeed there was far greater movement some three days previously, and again early on the morning of the following day ; but in regard to his affirmation that there exists a well-marked periodicity in magnetic outbursts corresponding to the period of the sun's rotation, whilst this in a limited sense may be in some degree true, I cannot say that my personal acquaintance with magnetic records during very many years enables me at present to accept such conclusion as a general one, or indeed what as a consequence follows, that anything really depends on theposi- tion in rotation which the sun occupies relatively to the earth. The whole subject is, however, exceedingly interesting, and various considerations arise. One bearing on the present ques- tion may be mentioned. Great terrestrial magnetic disturb- ances are evidently in character cosmical, produced, it would seem, or stimulated, by some external cause. For it has been shown (Froc. Roy. Soc. vol. Hi. p. 191) that, on occasions of unusually sudden magnetic disturbance, the commencement of disturbance, at places so widely separated on the earth's sur- face as Greenwich, Pawlowsk, and Bombay, is simultaneous within a much smaller limit of time than had before been sup- posed. Such sudden simultaneous action would thus appear to indicate an impulse, solar or otherwise, from without, but whether one distinctly solar, or in what other way produced, is a question yet to be determined. William Ellis. Greenwich, January 6. The Mendip Earthquake of December 30-31, 1893. I submit the following notes for the useofany of your readers who may be collecting information on the subject : — So far as I can judge, from statements obtained directly from inhabitants of the locality, and from the experiences of various persons, recorded in the Shepton Mallet J oiirnal oi January 5, the movements in this earthquake occurred chiefly along the south flank of the Mendip Hills between Shepton Mallet on the east-south-east, and Draycott (near Cheddar) on the west-north- west. The shock extended as far southwards as Evercreech and West Pennard ; it reached as high up as Priddy, which is near the axis of the hills, and was also noticed at Chewton, several miles distant on the northern flank. The force of the shocks appears to have been very irregularly distributed, in some houses the movements being quite alarming, while in others not far distant they weie trifling though unmis- takable. Some persons failed to hear the sound, which was very evident to others. Persons out of doors heard the sound most distinctly, even when they felt no shock. A lady at Shepton Mallet, who had previously experienced an earthquake in New Zealand, recognised at once what was occurring, but was not in any way alarmed. She says that her bed began suddenly to shake or rock, and as suddenly ceased. She was also conscious of a movement of the whole house, and in the sharper shock heard the furniture rattle ; but she did not observe any rumbling. Anotherlady in the same housenodced par- ticularly the " funny unusual sort of noise." Again, in the same house a man describes the movement as resembling a wave mov- ing from east to west. A school master and mistress got up under the impression that the water-heating apparatus had burst. At West Compton a lady in a farmhouse thought from the sound and movement "that some one was about the house, or that a barrel of cider had burst." At Westbury-below- Wells the shock was sharp enough to cause alarm. The policeman on duty at Shepton Mallet very naturally re- ferred the sound to the direction of the Midland Railway, which runs high on the hills in such a way that the rumble of its trains is heard at a great distance. It is well known that we have but little certainty in localising sounds, especially if of indefinite character, and that we usually refer them to positions whence we expect them. The area in which the earth-movements seem to have been 246 NA TURE [January i i, 1894 most felt, corresponds with a series of outlying masses of car- boniferous limestone, which are separate from the main mass of carboniferous limestone of the Mendip anticlinal. Whether these are parts of another anticlinal, or owe their position to faulting, I do not know. Westward of Wells these outliers form little knolls, as at Draycott and Westbury. Further east, in the area between Wells, Shepton Mallet, and West Compton, they form a group of prominent hills, whose valleys are occupied by later formations. If such outliers exist east of Shepton Mallet, they are deeply hidden by the oolitic strata. Evercreech and West Pennard lie off this carboniferous lime- stone, but it extends beneath the valley in which these villages lip. Priddy is on the main aniiclinal of the Priddy Mendip hills, 3nd Chewton is separated from all the foregoing by the exposure of Old Red Sandstone. It would be interesting to know how far the Old Red Sandstone shared the movements ; but in- formation is likely to be scanty, as the sandstone forms a bleak and sparsely inhabited region. F. J. Allex. Mason College, Birmingham, January 6. On the other hand, when ^ is rotational, let its conjugate be <^', then instead of (i) we have Quaternionic Innovations. That Prof. Tait should not be able to do justice to those who prefer to treat vectors as vectors, and quaternions as quaternions, instead of commingling their diverse natures, with the result, in the latter case, of confusion of physical ideas (and geometrical also, for of course geometry is itself ultimately a physical science, having an experiential foundation), is naturally to be expected. He does not know their ways, either of thinking or of working, as is abundantly evident in all that he has written adversely to Prof. Willard Gibbs and others. It is, however, a little strange, in view of Prof. Tait's often expressed conservatism regarding Quaternionics, that he should tolerate auy innovations therein, such as Mr. MacAulay has introduced. The latter may perhaps take this as a compliment to his analytical powers, which compel the formers admiration, and toleration of his departures from quaternionic usage. For myself, I welcome any quaternionic innovations that may (ultimately) tend in the direction of the standpoint assumed by Prof. Gibbs and others, and foresaw some two years since (when a very bulky manuscript came to me for my opinion) that there would be some quaternionic upstirring. Prof. Gibbs has already pointed out how the development of Quaternionics has involved first the elimination of the imaginary, and next the gradual elimination of the quaternion ! Now there is a capital illustration of this innate tendency in Prof. Tait's review (Nature, December 28, 1893), where, on p. 194, he explains by an example the meaning of a startling inno- vation of Mr. MacAulay's. Put it, however, in vectorial form, and let us see what it comes to then. Take the case of a stress and the force to correspond (which is a little easier than Prof. Tait's example, though not essentially different). Let ^ be a stress operator (pure, for simplicity), so that (^N, or N<|), is the stress per unit area on the N plane, N being any unit vector. Now we know, by consideration of the stresses acting upon the faces of a unit cube, that the N component of the force F per unit volume is the divergence of the stress vector for the N planes. That is, FN = VN, (l) for any direction of N. I employ my usual notation for the benefit of readers (now becoming numerous) who, though they cannot follow the obscure quaternionic processes, can under- stand the plainer ones of pure vector algebra. Now, may we remove the vector N (which is any one of an infinite number of vectors) and write F = V^ or —'N, (6) (7) Here if ^ is given by the first expansion in (4), ^' is given by the second. Now there are several things that deserve to be pointed out about the above, which should be compared with Prof. Tait on p. 194. First, that the result F = 4>v, irrespective of pureness, or F = v^ also when the stress is pure, when got quaternioni- cally seems to be a great novelty to Prof. Tait, and to give him. a " severe wrench," involving a " dislocation " and a " startling innovation." Perhaps, however, it is only Mr. Macaulay's peculiar way of arriving at the result, that Prof. Tait is alluding to. Moreover, secondly, in the vector algebra of Willard Gibbs and others the use of equation (2) or of (7) to express the force complete, by removal of the intermediate vector N, is neither new, nor does it involve any straining of the intellect, for it is actually apart of the system itself, done naturally and in harmony with Cartesian mathematics. See Gibbs's " Elements of Vector Analysis" (1881-4) for the direct product of vand^. (Also for the skew product, a more advanced idea ; it, too, is a physically useful result. ) Thirdly, note how very differently the same thing presents itself to Prof. Tait according as it is clothed in his favourite quaternionic garb or in vectorial vest- ments. In the latter case it is either unnoticed or is con- temptible ; in the former, it may be a novel and valuable improvement. I do not think that Prof. Tait does justice to Mr. MacAulay in making so much of a trifle such as passes unnoticed or un- appreciated in the previous work of others. There is, I know, much more in Mr. MacAulay's mathematics than Prof. Tait has yet fathomed. For my own part, I like to translate it into vectors, not merely because it is then in a form I am used to, and is plainer, but also because the true inwardness of these processes involving linear operators is properly exhibited by the dyadical way of viewing them in conjunction with vectors, without the forced and unnatural amalgamation with quaternions, and the attendant obscurities. This seems to me to be par- ticularly true in physical applications. I should not be writing this note were it not for the misconceptions that Prof. Tait indulges in about what he does not know, viz. vector algebra apart from quaternions. At the same time, to avoid possible misunderstanding, I disclaim any hostility to Mr. MacAulay's quaternionic innovations, although I must agree with Prof Tait as to the "singular uncouthness" of some of his expressions in their present form. I hope he may be able to see his way to do his work vectorially. It will be more amenable to innovations, I think, without mental wrenches. At any rate he is a reformer, and not afraid to innovate when he thinks fit. Oliver Heaviside. Paignton, Devon, December 30, 1893. The Second Law of Thermodynamics. I APOLOGISE to Mr. Bryan for unintentionally reading into the Report, Article 17, what he did not intend to be there. I understand now that according to his view conservative systems are not alone to be included in the Clausian proof. My point, however, is (or was) that they ought to be ex- cluded, at all events when there is only one controllable co- ordinate V, because (l) in conservative systems the virial equation gives a relation between T and v, so that only one of them is independent. That, I submit, is true in fact. And (2) the second law, I said, requires two independent variables. That, however, is a question of definition, and if Mr. Bryan were to take the equation r9Q _ „ for a complete cycle, whatever be the nature of the system, as a definition of the second law, I see no valid objection to that definition. I admit, and did admit, that for a conservative system, moving in a complete cycle, ■aQ_ T \' o, January ii, 1894] NA rURE 247 and therefore I admit that if Mr. Bryan attaches his wheel and windlass to my pistin of constant mass, we should get /' T for each complete turn of the wheel. Whether that equation can be correctly said to express the second law, where there is only one independent variable, is a question of definition of the second law. I said, also, that if we are at liberty to vary the mass of the pistin, we have two independent variables, but no longer a conservative system. Mr. Bryan, with greater generality, points out that the same effect would be produced by altering the gravitation-potential. The objections to Clausius's proof generally cannot be more forcibly stated than they are in the Report. What is required is a definition of the time "?." The absence of that definition is to my mind not only an objection, but a quite fatal objection. If, as I proposed, we make v~ that answers the purpose for the very limited class of cases in which __ ax = $^a-^. dv A treatment of the subject in generalised coordinates is as follows : — Let ^i . . . yi. be the unconstrainable, ^i . . . q^ the controllable coordinates, concerning which latter I assume, as does Boltzmann, that q or J, and also i-f are to be ne- ^ dt dt- glected. Let x be the potential, t the kinetic energy, T the mean value of t. Then we have generally aQ_ aio,T.i{a,,.(|-|),, dT In some cases the term does not appear, and therefore dq in this class of cases 9Q T = a log T + T-(9X ^P Now let/^/yi . . . dyn be the chance that in the stationary motion with the qi. constant, the coordinates shall lie between the limits ji and_;'i + dy\, &c., so that . xfdy^ and This makes dx dq dx dq- fd}\ dyn dyn. ¥'-i\ and aQ = a log T + j Y x^fdyx -^d/dy. dyn, dyn- In order that -;^ may be a complete differential, we must make /= MR, A. H. SAVAGE LANDOR, grandson of the poet; and himself a talented artist, recently made a remarkable journey round the island of Yezo, and up many of its large rivers, repeating Captain Blakiston's route in 1869 so far as regards the north-east and west coasts, but supplementing that traveller's journey along the whole east coast and in the interior. He travelled alone, with practically no equipment except for painting ; and during five months he lived almost exclusively with the Ainu, even sharing their food. He visited in this way nearly every native village in Yezo, and estimates the total number of pure- bred Ainu now on the island at about 8000, while ' "Alone with the Hairy Ainu ; or, 3800 Miles on a Pack Saddle in Yezo, and a Cruise to the Kurile Islands." By A. H. Savage Landor. (London ; John Murray, 1893.) NO. I 263, VOL. 49] the Japanese estimate of the whole Ainu population, in- cluding half-breeds, is from 15,000 to 17,000. Mr. Landor gives a lively and straightforward account of his journey, illustrated by numerous portraits, pieces of landscape, and drawings of houses and implements, which is replete with incidental information as to the ways of the primitive people and the minor adventures of the road. No European has previously covered so much ground in Yezo, and we are surprised at the modest size of the volume in which so many fresh observ- ations are recorded for the first time. The geographical results of the journey were communicated, shortly after his return, to the Royal Geographical Society, and pub- lished, with a map of the island (reproduced, with some additions, in this volume), in the last part of the Society's " Supplementary Papers." We are not aware that the anthropological data have yet been submitted to specialists, but we feel confident that they will assist notably in forwarding our knowledge of the difficult problems of Ainu ethnology. The author as an artist has a keen and dis- criminating eye for form and colour, so that his observations carry much more weight than the chance remarks of most non-scientific travellers. It seems a pity that some of the portraits are not reproduced in colour, and we trust that an effort will be made to secure for anthropological collections some of the original pictures, which we understand are still in Mr. Landor's possession. In the course of the narrative a chapter is inserted on the Koro-pok- kuru, or early pit-dwellers, the sup- posed aborigines of Yezo ; ten chapters at the end are devoted to Ainu archi- tecture, art, and graves, Ainu heads and their physiognomy, movements and attitudes, clothes, ornaments and tattoo- ing, music, poetry and dancing, heredity, crosses, psychological observ- ations, physiological observations, pulse-beat and respiration, odour of the Ainu, the five senses, superstitions,, morals, laws and punishments, marital relations and the causes that limit population. These and an appendix giving mea- surements of the Ainu body constitute a definite addition to science, which loses but little of its value through being expressed in popular language. Indeed,, it is a matter of some importance that such facts should be disseminated by a book which, altogether apart from its intrinsic value, will be widely read on account of its fascinating human interest. The illustrations which we reproduce are extremely characteristic portraits, showing admirably the hairy character of the men, and the well-known fashion of tattooing a moustache on the women. The average measurements of ten pure Ainu (five men and five women) of Frishikobets, on the upper Tokachi river, were as follows : — Height, 62^ inches for men, 58f- inches for women ; length from tip to tip of fingers with arms outstretched, 65 ^^ inches for men, 61] inches for women; chest measurement, 37 jV for men, 34-5- for women. The pure Ainu physiognomy is described as follows :— " When seen full-face the forehead is narrow and sharply sloped backward, the cheek-bones are pro- minent, and the nose is hooked, slightly flattened, and broad, with wide, strong nostrils. The mouth is generally January ii, 1894] NATURE 24.9 large, with thick, firm lips, and the underlip well developed. The space from the nose to the mouth is extremely long, while the chin, which is rather round, is comparatively short and not very prominent. Thus the face has the shape of a short oval. The profile is con- cave, and the mouth and eyebrows are prominent .... In the supraorbital region the central boss is extremely well marked ; also the brow ridges, which, however, are slightly less conspicuous than the central boss. The ears are usually large, flat, and simply-developed." Mr. Landor shows, by a series of detailed contrasts, that the pure Ainu has no similarity whatever to the Mongolian type. The colour of the skin he found to be light reddish brown. The eye is particularly contrasted to the Mongolian eye, having a similar form and setting to that of North Euro- peans, while the iris is light brown or dark grey — rarely black or dark brown, except in the case of half-breeds. The eyes are very expressive, and show the emotions in an interesting way. In adults the hair is black, wavy, and inclined to form large curls ; children have lighter hair, and in the north-east of Yezo several men were seen with reddish hair and beard. Mr. Landor never saw the pure Ainu laugh, though on one occasion he induced a man to "roar"' with surprise and delight. The various emotions are expressed by slight changes of posture or gesture, but the Ainu do not care to show their feelings ; they have no sense of shame, and even fear. appears hardly to be known. The women do most of the hard work, but the men when hunting can walk forty miles a day without fatigue, although they usually prefer to ride, ponies being plenti- ful and of a good breed. In moving a load or heavy object the Ainu neverpush, but always pull towards them. They appear to use the feet and toes very freely to help their hands and fingers, and they readily employ their teeth, preferring to pull with the teeth than the hand when an unusually heavy haul is necessary. The whole ap- pearance struck Mr. Landor as exactly like the recon- structions of the primitive man of northern Europe, and many of their movements recalled those of the anthro- poid apes. In sexual matters the Ainu appear to have no definite rules, but a form of endogamy is common, which scarcely differs from promiscuity. The people are extremely filthy, both in their persons and in their huts, the pre- NO. 1263, VOL. 49] valence of insect parasites being remarkable. They seem to have an acute sense of smell, distinguishing between the odour of an Englishman and a Japanese, but oblivious to their own very marked perfume— an intensified form of the "peculiar odour of an uncleaned monkey's cage." The sense of touch is singularly defective, and even when the extremes are painful, they cannot distinguish the sensation of heat from that of cold. Their hearing is very acute. Mr. Landor is severe on those writers whose imperfect acquaintance with the Japanese half-castes on the southern coast has led them to theorise on Ainu religion. He acknowledges only " a rudimentary kind of totemism " in connection with the bear festivals, and '' a certain amount of fear and respect for anything that supports their life or can destroy it." In every respect the new observations now published make the Ainu appear to be the most primitive of primitive races in the northern hemisphere. The author larings forward reasons which led him to believe that the Ainu, coming from the north of Asia, and possibly of the same stock as the North Europeans, conquered and dispossessed the Koro-pok-kuru who had come to Yezo from the Aleutian Islands and were akin to the Eskimo. H. R. M. THE PURIFICATION OF BACTERIA} SEWAGE BY 'T^HE diffusion of bacteriological knowledge amongst -■- the general public is already beginning to affect the patent list, and numerous inventions which the world is at present asked to take advantage of claim to have some special efficacy in regard to micro-organisms. The pamphlet before us is intended to introduce to public notice one of these bacteriological inventions in a field which has already exercised the ingenuity of many inventors — both professional and amateur — viz., the purification of sewage. In this case the invention is called the " cultivation filter-bed," and the inventor is Mr. Scott Moncrieff, whilst the investigation of its efficiency has been made by Dr. A. C. Houston. The new process of treatment consists essentially in passing the sewage up- wards through a filtering medium 14 inches in depth, and composed of successive layers of flint, coke, and gravel. To quote the words of the report, "the rationale of this system of sewage disposal seems to depend on the fol- lowing well-recognised truths : — " I. That bacteria under favourable conditions are capable of indefinite multiplication. " 2. That bacteria exist in sewage which are capable of peptonising solid organic matter, or, in other words, of preparing it, by a process comparable to that of digestion, for its final disintegration. " 3. That in nature the purification of the refuse of the organic world is effected by the life-history of these or similar micro-organisms." Having thus learnt what the nature of the method of treatment is — viz. upward filtration without aeration, or, in other words, putrefaction, we turn in the next instance for information as to the effect of this treatment. The report contains a number of analytical tables, but not one of the analyses shows us the composition of the crude sewage, and consequently the numerous analyses of the effluent furnish no data whatsoever as to the purifica- tion effected. Turning to the analyses of the effluent, however, we are not surprised to learn that it has generally an unpleasant odour, whilst the albuminoid ammonia in an average sample was i"i part per 100,000 ; but why this should be regarded as " very sm.all," we are 1 "Report upon the Scott JNIoncriefF Sifstem for the B icteriolo^ical Purification of Sewage." By Alex. C. Houston, M.B., D Sc. Edin. (London : Waterlow Bros., 1S03.) 250 NATURE [January ii, 1894 at a loss to discover. Nor was even the inventor appar- ently satisfied, for we are told in the report that '' in order to still further improve the quality of the effluent by longitudinal filtration, by oxidation, and by the action of micro-organisms, Mr. Scott Moncrieff devised what he has termed nitrifying channels. These in their sim- plest form consist of half-channel pipes joined together with cement and filled with coke." These channels were originally 30 feet in length, but subsequently they were increased to 80 feet. As regards the efficiency, or rather inefficiency of these channels, we are able to form an opinion from analyses given on pp. 19 and 20 of the report ; from these it appears that the free ammonia befor'!-vz.s 3'2 parts per 100,000, and <2// and of Dr. L. Krahmer, Ordinary Professor of State Medicine in Halle University. By the death of Dr. George Gordon, natural history in the north of Scotland has lost one of its most enthusiastic and oldest supporters. He died at the advanced age of ninety-two years, on December 12, after working nearly three-quarters of a century in the cause of science. A COMMITTEE of eminent men of science, art, and literature, with M. Pasteur at its head, has been formed in Paris for the purpose of raising the funds to erect a monument to the memory of the late Dr. Charcot. Dr. R. Brauns has been appointed Professor of Mineralogy in the Darmstadt Technical High School. A BOTANIC garden and arboretum has been established at Buenos Ayres, by M. C. Thays. Prof. G. Schweinfurth has started on his third botanical exploring visit to the Italian colony of Eritrea, on the Red Sea. Prof. F. Delpino, of Bologna, has been appointed Director of the Botanic Garden at Naples, and Professor of Botany in the University. One of the bequests in the will of Mr. A. Peckover, who died last month, is the sum of ^100 to the Linnean Society. Mr. F. E. Ives has been awarded the Elliott Cresson gold medal of the Franklin Institute for his system of colour photo- graphy, known as composite heliochromy. The Society for the Encouragement of Industry in the Netherlands offer a prize equivalent to ;^30, and a gold medal, for the best memoir on the production of electricity by wind- mills. Intending competitors must send in their schemes before July I, to the Secretary of the Society, Haarlem, Holland. Electrical engineers have as yet been unable to perfect a system of working tramways electrically along crowded thoroughfares. Inventors have long been engaged endeavouring to overcome the difficulties, and as an incentive to them to throw themselves into their task with renewed vigour is an an- nouncement in the Times that the Metropolitan Traction Com- pany of New York City has offered the handsome award of about ;/^io,ooo for a system of street-car propulsion which will be superior or equal to the overhead trolley system, but with- out possessing the objectionable feature of the trolley for crowded thoroughfares. The Committee on Science and the Arts of the Franklin Institute has issued a circular in which attention is directed to three awards under its control. The character and conditions of these awards are, briefly, as follows : — The Elliott Cresson Medal is of gold, and may be granted for some discovery in the arts and sciences, or for the invention or improvement of some useful machine, or for some new process, or combination of materials in manufactures, or for ingenuity, skill, or perfection in workmanship. The John Scott Legacy Premium and Medal (twenty dollars and a medal of bronze) is awarded for useful inventions. The Edward Longstreth Medal of Merit is 252 NA TURE [January ii, 1894 of silver, and may be awarded for useful invention, important discovery, and meritorious work in, or contributions to, science or the industrial arts. Full directions as to the manner and form in which applications for the investigation of inventions and discoveries should be made will be sent to interested persons on application to the Secretary of the Franklin Institute, Philadelphia. In the annual report just issued by the University of Edin- burgh, acknowledgment is made of several benefactions. We read that a legacy of ^looo has been bequeathed by the late M-:; Elizabeth Trevelyan for the foundation and endowment of a scholarship in engineering and mechanical and useful arts, and another bequest, by the late Mr. George Scott, of ;^iooo is destined for the foundation of a scholarship in arts. Since the close of the previous academic year a handsome bequest of ^5000 by the late Mr. Alexander Low Bruce, to assist in the foundation of a chair of public health, has been intimated. Of very special interest and value is a collection of Arctic and other relics and curiosities, made by the late Dr. John Rae, the distinguished Arctic explorer, along with his bust, presented by his widow. We would call attention to a new departure in University College. During the Easter Term Dr. L. E. Hill, Assistant Professor of Physiology, will give a practical course of instruc- tion in psycho-physiology. The course will take the student methodically over the several senses, and familiarise him with the methods by which the new branch of science known as physiological-psychology or psycho-physics determines the pre- cise manner in which sensation varies both quantitatively and qualitatively with variations of the stimulus, of the particular portion of the sensitive surface stimulated, and so forth. This is, we believe, almost the first attempt in this country to give to students systematic laboratory instruction in those experimental methods of investigating sense-phenomena which have already borne such valuable fruit in Germany and America. As supply- ing an exact and practical method of measuring sensibility the course should further prove valuable to teachers and others. The increasing interest in psychological investigation in America is shown by the establishment of many psycho-physical laboratories, and by the formation last year of the American Psychological Association, which drew to Columbia College at its second meeting, December 27 and 28, a distinguished gathering of original investigators. The programme, besides the annual address of the president, Prof. G. T. Ladd, of Yale University, included the following papers : — The psychological standpoint, by Prof. G. S. Fullerton, University of Pennsylvania ; the case of John Bunyan, by Prof. Josiah Royce, of Harvard University ; some account of investigations at Columbia College, by Prof. Cattell ; same at Harvard University, by Prof. Miin- sterberg ; same at Yale, by Prof. Scripture ; experiments on visual memory, by Mr. H. C. Warren, of Princeton University ; Do we ever dream of tasting ? by Prof. J. C. Murray, of McGill College, Montreal ; an early anticipation of Mr. Fiske's doc- trine as to the meaning of infancy, by Prof. N. M. Butler, of Columbia College ; accurate work in psychology, by Dr. E. W. Scripture, of Yale University ; the problem of psychological measurement, by Mrs. G. H. Mead, of the University of Michigan ; the perception of magnitude and distance, by Dr. J. H. Hyslop, of Columbia ; pain and pleasure, by Mr. H. R. Marshall, of New York ; pain contrasts, by Prof. Edward Pace, of Catholic University, Washington ; the confusion of content and function in the analysis of ideas, by Prof. D. S. Miller, ofBryn Mawr College. Prof. James, of Harvard, was elected president for the ensuing year, and Princetown was named as the place of the meeting on December 27 and 28 of this year. NO. 1263, VOL. 49] At the general meeting of the Association for the Improvement of Geometrical Teaching, to be held at University College, Lon- don, January 13, a new undertaking will be proposed by the Council, viz., the establishment of a journal of elementary mathematics, to appear three times a year, and to be specially devoted to such subjects as are usually taught in secondary schools. A COURSE of lectures on matters connected with sanitation will be given at the Sanitary Institute from January 26 to April 2. Among the lecturers are Sir Douglas Galton, Profs. Corfield, H. Robinson, A. W. Blyth, A. B. Hill, Dr. J. F. J. Sykes, Dr. A. Newsholme, and Dr. Hamer, The lectures have been arranged for the special instruction of those desirous of obtaining a knowledge of the duties of sanitary officers. On Tuesday next (January 16), Prof. Charles Stewart, the newly elected Fullerian Professor of Physiology in the Royal Institution, will begin a course of lectures on " Locomotion and Fixation in Plants and Animals." The Friday evening meetings will begin on January 19, when Prof. Dewar will discourse on the " Scientific Uses of Liquid Air." The annual general meeting of the Royal Meteorological Society will be held on January 17, when the report of the council will be read and the election of officers and council for the ensuing year will take place. The president of the society will deliver an address on "The Climate of Southern California." A PERIOD of very severe weather has recently been experienced over these islands and the whole of Western Europe. On the 1st inst. an anticyclone lay over Scandinavia^ and subsequently spread over the northern parts of this country, causing frost in many places, while snow showers occurred in England, accompanied by bitter easterly gales. For some days the frost and snow continued with increased intensity. The reports issued by the Meteorological Office show that on the morning of the 6th inst. the minimum temperature in South London fell to 13°, while on the previous day a temperature of 16° was recorded at Jersey, being 22" below the average mini- mum for January, and at Biarritz a reading of 14° was recorded on the 4th, being 20" lower than the reading at Bodo in Norway, within the Arctic Circle. Towards the end of the week the easterly gales had subsided in the south-east, but had spread to the northern parts of the kingdom. On Saturday morning the Meteorological Office reported a temperature of 5" in the Mid- land Counties and (y' in the centre of Ireland, but later inform- ation in the Weekly Weather Report shows that the absolute shade minimum recorded was minus 4° at Braemar and in the Midlands on that day. With reference to the temperature in the north-west of London, Mr. Symons recorded I3°'i on the 5th, and a maximum temperature of 18° '4. His long series of observations shows that the severity of the night of the 4th and 5th was only exc ceded three times in the last thirty-five years, viz. December 25, i860, January 4, 1867, and January 17, 1881 (the day preceding the blizzard); while as regards the maximum, there ha s been only one day as severe during the same period, viz, January 4, 1867, when the temperature did not exceed i6°'9. The frost continued until the morning of the 8th, when a deep depression appeared off the south-west of Ireland, causing southerly winds and a considerable rise of temperature, and by Monday evening a thaw had set in generally. Owing to delay at the Government Printing Office, Mr. H. C. Russell, the Government Astronomer for New South Wales, has only just been able to issue the results of rain, river, and evaporation observations made in that colony in 1892. In ad- dition to the usual matter, the report contains the results of an attempt to determine the average rainfall of Australia. It will January ii, 1894] NA TURE 253 be many years before the rainfall of Australia will be measured in all parts, but taking the values already obtained, and weigh- ing them in proportion to the area of each colony in which they were made, the average annual value of the rainfall for the whole of the mainland of Australia comes out as 2 1 • 1 5 inches. Another matter which Mr. Russell has investigated is the effect of alti- tude upon temperature. In works of reference it is usually stated that a rise of 300 feet causes a fall of 1° Fahr., but this quantity must evidently vary with the locality. A comparison of the average temperatures at ten different places with that of Sydney, making an allowance at the rate of 1° Fahr. for a difference of one degree of latitude, gave 344 feet as the mean elevation required to produce a fall of 1° Fahr. The report concludes with an average rainfall map, constructed on the plan described in these columns on December 21 ; a new rainfall map for the year ; a map showing the monthly distribution of rain over each square degree of New South Wales, and curves showing the height of the western rivers of that colony through- out 1892. The Transaclions of the Devonshire Association for the Advancement of Science for 1893 contain a good account of the climate of Torquay, by A. Chandler, from trustworthy instruments. This health resort is favoured by a large amount of sunshine ; dividing the year into two periods the summer has an average of 43"4 per cent., and the winter 30'5 per cent, of the possible amount. The average mean shade temperature is 5o°"2, and the mean annual range ii°'4. The mean tem- perature of summer is 56°*5, and of winter 43° '8. The highest summer temperature during the year 1892 was only 78°*2, and the lowest winter temperature was 22"'4. The mean annual rainfall for twenty-five years, 1864-88, was 37 inches ; June is generally the driest month, with an average of about 2 inches, and January the wettest, with a mean of a little over 4 inches. The prevalent winds are warm, being from south-west, and the town enjoys great freedom from storms. The observations are now organised and provided for by the Town Council. Writing upon the persecution of the Great Skua (Stercor- arius Catarrhactes) in the Annals of Scottish Natural History for January, Mr. W. E. Clarke points out that a fact worth remem- bering in the history of those birds which have become extinct within the present century, is that their extermination had, in all instances, become an accomplished fact for several years before such was realised to be the case. In order to lead orni- thologists to do something to prevent the Great Skua from a similar fate, Mr. Clarke gives an account of the persecution to which the bird is subject, and the wholesale stealing of its eggs. The evidence he brings forward shows that unless some measure of protection is immediately afforded to the Great Skua, this fine bird must soon cease to exist in Europe. Miss E. A. Ormerod contributes to the Times of Monday some observations on insect attacks upon crops and trees in this country during last year. She points out that the attacks of the year were much influenced by the exceptional deficiency of rain- fall in the early half of 1893, from March onwards, and by other weather peculiarities. With regard to the imported locust appearances, the specimens which reached her alive proved to be of a South European species, which is not gregarious, and in its own country, though of large size, is known to do no appre- ciable damage. From the climatic requirements of locusts, therefore, and also from recorded experience, there does not appear to be any reason to fear .even a possibility of locusts effecting a settlement in this country. It is pointed out by Miss Ormerod, however, that the presence of locusts in great quanti- ties in fodder might be detrimental to the health of animals fed upon it. NO. 1263, VOL. 49] Another note on locusts, more or less connected with the above, is contained in a statement recently issued by the Govern- ment of India {^Agricultural Ledger Series, No. 2, 1893). Dr. Glinther suggested to the Government, some time ago, that dried locusts might be used for insectivorous cage-birds and game- birds which are now reared at great expense upon ants' eggs. His letter was submitted to Mr. E. C. Cotes, of the Indian Museum, Calcutta, who has reported favourably upon it, but thinks there would be a difficulty in keeping up the supply from India at the present time. But though the invasion of India by the locxxst A cridium peregritnim, Oliv. , is now practically at an end, Mr. Cotes says that Northern Africa, which was badly in- vaded in 1892 by the same insect, and is still infested, might offer a favourable ground for experiment. The silk-spider of Madagascar forms the subject of an interesting article in Die Natur, by Dr. Karl Midler. Its native name is Halabe, meaning great spider. This Halabe, or Nephila Madagascaricnsis, spins threads of a golden colour, and strong enough, according to Maindron, to hang a cork helmet by. The female spider may attain a length of 15 cm., while the male does not exceed 3 cm. A single female indi- vidual, at the breeding season, gave M. Camboue, a French missionary, some 3000 m. of a fine silken thread, during a period of about twenty-seven days. The thread was examined with a view to creating a new industry. Specimens tested at a temperature of i"]^ C. showed an elongation of I2'48 percent, under a weight of 3*27 gr. Small textures woven of these threads are actually used by the natives for fastening flower? on sunshades, and for other purposes. Prof. J. Wiesner, who has recently been studying the influence of artificial rain upon European and exotic plants, gave an account of his results at a recent meeting of the Vienna Academy. Some of the plants, called by Prof. Wiesner ombrophobe, can only for a short time stand continuous rain, and soon shed their leaves and decay. Others, called ombrophil, can stand it for months together. Plants growing in dry places are, as a rule, ombrophobe, but the reverse cannot be said of plants growing under wet surroundings. Leaves appear to gain in power of resisting rain as they develop, and to reach a climax in this respect at the period of their greatest vital activity, after which they lose much of that power. Leaves which can be wetted by water are usually ombrophil, those which cannot are usually ombrophobe, but in cases where leaves are both ombrophobe and easily wetted, they. are extremely sensitive to rain. Prof. Wiesner thinks that ombrophobe leaves are enabled to resist the putrefactive action of water, especially at high temperatures, by certain antiseptic substances which they contain. The same may be said of hydrophil roots and submerged parts of aquatic plants. The edible lichen of Japan, known as " iwatake," is de- scribed in the Botanisches Centr alblatt (1893, No. 45) by Dr. M. Miyoshi, under the name Gyrophora esciilenta, sp.n. Its commercial value is due to the large amount which it contains of starch and of some gelatinous substance ; and it is also ex- tensively used in Japanese cookery as a condiment, having a pleasant flavour and being free from purgative properties. In some parts of Japan, especially the mountainous districts, it completely covers the moist granite rocks. After drying it is sent into the towns, and a large quantity is annually exported. In a recent number of \.ht Electrical IVorld {ofNew Yoik), Lieut. F. Jarvis Patten has described a novel method of obtain- ing sinusoidal alternating currents of very low frequency. The apparatus, which the inventor calls a "liquid commutator," consists of a circular vessel, provided with two conducting elec- trodes fixed at the opposite extremities of a diameter. A con- 254 NATURE [January ii, 1894 tinuous current is passed from one of these electrodes to the other, through the liquid contained in the vessel, the strength of the current being controlled by an internal resistance. A vertical spindle at the centre of the trough carries a revolving arm pro- vided with conducting plates or electrodes at its extremities. These plates are insulated from one another, and are connected to two ring contacts carried by the central spindle. Two brushes bear on these rings, and convey the alternating current. By suitably altering the connections and electrodes, it is possible in the same manner to obtain multiphase currents. The author finds that the currents obtained are practically sinusoidal, and lie suggests that they will be of considerable physiological use. At a recent meeting of the Societe Francaise de Physique, M. Hurmuzescu showed some experiments on electrical con- vection in air. He finds that if you cause dissymmetry between the two discharging knobs of a Wimshurst electrical machine, by fixing a point to one of them, then, on placing a sensitive gold-leaf electroscope at a distance of about two metres, when the machine is worked, the discharging knobs being separated, the electroscope becomes charged. The electroscope becomes more highly charged when it is fitted with a point than when it has only a varnished ball at the end of its electrode. That the charge is not due to induction, but to convection through the air, is shown by the fact that the interposition of a metallic screen does not interfere with the effect, while if the electroscope is covered over by an insulating shade no electrification is ob- servable. In addition, it is found that the charge on the electroscope is of the same sign as that of the terminal of the machine on which the point is fixed. The most marked and rapid results are obtained when the point on the machine is negatively electrified, while no effects are observed if the point is turned towards the plates of the machine. An account of Victor Schumann's successes in photograph- ing rays of very short wave-lengths is given in No. 50, of the Natunoissenschaftliche Rundschmi. These successes are entirely due to the elimination of absorption by the material used in the prisms and lenses and, what is especially note- worthy, of the layers of air intervening between the luminous source and the plate used for photographing the spectrum. This elimination has resulted in the exhaustive exploration of the hitherto doubtful ultra-violet region between 231 '4 and 185 '2 fi-fx., and the annexation of the region down to 100 yii^ to the known spectrum. For this it was necessary to get rid of the absorption due to the film of gelatine in which the sensitive silver salt was embedded, and this was accomplished by the substitution of a pure silver bromide plate. The camera, the spectroscopic apparatus, and the spark tube were all con- nected together and exhausted. The very first exposure on the hydrogen spectrum showed that the known radiations of that gas only represent a portion of '-its total radiance. The newly-traced portion turned out to be extremely rich in lines, with a maximum at about 162 ju/i, and consisted of fifteen groups of lines disposed pretty evenly, containing altogether about 600 lines, with intensities decreasing from the maximum in both directions, rapidly at first, and then very gradually. The wave-lengths of these lines are as yet undetermined. Pro- visionally, that of the smallest wave-length recorded is estimated at 100 ju/t. The spectra of aluminium, cadmium, cobalt, and other metals end at about 170 [x.11.. A layer of normal air i mm. in thickness appears capable of absorbing all radiation of smaller wave-length than that. Dry gelatine absorbs eagerly all waves beyond 217 ^/t,. Quartz is not suitable for prisms and lenses, and white fluor-spar is, so far, the only material that answers all requirements. The accurate determination of the new wave-lengths, the further investigation of the absorption due to air, and the further extension of the NO. 1263, VOL. 49] ultra-violet region, are the problems which Herr Schumann is now working at. In a note published in Nature on July 20, attention was drawn to the manner in which the virulence of the typhoid bacillus may be increased by the products of other organisms being inoculated along with it into animals. In an elaborate paper, recently published in the Aniiali deW Istitiito d'lgiene di Roma^ vol. iii. 1893, p. 117, Roncali shows how the virulence of the tetanus bacillus may be intensified by similar means. Thus an animal inoculated with this organism usually succumbs in three days ; if, however, the soluble products of this bacillus be accompanied with those of some other organism, death ensues with tetanic symptoms in from 12-26 hours. It was also found that if by some means or other the power of resistance inherent in the animal was first diminished, the action of the tetanus toxine was greatly accelerated. This condition of diminished resistance was obtained by either first inoculating some other organism, or by introducing putrid infusions of meat or vegetables in themselves proved to be perfectly harmless to the animal in question. To further illustrate this point, symptoms of chronic tetanus were induced in animals by the inoculation of the soluble products of the tetanus bacillus obtained after from 3-4 days' growth. After from 8-10 days, if pathogenic or non-pathogenic organisms were introduced, the animals died in from 16-18 hours, whilst if they were not subsequently interfered with, they usually recovered in from 20-35 days. In the course of these investigations the inter- esting discovery was made that the bacillus of rabbit septicasmia, which is usually non-pathogenic to mice, may be rendered fatal to the latter by cultivation on agar-agar containing the soluble products of the tetanus bacillus. These experiments indicate how harmless saprophytes, such as the b. prodigiosns, may under given conditions become the servants of disease organisms, either by diminishing an animal's power of resistance, and so preparing the way for the entrance and work of pathogenic bacteria, or by hastening the lethal action of the latter by subsequent intrusion into the system of the infected animal. We have received three fascicules of the forthcoming volumes of the Met/ioirs (Zapiski) of the Russian Geographical Society. One of them contains D. Pokotilov's elaborate paper, " U-tai,^ its Past and Present," given to the description of the holy mountain of the Buddhists and its numerous monasteries. M. Pokotilov has followed the same route as Dr. Jos. Edkins ("Religion in China"'); and also describes his journey from Pekin to the U-tai Mountain ; but he also gives a detailed description of the Buddhist sanctuary, and the history of the development of Buddhist monasteries at this spot. The learned Russian scholar has utilised, moreover, the Chinese works devoted to the same subject. Taken in connection with Prof. Pozdneev's large work, " Sketches of the Life of Buddhist Monasteries and Buddhist Clergy," lately published in the Memoirs of the same Society (Ethnography, vol. xvi., 1887), M. Pokotilov's paper is a very valuable addition to the literature of the subject. Another fascicule of the Zapiski (Geography, vol. XV. No. 3) contains F. Schwartz's report on his astrono- mical, magnetical, and barometrical observations in Bokhara, Darvaz, Karateghin, and Russian Turkestan, made in 1886. A third fascicule (Statistics, vol. vii. No. 2) contains a detailed description of the Eritrean colony of Italy, by M. A. Troy- ansky. The Physical Society of London has just issued the third part of vol. xii. of its Proceedings. The first part is published of the new Flore de France (in eluding Corsica and Alsace-Lorraine), by MM. G. Rouy and J. Foucaud. January ii, 1894J NA TURE 255 We have received No. 8 of the first volume of " Contribu- tions from the U.S. National Herbarium." It is chiefly •occupied by the description of American grasses, a large number of new species being described. The current number of the Asdepiad {\o\. x. No. 39), edited by Sir B. W. Richardson, F.R.S., contains a good account of the works of Robert Boyle, and an autotype of that eminent investigator, from an engraving by R. Woodman. The second edition of Clowes' and Coleman's " Quantitative I Analysis" (J. and A. Churchill) is about to be issued. The * authors have thoroughly revised the book, and have introduced many recent modifications in processes, as well as new methods of analysis. The yottrnal of the Royal Statistical Society (part iv. vol. Ivi.) has been received by us. It contains, among other papers, the presidential address delivered by Mr. Charles Booth in Novem- ber last, and that given by Prof. Nicholson before the Economic Science and Statistical Section of the British Association at the Nottingham meeting. We have received " Eau Sous Pression," by M. F. Bloch, being a new volume in the Aide-Memoire Series published by ■Gauthier-Villars, Paris. The early chapters in the book are devoted to enunciating hydrostatic and hydrodynamic principles, and stating the general theory of pumps, hydraulic rams, and -accumulators. The subject is then treated from a practical point of view. The book contains thirty illustrations in the "text, and does credit to an excellent series. The Technical Instruction Committee of the County Council of Cumberland has issued a Directory of the Science and Art Classes, &c. , under its control. We learn from this source that the average attendance of students at science classes held under the committee's jurisdiction is 1328. The subject that obtains the highest average is theoretical chemistry ; then come agricul- ture, mathematics, plane and solid geometry, and physiography. Sound, light, and heat shows, by far, the lowest number of students, the average attendance for the whole county being only eight. The third volume (Series 3) of the International Journal of Microscopy and Natural Science has been published. The journal is the organ of the Postal Microscopical Society of London, which has for its object the circulation, study, and ■discussion of microscopic objects. The volume just received ■contains a large amount of information of use to microscopists, and several excellent papers, notably one on polarised light and its applications to the microscope, by Mr. G. H. Bryan, and a translation Uom La Diatomiste of Dr. Miquel's long article on the artificial cultivation of diatoms. The journal is well illus- trated and does credit to the society the proceedings of which it reports. We have noticed two misprints, one on p. 8, where ^^Leek'' is printed instead of Lick, and on p. 69 "Wills" is printed instead of Wells. A useful series of "Handbooks of Commercial Products" has been provided to the Imperial Institute by the Government ■of India. The books contain descriptions of the economic products of India, and among several of them recently re- -ceived is one on Indian coal, in which a large number of facts concerning the geology and working of the coal districts are brought together. The iron resources and iron industries of the southern districts of the Madras Presidency are described in another of the handbooks, the account being accompanied by a plate showing the process adopted for the manufacture of wrought iron. The furnace employed is roughly circular in horizontal section, four feet high, two feet in diameter at the NO. 1263, VOL. 49] base, and only nine inches in diameter at the throat. Two other handbooks of interest to us summarise the present state of knowledge concerning the characters and occurrence of Indian micas and steatite. A NUMBER of new reactions of f ormaldehyde, resulting in the preparation of several new compounds, are described by M. Henry in the Bulletin de V Academic Royale de Belgique. This lowest number of the series of aldehydes, HCHO or O^CHj, appears to be endowed with very considerable chem- ical energy, as indicated by the readiness and frequently the violence with which it reacts with a large number of substances. The reactions now described are those which occur between formaldehyde and the primary and secondary amines. If a solution of methylamine is added to one of formaldehyde, in small portions at a time, a very energetic reaction occurs with evolution of so much heat that great loss occurs unless the vessel in which the operation is performed is surrounded by a freezing mixture. When the reaction is complete, the two substances being then present in equivalent quantities, the addition of solid potash precipitates methyl methylenamine, H^C— N-CH3, from the solution. This substance is readily purified, and proves to be a colourless mobile liquid, readily soluble in water, and boiling at I66^ At the temperature of a freezing mixture of ether and solid carbon dioxide it solidifies, and may be melted again at -27°. The ethyl compound maybe similarly obtained, and is likewise a liquid ; it boils at 207-208", and melts after solidification by ether and solid carbon dioxide at - 45°. Two molecular equivalents of dimethylamine react with even greater avidity in aqueous solution with one molecular equivalent of formaldehyde, and the reaction can only be safely carried out at a very low temperature. The product is tetramethyl methylene- /N(CH3), diamine CHo\ , a colourless and very mobile liquid ' ^N(CH3), which fumes strongly, dissolves in water, and boils at 85°. Ether and solid carbon dioxide will not solidify it. The tetraethyl compound, prepared in an analogous manner, is also a fuming liquid ; it boils at 168°. All these compounds are insoluble in strongly alkaline liquids. They readily absorb water, like the amines, formaldehyde and the substituted ammonia being regenerated. A somewhat curious fact is observed in connection with the boiling-points. Methyl methylenamine CHo : NCH3 boils at 166 , and methyl isocyanate CONCH^, the analogous oxygen compound, at 43^ ; so that the replacement of two atoms of hydrogen by one of oxygen is accompanied in this case by a reduction of the boiling point by 123 . On the other hand, while the compound .N(CH3)., CH„ boils at 85°, the corresponding oxygen com- ' \N(CH3). pound tetramethyl urea boils at 177', nearly a hundred degrees higher. In a further communication to the Bulletin of the Belgian Academy, M. Henry describes a new mode of preparing halogen substitution products of the oxides (ethers) of the alkyl radicles. The raonochlorine derivative of methyl ether CH._.Cl'0CH3 was prepared in 1877, by Friedel, by chlorination of the ether. It is now shown to be much more readily obtained by mixing a concentrated aqueous solution of formaldehyde with methyl alcohol and saturating the cooled solution with hydrochloric acid gas. The compound separates as a colourless liquid layer at the surface of the solution, and by distillation the pure substance is at once obtained, boiling at 60°. The monobromine derivative may be obtained in a precisely similar manner, and proves to be a pungently-fuming liquid, boiling at 87°. The iodine com- pound is also afforded by the analogous reaction with hydriodic acid, the pure liquid boiling at 1 24",-;but, in addition, the di-iodine 256 NATURE [January i i, 1894 derivative CHoI-O-CHoI is simultaneously formed. Incidentally M. Henry observed that phenol reacts in a most violent manner with formaldehyde, great heat being evolved, and a remarkable porcelain-like substance being produced which is insoluble in all the usual solvents. The additions to the Zoological Society's Gardens during tbe past week include a Black-handed Spider Vi-onVey {Atcles ater. ? ) from Eastern Peru, presented by Mr. L. Clarke ; a Coot {Fulica atra) European, presented by Mrs. L. Spender : two Wedge-tailed Eagles {Aquila audax) from Australia, pre- sented by Mr. F. W. Burgess ; a Long-billed Butcher Bird {Barita destructor) from New Holland, deposited ; a Salvin"s h.m2.zo^{Chrysoth salvini){xom. South America, two Purple- capped Lories {Lorius dofiiicella) from Moluccas, purchased ; a Yak {Paphagus grunnicns) born in the Gardens. OUR ASTRONOMICAL COLUMN. Harvard College Observatory Report. — In this, the forty-eighth annual report to the President of the University, Prof. Pickering, the director of the Astronomical Observatory of Harvard College, has a fine record of work to refer to, which has beencarriedoutduringthe twelvemonths endingOctober3i, 1893. We make the following brief extracts from the accounts given of the various branches of work done in the several departments. The East Equatorial was on the whole worked by Mr. O. C.Wen- dell, and employed for the systematic observation of variable stars upon the system lately adopted. Photometric observations of Jupiter's satellites (twenty-five in number) were made ; forty- eight series of wedge photometer observations (3354 measure- ments) for determining the brightness of 11 18 stars occurring in the Durchmusterung, were also made. Among other uses of this instrument were the observations of comets, measurements with the polarising photometer, &c. The Meridian Circle has been, as usual, at work under the direction of Prof. W. Rogers, while good progress has been made in the reductions of the observations of the southern stars with the meridian photometer. The observ- ing list for the latter observations contains about 6oco stars, and excluding the 4000 already contained in the Harvard Photo- metry, three quarters have now been made. Mr. W. Reed, with the West Equatorial, on eighty-seven evenings has made observ- ations on variable stars (489), comparison stars (1318), and ten on the brightness of Comet Holmes. With regard to the Henry Draper Memorial, Mrs. Fleming has given us, as usual, her list of stars with peculiar spectra, and her examination has resulted in the discovery of the new star in Norma. In addition to a classification of the 20149 spectra of stars for the new catalogue, work has been done with the 8-inch and 11 -inch, resulting in the production of 2424 and 1037 photographs respectively. A most interesting series (213 photographs) of j8 Aurigas has also been obtained. In the Boyden Department, in addition to an expedi- tion to observe the total solar eclipse in April last, important work was done by the 13-inch telescope, which was devoted to a study of the members of the solar system, an account of which has been previously referred to in this column. Prof. Bailey, the director of the third expedition, began work on April 4, and with an 8-inch and 13-inch telescope has obtained 1516 and 852 photographs with these two instruments respectively ; some ot these pictures show some very remarkable southern clusters. This observatory has also a meteorological station on Mount Chachani, 16,650 feet, the highest in the world ; a second one has now been established on the volcano El Misti, at an eleva- tion of 19,200 feet, with self-recording instruments. The Bruce photographic telescope will now be soon completed and ready for work, but the Bruce transit photometer has already made some progress towards the observations of tenth magnitude stars as standards for faint stellar magnitudes. Zodiacal phe- nomena have also been systematically observed. The new brick building for the thirty thousand glass photographic plates is finished, and the plates have been transferred. In his concluding remarks Prof. Pickering alludes to the diffi- culty, now becoming more and more significant every year, with regard to the observation of faint objects, owing to the increasing number of electric lights in the neighbourhood. An "electric tram" trouble seems also approaching a focus in A-0. /3. No. obs. 179-4 + o°-4 16 i79"4 + i°-3 16 179-6 4-0^-5 22 the near future. We hope Prof. Pickering will successfully override these difficulties. The "Gegenschein." — In order to find out the origin of this peculiar phenomenon an effort has been made to obtain observations as nearly contemporaneous as practicable, and made at widely separated points. The distribution of light in the zodiac, and particularly of the slight maximum nearly opposite the sun, and known as "Gegenschein," or Counter- glow, has for some time past attracted the attention of astro- nomers, and we hope the present systematic attempt will be rewarded with successful results. Those cooperating in this work are Prof. Barnard, of the Lick, Prof. Bailey at Are- quipa. Prof. Searle and Mr. Reed at Strafford, Vermont, and Mr. Douglass at Cambridge, U.S.A. Prof. Barnard, after describing the general appearance of this phenomenon (Astr. Journal, No. 308), besides noticing the change of form and its connection with a zodiacal band, finds that his observations show that the "Gegenschein" lags behind exactly opposite the sun, or, in other words, that its longitude is not quite 180° greater than that of the sun. His numbers are : — From 1883-1887 1888-1891 Sept. and Oct. 1893 His observations show no decided parallax to the object, but an appreciable north latitude, as seen from the value of ;8 in the table above, will be noticed. Prof. Barnard believes that the latitude of the " Gegen- schein" and the lagging in longitude to be due to "atmo- spheric absorption, and that the object is exactly opposite the sun, and that it lies in the ecliptic, and if its centre were a definite point the position of the sun could be accurately deter- mined from observations of the ' Gegenschein' by changing the sign of the declination and subtracting twelve hours from the Right Ascension." GEOGRAPHICAL NOTES. The Arctic expedition planned by Dr. Stein, of the U.S. Geological Survey, as the first of a series for the gradual ex- ploration of the Arctic regions from a base in Ellesmereland (see Nature, vol. xlix. p. 18), is being actively prepared. Accord- ing to Reuter's agency the command of the expedition has been offered to Baron Nordenskiold, who has contributed .!^25o to its fund and has arranged by cable to keep a place open for a Swede on the staff. l3r. Stein has agreed to the latter pro- posal, and has stated that his first duty will be to search for the Swedish naturalists Bjorling and Kalstennius, whose tragic story has been biiefly told in this column (p. 85). The possi- bility that the unfortunate party was able to reach the Eskimo of Ellesmereland and live with them for two years is very slight, but as long as the faintest chance remains it is satis- factory to find that arrangements are being made for a search and possible succour. M. E. A. Martel, whose researches on the subterranean watercourses of France and Greece are well known, has been investigating the Adelsberg Grotto and other karst phenomena of Carniola, in company with Herr Putick. They were able to solve conclusively some points in the hydrology of the river Piuka, and found their way into parts of the Adelsberg cavern never before reached, proving that the whole length of the under- ground passages in connection with it is not less than 10 kilometres. With the publication of vol. xix., dealing with South America, M. Elisee Reclus' great work, " Nouvelle Geographic Universelle : La Terre et les Hommes," has been completed. Twenty years have elapsed since the first volume was published, and these years have seen immense advances of geographical knowledge ; but by the device of treating the less known con- tinents at the end of the work, it has not fallen seriously out of date. Its great features are the philosophic grasp of the relation of man to his natural surroundings, and the working out of this relation for each continent and country. It is unfortunate that the state of public feeling on the continent makes it impossible for the University of Brussels to carry out the appointment of M. Reclus toaprofessorshipthere(seeNATURE, vol. xlvii. p. 327 on account of his political views. NO. 1263, VOL. 49] January i i, 1894] NATURE 257 At a meeting of the Royal Scottish Geogrnphical Society, held last week at Edinburgh, with Prof. J. Geikie in the chair, to consider the question of Antarctic research, the following resolution by the council of the Society was read : — " That at this meeting, held for the discussion of Antarctic research, the Royal Scottisii Geographical Society resolves to give its hearty support to the promotion of further exploration in the Antarctic. The Society's council is of opinion that at the present time a properly equipped Government expedition would, with the in- creased advantages of steam and modern appliances, have every prospect of successful explorations in the South Polar regions. The council is also convinced that the additions which might be made to our knowledge of climatology, terrestrial magnetism, geology, and natural history, would be of such practical scientific value as to fully justify the equipment of such an expedition at national expense. Towards the promotion of this object the council considers it desirable to submit a memorial on this sub- ject to her Majesty's Government, and in this action they invite the cooperation of all the leading scientific societies of Scotland. To this end the Society appoints an Antarctic committee, con- sisting of Dr. John Murray, Prof. James Geikie, Dr. Buchan, and Mr. J. G. Bartholomew, together with the delegates of the other scientific societies, with instructions to draft such a memorial and take such steps towards the promotion of Antarctic exploration as is deemed desirable." A committee of the Royal Geographical Society was formed on the occasion of Dr. Murray's paper (Nature, vol. xlix. p. 112), and has already been at work for some time with a view to bring the whole question of Antarctic exploration before Government. The course of action of this committee we understand to be the memorialisation of the Royal Society, requesting that body to take the lead in approaching the Government after ascertaining the feeling of all the leading scientific societies of the United Kingdom. THE RISE OF THE MAMMALIA IN NORTH AMERICA} II. Primitive Trituberailism . There is a very general tendency among the vertebrates as a whole, fishes and reptiles as well as mammals, to form what are called " triconodont " crowns by the addition of lateral cusps to simple cones. In the mammals alone, these three cusps pass into higher stages of evolution, through what is called " tri- tuberculy," in which these cusps form a triangle. The discovery of primitive widespread trituberculy by Cope was a great step forward. In looking over the odontographies of Cuvier, Ot\en, Tomes, and Baume, we find there is no suspicion of this com- mon type around which the highly diverse mammalian molars centre. The molars of the clawed and hoofed mammals can now be compared, as we compare the hand or foot of the horse with that of the cat, because they spring from a common type. All the specialised mammalian series — ungulates, primates, car- nivores, insectivores, rodents, marsupials — are found playing similar yet independent adaptive variations upon one type. We thus have a clue to the comparison of all molars with each other and with the reptile cones ; take the human grinders, for example. The anterior outer cusps in the upper jaw, and the anterior inner cusps in the lower jaw, are homologous with each other and with the reptilian cone. Leaving aside for the moment Multituberculates and Monotremes, every known triassic, Jurassic, cretaceous and basal eocene mammal (excepting Dicro- cynodon) is in some stage of trituberculy ; all the known cre- taceous molars are simple triangles above ; all later fossil mammals also converge to trituberculy, until in the lowest eocene every molar is tritubercular, and the early stages of divergence are so similar that it requires a practised eye to dis- tinguish the molar of a monkey from that of a horse. Embry- ology supports the evidence of these fossil series. Thanks to the recent admirable researches of Rose and Tsecker, we find in the primates, ungulates and marsupials, that in the calcification of its dental caps every molar is heralded by three cones placea in a triangle, and in the lower jaw these three cones invariably appear in the same order (protocone, paracone, and Continued from p. 238. NO. 1263, VOL. 49] metacone) in which they arose duiing the remote geological periods. It is necessary to mention this overwhelming pala:onlolo- gical evidence, because "trituberculy " is still not universally recognised ; Fleischmann and others have questioned the homo- logies of the upper and lower triangles, and two able writers. Rose and Forsyth Major, have independently ptojiosed an opposition theory that " multituberculy " or " polybuny "is the mammalian archetyjie, the latter author believing trituberculy has become a " dogma." So far, however, from there being any decline of evidence, I am now able to add the Cretaceous mam- malia to the tritubercular lists and bring forward evidence that the multitubercular molar instead of being primitive was derived from the tritubercular; moreover, all the researches I have been quoting tend to draw the mammals without exception into one of three great primary forms. The haplodont form, from which Dromotherium is just emerging in the Trias, is the oldest and nearest the reptiles ; the triconodont, or three cones in line, was a predominating lower Jurassic type ; the trituber- cular, or three cones in a triangle (trigonodont, Rlitimeyer), was the prevailing upper Jurass-ic and later form. The final pre- dominance of the tritubercular over the others was due to its possibilities of mechanical adaptation to work of every kind — its potential in evolution. Upon the polyphyletic theory of the origin of the mammals here advocated, we must admit, first, the independent evolution of trituberculy in different phyla ; and second, the branching off of several great groups in the pre- tritubercular stages. The tendency of late research is to show that all stem mam- mals were related in their diphyodontism, in their dental formula, and in their primitive molar form. These features point, not to a succession, but to a unity of ancestry of the Monotremes, Marsupials, and Placentals. Divergence of the Three Groups. The discovery of the complete double series seems to have removed the last prop from the theory of the Marsupial ancestry of the placentals, for the peculiar mode of suppres- sion of the second series in the Marsupials has been constant since the Purbeck ; this difficulty is added to the structure of the jaw, the epipubic bones, the profoundly dift'erent mode of foetal nutrition. None the less, any conclusion we can draw now as to the primary relations of the three great groups is more or less of a " Schwindelbau," and I put together the results of these later discoveries with a full realisation of the temporary character of present conclusions. The Permian Sauro-]\Iammalia (Baur) with a multiple suc- cession of simple conical teeth divided into : A, Theromorpha, which lost the succession and in some lines acquired a hetero- dont dentition and triconid single-fanged molars ; B, Pro- mammalia. The hypothetical lower Triassic Pro-mammalia retained a double succession of the teeth ; they became heterodont, with incipient triconid double-fanged molars; dental formula approx- imating 4, 1. 4-5. 8. They gave rise to three groups : I. The Prototheria which passed rapidly through the tritubercular into the multitubercular molars in the line of Multituberculates, and more slowly into trituberculy and its later stages in the ine of Monotremes. II. The Metatheria or Marsupials tended to suppress the second series of teeth, except those intercalated with the first; by this and by reduction the formula became 5. 1.3. 4-6 ; the molars passed slowly through the triconodont into the typical triiubercular type. III. The Eutheria or Pla- centals divided early into a number of branches, in which there was heterodontism, but no uniform modification of suc- cession. We may distinguish four chief branches among these, as follows : (A^ forms suppressing the .'^econd series in the molar region only, and acquiring a typical Eutherian dentition, 3. 1.4. 3-4. I. The Insectivores tended to partly suppress the anterior teeth of the second series or intercalate them with teeth of the first series ; the molars became tritubercular. 2. The higher Placentals retained the succession of the first and second series as far back as the first molar ; the molars entered rapidly into trituberculy and its higher stages. (B) forms retaining the double succession in part of the molar region, and retaining more of the primitive dentition, 4. i. 4. 8. 3. The Edentates branched off from an early triconodont or tritubercular 25« NA TURE [January i i, 1894 diphyodont stage, with numerous molars, and secondarily sup- pressed the first heterodont series, and established a numerous homodont second series. 4. The Cetacea also branched off from a diphyodont, heterodont stage, and second- arily established a numerous homodont first series, suppressing the second series. Breaks and Links in the Mesozoic Fauna. Bv our hypothesis all three sub-classes flourished together during the American Mesozoic ; the Marsupials disappeared, then the Monotremes, and by the end of the basal Eocene the Placentals were in exclusive possession of the northern continent. Although we have great reason to congratulate ourselves upon the rapid progress of discovery, there still remain great gaps in Mesozoic time between certain horizons, and in the lineal phyletic series of both the Mesozoic and Cenozoic. For a time standard we may take advantage of the remarkably con- stant evolution of the Plagiaulacidce in the Mesozoic, and of the Equidas in the Cenozoic — as certain invertebrates are made use of in older rocks. The grooves and tubercles of Plagiaulax and the cusps and styles of the horses are added with the precision of clockwork, and supposing that the rate of evolution has been about the same, we can approximately estimate both the periods of deposition and the intervals as follows. PLAGIAULACID^. Stonesfield. Purbeck. Laramie. Puerco. Cernaysian. Number of Premolars Grooves on Premolars, Molar Tubercles : outer inner ; 4- 7-9 2-1 12-15 11-14 4 '. 2 6 : 4 6:4 g ; 6 Estimating the geological intervals by dental evolution and faunal succession, there is first the great gap between the Trias of Microlestes and Dromatherium and the Jurassic of the Stonesfield slate ; there is a relatively shorter interval, but still a considerable one between this and the Purbeck or Atlan- tosaurus beds. Then follows another long and very important interval between the Atlantosaurus beds and the Laramie (Upper Cretaceous). The gap between the Laramie and Puerco was relatively short, as indicated by the comparatively limited evolution both of the Plagiaulacids and Trituberculates. The Puerco was itself a long period in which the Plagiaulacids underwent considerable changes. Then follows an interval which it is most important to fill by future exploration, for between the Puerco and the Wahsatch the diff"erentiation of the even and the oddtoed ungulates must have occurred. The Wahsatch proper does not mark a very extensive evolution of the forms it contains. It passes, after a slight break, into the base of the Bridger (Wind River), and then begins that splendid and almost uninterrupted succession of lake basins, terminat- ing in the pliocene. I append a table, to be compared with that published by Marsh in his admirable address of 1877, and which exhibits the great progress of the last sixteen years. THE SUCCESSION OF THE NORTH AMERICAN MAMMALIA. Periods. Horizons. Post or Upper PLIOCENE. EQUUS. True Pliocene. Blanco. MIOCENE. LOUP FORK. Upper. Deep River. Middle. JOHN DAY. WHITE RIVER. Protocfras. (Upper.) Lower. EOCENE. Upper. Middle. Lower. Oreodon. (Middle.) TiTANOTHERIUM. (Lower.) Uinta. BRIDGER. Washakie. (Upper.) Bridger. (Middle.) Wind River. (Lower.) WAHSATCH. Characteristic Genera. New Types Appearing. Eqinis, 5 species. Elephant, E. pritiiigenius. Mastodon. Llamas. Camels, Eschatius. Holoiiieniscus. Elk, Alces. Platygonus. Sloths, Mylodon, Glyptodon. Ursiis. Equiis, 3 species. Mastodon, 3 sp. Llamas, Pliaiichenia, Platy- gonus. Sloth, Megalonyx, Felidcu. (?) Hycenid{^. MnstelidcE. Protohipptis, Hippaiion. Mastodon. Rhinoceroses, Aphelops, 5 species. Canidcr. Fclida. Rodents. Edentates. Camels and Llamas, Procameliis, Protolabis. Oreodons, 3 genera. Deer, Blastovieryx, Cosoryx. Protohippiis, Anchithertum. First Mastodons. Oreodons, Cyclo- pidiiis. C halicotherunn. Tylopoda. liliohippus. Two-horned Rhinoceros, Dicerailierinin. Hyopota- ni7is. Peccaries. Oreodons. Rodents. Canidcr, Felida;. Tylopoda. Appearance of tragulines, Elotheres, Hyopotatniis, pigs and peccaries Types becoming Extinct. (?) liliohippus. Artionyx. Mesohippiis. Amynodon. Mcsohippns. Titanotherium. true dogs, cats, monkejs. Lcp- taiicJienia. Colodon. Chalico- theriiim, Aceratherimn, Prota- piriis, Agriocliocrus. Opossums. Tylopoda, Pochrotheriiim. Creo- donts, HycEnodon. Rodents. In- sectivores. Epihippus. Amynodon. Tilanothere, Diplacodon. First Oreo- dons, Protoreodon. First Tylopoda, Lepiot?-agutiis. Tapirs. Hyracodons. Rodents. Creodonts, ]\Iesonyx. Pachynolophus. Appearance of Amynodons and horned Titano- theres. Palceosyops. Hyrachyiis. Tripiopus. Achienodnn. Pac/iynoiophus. Appearance of Insectivora, Cheiroptera, Hyra- codons. Uintatlieriiem. Palceosyops. Creodonts. Dinocerata. Hyracotherinin. Palceosyops. codiLS. Coryphodon. Phena- Hyracotheriui)!. Appearance of Artiodactyls, Perissodactyls : tapirs, horses, titanotheres, lophiodons. First Rodents. First Corypho- dons, Lemurs and Monkeys. Creodonts, 6 families, Palcconictis. Interval. PUERCO. Interval. UPPER CRETACEOUS. LAFAMIE. Interval. MIDDLE JURASSIC. UPPER TRIASSIC. Atlantosaurus. Interval. Chatham Coal Beds. (Differeniiation of jnodem clawed and hoofed placentals^ Ptilodus, Neofilagiaulax, Polymastodon. Ancient types of Ungu- lates, Carnivores and Insectivores : Amblypoda, Condylarthra, Creodonla. Tasniodonta. Tillodontia. Lemurs. {^Differentiation of ancietU clawed and hoofed placentals.) Ptilodus. Bolodoniidcc (Multituberculates). Thlceodon, Trituber- culate Placentals and Marsupials. Typical dentition. Ctenacodon, Plagiaiilax, Bolodon, Multituberculates (? Mono- tremes). Triconodonts (? Marsupials). Trituberculates (? Pla- centals). Primitive dentition. Protodonta, Dromatherium, Microconodon, primitive Triconodonts (? Monotremes). NO. 1263, VOL. 49] Extinction of Oreodons and hornless rhinoceroses. Disappearance of Chalico- therium. Extinction of Creodonts, Hyaenodons. Extinction of Elotheres and Hyopotamus Extinction of Hyracodons. Extinction of Amynodons. Extinction of 1 itanotheres. Extinction of Dinocerata, of some Creodonts. Extinction of Tillodontia. Extinction of Coryphodontia and Condylarthra. E.\tinction of Arctocyons. Extinction of Multitubercu- lates (? Monotremes). Disappearance of Marsupials. January ii, 1894.] NATURE 259 The general faunal succession is marked by the sudden appearance and disappearance of certain series and rise and fall of great groups. In the Trias appears the remarkable pro- todont or primitive-toothed Dromotherium ; we cannot deter- mine its order at present. We still have no American fauna corresponding to the intermediate Stonesfield of England. In the Jurassic Atlantosaurus beds the three supposed repre- sentatives of the Monotremes (multituberculates), Marsupials (triconodonts), and Placentals (trituberculates), appear in equal numbers ; the latter are generally characterised by the primitive dental formula. In the Laramie the Multituberculates continue in great profusion, and the Marsupials and Placentals are also numerous. The serial succession of the Trituberculates from the Meso- zoic is still an unknown chapter ; we are utterly unal)le to connect the Dromatheriidae of the Trias, the Triconodontidse, Amphitheriidas and Amblotheriidfs of the Jura with each other, or with any Cretaceous or lower tertiary mammals. The serial relations of the Multituberculates, on the other hand, have been made much clearer by the discovery of the Laramie fauna. Cope and Marsh in this country, and Smith Woodward in England, have at last broken into the long barren Cretaceous. In studying the accurate figures pub- lished by Marsh and a large collection of teeth recently made for the American Museum by Wortman and Peterson, I find that this Laramie fauna is widely separated from the Jurassic in its general evolution, and as Gaudry, Lemoine, and Cope have observed, it approaches more nearly the basal Eocene of the Puerco and the Cernaysian of France. The Multitubercu- lates of the Laramie include the Plagiaulacidse, represented by Ptilodus, the form with two premolars, and Meniscoessus, with two premolars and crescentic tubercles. Meniscocssus has a smaller fourth premolar, and is found to lead off to the huge plagiaulacid Polymastodon of the Puerco. The only other Mul- tituberculates found are those related to Bolodon of the Jurassic and Chirox of the Puerco. The other mammals of the Laramie range from the mouse to the opossum in size ; they have superior molars of the simple tritubercular type — the low cusped or bunodent molar predominating in the upper jaw, and the tuberculo-sectorial in the lower. The dental formula is mostly the typical p. 4, m. 3. Yet, judging by the angular region of the jaws, we have here both Placentals and Marsupials. Some of the teeth remind us strongly of those in the Puerco ; their determination, however, is very difficult, for the jaws and teeth are almost entirely isolated. From another exposure of the Laramie, Cope has recently found the remarkable type Thlseodon — remarkable because it is a highly specialised trituberculate of typical dentition with a jaw which bears resemblance to that of the Multituberculates and of Ornithorhynchus. There is no placental angle nor strong marsupial inflection. This raises the supposition that Thlaeodon may be one of the per- sistent trituberculate Monotremes which we are now looking for. In the Puerco or basal Eocene, a very marked change occurs, for the American fauna loses some of its cosmopolitan character, the multituberculates or monotremes die out and the marsupials are not found at all ; in fact they do not reappear in North America until the Miocene. Ancient and Modern Placental Differentiation. The Puerco is essentially an archaic fauna and is to be regarded as the climax of the first period of placental differentiation, a culmination of the first attempts of nature to establish insectivorous, carnivorous and herbivorous groups. These attempts began in the Cretaceous, and some of the types thus produced died out in the Puerco, some in the Wahsatch and Rridger ; only a few flesh-eaters survived to the Miocene. It is most important to grasp clearly the idea of this functional radiation in all directions of this old Puerco fauna, resulting in forms like the modern insectivores, rodents, bears, dogs and cats, monkeys, sloths, bunodont and selenodont ungulates, and lophodont ungulate-;. This was an independent radiation of placentals, like the Australian radiation of marsupials. What was the cause of the wide-spread extinction of these types? So far as the ancient clawed types are concerned, their teeth and feet seem to be as fully adaptive in many cases as those of the later unguiculates ; the hoofed types were certainly inferior in tooth evolution, for all their molars evolved on the triangular basis instead of the sexitubercular ; the most sweeping defect of both the clawed NO. 1263, VOL. 49] and hoofed types was the apparent incapacity for brain-growth, their bodies went on developing while their brains stood still. Thus the stupid giant fauna, the Dinocerata, which rose outjo this period, gave way to the small but large-brained modern types. It is noteworthy that the latest survivors of this wreck of ancient life were the large-brained Hya^nodons. Some of the least specialised spurs of this radiation appear to have survived and become the centres of the second or mid- Tertiary radiation from which our modern fauna has evolved. Yet we have not in a single case succeeded in tracing the direct connection. To sum up, we find on the North American continent evidence of the rise and decline and disappearance of monotremes and marsupials, and two great periods of placental radiation, the ancient radiatio7t beginning in the mesozoic, reaching a climax in the Puerco and unknown post-Puerco, and sending its spurs into the higher tertiary, and the tnodern radia- tion reaching its climax in the Miocene, and sending down to us our existing types. Another Eocene centre was lower South America, which has of late dimmed the prestige of North America in yielding strange form.s of life. One theory of this Patagonian fauna is that it was an independent centre of functional radiation like the Puerco and Australian, full of adaptive parallels, but not yielding to Europe or America any of their older types. But Ameghino, to whose energetic researches we are chiefly in- debted, believes that he finds a lower Eocene life zone- — a sort of south polar centre — which supplied both America and Europe. The Puerco he believes is no older than the Santa- cruzian, which in turn is very much older than the Parana and Pampean formations, which Burmeister has made so well known. This yields the Homunculus Patagonicns which paral- lels Cope's Anaptomorphus in presenting a dentition as advanced in reduction as that of man. Ameghino finds here the ancestors of the Macrauchenidse ; he believes the Homolo- dontotheridse are the ancestors of the Chalicotheriida — thus deriving a buno-selenodont from a lophodont type ; the Proterotheriidas, he believes, replace the Condylarthra and Hyracotherium in the ancestry of the horses. Similarly the Microbiotheriidje are the stem of the creodonts and carnivores. I cannot coincide with any of these views. The Multitubercu- lates are far older and widely different from the Abderites to which Ameghino traces their ancestry. I fully concur with the opinion of Cope, Zittel, Scott and others that this fauna is of somewhat later age, that it was directly connected with Australia and somewhat later with North America, supplying us, as has always been supposed, with our sloths. 1 quote from a recent address by Scott : — "The oldest mammals from South America are those from Patagonia, which Ameghino has referred to the Eocene, but which are more probably Oligocene or Miocene. This fauna is of extreme peculiarity and isolation ; it is made up chiefly of edentates, rodents and ungulates of those very aberrant types known as Litopterna and Toxodontia, which are so widely different from the hoofed mammals of the northern hemisphere ; together with some primitive forms of primates, creodonts and marsupials. The marsupials are of extraordinary interest, for they comprise not only forms allied to the opossums, but also to recent Australian forms such as Thylacinus, Dasyurus and Hypsi- prymnus. This is a most unexpected fact, and seems to point unmistakably to a great southern circumpolar continent." The Puerco thus remains the most extensively known and most productive lower Eocene centre, yet we have very slender threads of positive evidence to connect its fauna with the later placental radiation. The Creodonts of Cope occupy the same relation to the modern insectivores and carnivores that the Condylarthra do to the ungulates. The American group has been recently enriched by the discoveries of Wortman, and the literature by the careful revision of Scott. This author has divided them into eight families, placing the forms which most resemble the Insecti- vora in the new family, Oxyclsenidae. These families illus- trate superbly the same law of functional radiation later repeated in the placental and marsupial carnivores. The Mesonyx family presents some analogies to the Thylacines. The modern bears are paralleled in the Arctocyons, with their low tubercular molars ; Wortman and myself, with fresh materials, have recently added Anacodon to this family, a genus which was doubtfully regarded by Cope as an ancient ungulate. The Cats and Hyaenas are imitated in the Oxyeenas and Hysenodons, some of the Miocene forms of which Scott I !6o NA rURE [January i i, 1894 suggests developed aquatic habits ; as above noted, some of this family acquired large brains, and persisted late into the Miocene. A still more remarkable likeness to the cats is exhibited in the Pal^onictis family, which, unlike the Hyte- nodons, forms its sectorials out of exactly the same teeth as the true cats. The first American Palaeonictis was found two years ago by Wortman, and this author and myself have suggested that this may be the long-sought ancestor of the Felidre. The Civets are anticipated in the Proviverridre ; yet both Cope and Scott, the highest authorities on this subject, believe that the dog-like Miacidse alone formed the connecting link between the Creodonta and the true Carnivora. The foot structure of the ancient Puerco ungulates is still only partly known. Cope has divided these animals into the Amblypoda and Condylarthra. The Amblypoda are repre- sented in the Puerco by a large form called Pantolambda, with selenodont triangular upper molars, and possibly by Perip- tychus, with bunodont triangular molars. The Pantolambda molais were, as Cope has shown, converted into those of Cory- phodon, the great lophodont Amblypod of the Wahsatch, by a process exactly analogous to that in which the anterior half of a Pal^otherium molar was formed, that is, they acquired outer and anterior crests but no posterior crests. This Coryphodon molar type was still later converted into the Uin- tatherium type by swinging around the outer crest into a transverse crest. I have recently made a careful study of the fore and hind feet of Coryphodon, and have found that while the fore-foot was subdigitigrade like that of the elephant, the hind-foot was fully plantigrade, the entire sole resting upon the ground. The relation or connection between the Bridger Dinocerata and these earlier Amblypoda is still unknown. The Puerco Periptychus left no descendants. The other ungulates of the Puerco were the Condylarthra, the primitive Phena- codontidse, the supposed ancestors of the Arliodaclyls and Perissodaotyls. Much remains to be done to clear up this question. Thus an immense number of problems still await solution, and demand the generous co-operation of European and Ameri- can specialists in the use of similar methods of research, in the prompt publication of descriptions and figures, and in the free use of museum collections. I may be pardoned for calling general attention to the service which the palceontological de- partment of the American Museum is trying to render in the immediate publication of stratigraphical and descriptive tables of western horizons and localities. The Factors of Evolution. A few words in conclusion upon the impressions which a study of the rise of the mammalia gives as to the factors of organic evolution. I refer also to recent papers by Cope, Scott, and myself. The evolution of a family like the Titanotheres presents an uninterrupted march in one direction. While apparently prosperous and attaining a great size, it was really passing into a great corral of inadaptation to the grasses which were intro- duced in the Middle Miocene. So with other families and lesser lines extinction came in at the end of a term of develop- ment and high specialisation. With other families no causes for extinction can be assigned, as in the lopping off of the smaller Miocene perissodactyls. The point is that a certain trend of development is taken leading to an adaptive or in- adaptative final issue — but extinction or survival of the fittest seems to exert little influence en route. The changes en rozite lead us to believe either in predestina- tion— a kind of internal perfecting tendency — or in kineto- genesis. For the trend of evolution is not the happy resultant of many trials, but is heralded in structures of the same form all the world over and in age after age, by similar minute changes advancing irresistibly from inutility to utility. It is an absolutely definite and lawful progression. The infinite number of contemporary developing, degenerating, and stationary cha- racters preclude the possibility of fortuity. There is some law introducing and regulating each of these variations, as in the variations of individual growth. The limits of variation seem to lie partly in what I have called the "potential of evolution." As the oosperm or fer- tilised ovum is the potential adult, so the Eocene molar is the potential Miocene molar. We have seen that the variations of the horse and rhinoceros molars, apparently so diverse, are really uniform — is not this evidence that the perissodactyl stem had these variations ?«/^/^«/?(r, waiting to be called foith by certain stimuli? This capacity of similar development under certain slimuli is part of the law of mammalian evolution, but this does not decide the ciucial point whether the reaction is spontaneous in the geim or inherited from the parent. I incline to the latter opinion. H. F. Osborn. A DYNAMICAL THEORY OF THE ELECTRIC AND LUMINIFEROUS MEDIUM.^ TT is only at the end of the last century that the somewhat vague principle of the economy of action or effort in physical actions — which, like all other general principles in the scien- tific explanation of nature, is ultimately traceable to a kind of metaphysical origin — has culminated in the hands of Lagrange in his magnificent mathematical generalisation of the dynamical laws of material systems. Before the date of this concise and all-embracing formulation of the laws of dynamics there was not available any engine of sufficient power and generality to allow of a thorough and exact exploration of the properties of an ultimate medium, of which the mechanism and mode of action are almost wholly concealed from view. The precise force of Lagrange's method, in its physical application, consists in its allowing us to ignore or leave out of account altogether the details of the mechanism, whatever it is, that is in operation in the phenomena under discussion ; it makes everything depend on a single analytical function representing the distribution of energy in the medium in terms of suitable co-ordinates of position and of their velocities ; from the location of this energy. Its subsequent play and the dynamical phenomena involved in it are all deducible by straightforward mathematical analysis. The problem of the correlation of the physical forces is thus divisible into two parts, (i.) the determination of the analytical function which represents the distribution of energy in the primordial medium. which is assumed to be the ultimate seat of all phenomena ; and (ii.) the discussion of what properties may be most conveniently and simply assigned to this medium, in order to describe the play of energy in it most vividly, in terms of the stock of notions which we have derived from the ob- servation of that part of the interaction of natural forces which presents itself directly to our senses, and is form.ulated under the name of natural law. It may be held that the first part really involves in itself the solution of the whole problem ; that the second part is rather of the nature of illustration and ex- planation, by comparison of the intangible primordial medium with other dynamical systems of which we can directly observe the phenomena. The chief representative of exact physical speculation of the second of these types has been Lord Kelvin. In the older attempts of this kind the dynamical basis of theories of the constitution of the aether consisted usually in a play of forces, acting at a distance, between ultimate elements or molecules of the medium ; from this we must, however, except the speculations of Greek philosophy and the continuous vortical theories of the school of Descartes, which were of necessity purely descriptive and imaginative, not built in a connected manner on any rational foundation. It has been in particular the aim of I^ord Kelvin to deduce material pheno- mena from the play of inertia involved in the motion of a structureless primordial fluid : if this were achieved, it would reduce the duality, rather the many-sidedness, of physical phenomena to a simple unity of scheme ; it would be the ulti- mate conceivable simplification. The celebrated vortex theory of matter makes the indestructible material atoms consist in \ vortex rings in a primordial fluid medium, structureless, homo- \ geneous, and frictionless, and makes the forces between the atoms which form the groundwork of less fundamental theories consist in the actions excited by these vortices on one another : through the inertia of the fluid which is their basis — actions j which are instantaneously transmitted if the fluid is supposed to be absolutely incompressible. In ca^e this foundation proves insufficient, there is another idea of Lord Kelvin's by which it may be supplemented. The characteristic properties of radiation, which forms so prominent ! an element in actual phenomena, can be explained by the 1 1 A paper read before the Royal Society on December 7, 1893, by Dr. I Joseph Larmor, F.R.S., Fellow of St. John's College, Cambridge. NO. 1263, VOL. 49] January i i, 1894] NATURE :6l existence of an elastic medium for its transmission at a finite, though very great, speed ; such a medium renders an excellent account of all its relations, if we assume it to possess inertia and to be endowed with some elastic quality of resistance to disturbance roughly analogous to what we can observe and study in ordinary elastic solids of the relatively incomptessible kind, such as indiarubber and jellies. Lord Kelvin has been the promoter and developer of a view by which the elastic forces between parts of such a medium may be to some extent got rid of as ultimate elements, and be explained by the inertia of a spinning motion of a dynamically permanent kind, which is distributed throughout its volume. If we imagine very minute rapidly-spinning fly-wheels or gyrostats spread through the medium, they will retain their motion for ever, in the absence of friction on their axles, and they will thus form a concrete dynamical illustration of a type of elasticity which arises so'ely from inertia ; and this illustration will be of great use in realising some of the peculiarities of a related type, which I believe can be thoroughly established as the actuaUype of elasticity transmitting all radiations, whether luminous and thermal or electrical — for they are all one and the same — through the ultimate medium of fluid character of which the vortices constitute matter. It has always been the great puzzle of theories of radiation how the medium which conveys it by transverse vibrations, such as we know directly only in media of the elastic-solid type, could yet be so yielding as to admit of the motion of the heavenly bodies through it absolutely without resistance. According to the view of the constitution of the aether which is developed in this paper, not only are these ditilerent properties absolutely consistent with each other, but it is, in fact, their absolute and rigorous coexistence which endows the medium with the qualities necessary for the explanation of a further very wide class of phenomena. The remark which is the key to this matter has been already thrown out by Lord Kelvin, in connection with Sir George Stokes's suggested explanation of the astronomical aberration of light. The motion of the ultimate homogeneous frictionless fluid medium, conditioned by the motion of the vortices existing in it, is, outside these vortices, of an absolutely irrotational character. Now, suppose the medium is endowed with elasticity of a purely rotational type, so that its elastic quality can be called into play only by absolute rotational dis- placement of the elements of the medium ; just as motion of translation of a spinning gyrostat calls into play no reaction, while any alteration of the absolute position of its axis in space is resisted by an opposing couple. As regards the motion of the medium involved in the movements of its vortices, this rotational elasticity remains completely latent, as if it did not exist ; and we can at once set down the whole theory of the vortical hydrodynamical constitution of matter as a part of the manifestations of an ultimate medium of this kind. The explanation of the laws of physical optics advanced by Fresnel, and verified by comparison with the phenomena which was possible in several very exact ways, chiefly by himself and Brewster, was, about the year 1835, engaging the attention of several of the chief mathematicians of that time — Augustin Cauchy in France, Franz Neumann in Germany, George Green in England, and James MacCullagh in Ireland. The prevalent mode of attacking the problem was through the analogy with the propagation of elastic waves in solid bodies ; and the com- parison of Fresnel's laws of propagation in crystalline media with the results of the mathematical theory of the elasticity of crystalline bodies gave abundance of crucial tests for the verification, modification, or disproof of the principles assumed in these investigations. The greatest achievement of MacCullagh is that contained in his memoir of 1839, entitled an " Essay towards a Dynamical Theory of Crystalline Reflexion and Refraction." He is in quest of a dynamical foundation for the whole scheme of op- tical laws, which had been notably extended and confirmed by himself already. He recognises, I think for the first time in a capital physical problem, that what is required is the dis- covery of the potential-energy function of Lagrange on which the action of the medium depends, and that the explanation of the form of that function is another question which can be treated separately. His memoir is subsequent to, but appar- ently quite independent of, that of Green, in which Green restricted the medium to a constitution like an elastic solid, laid down the general laws of such constitution for the first time, and made a magnificent failure of his attempt to explain NO. 126.3, VOL. 49] I optical phenomena on that basis. If this thing was to be done, I the power, simplicity, and logical rigour of Green's analysis might have been expected to do it ; and nothing further has come of the matter until the recent new departure of Lord Kelvin in his speculation as to a labile elastic-solid a;ther. To j return to MacCullagh, he is easily able to hit off a simple form j of the potential-energy function, which— on the basis of Lagrange's general dynamics, or more compactly on the basis of the law of Least Action — absolutely sweeps the whole field of optical theory so far as all phenomena are concerned in which absorption of the light does not play a prominent part. He is confident, as any one who follows him in detail must be, that he is on the right track. He tries hard to obtain a dyna- mical basis for his energy-function, that is, to imagine some material medium that shall serve as a model for it, and illus- trate its possibility and its mode of action ; he records his failure in this respect, but at the same time he protests against the limited view which would tie down the unknown and in several ways mysterious and paradoxical properties of the lumin- iferous medium to be the same as those of an ordinary elastic solid. The form of MacCullagh's energy-function was derived by him very easily from the consideration of the fact that it is required of It that it shall produce, in crystalline media, plane-polarised waves propagated by di>placements in the plane of the wave front. Though he seems to put his reasoning as demonstrative on this point, it has been pointed out by Sir George Stokes, and is indeed obvious at once from Green's results, that other forms of the energy-function beside MacCullagh's would satisfy this condition. But the important point as regards MacCullagh's function is that it makes the energy in the medium depend solely on the absolute rotational displacements of its elements from their equilibrium orientations, not at all on its distortion or compression, which are the quantities on which the elasticity of a solid would depend according to Green. Starting from this conception of rotational elasticity, it can be shown that, if we neglect for the moment optical dispersion, every crystalline optical medium has three principal elastic axes, and its wave-surface is precisely that of Fresnel, while the laws of reflexion and refraction agree precisely with experiment. Further, it follows from the observed fact of transparency in combination with dispersion, that the dispersion of a wave of permanent type is properly accounted for by the addition to the equations, therefore to the energy-function, of subsidiary terms involving spacial differentiations of higher order. To preserve the medium hydrodynamically a perfect fluid, these terms also must satisfy the condition that the elasticity of the medium is thoroughly independent of compression and distortion of its elements, and wholly dependent on absolute rotation. It can be shown, I believe, that this restriction limits the terms to two kinds, one of which retains Fresnel's wave-surface un- altered, while the other modifies it in a definite manner stated without proof by MacCullagh ; but the first terms depend on an interaction between the dispersive property and the wave motion itself, while the second terms involve the square of the dispersive quality. It seems clear that the second type involves only phenomena of a higher order of small quantities than we are here considering ; thus an account of dispersion remains which retains Fresnel's wave-surface unaltered for each homo- geneous constituent of the light, while it includes the dispersion of the optic axes in crystals both as regards their magnitudes and directions — -results quite unapproached by any other theory ever entertained. In this analysis of dispersions, all terms have been omitted which possess a unilateral character, such as would be indicated in actuality by rotatory polarisation and other like phenomena. The laws of crystalline material structures seem to prohibit the occurrence of such asymmetry as these terms would indicate, except to the very small extent evidenced by the hemihedral faces of quartz crystals. The influence of this asymmetric arrangement of the molecules on the optical medium must be very much smaller still, for the rotatory terms are in all media exceedingly minute compared with the ordinary dispersional terms. The form of these rotatory terms in the energy function is at once definitely assigned by our condition of perfect fluidity of the medium, both for crystals and for rotational liquids such as turpentine, and this form is the one usually accepted, on MacCullagh's suggestion, as yielding a correct account of the phenomena. When dispersional terms are included in the energy function, n 262 NATURE [January 1 1, 1894 our continuous analysis is not any longer applicable to the pro- blem of reflexion ; the condiiions at the interface are altogether too numerous to be satisfied by the available variables. There is in fact discontinuity at the interface in the discrete molecular structure, such as could not be representable by a continuous analysis. But if we proceed by the method of rays, and assume that there is a play of surface forces which do not absorb any energy, while they adjust the dispersional part of the stress, it appears that reflexion is independent of dispersion. The problem of the aether has been first determinedly attacked from the side of electrical phenomena by Clerk Maxwell in quite recent times ; his great memoir on a " Dynamical Theory of the Electromagnetic Field " is of date 1864. It is in fact only comparatively recently that the observation of Oersted, • and the discoveries and deductions of Ampere, Faraday, and Thomson had accumulated sufficient material to allow the question to be profitably attacked from this side. Even as it is, our notions of what constitute electric and magnetic phenomena are of the vaguest as compared with our ideas of what consti- tutes radiation, so that Maxwell's views involve difficulties, not to say contradictions, and in places present obstacles which are to be surmounted, not by logical argument or any clear repre- sentation, but by the physical intuition of a mind saturated with this aspect of the phenomena. Many of these obstacles may, I think, be removed by beginning at the other end, by explaining electric actions on the Imsis of a mechanical theory of radiation, instead of radiation on the basis ot electric actions. The strong pomt of Maxwell's theory is the electromotive part, which gives an account of electric radiation and of the phenomena of electromagnetic induction in fixed conductors; and this is in keeping with the remark just made. The nature of electric displacement, of electric and magnetic forces on matter, of what Maxwell calls the electrostatic and the magnetic stress in the medium, of electrochemical phenomena, are all left obscure. We shall plunge into the subject at once from the optical side, if we assume that dielectric polarisation consists in a strain in the aether, of the rotational character conteiuplaied above The conditions of internal equilibrium of a medium so straine't are easily worked out from MacCullagh's expression for W, its potential energy. If the vector (/, g, h) denote ihe curl or vorticity of the actual linear displacement of the medmm, or twice the absolute rotation of the portion of the medium at the point considered, and the medium is supposed of crystalline quality and referred to its principal axes, so that W = i /" («-/- -t- b^-g"^ + cVC) dr, where dr is an element of volume, it follows easily that for in- ternal equilibrium we must have ar/dx + b-g dy + c"h dz ■=. —dV, a complete differential, and that over any boundary enclosing a region devoid of elasticity the value of V must be constant. Such a boundary is the surface of a conductor ; V is the elec- tric potential in the field due to charges on the conductors ; {/, g, h) is the electric displacement in the field, circuital by its very nature as a rotation, and {a-f, b'^g, c'-h) is the electric force derived from the electric poiential V. The charge on a conductor is the integral of (f, g, h) over ary surface enclosing it, and cannot be altered except by opening u^) a ch;innel devoid of elasticity, in the medium, between ihis conductor ani some other one ; in other words, electric discharge can take place only by rupture of the elastic quality of the setherial n.ediuni. At the imerlace between two dielecitic media, taken to lie crystalline as above, the condition comes out 10 be thai the tnngential electric force is continuous. When the circum-tances are those of equilibrium, and therefore an electric (joiemial may be introduced, this condition allows discontilaJit^ in ihe value of the potential in crossing the interface, but demanils that the amount of this discontinuity shall be ihe same all along ihe interface ; these are precisely the circumstances o the observed phenomena of voltaic polen'ial differences. The com- ponent, no mal to ihe interface, of the eleciiic di-pl icemen' is of course aUays continuous, from the nature "f that vector as a flux. It may present itself as a difificuliy in this theory that, as the electric displacement is the rotational .li^,.lacement of the medium, its surface integral over any sheet should be equal to NO. 1263, VOL. 4q] the line integral of the linear displacement of the medium round the edge of the sheet ; therefore that for a closed sheet surrounding a conductor this integral should be null, which would involve the consequence that the electric charge on a conductor cannot be different from null. This line of argument, however, implies that the linear displacement is a perfectly con- tinuous one, which is concomitant with and required by the electric displacement. The legitimate inference is that the electric displacement in the medium which corresponds to an actual charge cannot be set up without some kind of discontin- uity or slip m the linear displacement of the medium ; in other words, that a conductor cannot receive an electric charge with- out rupture of the surrounding medium ; nor can it lose a charge once received without a similar rupture. The part of the linear displacement that remains, after this slip or rupture has been deducted from it, is of elastic origin, and must satisfy the equations of equilibrium of the medium. Wc can produce in imagination a steady electric current, without introducing the complication of galvanic batteries, in the following manner, and thus examine in detail all that is involved, on the present theory, in the notion of a current. Suppose we have two charged condensers, with one pair of coatings connected by a narrow conducting channel, and the other pair connected by another such channel, as in the annexed diagram, where the dark regions are dielectric and the white regions conducting. If we steadily move towards each other the two plates of the condenser A, a current will flow round the circuit, in the form of a con- duction current in the conductors and a displacement current across the dielectric plates of the condensers. Let us suppose the thicknesses of these dielectric plates to be excessively small, so as to minimise the importance of the dis- placement part of the current. There is then practically no electric force and therefore no electric displacement in the surrounding dielectric field, except between the plates of the condensers and close to the conducting wires. Consider a closed surface passing between the faces of the condenser A, and inter- secting the wire at a place P. A movement of the faces of this condenser alters the e'ectric force between them, and therefore alters the electric displacement across the portion of this closed surface which lies in that part of the field ; as we have seen, there is practically no displacement anywhere else in the field except at the conducting wire ; therefore to preserve the law of the circuital character of dis|>lacement throughout the whole spare, we must suppose that this alteration is comiensaled by a ve^ V iiiten^e change of displacement at the conducting wire. So long as the movement of the plates continues, as long does this fl w of displacement along the wire go on ; it cons' itutes the eleciiic current in the wire. Now, in calculatint; the magnetic force in ihe field, which is the velocity of the seiheieal medium, from the change of electric displacement, we mus' include in <.u integration the effect of this sheet of electric di-|Iacement flowing along the surface of the perfectly conducting wires, for exactly the same reason as in the correlative problem in hydro- d}namics, of calculating the velocity of the fluid from the dis- tribution of vorticity in it, Helmholtz had to consider a vortex sheet as existing over each surface across which the motion is discontinuous. {To be continued.) i Januarv 1 1, 1894. 1 NA TURE 26' SCIENTIFIC SERIALS. American Meteorological Journal, December.— The winds of the Indian Ocean, by W. M. Davis. The facts for this dis- cussion are drawn from the " Atlas of the Indian Ocean," pub- lished by the Deutsche Seewarte, and the author reproduces two charts (l) for January and February, when the heat equator and the belt of low barometric pres-ure have advanced to aliout latitude 10^ south in the middle of the Indian Ocean, and (2) for July and August, showing the position of the high pressure belt about 5" more northward than before, in consequence of the increased velocity of the circumpolar whirl. The most striking feature of this second chart is the extension of the south-east trade wind across the equator, as the south-west or summer monsoon. The author clearly points out the sufficiency of the rotation of the earth to influence the course of the winds, and explains the causes of the monsoons. He shows that it is not only true that continents are unessential to their development, but that they may even destroy their normal conditions. — South American meteorology, by W. H. Pickering. This paper chiefly deals with the climate of Arequipa, Peru ; altitude 8,060 feet. The temperature seldom falls below 40° or rises above 75^ The winds blow with great regularity, except in the rainy season, a sea-breeze prevailing during the day, and a land- breeze for some hours before sunrise. The mean annual rainfall dues not exceed four inches, while on the sea-coast rain is a great rarity ; the rainy season occupies the first three months of the year ; rain in the morning is practically unknown. (This and the previous paper were read before the New England Meteoro- logical Society on October 21 last). — A South American Tornado, by W. G. Davis. This tornado occurred on Novem- ber 13, 1891, and devastated the village of Arroyo Seco, near Rosario. An illustration, taken from a photograph, shows a number of heavily laden railway carriages which were upset or carried to a distance by the violence of the wind. The cause appears to have been the diffisrences of temperature and humidity in adjacent strata of the atmosphere. —Errors of the psychro- meter, by H. A. Hazen. This is a summary of a paper recently read by Mr. W. W. Midgley before the Royal Meteorological Society. The important poinf is that Prof. Hazen entirely confirms a statement made by Mr. F. Gaster at that meeting, that the temperature of the dry bulb thermometer is not affected by the proximity of the water cup of the wet bulb thermometer, a statement which was contrary to the general opinion of the meeting. We believe that a further confirmation of t/iis fact will be brought forward by Mr. Gaster later on, from recent careful experiments. L'Antkropologie, Tome iv. No. 4, July-August, 1893. — Mons. Maurice Delafosse contributes an interesting paper on a little-known tribe of fair negroes, called the Ag?ii, who dwell on the Ivory Coast between the River Tanoue on the east, and the Rio San Pedro on the west. These albinos are neither so tall as some of the tribes of Senegal, nor so powerfully built as the natives of Dahomey. Their height varies from I '65 m. to l'8o m. ; their body is well proportioned, they are quick and graceful in their movements, and they have sharp, bright eyes of unquestionable beauty. Their colour is in general of a beautiful bronze, more often light than dark. The Agni tattoo themselves, but the men are not circumcised. In the same number M. Eugene Mouton describes a dioito-dorsal movement peculiar to man ; and there is a paper by M. D'Acy on orna- mented neolithic hammers, tomahawks, and axes. SOCIETIES AND ACADEMIES. London. Royal Society, December 14, 1893. — "Note on some Changes in the Blood of the general Circulation consequent upon certain Inflammations of an acute local character," by Dr. C. S. Sherrington, F.R.S. Linnean Society, December 21, 1893.— Prof. Stewart, President, in the chair. Gen. Sir H. Collett and Mr. H. H. Johnson were admitted, and Messrs. G. E. Greene and A. G. Tansley were elected. — Mr. P. L. Simmonds exhibited acollec- tion of New Zealand mosses found by Mr. G. W. Simmonds while surveying in H.M.S. Pandora. Mr. Murray offered some remarks on the nature and value of the colleciinpo)iotiis planatus with Pctudomyrma Belli, the plant being Acacia Hindsii. — Mr. J. E. Ilarting exhibited some shells of Planorbis corneics, which had been founrl by the river-side at Weybridge, which from some unascertained cause were curiously bisected. Alluding to the piscivorous habits of the water shrew, Sorex fodiens, he suggested that it might be the work of this little animal. Mr. A. D. Michael thought it likely to be the result of frost, the lower half of each shell being preserved by being imbedded in or adherent to the frozen mud. Referring to a MS. letter of Dr. Stephen Hales (the author of " Vegetable Staticks," and a friend and neighbour of Gilbert White), which was exhibited by Mr. G. Murray, an excellent engraved portrait of him was exhibited by Mr. Hart- ing, who made a few remarks upon his life and work. As this portrait was not to be found amongst the 600 engravings of " scientific worthies " lately presented to the library by the late Lord Arthur Russell, he offered it for the acceptance of the society. ^On behalf of Mr. H. X. Ridley, Director of the Gardens and Forests Department, Singapore, the Secretary read a paper dealing with all the Orchidds hitherto recorded from Borneo. In the discussion which followed, IVIr. C. B. Clarke made some remarks on the distribution of these plants in the Indian and Indo-Malay regions, and on the way in which a knowledge of the species had been gradually acquired and extended. — On behalf of Mr. R. Spruce (whose death since the reading of this paper the Society has to deplore), Mr. A. Gepp read a paper on the Hepaticts collected by Mr. W. R. Elliott in the islands of St. Vincent and Dominica, and took occasion to describe in some detail the nature and extent of Mr. Spruce's work, which he characterised as a most careful and excellent contribution to botanical science. The paper was accompanied by a series of minute and beautiful drawings. Royal Microscopical Society, December 20, 1893. — Mr. A. D. Michael, President, in the chair. — Mr. E. M. Nelson exhibited and described a new pattern microscope specially designed for agriculturists. — Mr. Nelson also exhibited a new form of metallic chimney for microscope lamps. — On be- half of Mr. J. W. Lovibond, Mr. Nelson exhibited some new coloured screens for use with the microscope. — Mr. J. W. Gif- ford read a paper on a new monochromatic light screen, illus- trating the subject by means of the lantern. — Mr. T. F. Smith read a paper on the resolution of Pleurosigma angulatwn, illus- trated with photomicrographs shown by the lantern. Paris. Academy of Sciences. January 2. — M. de Lacaze- Duthiers in the chair. — A mechanical problem, by M. J. Bert- rand. — On the equation to the derived partials occurring in the theory of the propagation of electricity, by M. Eaiile Picard. An application of Riemann's method to the problems con- sidered by M. H. Poincare at the previous meeting. — A chemical study of the nature and causes of the green colouration in oysters, by MM. Ad. Chatin and A. Muntz. The authors trace a connection between the percentages of iron contained in the coloured parts and colourless parts of the oysters and the intensity of the colouration. The branchiae contain much more iron than the remainder of the body, and are most deeply coloured. The proportion of iron corresponding to a deep green or brown coloration is about 0'07 to o"o8 per cent, of the dried brafichise. The mud of the oyster beds where colouration occurs contains a large proportion of sulphide of iron. Though it is insoluble in the solvents for chlorophyll and hzematosin, the green colouring matter resembles those pigments in con- taining a large proportion of iron. — Graphic determination of position at sea, by MM. Louis Fave and Rollet de ITsle. — Regulation of the compass by observations of the horizontal force, by M. Caspari. — A newisomeride of cihi honine, by MM. E. Jungfleisch and E. Leger. A ba^e to which the name cin- ch nine 5 has been given is obtained from hydrobromocin- chonine by boiling with 85 per cent, alcohol and subsequent separation of unaltered base, apocinchonine, and cinchoniline. It forms very l>ng prisms insoluble in water, but soluble in alcohol, bc-nzene, chloroform, and acetone. It melts at l5o\ For a I per cent, solution in 97 per cent, alcohol od = -1- 125'2'. In aqueous solution -f2HCl, we have od = -f 176 -g", and with 4licl its rotation becomes aD=■fI78■2^ The ba-e and its salts decompose rapidly in air with formation of brown pro- ducts less alkaline than the base itself. The salts of cinchonine 264 NATURE [January 11, 1894 8 are generally very soluble in water, but the hydrochloride, hydrobromide, and basic oxalate form exceptions, and may be easily crystallised. — On the ophites of the Western Pyrenees, by M. P. W. Stuavt-Menteath. The author controverts the supposed necessary connection between the Trias and the Ophites of this region, and shows that the presence of the latter is due to the faults of the district. He also shows that the intercalation of the ophites parallel to the surrounding beds is not an invariable case, many instances being now known of penetration of neighbouring strata, and that the granites, por- phyries, and ophites of the Pyrenees are not independent of each other, but rather that the latter become important as the former die out.— On the composition of the waters of the Dranse du Chablais and the Rhone at their entrance into the Lake cf Geneva, by M. A. Delebecque. The varying quantities of solid residue in the waters of these two rivers are given for various times in the year. The proportions of the substances dissolved vary, calcium sulphate being found more abundantly in winter, and the alkalies in greater proportion in summer. An approximate calculation gives for the amounts of dissolved matter carried annually into the Lake of Geneva by the Rhone and by the whole of its affluents, respectively, the figures 750,000 and 1,150,000 tons. New South Wales. Linnean Society, November 29, 1893. — Prof. David, the President, in the chair. — The following papers were read : — A Thylacine of the earlier Nototherian period in Queensland, by C. W. De Vis. The occurrence of a Thylacine, for which the name Thylacimts rostralis was proposed, larger than the existing species, and differing from it in other expressive features, was recorded from the Darling Downs deposits. A number of fragmentary portions of the cranium have been for some time in the Queensland Museum ; but the most valuable evidence has been furnished by a recent acquisition, in the shape of the major part of the left side of an adult skull, with all the teeth except the second upper premolar in place, together with the first four cervical vertebrre. — A second note on the Carenides, with descriptions of new species, by T. G. Sloane. Nine new species were described, and the opportunity of reviewing the classification of the group has been taken, synoptical tables of the more important genera being furnished. — Additions to and emendations in the reference list of the land and freshwater mollusca of New Zealand, by Henry Suter. In the " Reference List " published in last year's Proceedings, a further account of several new species was promised. Descriptions, which will be fully illustrated, of these novelties have now redeemed this promise. Critical notes on various other New Zealand land mollusca accompany the descriptions. The existence in New Zealand of an undetermined species of Gundlachia, the young of which were formerly mistaken for an Ancyhis, was also an- nounced.— On the Australasian Gundlachia, by C. Hedley. Two Australian species, G. Petterdi, Johnston, and G. Beddomei, Petterd, were figured and described, and the dentition of the former was also elaborated. A summary was given of the whole genus, with especial reference to its discontinuous distribution, and probable path of migration. — Description of CcEcum am- putatiim, an undescribed mollusc from Port Jackson, by C. Hedley. The newest addition to the Port Jackson molluscan fauna, figured and described by the author, stands nearest to C. auriculatum, de Folin, from the Mediterranean. It is the first of its genus observed in extratropical Australia. — Notes on the red-crowned parrakeet {Cyano7-hamphus Cooki) »f Norfolk Island, by A. J. North. Having recently examined two speci- mens of this parrakeet forwarded by Dr. P. H. Metcalfe, of Norfolk Island, the author has found it to be specifically dis- tinct from C. novcB-zealandice, as maintained by Count Salvadori, in whose views as to the incorrectness of the habitat assigned to G. Cooki by Gray, and the necessity of regarding C. Rayneri as a synonym of C. Cooki he therefore concurs. — -Fourth con- tribution to a knowledge of the geographical distribution of Australian batrachia, with description of a new cystignathoid frog, by J. J. Fletcher. The collections recorded are mainly from the Lower Clarence and the Northern Tableland of N.S.W. ; and a new species of Crinia — with vomerine teeth, the tympanum indistinct, the throat very dark, the belly macu- late and granulate, a light vertebral line — from Jervis Bay, proposed to be called C. Haswelli, was described. — Description of a new Australian Acacia, by J. H. Maiden and R. T. Baker. A well-defined and somewhat remarkable species from Murrumbo, near the Goulburn River, N.S. W., was described. NO. 1 263, VOL. 49] It bears some superficial resemblance to A. decurreiis, van normalis, but the length of the leaflets, the fewness of the glands, the pinnse, and the flowers in the heads (six or eight only), are the principal distinctive differences upon which the specific rank is based. This species commemorates Baron Ferd. von Mueller, the eminent botanist, to whom we are indebted for the classical " Iconography of Australian Acacias." Netherlands. Zoological Society, November 25, 1893. — M. Hubrecht in the chair. — M. Hubrecht contributed a paper on the development of the Shrew {Sorex vulgaris), and especially on its placentation. The placenta is an embryonal organ ; the part which the tissue of the mother plays in its formation is considerably smaller than has been supposed. — M. Seydel exhibited models of embryonary skulls of Anguis and Lacerta, made of wax after the method of Born. — -M. Bolsius dealt with the anatomy especially of the generative organs of BranchiobdeUa parasita. — M. Vosmaer treated on the so-called membrane of Sollas, in sponges of the genus Sycon. — M. Hoek described a hermaphroditical ray {Rajaclavata). A specimen of a length of 44 centim.etres (without the tail) was in possession of a single pterygopodium (the left one) only. On dissecting it was found to be furnished with a complete set of female reproductive organs (ovaries, oviducts, oviductal glands, uteri), and at the left side with a well-developed testis containing mature spermatozoa. BOOKS, PAMPHLET, and SERIALS RECEIVED. Books. — Electromagnetic Theory: O. Heaviside, Vol. i. {Elecifician Publishing Company).— Eau Sous Pression : F. Bloch (Paris, Clauthier- Villars). — Annuario pubhcado pelo Observatorio do Rio de Janeiro, 1893 (Rio de Janeiro). — The Crinoidea of Gotland, Part i — The Crtnoidca Tna- dutiato: F. A. Bather (Stockholm, Norstedt).— Index-Catalogue of the Library of the Surgeon-General's Office, U.S. Army, Vol. xiv. (Washing- ti-,n). — Results of Rain, kiver, and Evaporation Observations made in N.S.W. during 1892 : H. C. Russell (Sydney). Pamphlet. — Report of the Meteorological Council to the Royal Society for the year ending March 31, 1893 (Eyre and Spoltiswoode). Serials. — Geographical Journal, January (Stanford). — Natural Science, January (Macmillan). — Handbuch der Palseontologie Erste Abthg. iv. Band, 3 Liefg. (Williams and Norgate).— Observatory, January (Taylor and Francis). — Bulletin of the New York Mathematical Society, December (New York. Macmillan). — Revue G^niirale des Sciences, No. 24 (Paris). — Annals of Scottish Natural History, January (Edinburgh, Douglas). — American Journal of Science, January (New Haven). — Journal of the Royal Statistical Society, December (Stanford). — The Physical society of London, Proceedings, Vol. xii. Part 3 (Taylor and Francis). — Contributions from the Botanical Laboratory of'the University of Pennsylvania, Vol. i. No. 2 (Philadelphia). — Medical Magazine, January (Southwood). CONTENTS. PAGE The Kew Index of Plant-Names 241 Astronomy for the Public. By R. A. Gregory . . . 243 Our Book Shelf:— Coleman: "Practical Agricultural Chemistry for Elementary Students."— C. J 244 Walther : " Bionomie des Meeres " 244 Letters to the Editor : — Correlation of Solar and Magnetic Phenomena. — Dr. M. A. Veeder: William Ellis, F.R.S 245 The Mendip Earthquake of December 30-31, 1893. — Prof. F. J. Allen 245 Quaternionic Innovations. — Oliver Heaviside, F. R. S. 246 The Second Law of Thermodynamics. — S. H. Burbury, F.R.S 246 The Fauna of the Victoria Regia Tank in the Botanical Gardens.— Frank E, Beddard, F.R.S. . . . 247 Rudimentary (Vestigial) Organs. — W. E. H. ; C. Mostyn 247 Fresh Lightjon the Ainu. {With Illustrations.') By H. R. M 248 The Purification of Sewage by Bacteria .... 249 Arthur Milnes Marshall 250 Notes 251 Our Astronomical Column. — Harvard College Observatory Report 256 The " Gegenschein " 256 Geographical Notes 256 The Rise of the Mammalia in North America. II. By Prof. H. F. Osborn .257 A Dynamical Theory of the Electric and Lumini- ferous Medium. I. i^With Diagram.) By Dr. Joseph Larmor, F.R.S 260 Scientific Serials 263 Societies and Academies 263 Books, Pamphlet, and Serials Received 264 \ NA rURE 26s H EI N RICH HERTZ. THE last day of 1893 witnessed the tragic death of Prof. Milnes Marshall on Scawfell : on the New Year's Day Prof. Heinrich R. Hertz passed away, and his death will be even more severely felt in many circles and more widely mourned. For some time he had not been in good health. Last winter a severe illness prevented him from discharging his professional duties : for some weeks he was confined to his bed, and fears were entertained that he might not recover. During the summer-semester he got better and was again able to lecture ; a casual observer would scarcely have thought that there was anything wrong with him. He was in excellent spirits, and his friends hoped that the vacation would com.plete his restoration to health and strength. But with the returning winter there came a relapse. A chronic, and painful, disease of the nose spread to the neighbouring Highmore's cavity and gradually led to blood-poisoning. He was conscious to the last, and must have been aware that recovery was hopeless ; but he bore his sufferings with the greatest patience and fo: titude. Hertz is best known through his magnificent series of reicarches on electric waves. He was led, somewhat indirectly, to these by a problem proposed in 1879 by the Berlin Academy of Sciences, viz. to establish experi- mentally a relation between electromagnetic forces and the dielectric polarisation of insulators. At this time Hertz was assistant in the Berlin Physical Institute, and his attention was directed to the problem by Prof, von Helmholtz. The oscillationsof Leyden jars and of open induction-coils first attracted his attention ; but he reluctantly came to the conclusion that any decided effect could scarcely be hoped for. Yet he kept the matter in mind ; and certain experiments made a few years later — when he had become Professor of Physics at the Karlsruhe Polytechnic — led him to the production and examination of electric oscillations of very short period (about a hundred-millionth of a second). The paper "On very Rapid Electric Oscillations," which was published in 1887, was the first of a splendid series of researches which appeared in Wiedemantis Atmalen between the years 1887 and 1890, and in which he showed, with ample experimental proof and illustration, that electromagnetic actions are propagated with finite velocity through space. These twelve epoch-making papers were afterwards republished — with an introductory chapter of singular interest and value, and a reprint of some observations on electric discharges made by von Bezold in 1870— under the title Utitersuchungen iiber die Ausbreitung der elektrischen Kraft. (An English translation of this book, with a preface by Lord Kelvin, has just been published.) As early as 18S3, Prof. G. F. Fitzgerald read a paper at the Southport meeting of the British Association, " On the Energy Lost by Radiation from Alternating Currents," and at the same meeting pointed out that electromag- netic waves of as little as two metres wave-length, or even less, could be obtained by discharging an accumulator through a small resistance. In a paper on " The Theory of Lightning-conductors," published in the Phil. Mag. in August, 1888, Dr. O. J. Lodge suggested that waves of 20 or 30 cm. length from a small condenser might be concentrated upon some sensitive detector ; that shorter waves still might be obtained by discarding the condenser and simply producing oscillations in a sphere or cylinder by giving it a succession of sparks ; and that light- waves in all probability were only smaller editions of these. It was reserved for Hertz to discover, and apply with marvellous ingenuity, the necessary " detector," a NO. 1264, VOL. 49] resonating circuit with an air-gap, the resistance of which is broken down by well-timed impulses so that visible sparks are produced. It was only after this paper was written that Dr. Lodge read how Hertz had succeeded in detecting electromagnetic waves in free space, in inves- tigating their reflection, and measuring their velocity ; and at the end of a postcript to the same paper anno'mc- ing the news there occurs the sentence : " The whole subject of electrical radiation seems working itself out splendidly." How amply this statement has been sub- stantiated we now know.i When his earlier papers on electric oscillations were written, Hertz was not aware of von Bezold's observa- tions, nor that the subject was engaging the attention of physicists in Great Britain. He readily and gracefully acknowledged the value of the work done by others ; and it is equally pleasant to recollect that, when he had attained the goal towards which others were striving, Profs. Oliver Lodge and Fitzgerald were foremost in an- nouncing his success and in preparing the English- speaking world to appreciate the importance of the discoveries which he had made and might yet be expected to make. None, we may be sure, more deeply mourn the death of this brilliant investigator — in his thirty- seventh year — than those who have travelled along the same path, and can fully appreciate the value of his work. It would perhaps be an exaggeration to say that the news of Hertz's discoveries (with his consequent appoint- ment as successor to Clausius in the chair of Physics at Bonn) reached Germany by way of England. But at the time when these researches were undertaken Maxwell's theory does not appear to have been very widely known in Germany, and it is certain that its importance was not generally recognised. It seems that Hertz himself did not at first appreciate how rich and suggestive it was. But when he showed how worthily he could follow in the foot- steps of Faraday and Maxwell, his work received instant and ample recognition in England. In December, 1890, he came over to England to receive the Rumford medal, which was conferred upon him by the Royal Society for his researches on electromagnetic radiation. He was delighted with the warm welcome which he received, and often spoke of it with obvious pleasure. It might be thought that a world-wide reputation so rapidly attained would produce in a young man some feeling of elation and pride, and in his colleagues some- what of envy. But Hertz's modesty was proof against the one, and his unvarying courtesy and ready recog- nition of the merits of his co-workers made the other well-nigh impossible. He was a most lovable man, and was never happier than in giving pleasure to others. He was always ready to show hospitality to scientific men from England and America who came to Bonn. Even under the restraint of a foreign tongue (he spoke and wrote English with considerable fluency) his conversa- tion was charming. When entertaining friends he kept the learned professor well in the background, and his one desire was to make every guest feel at ease and happy. Many of his students will remember with pleasure certain trips to the Siebengeberge, and delightful evenings spent in his house in the Ouantius-Strasse. Absolutely devoid of any desire to pose before the public. Hertz yet showed on occasion that he could ably act as a popular exponent of experimental research. After the publication of his fascinating researches on electric radiation — its rectilinear propagation, reflection, refraction, and polarisation — he was invited to address the Naturforscheiversammlung (which corresponds to our British Association) at Heidelberg, in 1889. He Mt may not be out of place to observe here that Hertz appears to have made a mistake in saying that Poincare first pointed out the error of calcu- lation in his important paper " On the Finite Velocity of Propagation of Electromagnetic Actions." (English edition, pp. 9, 15, 270.) It seems clear that Lodge {Phil. Mas;. July, 1SS9) first drew attention to it. 266 NATURE [January i8, 1894 chose as his subject " The Relations between Light and Electricity." The lecture, afterwards published by Strauss, of Bonn, attracted great attention in Germany, and rapidly passed through half a dozen editions ; it deserves to be better known in England. To students of science it will be a pleasure — not unmixed with sad- ness— to know that shortly before his untimely death he i,ompleted the manuscript of a new work on "The Prin- ciples of Mechanics." This book is already being pre- pared for publication, and those who have learned to value the insight and originality of the gifted author will eagerly watch for its appearance. D. E. J. PROF. DR. RUDOLF WOLF. IN Prof. Dr. Rudolf Wolf astronomical science loses one of her most devoted servants, and his death will be deplored not only by his countrymen and the observ- atory which he has directed since its foundation, but by astronomers all over the civilised world. The services which he has rendered to astronomical science have not been restricted to one branch, although his name is generally spoken of with reference to sunspots. Born on July 7, 1816, at Fallanden, near Zurich, he attended in his youth the higher schools in the last- mentioned city, where he made the acquaintance of the astronomer Horner, and began his first studies in mathe- matics and astronomy. He then went to the Vienna University in , order to study astronomy under Littrow, and later to Berlin, at which place and time were Encke and Poggendorf. The year 1838 saw him in his home again, and this time his opportunities for astro- nomical studies were few and far between, as he had little time to spare, owing to his having accepted the post of a teacher in mathematics and physics at the town " Realschule" in Berne. In the year 1844 he commenced lecturing at the university, and in 1852 he obtained his Doctor's degree from the Berne Faculty, the same year becoming a member of that body itself by being appointed an Ausserordentliche Professor. About this time Wolf busied himself with a series of fine pieces of mathematical work, some of which were published singly, and others in various " Fachbliittern,'' and in this year ( 1 852) he pub- lished his " Taschenbuch der Mathematik, Physik, Geo- diisieund Astronomic," a book which, owing to its clearness of exposition, passed quickly through a series of editions. One of the last pieces of work at which he was em- ployed before he was overtaken by his illness was the sixth edition of this small book. The year 1847 was a very important one in the life of Prof. Rudolf Wolf, for it was at this period that he was appointed to the director- ship of the small observatory of Berne. It was there that he began his well-known series of observations on sunspots, which he carried on without intermission to the end of his life, and which in connection with previous observations led to such important results. Owing to his memorable discovery of the relation between sunspots and earth magnetism his name first became better known, and it was more especially on this account that he received his promotion and a professorship of mathe- matics at the Berne University. In the year 1855 we find him returning as Professor of Astronomy to the newly- founded Swiss Polytechnikum, and at the same time to the university in his " Vaterstadt," where at a later date (1864) he received the appointment as director of the newly-built observatory in which he worked with great zeal to the end of his life. The chief work which Prof. Wolf set himself to do was to obtain a continuous record of the spots on the solar surface ; this led him later to examine older observa- tions, and finally to compare their periods with those obtained from magnetic observations. As an astronomical observer Prof. Wolf was most diligent. Besides busy- NO. 1264, VOL. 49] ing himself with observations of many different kinds, he made a point of regularly watching the sun's surface. For fifty years, it is said, he did not allow a single day, in which the sun was at all visible, to pass without observing its surface with one of the observatory instru- ments, or with a small pocket telescope he carried about with him for that purpose. The importance of Prof. Wolf's work will be gathered from the following brief historical sketch. In 1851 Lamont, the Scotch director of the Munich Observatory, in reviewing the magnetic observations made at Gottingen and Munich from 1835-50, per- ceived that they gave indications of a period of io^> years. Sabine, in the following winter, ignorant of Lamont's conclusion, undertook a similar examination with very different data, and found that there was a maxi- mum of violence and frequency about every 10 years ; he it was, also, who first noted the coincidence betv/een this result and Schwabe's sunspot period. The memoir containing this remarkable communication was presented to the Royal Society March 18, and read May 6, 1852 ; but on the 31st /July following, Prof. Rudolf Wolf at Berne, and on the i8th August, Alfred Gautier at Sion, both announced similar conclusions, arrived at quite separately and independently. Prof. Wolf's work began then in real earnest, and he corrected Schwabe's decen- nial period to one a little larger than eleven (irii), and pointed out the better agreement in the ebb and flow of magnetic change than Lamont's \o\ year cycles. So minute and exact were his inquiries that by 1859 he found that very considerable fluctuations on either side of the mean period, which he had previously deduced, were noticeable ; for might not two maxima rise to sixteen and a half years, or sink below seven and a half years ? Prof. Wolf pointed out later (1861) that the shortest periods brought the most acute crises, and vice versa ; he It was, also, who suggested the idea of a longer sunspot period (55/, years). Among other branches of astronomy to which Prof. Wolf turned his attention maybe mentioned that of variable stars. It was in i8522that' he pointed out the striking resemblance between sunspot curves (representing fre- quency) and curves representing the changing luminous intensity of many variable stars. Aurorse, too, received Prof. Wolfs attention, and it was in the same year that, as he was examining Vogel's collection of Ziirich chron- icles for evidence to connect the weather with sunspots, he was led to associate luminous manifestations with solar disturbances. He also interested himself with regard to the announcement of the discovery of Vulcan, and col- lected all information of recorded appearances (.^) of what were thought to be intra-Mercurian planets. From his youth up, Prof. Wolf had a great liking for his- torical study, and was as familiar with the history of his science as he was with the special branch which he made his own. For several years he collected and brought to- gether a great amount of " quellenmaterial," which was published in the form of his " Geschichte der Astronomie." Perhaps his " Handbuch der Astronomie" may be said to be his best work, for there his thorough knowledge of his science and his cleverness had complete scope. The matter in this book is treated with both scientific ac- curacy and literary ability, and is a wonderful instance of his still youthful capacity for work. Towards the end of November last the first sign ot illness showed itself, and during the first few days of December quickly developed, resulting in his death on December 6, at the age of 77. Wholly devoted to the science which he loved, and a large contributor to astronomical knowledge, his name will be handed down to posterity. When the principles played with to-day are thoroughly perfected at some future date, and we can produce perfect pictures of all solar phenomena on a single plate, our future astronomers will January i8, 1894] NA TURF. 267 still look back on the work accomplished by Prof. Rudolf Wolf as a germ from which their work had developed, and as a monument of pains and industry. In his death, besides a true friend, we lose a thorough devotee to science, and we can ourselves mourn with his friends who say, " Und heute stehen seine Freunde aus alien Gauen des \'aterlandes trauernd am offenen Grabe, der Erde die sterbliche Hlill? eines Mannes ubergebend dessen geis- tige Grdsse, personliche Bescheidenheit und herzlichste, oft aufopfernde Liebenswiirdigkeit alien die ihn gekannt haben unvergeszlich bleiben wird " W. J. L. CLOUD PHOTOGRAPHY. T A NATURE recently printed an article by M. A. -^ Angot on the methods he has been employing in order to obtain the excellent photographs of clouds exhibited at the Paris Physical Society at the beginning of last year. The following is a free translation of the article : — It is well known that ordinary photo- graphic plates are most sensitive to blue and violet rays ; hence the blue background of the sky acts, in general, nearly as much upon the plates as the white parts of clouds, which are thus rendered almost or entirely indistinguishable upon the photograph. It is possible, however, easily to obtain views of an interesting effect when, on a back- ground of blue sky, large clouds pass be- fore the sun. The edges of the clouds are then lit up to such an extent that they make much stronger impressions upon the sensitive plate than the sky itself; the remainder of the cloud is, on the contrary, dark, grey or black, and does not come out as well as the sky. To obtain an accurate picture under these conditions it is neces- sary to develop with great care : or better, to use a dilute pyro developer — a few drops of bromide of potassium solution and very little pyro to begin with ; the development is then slowly carried on with the addition of carbonate of soda, and pyro is only added again towards the end if the plate lacks clearness. This method ceases to give good results when it is applied to ordinary clouds, and becomes altogether useless for cirrus clouds. But these are precisely the clouds the study of which is most interesting ; they are com- posed not of water vapour, but of ice- needles ; and their forms and movements are closely connected with changes of weather. Cirri are the most difficult to photograph because, being farther from us than other kinds, they are less brilliant ; and further, when they are seen, the sky is very frequently pale blue in colour, or covered with a milky veil, which diminishes the contrast. Numerous plans have been proposed to photograph cirrus clouds. The first consists m photographing from the summits of high mountains, but that method is not within the reach of everybody. At such places the sky is, in general, much darker, and the clouds are better seen upon the background, so that excellent photographic images can be obtained with- out special devices. Another method has been pro- posed by Prof. Riggenbach, and appears to have some advantages. It consists in photographing the sky, using a diaphragm so small and giving an ex- posure so short that only a trace of the cloud-image NO. T264, VOL. 49] appears after development. The plate is then intensified, and the image brought out by means of bichloride of mercury and sodium sulpho antimoniate. This method, however, has little to commend it. In the first place, intensification is always inconvenient and destroys details, and further, the sodium salt very rapidly deteriorates, so there is always a risk of the plates being spoiled by becoming a very intense yellow colour, or being covered with a metallic deposit. Prof. Riggenbach has suggested another and abetter method, which is found to give excellent results. The method is based upon the fact that the blue light of the sky is partially polarised, whilst the light of clouds does not possess the same property. If, therefore, a con- venient analyser (a Nicol's prism or black glass inclined at 55 ) is placed in front of the lens of the camera, only a portion of skylight is obtained, while the light of the Fig. I. — Cirrus Cloud prececiing a Storm (March 31, 1892). clouds remains unaltered, and the increased contrast renders it an easy matter to obtain a good picture. But at the same time, this method possesses inconveniences. The proportion of polarised light is far from being the same in all parts of the sky ; hence it is not possible to photograph clouds in any direction. Moreover, many photographers object to the complications which are 268 NATURE [January i8, 1894 involved in the introduction of an analyser in front of the lens of the camera. Thei'e is still another method, unquestionably the most simple one, and the one which, at the same time, gives the best results : it is the employment of coloured screens. In front of the lens of the camera is placed a a screen which transmits yellow and green rays, but is opaque to blue and violet rays. The light of clouds is rich in yellow and green rays ; hence a large proportion of it is able to traverse the screen, and act upon the photographic plate, while, on the other hand, the blue background of the sky emits very little yellow light ; in fact, the proportion of rays of this refrangibility decreases as the blue colour increases in depth, so its action upon the sensitive film is considerably diminished or altogether obviated. The only inconvenience of this method is that yellow and green rays have very little i'lG. 2.— Cirrus cnc C'rcc-cuir-u'us (Feliuary i;, 1193.) action upon an ordinary photographic plate. Under these circumstances it would be necessary to give a very long exposure, which is impossible in cloud photo- graphy on account of the movements of the objects and the rapid changes of form. It is probably for this reason that coloured screens, which w( re adopted in the earliest stages of cloud photograjhy, appear NO. I 264, VCL. 49] now to have almost been abandoned. But this diffi- culty has been practically overcome by the produc- tion of the orlhochromatic or isochromatic plates of commerce, which are sensitive to yellow [[and green light. iM. Angot finds that the best brands of plates for use in cloud photography are the Lumiere orthochromatic and Edwards' isochromatic. Other brands have been tried, but none gave better results than these. As to the yellow screen, the best is obtained by placing a cell having parallel faces, about five or seven millmietres apart, in front of the lens, and filling it with an almost saturated solution of bichromate of potash to which a few drops of hydrochloric or sulphuric acid have been added. A mix- tuie of saturated solutions of bichromate of potash and copper sulphate in the proportion of three of the former to one of the latter may also be employed. In either case the cell is hermetically sealed, and it can easily be fixed in front of the lens or behind it in the bellows of the camera. Evidently it would be simplest to use a screen of coloured glass, and, as a matter of fact, certain glasses give as good results as the cell containing one of the above-men- tioned solutions. But most yellow glasses are quite inadequate for the purpose. It is to be hoped that coloureJ-glass manufac- turers will soon make a glass which will transmit exactly the same rays as the solu- tions. It will be a good thmg to have a series of glasses of graduated tints ; the clearest to serve for very bright white clouds standing ou: boldly upon a fine blue sky, while the darkest could be used for faint clouds when the blue colour of the sky is not so pronounced. The time of exposure must, of course, be increased as the glass used is increased in tint. The two illustrations here given are re- duced copies of two of M. Angot's negatives. The originals are eighteen centimetres long by thirteen wide. Fig. I was obtained on March 31, 1892 ; it shows some patches of cumulus cloud, and an extremely remarkable sheaf of cirrus which preceded a violent storm by two hours. The second illustration (Fig. 2) shows a form intermediate between cirrus, properly so called, and cirro-cumulus, observed on Feb- ruary 19, 1893. Both these pictures were obtained by means of Lumiere orthochro- matic plates, with a cell containing a solu- tion of potassium bichromate and copper sulphate, and a wide angle lens having a focal length of o-i6o metres. The aperture was cut down by means of a diaphragm of about one-twentieth the focal length, and the time of exposure for Fig. i was three- quarters of a second, and one-half a second for Fig. 2. The usual developers may be employed, but pyrogallic acid was used by M. Angot on account of the latitude of exposure it permits. As photography is being widely used in the future to increase our knowledge of clouds, it is recommended that the date and hour of ex- posure be written upon each picture. M. Angot's photo- graphs are a sufficient testimony of the excellence of his method of work, and their multiplication in different parts of the world would considerably extend our knowledge of cirrus clouds, and very probably prove of use in forecasting weather. January i8, 1894] NA TURE 269 LETTERS TO THE EDITOR. { The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he tntdertake to return, or to correspond -with the ivriters of, rejected manuscripts intended for this or any other part ^^/Natuke. No notice is taken of anonymous commiinications.'\ The Directorship of the British Institute of Preventive Medicine. The position of Director of the above-named Institute is one which corresponds to that of M. Pasteur in Paris, and to that of Dr. R. Koch in Berlin, and is therefore one of great im- portance. The Institute is now about to be built, and it is of the utmost consequence that the first holder of the office in question should be very carefully chosen, as he will necessarily have a gieat deal to do with the arrangement of the plans of the laboratory, and theorganisaUon of the work lo be done in it. The Institute is intended to do in England the work done in France by ihe Institut Pasteur, and in Germany by the Berlin Hygienisches Institut ; and the Council have already in their hands sufiicient money to begin to build and carry on a laboratory on a scale comparable to that of the great continental ones referred lo. The Directorship is a scientific post, and there are certain customs regarding the election to such offices which it is, in my opinion, extremely unwise to neglect. It is customary, for exa nple, to advertise that such a post is vacant, and to examine the qualifications of the candidates who apply for the office. These and other customiry modes of pro- cedure having without sufficient reason been disregarded at a recent meeting of the Council of the Institute, I feel constrained to make a public protest. S:nce the Institute was first initiated at my suggestion on December 5, 1889, the meetings of the executive committee and Council have been very ill-attended, a fact for which I believe the officebearers have been mainly responsible ; the result, in any case, being that the officers «f the Council have gradually come to control the decisions of the meetings to a much greater extent than I have experienced in any council, syndicate, or board of which I have been a member. While I was one of the hon. secretaries of the council, I noted what seemed to me grave irregularities in the mode of conducting the business of the council, against some ot which I protested in writing to JNlr. Ernest Hart (^who had occupied the chair at the previous meeting), and verbally to Sir Joseph Lister, who th:;n, as now, was chairman of the Council, ^ir. Ernest Hart disclaimed all knowledge of or sympathy with the measures to which I objected, but our chairman not seeing the full point of my protests, I emphasised my strong disapproval ot the measures in question by resigning my post of Hon. Secretary. On Monday, the nth ult., I received a notice, signc:d by the Hon. Secretary ( Dr. A. Ruffer), calling a meeting of the Council of the Institute for December 13, with the agenda (which 1 append) containing, amongst formal business, the statement that the "report of committee appointed at last meeting" would be considered. At the Council meeting of December 13, I saw for the first time a copy of the report in question. This, with the instruc- tions lo the committee which supplied the report, I append. The question was at once asked why a report concerning a subject of this importance, had not been, as is customary, dis- tributed to members of the Council before the meeting, see- ing that there are among the Council gentlemen who are directors of laboratories, whose aid in considering so important a sabject must be of ihe utmost value, but which could not be given without time to consider the hastily drawn up and imperfect report submitted to the meeting? To this it was replied from the Chair that the matter was considered so pressing by the office-bearers, that there had been no time to send round copies. As the Institute has been four years reaching iis present position, during the whole of which lime the office-bearers knew that a Director would have to be appointed, this reply did not appear to me to carry any weight with it. To the question why, assuming for the moment that the adoption of some such report were pressing, its nature had not been clearly indicated in the agenda, in order that those members of Council whose opinion would be of special value in discussing it, might try to arrange, even at some sacrifice, to be present. To this no satisfactory answer was given. As less NO. 1264, VOL. 49] than a third of the members of the Council were present at the meeting. I, and others, strongly urged that the considera'ion of the report be adjourned for, say, a week, in order ihat it might be distributed in the usual way. This being opposed by the two office-bearers present, viz. ihe Chairman and the Treasurer (Sir H. Roscoe), was not agreed to, their opinion in such a matter necessarily carrying great weight. It' the appended report be examined, it will be seen that the instructions to the committee give no authority lo nominate a Director. This view was upheld by one of the members of Council present, who had been appointed member of the com- mittee, but had been unable lo be present at its meetings (although that is obviously not the view of the members of committee who signed the report). The Council decided, how- ever, to leave out the name ot the Interim Director fromClau-e I of their report. The report so modified was then considered, and although I and others expressed strong disapproval of its being pressed forward wilhoui due consideration by the Council, it vva=, v\iih a i&\\ verbal alteration-, adopted. It was then proposed to add to it a tenth clause nominating the Hon. Secretary to the Directorship. It was objected, how- ever, that such a nomination could not be appended in this way to the repjrt, and this obj.'ction was upheld by the Council. Tne motion was still, however, pressed forward by the signers of the report, which was, as I take it, hopelessly ir- regular, and which was strongly objected to. It was urged that notice of such a motion should have appeared on the agenda ; that the committee had not apparently made any inquiiies as to possible candidates, or their qualifications for so important a poft ; that they had no authority to nominate any candidate, and were therefore acting ultra vires in doing so ; that in pro- posing to elect one of themselves in this irregular manner the nvo otlice-bearers present were exposing their aciion to serious misconstruction. In spite of tliese and other protests, which I need not detail, the motion was pressed, and was eventually formally proposed, seconded, and carried. I will not seek lo state the arguments advanced by our Chair- man and Treasurer for their action as office-bearers, seeing that these can be best stated by themselves ; nor will I do more in the meantime than mention that on leaving the Council meeting I at once protested in writing to the Chaiiman, and have since done my utmost to get the election re-cmded. It is unnecessary for me to make more than one or two com- ments on the above-stated facts. The legality of the election in question may reasonably be doubted, as members of Council had not sufficient notice that it was to take place. There can, however, be no doubt as to ihe harm to science in the election to a scientific post being carried out in this manner. I am also of opinion that, independently of the manner of conducting it, ihe election itself was a grave mistake in so far as the interests of the Institute are concerned. Charles S. Roy. Pathological Laboratory, Cambridge, January 8. [APPENDIX.] Agenda of Meeting of December 13, 1893. 1. Completion of purchase of site. 2. Appointment ot building committee. 3. Sealing of deed with college of State medicine. 4. Report of committee appointed at the last meeting. 5. Memorandum to be addressed to the trustees of the Berridge bequest. Report of the Committee .-appointed at the last MEETING of the COUNXIL. The committee appointed to consider the appointment of the director, his duties and salary, and his relations to the council and staff of the institute, met on December 12, 1S93. — Present : Sir Henry Roscoe, Professor Victor Horsley, and Sir Joseph Lister. They beg to report as follows : 1. That Dr. Ruffcr be appointed interim director of the institute for a period of three years, at a salary of /200 a year. 2. That Dr. IMcFadyen receive the title of lecturer on bacteriology and that, he be entrusted with i.he systematic instruction in that subject. 3. That the director and the lecturer on bacteriology should r 270 NA TURE [January 18. 1894 have each his own la'ioiatf ry and rooms where research may be comlucted under his supervision. 4. That the scheme of any course of lectures delivered at the institute, whether by the director, the lecturer on bacteri- ology, or anyone else whom the council may appoint, be sub- mitted to the council for their approval. 5. That the director should exercise a general supervision over the conduct of the institute, and be responsible for it to ihe council. 6. That all matters of expenditure at the institute should pass through the hands of the director, and that he should be entrusted with the appointment and dismissal of the servants of the institute. 7. Thai anyone desiring instruction at the institute, or wish- ing to tngage in original research there, should make applica- tion to the director, who should have power to admit him. 8. That the director should present to the council a quarterly statement of the work carried on at the institute, and furnish a written annual report. 9. That leave of absence b2 granted by the council to the director and the lecturer on bacteriology, on the understanding that in each case an efficient substitute, approved by the council, be provided. (Signed) II. E. Roscoe. Victor Horsley. J. Lister. Electromo'.ive Force from the Light of the Stars. On the invitation of Mr. W. E. Wilson, I came here a few days ago for the purpose of trying whether it was possible or nit to obtain measuia ile el^c romotive forces from the li^ht of the planets and of the t'lxed stars. Tne sensitive cells which we employed are seleno-alu'iiiniumrc lanthol cells, and (excepting the liquid) are the same as the selenn-akiminium-acetone cells which I described in the rhU. Jl/jt;. for March, 1892. Last night was the on!y one 01 which observations were possible ; and, owing to the stale of the weather, it does not seem likely that, in the time at our disposal for joint-work, any more photo-electric measures can be made. The result of last night's work is to prove that the electromotive force of starlight is easily measurable. The electrometer which we employed is Clifton's form of the quadrant electrometer of Lord Kelvin. It was placed in a room beneath that in which the telescope is fixed, and was thus kept quite dry and free from draughts. The telescope is Mr. Wilson's two-feet reflector ; and the photo-electric cell, attached to a cell-carrier, was connected with the telescope in place of the eye-piece, and could be moved into or out of the image of the star at pleasure. The poles of the cell were connected with those of the electrometer by naked but well insulated fine wires led through a hole in the floor of the observatory. The area of the sensitive plate in the cell is about 3 square millimetres. An E. M.F. of i volt was represented by 460 divisions of the scale, and the light of Venus gave about 40 divisions. Only about one quarter of the disc of the planet is at present illum- inated, so that the E.M.F. of the whole light of the planet would have been represented by 80 divisions. [The square of the E.M.F. is proportional to the incident energy.] Thus the light of Venus concentrated by this telescope is represented by about "17 volts. With Jupiter about 14 divisions on the scale were obtained ; but no conclusion can be drawn from this, because the image of Jupiter covered much more than the area of the sensitive plate. Hence the energy of his light corresponds to a much larger number than that given. From the light of Sirius we obtained an E.M.F. of about •02 volts (a little over 9 divisions on the scale). An attempt on Aldebaran was not productive of any certain result, and was interfered with by an accident to the cell. However, we consider that we have succeeded in our object, and we hope that, with a slightly improved cell-carrier and a much more sensitive electrometer, results will be obtained from the lights of a large number of fixed stars. I would observe, in conclusion, that the relative values of the lights of Venus and of Sirius as given in the " Encyc. Brit," ("Photometry"), are most probably erroneous. It seems to me that the light of Venus very much exceeds the value there given. George M. Minchin. Daramona House, Westmeath, January 8. NO. 1264, VOL. 49] THE THYROID GLAND. (With apologies to Mrs. Hemans). " \A/^ ^^^^ ^'^^^ speak of the thyroid gland, * * But what thou say'st we don't understand; Professor, where does that acinus dwell ? We hashed our dissection, and can't quite tell. Is it where the macula lutea flows, And the suprachoroidal tissue grows ?" — " Not there, not there, my class ! " " Is it far away where the bronchi part, And the pneumogastric controls the heart ? Where endothelium endocardium lines, And a subpericardial nerve intertwines ? Where the subpleural plexus of lyinphatics expand. -'- Is it there, Professor, that gruesome gland? " — " Not there, not there, my class ! " " I have not seen it, my gentle youths, But myxoedema, I'm told, it soothes. Landois says stolidly, ' functions unknown ' : Foster adopts an enquiring tone. Duct does not lead to its strange recess. Far below the vertex, above the pes, It is there, I am told, my class ! " R. M. NOTES. Prof. Ernst Haeckel completes his sixtieth year on February 16 next. On the following day a marble bust of him is to be placed in the Zoological Institute at Jena. Dr. Richard Simon, of Jena, is the treasurer for the fund opened for this purpose, and the following Englishmen are on the general com- mittee : — Mr. F. Darwin, Dr. Gadow, Prof. Huxley, Prof. Ray Lankester, Sir John Lubbock, Prof. Alfred Newton, Mr. Poulton, Mr. Adam Sedgwick, Mr. Sollas, Mr. Herbert Spencer, and Sir Wm. Turner. The competition for the prize of 500 francs, founded by De Candolle for the best monograph on a species or a family of plants, has been opened by the Societe de Physique et d'llis- toire Naturelle of Geneva. The memoirs may be written in Latin, French, German, English, or Italian, and should be sent to the President of the Society before January 15, 1895. Mem- bers of the Society are not admitted into the competition. M. Marey has been elected vice-president of the Paris Academy of Sciences for the ensuing year. The death is reported, at Vienna, on December 2, 1893, at the age of 62, of Dr. J. Boehm, well known for his researches on the circulation of the sap in plants. The death is also announced of Baron K. von Kiister, eminent in botanical circles ; of M. Quinquand, known for his investiga- tions on nutrition and toxicology, and other important physio- logical works ; and of Dr. Heider, Privatdocent in Hygiene in Vienna University. We regret to record the death of Herr W. von Freeden, which occurred at Bonn, on the nth inst., after a short attack of inflammation of the lungs. Herr v. Freeden is best known to science as the founder and first director of the Noiddeutsche Seewarte of Hamburg, which in 1875 was developed into the Deutsche Seewarte, under Dr. George Neumayer, Herr v. Freeden was born at Norden, in Hanover, in 1822 ; he was first appointed Teacher of Physics and Modern Languages at the Gymnasium at Jever, a post which he exchanged for the Headmastership of the Navigation School at Elsfleth, near January i8, 1894J NA TURE 7^ Bremen. Daring his stay at Elsfleth he took an active part in the founding of the North German Lloyd's Company. In 1867 he resigned his position, and moved to Hamburg, where he established the Norddeutsche Seewarte, and in connection therewith organised the first system of storm warnings for the German coaUs. The activity of this institution, which existed under the above title for eight years, was most creditable to its management. In February, 1S75, the organisation was taken up by the Imperial Government, and Dr. v. Freeden was re- lieved of his office. He retired to Bonn, where he occupied him- self with editing the Ilitnsa, a nautical newspaper which he had started. He was for five years from 187 1 Member for Hamburg of the Reichstag, but he declined re-election on removing his residence to Bonn. The FCe-M Bulletin says that Mr. W. Scott has been nppointcd Director of Forests and Botanical Gardens in Mauriliu , in succession to Mr. J. Home, who has recently retired. Dr. W. Migula has been appointed Professor of Hutany at Karlsruhe Technical High School, Dr. W. Laposchnikoff Pro- fessor of Botany in Tomsk University, S.beiia, and Dr. Zelinka Extraor. inary Professor of Zoology in Graz University. The medals and funds to be given at the anniversary meeting of the Geological Stciety of London to be held on February 16 next, have been awarded as follows : — The WoUaston Medal to Prof. Karl A. von Zittel ; the Murchison Medal to Mr. W. T. Aveline ; the Lyell Medal to Prof. John Milne, F.R.S. ; the balance of the proceeds of the Wollaston Fund to Mr. A. Strahan ; that of the Murchison Fund to Mr. G. Barrow ; that of the Lyell Fund to Mr. William Hill ; and a portion of the proceeds of the Barlow-Jamieson Fund to Mr. Charles Davison, Dr. E. Symes Thompson will deliver four lectures at Grcjham College from January 22-26, his subject being "The Sense of Touch.'' The forty-seventh annual general meeting of the Institution of Mechanical Engineers will be held on February i and 2, when the President, Dr. William Anderson, F. R.S., will retire, and will be succeed :d by Prof. A. B. W. Kennedy, F.R.S. A COMPLETE skeleton of a Plesiosaurus, about 3i yards long, has been found, with other fossil remains, at Holzmaden in Wiirtemberg. It is being t"ken to the Berlin Museum. Prof. Carr informs us that a very extensive and valuable collection of British and foreign plants has been presented to the Nottingham Natural History Museum by Mr. H. Fisher late of Newark. Some idea of the nature and extent of the collection may be gathered from the following enumeration of the more important series included in it : (i) A practically com- plete herbarium of British plants, comprising about 2000 species and varieties, and about 10,000 specimens. (2) A European collection, comprising many thousand species from France, Germany, Switzerland, Austria, Roumania, Russia, Norway, Sweden, &c. (3) Several thousand species from North America. (4) A very fine collection from the Bombay Presidency. (5) About 1500 species from Natal, the Transvaal, and other plants of South Africa. (6) A small collection from Australia. Of the above collection that from Russia is of quite exceptional value and interest. It comprises species from all paits of the Russian Empire— from St. Petersburg, Lapland, and the Crimea, through Siberia to Kamskalka and Turkestan, also from the Trans-Caucasus and the Caspian region. The Spanish collection is an extremely fine and valuable one— probably one of the best in existence. In order to hand over the collection to the town in as complete and accessible a form as possible, Mr. Fisher is himself arranging and labelling the collection. NO. 1264, VOL. 49] M ucii has been wi itlen and conjectured as to the origin of music and the rhythmical movement of the body which is intimately associated with musical sounds. Dr. S. Wilk.= , F.R.S., discusses this problem in the January number of the Medical Afagazitie. He points out that it is felt by many that the origin admits of a physiological explanation ; but others prefer to regard muiic as a purely spiritual faculty. All, however, who have con- sidered the nature and origin of music believe that rhythm, as exemplified by movement, is very closely connecied with it. The latest work on piimilive music is by Wallaschek, and the conclusion he arrives at is that rhjthm, or keeping time, lies at the very foundation of the musical sense. But rhythm and the time sense can be referred to muscular contraction and relaxa- tion, for it has been long maintained by physiologist - that the muscular jense is the measuie of lime, and intin.ately bound up with the idea of music. As Dr. Wilks remarks, there must be an up and down movement or rhythm in all muscular action, and this seems to be the same thing as the sense of time or rh}thm of which Wallaschek speaks. In fact, the rh)thmical sense insisted on by Wallaschek as the basis of music is, in all probability, the muscular sense which physiologists believe to form an intimate part of the musical faculty. Not in the different passions of the mind, but in muscular action, therefore, music appears to have had its origin. The internal temperature of trees has formed the subject of some investigations by M. W. Prinz {La Nature). The results show that the mean annual internal temperature of a tree is practically the same as that of the surrounding air, but the monthly means diff"er by two or three degrees. In general it takes a day for a thermal variation to be transmitted to the heart of a tree. On some days the internal temperature differs by as much as 10° C. from the air outside, but generally the difference is only a few degrees. When the air-temperature falls below the freezing point, the internal temperature of a tree descends to a point near that at which the sap freezes, and appears to remain there. The maximum temperature of the interior of the trunk of a tree may occur some time before the maximum is reached by the sun ounding air, owing to the action of the spring sun upon the tree while devoid of foliage. During the high temperatures of summer, the internal temperature was proved by the investigations to be about 15' C. with a variation of2°C. at the most. Speaking generally, a large tree is warmer than the air in cold months, and a little colder than the air during the summer months. During the recent frost, large masses of ice containing numer- ous freshwater eels were carried down the River Arun to Little- hampton. This affords an interesting example of the manner in which freshwater fish in a perfect state of preservation may be buiied in some number in marine deposits. Mr. J. Stirling, in his second special report on the Victorian Coal-fields, describes the various areas in detail, referring amongst other points to littoral and subaerial denud- ation and to the origin of soils. In the Kilcunda district numerous boreholes for coal have been put down by Govern- ment— one to a depth of 1158 feet. Mr. J. J. Stevenson, in the jSm/Z^/Zw of the Geological Society for America, vol. v., discusses the origin of the Pennsylvania anthracite, and shows that there is no relation between the amount of disturbance of the strata and the production of anthracite. The coal becomes more anthracitic as the seams thicken towards the north-east ; in this direction the coal seam, whilst in process of formation, would be lorger exposed to chemical change. Dr. W. F. Hu.me read a paper on "The Genesis of the Chalk " before the Geologists' Association on January 5. He 2/2 NA TURE [January i8, 1894 showed that, viewed in its general aspect, the Chalk Period hears evidence of the almost continuous gain of elevation over depression influence. According to his researches, the Upper Greensand is the expression of coast-line conditions, the currents transporting shore material being sufficiently strong to make their influence felt over 150 miles from land. The chloritic marl probably represents the denuding effect of the advancing sea opon the sinking land. The chalk marl and grey chalk seen; to have been deposited in areas of gradual subsidence ; j judging from the change in the Foraminifera, the gradual re- duciion in size and quantity of quartz and glauconitic grains, and the absolute disappearance of heavy minerals (zircons, &c. ) in the higher zones of the Lower Chalk. The great purity of the chalk in the Tercbratulina gracilis zone, and the almost entire absence of a heavy residue, indicates that the maximum depression for the Middle Chalk period very probably occurred about the time of the laying down of its central beds. From this zone onwards the chalk becomes more and more marly, passing finally into the condition of the chalk rock, that is, a truly nodular bed. The reappearance of quartz and glauconite i grains, and heavy minerals (Tourmaline, Augite, and Horn- blende), all point to this rock as having been formed during a period of elevation. The zones of the Upper Chalk show typically the continuation of great depression, for the flints gradually become reduced in size, and pass through various changes of shape, that is to say, from irregular to zoned, and finally to the tabular form. An important experimental research on the " Decomposition of Liquids by Contact with Powered Silica, " was described by Dr. G. Gore at a recent meeting of the Birmingham Piiilosoph- ical Society. The method of experiment employed was simply to take 25 centims. of a solution of an acid, salt, or alkali, of known composition, which had no chemical action upon pure precipitated silica (or other suitable insoluble powder), in a stoppered bottle ; add to it 50 grains of the powder, thoroughly agitate the mixture, set it aside, usually about sixteen hours, and analyse the clear liquid portion. This enabled the chemical composition of the film of liquid wfhich adhered to the powder to be approximately ascertained, and the influence of surface tension upon such composition to be examined. The experi- ments show that the chemical composition of films of liquid adhering to solids may be approximately ascertained by this method. They further show that the power of abstracting dis- solved substances from liquids is a common property of finely divided solid bodies, and that the amount abstracted varies with the kind of powder employed ; the degree of fineness of the powder, and consequently the amount of its surface ; the kind of dissolved substance ; the proportion of powder to dissolved substance ; the kind of solvent ; the proportion of solvent to powder ; the proportion of dissolved substance to solvent : and, in a small degree, with the temperature. The union takes place quickly, and a long period of time has but little inflaence. Fmely precipitated silica possesses the property in the greatest degree, and alkaline substances are the most affected ; with very dvlule alkaline solutions more than 80 per cent, of the dissolved substance was abstracted by the silica. The results appear to throw some light upon the purification of water by filtration through the earth and upon agriculture, and to show that the alkaline constituents of soils are retained much more by the silica than by the alumina. The effects of silica upon weak solutions of potassium cyanide indicate that the great loss of the latter substance in the commercial process of extracting gold and silver from powdered qaartz is largely due to the " adhesion " of that salt to the silica. And the results obtained with silica and a very weak solution of iodine indicate a possible method of ex. tracting the latter substance from solutions, and the recovery of NO. 1264, VOL, 49] the iodine from the silica by distillation. The research brings more closely together the sul>jects o( physic-; and chemistry. The Analele of the Roumanian Meteorological Institute, vol. vii., contains an account of a glazed frost, or smooth coat- ing of ice, which occurred on November 11 and 12 last over a very large tract of country, and caused much damage to trees and telegraph lines ; some of the trees had not only their boughs, but even their trunks broken by the weight of the deposit. Dr. Hepites states that in this case the cause of the formation of the glazed-frost was not that the rain fell upon objects at a temperature below zero, as the phenomenon has sometimes been explained, but that it is probable that the drops of rain were in a state of superfusion, and became frozen on touching the objects on which they fell. When the glazed-frost commenced, the temperature on the ground was Z^^'S- ^^ ^^^ neighbour- hood of Bacharest the telegraph wires were coated with ice an inch in diameter, and were thickly studded with stalactites of ice. The weight of this coating over the length of a metre of the wire was thirteen times as heavy as the wire itself. The numerous attempts which are at the present time being made to utilise the energy which runs to waste wherever there is a waterfall, and which have lately had considerable public attention drawn to them on account of the publication of Prof. Forbes' paper on the utilisation of the Niagara Falls, have received an interesting addition in the attempt that is being made on the canal between the Seine and Saone. It occurred to M. Galliot, an engineer at Dijon, to utilise the water power of the fall of water at the lock sluices to drive turbines and dynamos, the current obtained being used to propel the boats on the canal. The electric power is conveyed along the canal by means of a wire supported on posts, and each tow-boat is provided with a motor which takes its current from this wire. The propulson of the tow-boat is effected, not by means of a screw propeller on the boat, but by a train of gear wheels connecting the motor to a chain which extends along the bottom of the canal, and by means of which the boat drags itself along. In addition to working the canal boats, the electric power is utilised to light up the interior of a tunnel through which the canal passes. A PROPOSAL for a standard of " noraaal air " is made by M. A. Leduc in the Comples Kendiis. It is to be one litre of air taken at a place outside any town in a level country, and during calm weather. Freed from carbonic acid and water vapour, as well as traces of other accidental gases, such a litre of air would contain 23"2 per cent, by weight of oxygen. Since this propor- tion is variable in the same place by about 4 units in the second decimal place, it is useless to determine the weight of this litre of air to within more than i/ioooo of its value. A careful series of determinations gave i'2932 gr. for this weight at o^^ C, at the latitude of Pari;, and at 760 mm. pressure. Under I C.G.S. atmosphere, this weight would be i "2758 gr. This Stan lard would be sufficiently well defined for most practical purposes, but where greater accuracy is required, M. Leduc proposes to employ nitrogen as a standard of reference for gas densities. The weight of the normal litre of nitrogen at Paris is i'2570gr., or i'24 gr. under i C.G.S. atmosphere, within O'l mgr. The Journal de Physique for December contains a paper by M. Violle, on the electric furnace and the light given out by, and the temperature of, the electric arc. In a lormer note a description of the form of furnace used by M. Violle has been given. The author considers that his experiments show that the electric arc is the seat of a perfectly definite physical pheno- menon, namely, the ebullition of carbon, for the arc is character- ised by a constant brightness {i.e. the light given out by a giv.'n January i8, 1894.] NATURE ^7o area of the positive crater is constanl), and by the temperature being always the same, a^; well as by all the circumstances which ; characterise normal ebullition. The constancy of the character j of the light given out by the arc has been noted by Abney and j Fesling, who have adopted it as the standard of white light, and the author's observations show that whatever b.e the watts , consumed in the lamp, the brightness remains constant. This he has shown by direct comparison with a standard light, and also by photographing the positive carbor, when the density of the image remained constant. Prof. S. P. Langley, who has recently been giving a ' large amount of attention to cerodynamic?, contributes a ; remarkable paper to the current American J otirnal of Science on what he calls "The Internal Work of the Wind." The conclusions attained in this paper lead the author to the con- j fident assertion of the mechanical and practical possibility of a heavy body, provided with suitable plane or curved surfaces, being suspended indefinitely in a wind, or even advancing against it without connection with the ground or the expendi- ture of internal energy. This is to be brought about by utilising the heterogeneous structure of wind, which Prof. Langley shows to consist of puffs succeeding each other several times per minute. This was proved by the records of some very light anemometers with paper cups, mounted on the roof of the Smithsonian Institutiop, at 153 feet above the ground. The electric record was made at every half revolution. In one case a wind of 23 miles an hour rose within 10 seconds to a velocity of 33 miles an hour, and fell to its initial speed in another 10 seconds. It then rose within 30 seconds to 36 miles an hour, and so on, passing through a series of maxima and minima separated by intervals of about lo seconds, and sometimes stopping alto- gether. This observation may serve to solve the long-discussed problem of the soaring of birds. A wind acting against a free plane at a suitable angle will urge it upwards until the plane has assumed the velocity of the steady wind. If the wind- velocity is then reversed, absolutely cr relatively, and the inclination of the plane is reversed at the same time, the plane will be urged still further upwards, and the more so the greater its weight. If a heavy body can thus rise, it follows at once that it can also advance against the wind if not too strong, by utilising the energy thus acquired, and descending in the direc- tion whence the wind blows. The main difficulty in construct- ing a contrivance to effect this would lie in the adjustment of the inclination to a varying wind, but Prof. Langley is con- fident that this difficulty will not prove insuperable. The alleged discovery of the northern end of Greenland in the NordenskiiJld Inlet seems to have been based upon a very bold interpretation of Peary's observations. Peary himself has, in his first account, said nothing about having discovered a passage from Nordenskiold Inlet to Independence Bay, and the report now issued by his companion, J- Astiup [Geogr. Selsk. Aarhog), which gives particulars of what was actually observed, does not allow any conclusion as to a waterway connecting them. It would be strange indeed if Astrup let the discovery of the north end of Greenland unmentioned, as if it were some- thing unessential. An ingenious .method for making permanent microscopic preparations of particular colonies on a gelatine plate, has been recently devised by Hauser {Miienchener med. Iloc/iai- schrift, 1893, No- 35)- It was found that when exposed for some time to the vapour of formalin, gelatine becomes so rigid that no temperature is able to melt it ; even submitting it to the heat of a bunsen flame, or boiling it in a soda solution, fail to liquefy it. This formalin-gelatine becomes, moreover, strongly antiseptic, for when freely exposed to the air no colonies make their NO. 1264, VOL. 49] appearance, and neither will those organisms grow which are purposely introduced into it. Gegner, in an earlier numl)er of this journal, stales -that although solutions of formalin had a^ bactericidal action, the vapour was a far more powerful anti- septic ; this investigator also notes that gelatine exposed to this vapour would not melt at 37° C. To prepare bacterial colonies for microscopic examination, Hauser takes a thin film of the solid gelatine containing the particular growth required, and places it on an object glass, and, superposing a cover-glass, seals it from the outer air by a rim of melted gelatine. The prepara- tion is then placed in the formalin chamber for twenty-four hours, during which it becomes quite solid, and on being re- moved may be further protected by a border of sealing-wax. If it is desired to stain the colonies before the formalin process, the gelatine film should be immersed for twenty-four hours in a weak aqueous solution of fuchsin, by which means the bacterial growth becomes fairly strongly coloured, whilst the gelatine itself only assumes a much paler hue. We have received the 1S94 Aniniairc of the Brussels Academic Royale des Science^, des Lettres et des Beaux-Arts. "The Elements of Co-ordinate Geometry,"' Part i, by W. Briggs and G. II. Bryan (Univ. Corr. Coll. PressS has reached a second edition. A THIRD edition, enlarged and revised, of Dr. T. Button's little book on " Indigestion" (Kimpton, and Hirschfeld Bros.) has been published. Mr. William Clay, Edinburgh, has issued a new catalogue. No. 60, of standard second-hand and new books on physical science offered for sale. Dr. H. Wagner gives an account, in the Oeslerreichische Boianische Zeitschrifl,oih.\S: botanical exploration of the Balkan^, in company with Herr J. Stipanics, entomologist. Thy. Journal of Anatomy and Physiology for January contains an article by Mr. A. Keith, on the ligaments of the Catarrhine monkeys, with references to corresponding structures in man. Profs. J. C. Ewart and A. Macalister are among the other con- tributors to the number. The first part is published of Dr. II. Trimen's "Handbook to the Flora of Ceylon," containing descriptions of all the species of flowering plants indigenous to the island, and notes on their history, distribution, and uses. It is issued under the authority of the Government of Ceylon. The Calendar just issued by the Department of Science and Art contains the foUou ing names of recently appointed In- spectors of Science and Art Schools: — Dr. E. J. Ball, F. Blair, S. F. Duflon, C. Geldard, Dr. II. H. Hoffert, D. E. Jones, Dr. MacNair, C. McRae, T. Preston, F. Pullinger, Captain T. B. Shaw, R. E. , and H. Wager. The National Fool path Preservation Society, of which the late Prof. Tjndall was a member, has issued its ninth annual report. The large number of cases of footpath interference, encroachments, &c. described in the report, shows that the society exerts a salutary influence upon those who are inclined to disregard ancient rights. Subscriptions are invited by Laidley and Co., of Port Elizabeth, to the issue of a complete botanical collection for the Cape Colony, Kaffraria, Natal, Zululand, Swazieland, Matabele- land, Bechuanaland, Mashonaland, the Transvaal, Orange Free I State, and the Portuguese territoiies of the Zambesi. The flora is computed to exceed 20,000 species. Messrs. Blackie and So.\ have sent us several of their Guides to the Science Examinations of the Department of Science 274 NA TURE [January i8, 1894 and Art. The books contain some useful hints to intending examinees, and answers to questions that have been set at the Departmental examinations. A number of test-pipers in mathe- matics, arranged by Mr. R. Roberts, has also just been pub- lished by Messrs. Blackie. " La Terre avant I'apparition de THomme " (MM. Bailliere et Fils) is a bulky tome by Prof. F. Priem, in Brehm's Merveilles de la Nature series. In it the author recounts the numerous changes through which our globe has passed in geobgical time. He describes the distribution of land and water during the well- marked periods of this world's history, and deals particularly with the fauna and flora of bygone days. In the latter half of the work, the geology of France is dealt with in a very detailed manner. The book is an courant with recent investigations in geology and palaeontology ; it contains 850 figures illustrating fossils, geological sections, picturesque regions and interesting formations, and is worthy of a high place in the fine series to which it belongs. During the last few months we have had the pleasure of com- nnenting upon sever il chatty books on natural history matters — books in which instruction is happily combined with interest. Another volume of a similar kind, " Random Recollections of Woodland, Fen, and Hill,"' by Mr. J. W. Tutt (Swan Sonnen- schein and Co.), has recently been published. We recommend the book to the nature-lover and entomologist because it contains a large amount of information brightly put and generally accurate ; and all who can appreciate the beauties of natural creatures and things would do well to read it. A VERY important collection of works is being offered for sale by Messrs. W. Wesley and Son. We refer to the Paracelsus Library of Dr. E. Schubert, who died at Frankforton-the Main in 1892. The library contains 194 editions of the writings of Paracelsus. 548 works which partly or chiefly treat of Para- ceLus, description of his times and the places where he worked, publications of his friends and opponents, and a selection of 351 works on alchemy. Altogether this unique collection comprises about eleven hundred books, manuscripts, portraits, and tracts, and it is richer in original editions of Paracelsus than that of the British Museum. It is satisfactory to know that no part of the library will be disposed of separately, with the exception of the portion on alchemy. 1 An investigation of the mechanics of the interaction of ethyl alcohol and hydrogen chloride is communicated from Prof. Lothar Meyer's laboratory to No, 12, 1893, of l^e Zeitschrift fiir physikxlische Cheinie by Mr. Cannell Cain, Solutions of hydrogen chloride of different strengths were ob- tained by leading the dry gas into the dry alcohol, which was coated by a freezing mixture. A definite quantity of such a solution was then sealed up in a small glass tube, and kept for a definite length of time at a constant temperature in a water bath. The composition of the solution before and after the interaction was ascertained by titrating a known amount with dicinormal soda solution. The results show that concentration and time of reaction being the same, the extent of the chemical change increases rapidly with the temperature. Up to 15° there is no appreciable interaction, but in a solution containing 100 equivalents of alcohol and 81 of hydrogen chloride at 80° some 15 per cent., and at 99 some 50 percent, of the latter enter into combination in one hour. For a given temperature and concentration the amount of decomposition increases with the time at a rate which gradually diminishes, and finally becomes zero. Temperature and time of reaction being the same, it is also shown that increase in the quantity of alcohol in the above solution, or addition of water or ethyl chloride, retard the rate of change. By experiments with water and ethyl chloride the NO. 1264, VOL. 49I author makes clear the reversible character of the action, and next makes observations to ascertain the relative proportions of the substances present when equilibrium is established. In these experiments various solutions of hydrogen chloride in alcohol, alone, and in presence of different amounts of water are employed. Here it is shown that Guldeberg and Waage's law is obeyed, as the product of the active masses of alcohol and hydrogen chloride bears a constant ratio to the product of those of water and ethyl chloride unless in cases where ethyl chloride separates out, and the solutions thus become hetero- geneous. If the alcohol and hydrogen chloride be present in equivalent amounts the results indicate that the equation C2H5OH + HCI + 3C2H5CI + 3II2O approximately represents the condition of things when equilibrium is attained. In the review of Mr, Richard Inwards' " Weather Lore," that appeared in these columns on January 4, p. 219, the author's attention was commended to a collection of " wise saws" made for the U.S. Signal Service by Major Danwoody. Mr. Inwards points out to us that his book contains extracts from this collection, and that he acknowledges his obligations to it in the introduction. We regret that this acknowledgment was over- looked by the writer of the notice. The additions to the Zoological Society's Gardens during the past week include two Mozambique Monkeys (C^r^/zV/^^j-wj pygerylhrus) from East Africa, presented respectively by Mr. H. P. East and Mrs, Adams ; two Common Marmosets (Hapale jacchits) from South-east Brazil, a Common Hamster [Cricettis fnimentarius) European, presented by Mrs, Brightwen ; two Jackdaws {Corviis moneJida) British, presented by Miss Williams; a Clifford's Snake {Zamenis Cliffordi) from Egypt, presented by Mr, W. L, Tod; a Malaccan Parrakeet {Pahvornis longicaiida) from Malacca, deposited ; a Snow Leopard (Felis jincia) from Lahoul, Punjaub, Himalayas, an Alpine Marmot {Arctoviys marinottd) European, two Hairy Armadillos {Dasyptis villosus), a Black-necked Swan {Cygnus iiigricoUis), two Rufous Tinamous {Rhyncholus 7-ufescens), two Brazilian Caracaras {Polyboi'iis brasiliensis), two Common Teguexins ( Tupinambis teguexin), a Common Boa {Boa constrictor) from South America, a Melodius Jay Thrush {Leucodioptron canontm) from China, purchased; two Lapwings {Vanelltis vulgaris), two Dunlins [Tiittga alpina) British, received in exchange. OUR ASTRONOMICAL COLUMN. SuNSPOTS AND SoLAR RADIATION. — Spectroscopic observ- ations, the discussion of the frequency of tropica! cyclones, and cyclical variations of barometric pressure, indicate that the greatest amount of heat is received from the sun by the earth during a maximum epoch of solar activity. But, on the other hand, the discussions of s'atistics of air temperature and solar radiation suggest that that the sun's heat is greatest when his surface is least spotted. Some new facts in connection with this paradox are described by M. R. Savelief in the current Coinptes Rendtis, and seem to combat the latter result. He has made a large number of observations with a Crova's actinograph since June 1890, and compared them with the late Dr. Wolf's num- bers showing the relative frequency of solar spots. A few ob- servations are given indicating that the solar constant increases with the increase of solar activity. M. Saveliel has also calcu- lated the mean quantity of heat received on one square centimetre of horizontal surface on the ground during one day, and for an hour of solar radiation. The results obtained by this method, like those deduced from the solar constant, point to the con- clusion that the calorific intensity of solar radiation increases with the activity of the phenomena visible upon the surface of the sun, that is to say, with the increase of solar spottedness. These results are diametrically opposed to those obtained by previous investigators (see Nature, vol. xliii. p. 583), and, if they are confirmed, a real difficulty in the way of explaining the correlation of solar and meteorological phenomena will hive been removed. January i8, 1894] NA TURE ^75 The Measurement of Stellar Diameters.— When the objective of a telescope is covered with a screen having two slits in it, the image of the object under observation takes the form of a seiies of fringes lying in the direction of the slits ; and every one with an elementary knowledge of physics knows that this appearance is due to the interference of the beams of light traversing the instrument. Fizeau appears to have been the hrst to point out that the size of the fringes depends upon the angular dimensions of the luminous source producing them, and that this fact might be utilised to determine stellar di- ameters. The means by which Prof. Michelson has applied the principle to the measurement of the diameters of Jupiter's satellites has already been described in these columns (vol. xlv. p. 160); but the suhject is so important that we give here the gist of a discussion of the theory of the matter, contributed by M. Maurice Ilamy to the number of the Bulletin Astronomiqiie just issued. By means of Prof. Michelson's interferential re- fractometer — an instrument with a life of usefulness before it — it is possible to measure diameters down to o'Oi, that is, to the angle which the sun would subtend if it were removed to the distance of o Centauri. In fact, there is little doubt that the diameters of stars are measurable by this means. All that is necessary theoretically is to cover the object glass of the tele- sco]ie with a screen having two rectangular, parallel slits, equal and of variable width. The interference fringes produced at the focus of the inslrument are made to disappear by separating the slits, and when the fringes corresponding to light of a wave- length represented by A have vanished, the distance (/) be- tween the centres of the slits must be measured. The exact formula which enables the diameter (e) of the object under ex- amination to be determined from these data is, according to M. Himy, A. € = 1 '22 /sin 1 There are, of course, a few difficulties in the way of perfectly realising the theory, but they are being overcome, and it is not too much to say that the interferential refractometer will add very considerably to astronomical knowledge before the end of this century. It would be interesting to measure the diameters of Algol, and some of the spectroscopic binaries, and compare the results with those deduced from observations of motion in the line of sight. The Moox and Weather. — The solitary observable eflect of the moon on our atmosphere was believed by Sir J. Herschel to be exhibited in the tendency of clouds to disappear under a Full Moon. He attributed this to the heat radiated from the lunar surface. Humboldt speaks of this connection as well- known in South America, and Arago indirectly supports the theory by stating that more rain falls about the time of New Moon than at the time of Full Moon ; the former period being cloudy, and the latter cloudless, according to theory. With the idea of obtaining information upon the matter, the Rev. S. J. Johnson has examined the state of the sky at moonrise and at midnight on the day of Full Moon only for the last fifteen years. His results were communicated to the Royal Astronomical So- ciety on January 12, and they confirm the opinion now held by almost every astronomer, viz. that the Full Moon has no effect in breaking up clouds. GEOGRAPHICAL NOTES. Mrs. Bishop (Miss Isabella Bird) has set out via Canada for Korea, where she intends to spend some time studying the country, and whence she may afterwards make a journey into Manchuria. Three Christmas lectures to young people by Mr. Douglas W. Freshfield, were arranged by the Royal Geographical Society, and were delivered in the second week of January to an interested audience. The subject was mountain-study as a branch of geography, and the lectures were illustrated by a large collection of extremely fine photographic views of the Alps and Caucasus. Mr. H. J. Mackinder commenced the second series of his lectures on the relation between geography and history, in pursuance of the Royal Geographical Society's Educational Scheme, on January 11, in the theatre of the Royal United Service Institution, Whitehall Yard. The lecture was intro- ! ductory to the present course, which will be continued weekly, and consisted of an epitome of last yeai's lecturer, showing that physical and geographical conditions largely determine the order of history and the movements of peoples. The remaining lectures will deal with a series of concrete examples, focussing the essential features of the relation between the geography and history of the chief countries of Europe, and especially of the British Islands. The Zeilschrift of the Berlin Geographical Society publishes an interesting paper, by Dr. Wegener, on the Chinese map of northern Tibet and the Lob-nor District, being a sheet of the official Chinese Atlis compiled by the labours of the Jesuit missionaries at the Court of Pekin, who trained and superintended Chinese surveyors. It was first published in 1718, and an enlarged edition appeared in 1863 extending over the greater part of Asia. This work still is the basis of the European maps of many parts of Tibet, and the careful index of names prepared by Herr Himly, which accompanies the report, is of extreme value, as, not content with the Chinese lettering, he has had recourse to the original Tibetan, Turki, and other native names, which he transliterates with great care. August Artaria, the eminent Austrian map publisher, who has done much to maintain the character of scientific carto- graphy, died at Vienna on December 14, 1893, aged 87. MM. Schrader and de Margekis, whose long study of the geology of the Pyrenees is well known, have contributed to the last volume of the Annuaire of the French Alpine Club a concise discussion of the geographical conditions of the chain illustrated by a large- scale coloured orographical map. The denudation of the northern slope his been much more complete than that of the southern ; the tertiary strata remain on the latter, but on the French side have been eroded away to form the vast fans of alluvium of the lower plain. Despite their general form, the Pyrenees are not composed of ranges running east and west, but of mountain knots and short ranges oblique to the general direction running towards E. 30' S. and then turning towards E.N.E. as a rule. The mean altitude of the chain is about looo metres, or say 3300 feet. Elie de Beau- mont, on the assumption that the southern slope was strictly similar to the northern, made his estimate of the mean height 500 metres greater. The mass of the Pyrenees, if spread over the suiface of France, would raise the level of that country by 102 metres, or 330 feet. A NEW SULPHIDE OF CARBON A NEW liquid sulphide of carbon of the composition C^S.j ■^^ has been isolated in a somewhat remarkable manner in the chemical laboratory of the university of Buda-Pesth, by Prof, von Lengyel, who contributes an account of it to the current Be7-ichte. In addition to the well-known disulphide of carbon, several other substances supposed to be compounds of carbon and sulphur have from time to time been de-cribed ; but as they appear to have been amorphous insoluble solids very difficult to purify, there is very little evidence of their being definite compounds. The substance now described, however, appears to be a very well characterised liquid compound of unmistakable odour and corrosive action upon the skin, and capable of being distilled under diminished pressure. The method of preparing it was accidentally discovered during the elaboration of a number of lecture experiments illustrating the synthesis and decomposition of carbon disul- phide. It was long ago pointed out by Berthelot that this familiar substance decomposes at a temperature but slightly higher than that at which its formation from its constituents occurs. Buff and von Hofmann subsequently showed that the temperature of a glowing platinum wire was ample to bring about slow dissociation of the vapour, and that the disruption of the compound occurred very rapidly indeed at the tempera- ture of red-hot iron wire. An experiment was therefore arranged to ascertain whether rapid removal of the vapour of the synthe- sised compound from the heated sphere of action would largely prevent the loss by dissociation, and in order that the test should be a severe one, the rapidly moving vapour was subjected in its passage to the high temperature of the electric arc. It was during this experiment that the new sulphide of carbon was unexpectedly produced. A little more than a hundred cubic centimetres of carbon NO. 1264, VOL, 49] 2/6 NA TURE [January i8, 1S94 disulphide were placed in a flask arranged over a water bath. A large globe had been previously sealed on to the neck of the llas-k, through tubuli in which the carbon electrodes were in- serted. To a third tubulus of the globe an upward condenser was fitted, the interior lube of which was finally bent down- wards to serve as a gas delivery tube. The water bath was then heated and the carbon disulphide maintained in rapid o'lallition, the electrodes were approached until the powerful cuirent from accumulators was transmitted, and then withdrawn so as to generate the arc. The electric arc in carbon disulphide vapour under these conditions is a remarkable phenomenon ; it is seamed with a datk band passing along its centre from pole to pole, and the brightest spots of the incandescent terminals are ji'st where the band appears to touch them. The carbon diculphide was kept boiling and the arc passing for a couple of hours, during which the globe was filled with the vapour, which condensed in the condenser, and fell back into the flask. The interior of the apparatus soon commenced to blacken with liber- ated carbon, which collected upon the surface of the liqui', and an extraordinaiily strong tear-exciting odour soon made itself eviderit in the neighbourhood of the apparatus. At the conclu- sion of the experiment the residual liquid was cheiryred in colour, and was transferred to a closed vessel containing copper turnings in order to remove the free sulphur present. After being thus left for a week it was filtered, and the carbon disulphide evaporated at a low temperature in a current of dried air, in order, if possible, to isolate the substance endowed with the powejful odour. Eventually a few cubic centimetres of a deep red liquid, the new sulphide of carbon, were left, «hich possessed the odour in greater intc i sity, a trace of the vapour producing a copious flow of tears, accompanied by violent and persistent catarrh of the eyes and mucous membrame. A drop of the liquid, moreover, at once blackened the skin. The specific gravity of this liquid is I '2739, so that it sinks under water, with which it does not mix. When heated it polymerises into a hard black substance. If the rise of tem- perature is gradual the change occurs quietly, but when rapidly heated to 100-120' the polymerisation takes place with ex- plosive foice, the interior of the vessel being covered with pro- jected deposits of the black substance. Analyses both of the liquid and of the black solid indicate the same empirical formula, C3S.2, and molecular weight determinations of the liquid, dis- solved in benzene, by Raoult's method, agree closely with the molecular weight corresponding to that formula. The liquid can be partially distilled at 60"" in vacuo, a small portion, how- ever, always polymerising. The liquid, moreover, spontaneously changes in a few weeks in;o the more stable black solid modi- fication. . The soIu;ions of the liquid in organic solvents likewise slowly deposit the black form. The liquid readily ignites, burning with a luminous flame, and forming dioxides of carbon and sulphur. Caustic alkalies dis- solve if, forming dark coloured solutions from which dilute acids precipitate the polymerised black compound. With alcoholic potash the action is very violent. A drop of concentrated sul- phuric acid causes instant passage to the black form accompanied by a hissing noise. Nitric acid provokes an explosion and ignition, but 70 per cent, acid dissolves it completely and quietly. The black polymeric modification is readily soluble in caustic alkalies, but acids reprecipitate it unchanged. When heated it undergoes a remarkable change, sulphur subliming, and a gas, \ inflammable and containing sulphur, but not carbon disulphide, is liberated, the nature of which is reserved for a further com- ! municati&n. The liquid sulphide combines readily with six atoms of bromine, with evolution of heat. The substance is readily isolated when bromine is dropped into a solution of CsS., in chloroform, as it is insoluble in that solvent. Strangely enough this comj ound, CjS.jBrg, is endowed with a pleasant aromatic odour, two substances of frightful odours thus uniting to form an agreeably odoriferous compound, a striking example of the efifect of chemical combination. A. E. Tuttox. DR. GREGORYS JOURNEY TO MT. KENIA. AT the meeting of the Royal Geographical Society on Mon- day evening, Dr. J. \V. Gregory read a 1 aper, of which the following is a lull abstract : — It has long been known that the lakes of Equatorial Africa are developed on two types, first those which have low shores ' and are rounded in shape, and second those which have high, steep shores and are long and narrow. The lakes of the latter group, moreover, are distributed on a definite plan, occurring at intervals along lines of depression across the country. The chief of these runs from Lake Nyasa through a large series of lakes, including Natron, Nawasha, Baringo and Basso Narok (Lake Rudolf) ; from the last of these the line of depression runs through Abyssinia into the Red Sea, which continues the same type of geographical structure for 18" to the north ; thence it can be followed up the Gulf of Akaba to the Dead Sea and Jordan Valley. It seems not unlikely that the whole of this great line is due to one common earth movement of no very great age, for the traditions of the natives around Tanganyika, of the Somalis and Arabs, and of the destruction of Sodom and Gomorrah may have reference to it. It «as the interest which these problems excited that led to Dr. Gregory's desire to visit the district, as he was recently enabled to do, by the permission of the Trustees of the British Museum. He started with a large expedition, intended to explore this "Rift Valley" in the neighbourhood of Lake Rudolf, which landed at Lamu, and thence started up the Tana Valley, where it unfortu- nately collapsed. On his return to Mombasa Dr. Gregory himself ^ organised a small caravan of forty Zanzibaris, and travelled to the highest part of the " Rift Valley" between Nawasha and Baringo, examining its structure and natural history. The most risky part of the journey was crossing ihehigh plateau of LeiUipia, which has only twice befcre been traversed, by Teleki and Hulinel in 1887, and by the German Emin Relief Expedition under Dr. Peters in 18S9-1890. Mr. Joseph Thomson reached its western side, but had to abandon his camp and escape under cover of night. The expedition crossed Leikipia by a new route, and traversing the plateau which is marked as the site of the " Aberdare Mountain"^,'' reached Northern Kikuyu without trouble, except for want of food. The natives at first refused to sell any, as some white men who had visited a neighbouring distiict had seized food without pay- ment, shot the elders, and carried off the young men as porters. After much " shauri " the natives were satisfied as to the peace- ful olject of the expedition, the right of blood-brotherhood was celebrated, and food obtained. The party then turned noith, to the western foot of Mount Kenia. Most of the men were left in the camp while Dr. Gregory and twelve men started for the central peak. Three days were spent cutting away through the dense forest and bamboo jungle on the lower slope. Owing to the damp, mist, and cold, this work was very severe on the Zanzibaris. On the four;h day they emerged on to the Alpine pasturages, only to be caught in a furious blizzard of snow and hail, which necessitated camping for the night on a frozen peat bog. Next day a tent was carried higher up, as a base for reconnoitring excursions. The most important of the peaks on the south slope was ascended, and named Mount Hohnel, after the Aus- trian explorer. Five glaciers and eight lakes were discovered, as well as an interesting flora and fauna. A small shelter-tent was taken to near the end of the largest glacier, in readiness for an ascent of the central peak. A snow-slip during a severe storm in the night nearly buiied this, and did cover all the food. The ascent had therefore to be attempted after a night's exposure to a severe storm, and without food. The main glacier, which was named after the late Prof. Carvtll Lewis, was explored, and the nh'c field at its head crossed to the main south arete. After ascending this for some distance it became badly corniced, tii£ . risks of further progress were too serious to be encountered alone, and after reaching the height of a little over 17,000 feet it was necessary to return. In a subsequent attempt on the west aiite, Dr. Gregory was caught in a severe snowstorm, which rendered the route followed in the ascent impas;able, and might have entailed serious consequences. lie was then recalled to attend to his men, many of whom were suftering severely from the cold and altitude, and an immediate descent to Leikipia was necessary ; he had, however, achieved the five purposes for which he visited the mountain. During the return to the coast much new ground was covered with some interesting topographical results ; but except for securing a passage across Kikuyu, by curing the chief of tooth- ache, this part of the journey presented little of general interest. In conclusion, some of the scientific results of the expedition were summarised, though it was said to be too early to do this properly. Among the more interesting results was the dis- covery of the former greater extension of the glaciers of Mount NO. 1264, VOL. 49] January i8, 1894] NATURE 277 Kenia, as their moraines were found 5000 feet below their present level ; this would have a great inflaeiice in the distribu- tion of the Alpine flora in equatorial Africa. In spite of the numerous detailed studies of Kilima Njaro, no such evidence had been recorded from that mountain. The fish faunas are remarkably mixed, and show, as has long been surmised, that the distribution of the African rivers was once very different from ihe present. The geological results of the expedition suggest that at one time the Nile did not flow from theNyanza, but rose in the mountains to the north ; and the drainage of the lakes flowed away to the east and then to the north, past the site of Lake Ra lolf to the Red Sea. Thus it was pointed out that the exploration of this part of Africa is of value not merely as supplying topographical information, but from its bearing on some important problems of geographical evolution. THE GEOLOGY OF AUSTRALIA.' TX the distant future the antiquity that this country can ever possess is the history of the occupation by its present holders ; its abDriginal people have not furnished any evidence of a past history, insomuch, had it happened that they had become extinct a quarter of a century before their discovery, the only traces of prior occupation would have been in the form of stone knives and hatchets an 1 flint spearheais. Interwoven with the history of the progress of discovery and occupation is that of the successive additions to our knowledge of its physical structure and its natural history. The records of botanical science and of geographical exploration have been brought up to a recent date ; but the annals of the history of geological progress have not yet been consecutively placed on record. In ihe selection of a subject for my address I had experienced great difificalty in discriminating between personal interest and repre- sentative duty, and in choosing a "century of geological pro- gress " for my theme I have sacrificed the former. The labour involved in the preparation of this address has been very heavy, as I have read a hundred volumes to produce a very modest accounc ; thus what I have dona looks small when I recall the continuousness of the effort that accom- plished it. The history of the progress of geology in Australia is intimately associated with that of its geographical discovery and of its advancement in scientific cu'ture ; it will constitute a chapter in the early history of modern Australia, and I venture to give some connected view of it, which, how- ever bad it may be, is bat'er than to have no view at all ; more- over, there are associated with the subject personal histories which should be recorded whilst the knowledge of them is still within our memory. And although it is my special object to depict actual culminating results without any extended notice of the facts and events which may have led up to them, yet to a certain extent a knowledge of such facts and events is essential to their proper appreciation, and may be productive of increased interest. Just prior to the close of the last century, the controversy between the Wernerian and Huttonian schools, or between Vulcanists and Neptunists, relating to the origin of the crust of the earth, was at its height. The Huttonian theory, which prevailed, recognises that the strata of the present land surfaces were formed out of the waste of pre-existing continents, and that the same forces are still active. The characteristic feature of Huttou's theory is the exclusion of all causes not recognised to belong to the preeat order of nature. With the opening of the present century a new school arose, which laid the foundation of modern geology. Tnree men were largely concerned in this achievement — Cuvier, Lamarck, and William Smith ; the two former in France had a'l the powers which great talent, educa- tion, and station could give, whilst the last was an English land surveyor without culture or induence. George Cuvier laid the foundation of comparative osteology, recent and fossil ; Lamarck that of invertebrate palaeontology ; whilst Smith established the fundamental principles of stratigraphical palaeontology, viz. the superposition of stratified rocks and the succession of life in time. The earliest geological observation? relating to Australia antedate by only a few years the beginning of this century, so 1 A part of the inauguraradJress delivered at Adelaide, on September 26, 1893, by Prof. Ralph Tate, the newly elected President of the Australian Association for the Advanisment of Scienc;. that the history of our progress in geology is concurrent with that of modern geology, and it affords grand illustrations of the methods of application of the laws as they were successively evolved in the European schools, to an area so distantly removed from that which gave them birth. Thus our history begins at a m 1st fortuitous period. No prejudices or scholastic disputations have retarded our progress, for those who have aided in the work were disciples in the modern school of geology. And though, on a retrospective glance, we may hesitate to attach any high value to the labours of pioneer geologists, yet we should not forget that our horizon is so much vaster than theirs was, and to the extension of it they had lent their aid. And though it m\y be true that if the geological progress of the first half of this century were quite ignored, we would not probably suffer any great loss, as I believe that nearly all the areas explored at the earliw'St period have been re-examined in later times by men more carefully trained than was previously possible, nevertheless the gradual accumulation of data supplies us with a history, and makes us better acquainted with the causes that at certain times made that progress slow, or even retarded it. For the first three or four decades of this century our geological knowledge had been almost entirely the outcome of maiitime surveys, whilst in later years it has been largely supplemented by inland explor- ation ; thus, for a half-century or so the geological progress is part of the history of topographical discovery, which explains why our earlier geological information is inseparable from the achievements of such renowned geographers as Flinders, Baudin, King, Sturt, Mitchell, Stokes, Wilkes, Leichardr, Gregory, &c. The subsequent history of our geological pro- gress commences with the establishment of systematic geological surveys in New South Wales and Victoria, which afterwards led to their extension to the other provincial areas. Almost simul- taneously, universities were founded at Melbourne and Sydney ; thus whilst the surveys dealt with geology more in its industrial applications, the universities upheld its value on purely scientific grounds. By these agencies a large interest was awakened in the science, and many in whom zeal had been latent were added to the ranks of geological investigators. Much of the knowledge gained in these various ways is expressed on the geological map of Australia, published by the Victorian Government in 1887. The several steps by which this map has been built up, I will endeavour to make known to you, and though my geological reminiscences do not extend far back, yet they embrace some of the most important discoveries made on this continent ; at the same time I wouhi wish to avoid the mistake of claiming too large an authority on account of my years. Though the discovery of Australia may date back to the middle of the sixteenth century, yet it continued a terra inco^'uila, at least from a scientific point of view, until Cook — the Columbus of the south — began in 1770 the present phase of scientific ex- peditions ; and though geology reaped no gain, yet in botany was laid the foundation of a knowledge of that marvellous and peculiar flora of Australia through the labours of Banks and Solander, the companions of Cook. Vancouver, who discovered King George Sound in 1791, describes the summit of Bald Head to be covered with a coral structure, amongst which are many sea-shells, and argued a modern date of elevation. However faulty the interpretation I of the nature of the data may be, yet the deduction is sound, and that may be claimed as the first recorded geological observation for Australia, made 1025 years ago. Coal was discovered in New South Wales in 1797, first to the south of Sydney, and in the same year on the banks of the River Hunter, at what is now Newcastle. Flinders and Bass, jointly and separately, between the years 1797 and 1798, had explored the coast-line southward from Sydney, reaching as far west as Western Port, and embracing the circumnavigation of Tasmania. The more prominent rock phenomena were described. In 1801 Flinders was commissioned to complete the examination and survey of New Holland. The coast-line of Australia was traced with care as far as the tropics ; Flinders paid much attention to physiographic features, whilst Brown collected rock specimens. The rock specimens col- lected on this survey were reported on by Dr. Filton in 1825, but beyond their mere enumeration and their agreement with those of the same denomination from other parts of the world, no attempt was made to chronologically arrange them ; others collected by Bro vn, during his sojourn in New South Wales, were reported on by Dean Buckland in 1821, hereafter referred to. Contemporaneously with the marine survey by Flinders was NO. 1264, VOL. 49] 278 NA TURE [January i8, 1894 that by the French under Baudin. The scientific f qaipment was unrivalled in the annals of Australian exploration. To Depuch and Bailly were entrusted the mineralogical and geo- logical researche'^. The former left the ship at Sydney to return to Europe, but he died at Mauritius, and his manuscripts, which he had taken with him, and were to serve for a geological his- tory of New Holland, were irrecoverably lost. Peron was the senior zoologist, and the author of the narrative of the expedition. Peron s account of the physiography and geology of the places visited is not only graphic but rich in details ; he closely investigated the nature and origin of the /Eolian calciferous sandstones, and fully recognised their relationship to the blown-sand of the dunes. The entombed calcifierj shapes of bianches and stems of trees were correctly recognised, though Vancouver and Flinders had erroneously considered them as coral reefs. He rightly referred the funda- mental rocks of Kangaroo and King Islands to different kinds of primitive schists, and the superimposed fos.-iiiferous lime- stone at the former place was correctly observed, though not at tributed to any particular epoch. The occurrence of corals and marine shells of recent apearance at considerable elevations on the coast was justly regarded by him as demonstrating the " former abode of the sea" above the land, and very naUirally suggested an inquiry as to the nature of the evolutions to which this change of situation is to be ascribed. Few geologists have been more in advance of the age in which they lived, or have suffered so long an undeserved oblivion, as Peron. After the termination of the survey by Flinders, through the loss of his ship, and subiequent detention by the French, in which France was the first to debase, as she was the first to promulgate, that principal axiom of international law, "Causa scientiarum, causa populorum " (the cause of science is the cause of the people), twelve years elapsed before England's attention wa; diverted from the battle- field to geographical discoveries in Aus- tralia by the appointment of Captain King to complete the coast surveys left unfinished by Flinders, which occupied him from 1818 to 1822. King could spare but little time to land, and, with few exceptions, merely traced the coast. The paucity of geological information is thus accounted for, and the few references are merely lithological. John Oxley, Surveyor- General, to whom we owe the earliest topographical map of New South Wales, took charge in 1817 of an expedition to ascertain the character of the western interior, a practicable route across the Blue Mountains having been opened in 1815. He traced the Lachlan down to longitude 144', and completed the discovery of the Blue Mountains, which constitute the pro- minent physiographic feature of New South Wales. In 1818 he traced the Macquarie River to its junction with the Darling. In the volume of his narrative are brief references to the occurrences of different rocks, amongst which the more noteworthy are coal at Port Macquarie Harbour, coal indications at the head of the Macleay River, and lime- stone at Limestone Creek on the Lachlan, and at Wellington Valley on the Macquarie, " which is the first that has hitherto been discovered in Australia." The geological specimens which were collected during the two expeditions were reported on by Dean Buckland as affording indications of primitive rocks (granite, mica, slate, clay-slate, and serpentine), trap, and limestone (resembling the transition limestone of England), as also those gathered by Robert Brown on the Hun- ter River, which are described as coal and shale with plant im- pressions, and the author states that there is analogy between the coal formation of the Hunter River and that of England, whilst certain fossiliferous rocks from Hobart are nearly, if not quite, identical with those of the mountain limestone of England and Ireland. This is the first application of palaeontology to the stratigraphical chronology of the Australian rocks, and a suc- cessful one, as the positions assigned by Buckland to the two formations are substantially those accepted by the local geologists of to-day. Scott (Rev. Archdeacon) refers to the strata of the Newcastle coalfield as the " coal formation," and to the lime- stone as resembling in the character of its organic remains the "mountain limestone" of England, and thus independently arrived at the same conclusions as Buckland. Jesson, the naturalist to the French surveying ship,Z^a CoquiUe, and author of the history of the voyage during the years 1S22-25, describes the geological features about Port Jackson. His arrangement is a great advance on prior contributions, as it establishes a definite successional order of deposits, and for the first time, though foreshadowed by his countryman Bailly, NO. 1264, VOL 49] the superposition of the Sydney sandstone on the coal measure.*, and of the coal measures on the granites, is recognised. Up to this date no described fossil had been referred to as occur- ring in Australian depos-iis, and it was not till 1828 that Alex. Brongniart described Glossopteris browniaua and Pliyllotheca Australis fiom the Newcastle coal measure?. Sturt, in 1829, on his passage down the Murray, arrived at Overland Corner, and noted the sudden change from cliffs of sand and clay to fossiliferous limestone, which continued unin- terruptedly to Lake Alexandrina. Sturt referred examples of the fo.-sil mollusca, echinoids, and polyzoa, to species of the Eocene of England, Paris, and Westphalia, and thus established by similarity of organic remains, an old tertiary formation in Aus- tralia. Mitchell (Major, afterwards Sir Thomas), in 1832 penetrated north, and reached the River Dailing. His western limit in 1835 vvas the i unction of the rivers Bogan and Darling, and the southern, in 1836, was Portland Bay. The chief geological facts recorded by Mitchell are: (i) That the higher ground about the sources of the tiibutary of the Murrumbidgee is composed of granite, on the flanks of which rests a fossiliferous limestone " much re:embling the carboniferous of Europe," and another limestone containing corals belonging to the genus Favosites, and crinoids ; (2) in Victoria, nortli of the divided lange, granites an \ syenites are signalled, and clay slate on the river Campaspe ; (3) the lower part of the Glentlg River and the coast districts as far as Portland Bay are occupied with a fossili- ferous tertiary formation, frequently inteirupttd by trap and vesicular lava ; hills of lava often occur, and one at lea■^t, Mount Napier, is described as still exhibiting a perfect circular crater. The paloeontological collections, which were made du'ing Mitchell's three expeditions, were deposited in the British Mu- seum, and reported on by specialists. The results appended to Mitchell's work demonstrated the presence of representatives of the following life epochs : Carboniferous and Mesozoic. The collection included also a portion of the guard of a belemnite obtained near Mount Abundance. Its occurrence is noted on Mitchell's chart, though not referred to in the Ktier-press. This is the first secondary fossil recorded for Australia, though it was not till 1880 that it was brought to scientific notice. Diprotodon Period. — The ossiferous caves of the Wellington Valley and at Buree were discovered by Mitchell in 1830, and an account of the survey of them was published in 1831. In 1835 more extended researches were undertaken, and the par- ticulars respecting the animal remains then found were supplied by Owen (afterwards Sir Richard), who demonstrated that the existing marsupial fauna was preceded in the same area in later tertiary limes by a similar one, differing specifically for the most part, and to some extent, generically ; some of them presenting colossal forms in comparison with their largest modern repre- sentatives ; such are Diprotodon and Notothtrium. This eaily work of Owen's was only the commencement of those investi- gations which culnrinaied in that monument of marvellous industry and talent, the " Fossil Mammals of Australia." Charles Darwin was naturalist to the surveying ship, the Beagle, on her second voyage, 1832-36. The Beagle, on her homeward passage, called at Sydney and King George's Sound, and the geological observations relating to those places are brief, and, to a large extent, had been anticipated by Mitchell in re- spect of the first, and by Peron as to the second, though in the latterconnection Darwin corrected some of the erroneous observa- tions recorded by Vancouver and Flinders. Lonsdale describes some Australian carboniferous polyzoa, and Sowerby some Spiriferidse, and we have thus another instance nf the early ap- plication of paLieontology to the determination of the correlative age of stratified deposits. Lieutenant Grey (now Sir George) was commissioned to explore the coastline between Prince Regent River and Swan River. In 1839 he was shipwrecked in Gantheaume Bay, and his party was forced to make an overland journey to Perth, in the course of which he discovered the Murchison and other rivers, and carboniferous rocks in the Victoria Range. Commander Wickham was commissioned in 1S37 to the Beagle s third voyage, but in consequence of his retirement in March, 184 1, owing to ill-health, the command devolved on Captain Stokes, who is the author of the narrative of the six years' voyage. The objects of the survey did not permit of any connected observations of the geological structure of the islands or coast, and though the author disclaims any pretensions to be versed in geological science, yet some of his January i8, 1894J NA TURE 279 recorded observations have the merit of discoveries which have stood the test of critical investigation. The escarpment of the table-land of Arnheim Land .is desciibed as constituted of horizontally-bedded sandstone overlying slaty rock ; a some- what similar arrangement is noticed at Talc Head and Fort Hill, Poit Darwin ; the covering, fine-grained sandstone, the stratigraphical position of which was first observed by Stokes, has lately acquired considerable importance by the discovery of Radiolarians within its mass. Strzelecki (Count). — To this highly accomplished man of science we are greatly indebted for arduous and gratuitous researches and labours in the field of Australian geology, the outcome of five years' travel, commencing from his traverse of Gippsland in 1840, and embracing the survey of 7,000 miles. The rocks of New South Wales he arranges in an ascending successional series, and in this first attempt to construct a table of the stratified deposits of New South Wales he laid the foundation of stratigraphical geology in Australia. Strzelecki's volume is accompanied by a map in which the areas occupied by each epoch are indicated by colours, and is the first attempt at geological mapping in Australia. Leichardt (Dr. Ludwig). — In 1844 this lamented traveller started on his adven'urous journey from Moreton Bay to Port Essington, a distance of 3000 miles. The narrative of Dr. Leichardt contains as much botany as geology. The accom- panying maps and illustrations supply important information respecting the physiographic and geologic features. Necessity compelled him to abandon one portion after another of his col- lections, so that the opportunity of determining the age of the various deposits encountered, from the nature of their fossil con- tents, was lost. This is much to be regretted, because for long years this line of country was geologically known only through Leichardt's memoranda, which still contain for some portions the only information extant. Dana (Prof. James D. ) was naturalist to the United States exploring expedition during the years 1838-42, under the command of Charles Wilkes. Sydney was visited in 1839-40, but as the geol gy of the expedition was not published till 1849, Dana's observations w re to some ex'ent anticipated. Never- theless, the credit must remain to Dana of having laid the foundation of the classification of the great carboniferous de- velopment in New South Wales, both in respect of its palaeontology and stratigraphy. Sturt (Captain Chailes), in 1844, under the authority of the Imperial Government, pushed into the central parts of Aus- tralia. From the River Darling, at what is now Menindie, he reached the Barrier and Grey Ranges, and became entangled in the delta-like ramifications of the River Cooper ; thence he penetrated in a north-west direction into the sand-dune country to the north-east of Lake Eyre, and thus missed the object of his ardent search. Sturt describes the general structure of the Barrier Range as of slate', gneiss, and other metamorphic rocks, and notes the prevalence of iron ores. In or.e case he describes what is evidently the ironstone outcrop of a massive mineral lode, and though I cannot identify the locality, yet it is not at all improbable that one of the silver lodes of the Barrier (if not Broken Hill itself) is here referred to ; in the same con- nection that prominent landmark, Piesse's Knob, is indicated. The most noteworthy observations recorded by Sturt are those relating to the physical character of the interior of Australia, which will be considered hereafter. A tribute is due to Sturt's scientific merit and sagacity, and I would add my mite to the general testimony of admiration for that learned traveller ; he stands pre-eminent among land explorers for the accuracy of his observat'ons — evincing the most patient and thoughtful investi- gation— for the great power of generalisation which throws a charm over all his narratives, and for his highly philosophical deductions. Sturt never received that honour in his lifetime which was his due ; and much of his geological work and specu- lations have either been overlooked or ignored, because it was thought, by reason that geology then was not in a very advanced state, he was not a very experienced geologist. In his work, " A Sketch of the Physical Structure of Australia" (1850), the author gives a connected outline of the geology of Australia, so far as it was known to him. The great merit of this attempt to exhibit approximately the principal features of this continent is that of piecing together the isolated observations of previous authors into a connected outline, which, because of his personal knowledge of considerable portions of the coastline of Aus- tralia, he was, of all others, the best able to do successfully, NO. 1264, VOL. 49] The result is a general but distinct notion of the geological structure of Australia, which is further illustrated by a geolo- gically-coloured map, the first on so broad a survey. The author aided nothing to our previous knowledge, but systematised what was known, and the speculations and general- isations which he ventured have, for the most part, proved correct. Some of the most valuable contributi )ns of later authors will be found to have been foresha lowed, or even clearly noted, by Jukes, whilst some actual discoveries were anticipated by him. The last of the maritime surveys under Imperial direction which concerned Australia was that conducted by Captain Owen Stanley, of H. M.S. Rattlesnake; it is also noteworthy from the high scientific attainments of its officers. The com- mander, who was the only son of Dean Stanley, an eminent ornithologist, took a keen interest in natural history ; he died soon after the final return of the ship to Sydney, from a severe illness, contracted during the last cruise, but after the successful accomplishment of the chief object of his mission. The assis- tant-surgeon was Thomas H. Huxley, a name familiar to all, who achieved fame at this early period of his career by the zoo- logical researches made during the voyage. A. C. Gregory. — The discouraging character of the interior of Australia, as made known by Sturt, and the utter disappear- ance of Leichardt's expediti )n of 1848, checked the progress of exploration for a few years ; but in 1855 a successful effort was made to penetrate the interior from the north-west by the North Australian expedition, which was fitted out by the Imperial Government, and was the last of the series. The expedition was placed under the leadership of Mr. A. C. Gregory, who was accompanied by Dr. (now Baron Sir F. von) Mueller as botanist. The Victoria River was ascended to its source, and the country to the south of the Dividing Range was explored beyond the northern limits of the great interior desert. The physiographic features of the Lower Victoria had been made known by the descriptions of Stokes ; the region about the Upper Victoria was found to consist chiefiy of extensive valleys of good soil, well grassed, and of more arid sandstone table-land, vaieil with outcrops of basalt, constituting rich grassy downs. The table-land rises abruptly from the coastal tracts. By removal of the upper strata deep gorges 600 feet in height are formed, which open out into large valleys or plains. Mr. Gregory struck across from the Lower Victoria to the head of Roper River, and thence followed the base of the table-land from which he had descended, passing near the sources of the rivers dis- charging into the Gulf of Carpentaria. From the xVlbert River to Brisbane he followed Leichardt's route of 1844. This extra- ordinary achievement is second to none in point of interest of unknown country traversed, and of the scientific results gained, a vast void in the geological map was filled in. Since Gregory's expedition the interior of Australia has been traversed in various directions ; and with such efforts are honourably associated the names of Stuart, Burke and Wills, Warburton, Giles, J. Forrest, &c. , but the geological gain has been of a purely local import- ance. I may therefore be pardoned if I make exception by the mention of the expedition recently fitted out by Sir Thomas Elder. The object — to fill up the blank spaces in the topographical and geological maps of Australia — was ambitious, and the scientific equipment of the expedition gave hope that permanent results would be gained, but its premature disbandment has indefinitely protracted the realisation of this cherished consummation. So far as the area traversed is concerned, a very great deal was ac- complished. It was a failure simply by reason of the limitation of the original scheme. In geology nothing new has been brought to light, though certainty has replaced previous guess- work or speculation. Nevertheless, such problems as the exact relation of the fossiliferous Silurian to those of older date, the stratigraphy and fossils of the marine Cretaceous, and its relation to the supra-cretaceous rocks, still await solution. Thegeologi-t to the expedition has done his work so conscientiously and thoroughly, that the poverty of his report is to be ascribed to nature's deficiency. In other departments of natural history our expectations have been satisfactorily realised. May we hope that the Australian Macrenas of our time will crown his efforts to unfold some of the mysteries of our dry interior by directing a systematic exploration of some well-defined area, such as the oasis of the MacDonnell Range. The year of 1851 marks an epoch in the history of Australia, because in that year the rich goldfield of Ophir was discovered. Gold was scientifically discovered by Strzelecki, in 1839, and by 28o NA TURE [January i8, 1894 Clarke in 1841, thous^h its existence would appear to have been i known as early as 1823. In 1844, without being aware of these discoveries, Sir Roderick Murchison pointed out the similarity of the rock structure of the eastern Cordillera of Australia to that of the Ural Mountains, and predicted the occurrence of gold. Subsequent events afforded a proof that geology, like the more exact sciences, is capable of advancing philosophical in- ductions to very important results. But the precious metal was not commercially di-covered, so to speak, till 185 1, by Har- greaves, who had spent some of his earlier years as a stock- raiser in Eastern Australia ; in 1849 he was gold mining in Cal fornia, and his experiences there gained convinced him of the similarity in structure of the auriferous rocks of California and cer'?.in districts in New South Wales. He revisited New South Wales early in 1S51, to put to the test his geological instinct and the accuracy of his observations ; in this he suc- ceeded, and ultimately, under Government direction, the gold- field of Ophir in the district of Bathurst was declared open. He was awarded ^10,000 for his discovery, and in 1876 a pen- sion was granted him. He died in 1 891, at the age of 75 years. The practical discovery of gold proved a source of an enormous amount of wealth to New South Wales, and was soon followed in the same year by the di.-covery of much richer goldfieldsin A^ictoria, which had just then been separated into an indepen- dent colony, and thus added a powerful factor to the economic and scientific advancement of the continent. The consequent stimulus to a higher intellectual culture resulted in the founda- tion of the Universities of Sydney and Melbourne, and the establishment of systematically organised geological surveys. By the concurrence of the memorable events just alluded to, the history of geological progress enters a new period. Up to 1854 our exact knowledge of the sedimentary deposits, as derived from the organic remains, was confined to the Carboniferous, to a late Tertiary (represented by the Diprotodon period), and a more recent ^Eolian formation ; no distinct identification to prove the existence of Upper Silurian, Devonian, or Eocene had been forihcoiaing, though it was implied, whilst the only evidence of a Mesozoic epoch was a single imperfect example of a Belemnite. Restricted means of communication in a vast extent of country was the main cause which retarded advancement in geological investigation ; with increasing population this barrier is gradu- ally being removed. Expansion of our pastoral occupation, and the opening out of new trade routes bring new fields within the horizon of geological vision. It is, therefore, not a matter for surprise that in the next decade great and rapid advances were made in establishing a comparison on paloeontological grounds with corresponding geological systems of Europe. The history of geological progress in the second half-century is mainly that of the geological surveys, and the chronological treatment of my subject must be abandoned at this stage. It is a general impression that Australia is a very old con- tinent ; undoubtedly it is, because it presents an equal range of the geological record as other continental masses. But this impression is based on illogical deduction, derived solely from the fact that certain characteristic types of the Jurassic fauna of the northern hemisphere still linger in the Australian area, *uch as Trigonia, Ceratodus, and Marsupials among animals, Cycads and certain Conifers am ^ng plants. But the physio- graphic aspects of Australia have not always been absolutely continental. Since Upper Devonian times there have always been land-surfaces, at any rate in Eastern Australia, where partial interruption to an absolute continuity (and the area locally affected is not relatively greal) was frequent during the deposi- tion of the Carboniferous series, which is, however, in a large measure littoral. It may safely be asserted that Australia, <:er!ainly so far back as the deposition of the extensive marine Cretaceous occupying the low level tracts of the interior, pre- served the aspect of a vast archipelago. At the close of that epoch the various insular masses became welded together, so that the antiquity of Australia as a whole is only post-Cretaceous. In early Eocene or late Cretaceous times, the flora was of a cosmopolitan type, consisting of an admixture of generic forms, some of which are now proper to the temperate and sub-tempe- Tate parts of the northern hemisphere, such as oaks, birch, alder, ^')' which is in the present case a line integral round dt the electric circuit. The result is Franz Neumann's celebrated formula for the electromagnetic energy of a linear electric current, T = \C- \ ^ icos idsds; or we may take the case of several linear circuits in the field, and obtain the formula T = ^Si- I f ^ cos € ds ds + 2i|i2 I i '' ^ cos e ds^ ds^, which is sufficiently general to cover the whole ground of electro-dynamics. Our result is in fact that a linear current is a vortex ring in the fluid selher, that electric current is represented by vorticily in the medium, and magnetic force by the velocity of the medium. The current being carried by a perfect conductor, the corresponding vortex is (as yet) without a core, i.e. it circulates round a vacuous space. The strength of a vortex ring is, how- ever, permanently constant ; therefore, owing to the mechanical connections and continuity of the medium, a current flowing round a complete perfectly conducting circuit would be un- affected in value by electric forces induced in the circuit, and would remain constant throughout all time. Ordinary electric currents must therefore be held to flow in incomplete conduct- ing circuits, and to be completed either by convection across an electrolyte, or by electric displacement or discharge across the intervals between the molecules, after the manner of the illus- tration given above. Now we are here driven upon Ampere's theory of magnetism. Each vortex-atom in the medium is a permanent non-distipative electric current of this kind, and we are in a position to appre- ciate the importance which Faraday attached to his discovery that all matter is magnetic. Indeed, on consideration, no other view than this seems tenable ; for we can hardly suppose that so prominent a quality of iron as its magnetism completely dis- appears above the temperature of recalescence, to reappear again immediately the iron comes below that temperature ; much the more reasonable view is that the molecular rearrange- ment that takes place at that temperature simply masks the permanent magnetic quality. In all substances other than the 1 A paper read before the Royal Society on December 7. 1S93, by Dr. Joseph Larmor, F.R S., Fellow of St. John's College, Cambridge. (Con- 'inucd from p. 262 ) NO. I 264, VOL. 49] January iS, 1894] NATURE 2»1 magnetic metah, the vortex atoms pair into molecules and mole- cular aggregates in such way as to a large extent cancel each other's magnttic fields; why in iron at ordinary temperatures the molecular aggregates form so striking an exception to the general rale is for some reason peculiar to tlie substance, which, cjniidering the complex character of molecular aggregation in solid'^, need not excite surprise. We have now to consider the cause of the pairing together of atoms into molecules. It cannot be on account of the magnetic, i.e. hydroiynamical, forces they exert on one another, for two electric carrents would ihen come together so as always to rein- force each other's magnetic action, and all substances would be strongly magnetic. The ionic electric charge, which the phenomena of electrolysis sho.v to exist on the atom, supplies the attracting agency. Furthermore, the law of attraction be- tween these charges is thatoftheiaversesquareofthedistance, and between the atomic currents is that of the inverse fourth power ; so ihaf, as in the equilibrium state of the molecule these forces are of the same order of intensity and counteract each other, the first force must have much the longer range, and the energy of chemical combination must therelore be very largely electro- static, due to the attraction of the ions, as von Helmholtz has clearly made out from the phenomena of electrolysis and electro- lytic polarisation. Bat in this discussion of the phenomena of chemical combina- naiion of atoms we have been anticipating somewhat. All our conclusion^, hitherto, relate to the eether, and are therefore about electromotive forces. We have not yet made out why two sets of molecular aggregates, such as constitute milerial bodies, should attract or repel each other when they are charged, or when electric currents circulate in them ; we have, in other words, no.v to explain the electrostatic and electrodynamic forces which act between conductors. Consider two charged conductors in the field ; for simplicity, let their conducting quality be perfect as regards the very slow displacements of them which are contemplated in this argument. The charges will then always reside on their surfaces, and the state of the electric field will, at each instant, be one of equi- librium. The magnitude of the charge on either conductor cannot alter by any action short of a rupture in the elastic quality in the jether : but the result of movement of the conductors is to cause a rearrangement of the charge on each conductor, and of the electric displacement (/, g, h) in the field. Now the elec- tric energy W of the system is altered by the movement of the conductors, and no viscous forces are in action ; therefore the energy that is lost to the electric field mast have been somehow spent in doing mechanical work on the conductors ; the loss of potential energy of the electric field reappears as a gain of potential energy of the conductors. We have to consider how this transfoimatioii is brought about. The movement of the coaductors involve^, while it lasts, a very intense flow of ideal electric displacement along their surfaces, ani also a change of actual displacement of ordinary intensity throughout the dielec- tric. The intense surface flow is in close proximity with the electric tljws round the vortex atoms which lie at the surface ; their interaction produces a very intense elastic disturbance in the medium, close at the surface of the conductor, which is distribute 1 by radiation through the dielectric as fast as it is proluced, the elastic co.idition of the dielectric, on account of its extreme rapidity of propagation of disturbances compared with its finite extent, being always extremely nearly one of equilibrium. It is, I believe, the reaction on the conductor of these wavelets whicharecontiuually shooting out from its surface, carrying energy into the dielectric, that constitutes the mechani- cal forcive acting on it. Bat v/e can go further than this ; the locality of this transformation of energy, so far at any rate as regards the material forcive, is the surface of the conducor ; and the gain of mechanical energy by the conductor is therefore correcdy located as an absorption of energy at its surface ; there- fore the forcive acting on the conductor is correctly de- termined as a surface traction, and not a bodily forcive throughout its volume. One mode of representing the dis- tribu'.ion of this surface traction, which, as we know, gives the correct am )unt of work for every possible kind of virtual dis- placement of the surface, is to consider it in the ordinary electro- static manner as a normal traction due to the action of the electric fo'ce im the electric density at the surface ; we conclude that this distril)ution of traction is the actual one. To recapitulate : if the dielectric did not transmit disturbance sd rapidly, the result of the commotion at the surface produced by the motion of the conductor would be to continually start wavelets which would travel into the dielectric, carrying energy with them. But the very great velocity of propagation effectually prevents the elastic quality of the medium from getting hold ; no sensi- ble wave is produced and no flow of energy occurs into the dielec- tric. The distribution of pressure in the medium which would be the accompaniment of the wave motion still persists, though it now does no work ; it is this pressure of the medium against the conductor that is the cause of the mechanical forcive. The matter is precisely illustrated by the fundamental apercit of Sir George Stokes with regard to the communication of vibrations to the air or other gas. The rapid vibrations of a tuning fork are communicated as sound waves, but much less completely to a mobile medium like hydrogen than to air. The slow vibrations of a pendulum are not communicated as sound waves at all ; the vibrating body cannot get a hold on the elasticity of the medium, which retreats before it, preserving the equilibrium condition appropriate to the configuration at the instant ; there is a pressure between them, but this is instan- taneously equali ed throughout the medium as it is produced, without leading to any flow of vibrational energy. Now let us formally consider the dynamical system consisting of the dielectric media alone, and having a boundary just inside the surface of each conductor ; and let us contemplate motions of the conductors so slow that the medium is always indefinitely near the state of internal equilibrium or steady motion, that is conditioned at each instant by the position and motion of the boundaries. The kinetic energy T of the medium is the electro- dynamic energy of the currents, as given by Neumann's formula ; and the potential energy W is the energy of the electrostatic distributioa corresponding to the conformation at the instant ; in addition to these energies we shall have to lake into account surface tractions exerted by the enclosed conductors on the medium, at its boundaries aforesaid. The form of the general dynamical variational equation that is suitable to this problem is, for currents in incomplete circuits, and therefore acyclic motions, S j {T- W) d/ + \dl i 57U dS = o, where Szv di represents the work done by the tractions acting on the element dS of the boundary, in the virtual displacement contemplated. If there are electromotive sources in cer- tain circuits of the system, which are considered to introduce energy into it from outside itself, the right-hand side of this equation must also contain an expression for the work done by them in the virtual displacement contemplated of the electric coordinates. No.v this variational equation can be expressed in terms of any generalised coordinates whatever, that are suffi- cient to determine the configuration in accordance with what we know of its properties. If we suppose such a mode of ex- pression adopted, then, on coiducting the variation in the usual manner and equating the coifticients of each arbitrary variation of a coordinate, we obtain the formulae cl^dT dt ^ ■p _ d rt'T ~d}'d^' In these equations is a component of the mechanical forcive exerted on our dielectiic system by the conductors, as specifietl by the rule that the wo:k done by it in a displacement of the system represented by 5;^, a variation of a single coordinate, is ^dp : the corresponding component of the forcive exerted by the dielectric system on the conductor is of course — *. Also E is the electromotive force which acts from outside the system in a circuit in which the electric displacement is e.; so that the current in it is i ; the electromotive force induced in this circuit by the dielectric system is - E. These equations involve the whole of the phenomena of ordinary electrodynamic action^, whether ponderomotive or electromotive, whether the conductors are fixed or in motion through the medium : in fact, in the latter respect no distinction appears between the cases. They will be completed presently by taking account of the dissipation which occurs in ordinary conductors. These equations also involve the expressions for the electro- static ponderomotive forces, the genesis of which we have already attempted to trace in detail. The generalised c im- ponent, corresponding to the coordinate (p, of the electrostatic * = dT d\N N. [ 23 i- , VOL. 49] 282 NA TURE [January i8, 1894 traction of the conduct irs on the dielectric system, is d\ct-book of Solid or Descriptive Geometry ; A B. Djbbie(Blackie).— A Pocket-Book of Marine Engineering, Ru'es and Tables : A E. Seaton and H. M. Rounthvvaite (Griffi.i).— Do y )U Know it ? &c. C. E. Clark (Saxon). — .\nniiairp de I'Academie Royale des Sciences, &c , de Belgique, 1894 (Bruxelles). — Forschungsberichte aus der Biologischen Station zu Piiin ; Theil 2 : Dr. O. Zacharias (Berlin, Friedliinder) —Elements of Synthetic Solid Geometry: Prof. N. F. Dupuis (Macmillan). — Electric Waves : Dr. H. Hertz, translated by D. E. Jones ! Macmillan). — Discovery of Lakes Rudolf and Stefanie, 2 Vols. : Lieut. L. von Hohnel, translated (Longmans). Pamthlets.— Guide to the Examinations in Agriculture, and Answers to Questions, Advanced Series (Blackie) — Ditto, Physiology, ElementaryJSeries (Blackie).— Ditto, Elementary Metallurgy, ditto(Blackie). — Ditto, Elemen- tary Principles of Mining, ditto(Blackie). — Ditto, Chemistry, ditto (Blackie) — Test Papers in Mathematics: R. Roberts (Blackie). — Twenty-third Report of the Aeronautical Society of Great Britain (Greenwich, Richardson). — Re- port on the Destruction of Beer-casks in India by the Attacks of a Boring Beetle : W. F. H. Elandford (Eyre and Spottiswoode). — The Palm Weevil in British Honduras : W. F. H.Blandford (Eyre and Spottiswoode). — Annales de rObservato're Magnetique de Copenhague 18)2 : A. Paulsen (Cop^nhagiie). Entwurfeiner Neuen Integralrechnung auf Grund der Poteniial-Logarith- mal-und Numeralrechnung. Zweites Heft : Dr. J. Bergbohm (Leipzig, leubner). Sekials. — Actes de la Sociiit^ Scientifique du Chili, Tome 3, i and 2 Livr. (Santiago).— Engineering Magazine, Souvenir No. (New York). — Journal of Anatomy and Physiology. January (Grififin). — American Meteoro- logical Journal, January (Ginn). — Himmel und Erde, January (Berlin). — Xenia Orchidacea, Dritter Band, Sechstcs and Siebentes, Heft (Leipzig, Brockhaus). — Mind, January (Williams and Norgate).— Bulletin Astrono- mique, December (Paris). CONTENTS. PAGE Heinrich Hertz. By D. E. J 265 Prof. Dr. Rudolf Wo'f. By W. J. L 266 Cloud Photography. {Illustrated.) 267 Letters to the Editor : — The Directorship of the British Institute of Preventive Medicine. — Prof. Charles S. Roy, F.R. S. . . 239 Electromotive Force from the Light of the Stars. — Prof. George M. Minchin 259 The Thyroid Gland. By R. M 270 Notes ■ 270 Our Astronomical Column . — Sunspots and Solar Radiation 274 The Measurement of Stellar Diameters 275 The MoDn and Weather 275 Geographical Notes 275 A New Sulphide of Carbon. By A, E. Tutton . . 275 Dr. Gregory's Journey to Mt. Kenia 276 The Geology of Australia. By Prof. Ralph Tate . 277 A Dynamical Theory of the Electric and Lumini- ferous Medium. II. By Dr. Joseph Larmor, F.R.S 280 University and Educational Intelligence 283 Scientific Serials 283 Societies and Academies 283 Books, Pamphlets, and Serials Received 284 Supplement. The Story of our Planet iii Cayley's Papers. By Major P. A. MacMahon, R. A., F.R.S iv The Pamirs. {Illustrated.) vi The Genus Madrepora. By Prof. Alfred C. Haddon ix Physiological Chemistry. By Dr. J. S. Edkins . . x An Essay on Newton's "Principia" "ii Wells on Engineering Design, By N. J. Lockyer xiii The Egyptian Collections at Cambridge xiii Horns and Hoofs '''^ NA rURE 285 THURSDAY, JANUARY 25, i?94. RECENT PUBLIC HEALTH WORKS. A Treatise on Hygiene and Public Health. By T. Stephenson, M.D., F.R.C.P., and Shirley F. Murphy. Vol. ii. (London : J. and A. Churchill, 1893.) Public Health a?ul Demography. By Edward F. Willoughby, M.D., D.P.H. (Macmillan and Co., 1893.) Methods of Practical Hygiene. By Prof. K. B. Leh- mann. Translated by W. Crookes, F.R.S, In two vols. (London : Kegan Paul, Trench, Triibner, and Co., Limited, 1893.) IN our review of vol. i. of the "Treatise on Hygiene and Public Health," it was pointed out that the various articles comprising it were written by men whose knowledge and experience upon the subjects allotted to them for treatment was a sufficient guarantee of good work, and that any faults that the reviewer might pos- sibly detect in the volume must almost of necessity be those of omission. To this second volume — which contains matter of the greatest possible interest and im- portance to the student and practitioner of preventive medicine — the same remarks apply. It is at least equal in all-round excellence to vol. i. ; but here and there a few points might, in our opinion, have been more fully dealt with than they are, especially in a book which is destined to become essentially the work of reference for those interested in public health matters. Article i treats of " The Pathology of Infectious Dis- ease," and is written by Dr. Klein. This is an excellent resume of what is undoubtedly the most important branch of preventive medicine, and it forms one of the best features of the book. No one can question the authoritative value of an article coming from such a source ; and the fact that it is well written, and the various stages of the study are carefully arranged and treated of in admirable sequence, make this difficult subject both easy and pleasant reading. Appended to the article is a weahh of illustrations, comprising plates of a large num- ber of cover-glass specimens of cultures of the different bacilli, all beautifully clear, and many coloured to show the characteristic staining of bacilli and fungi in tissues and fluids ; sections through pathological tissues, &c. ; specimens of blood, mucus flakes and pus, showing bacilli ; representations of a large number of tube cul- tures— streak, stab, shake, and surface ; cultures on potato, and plate cultures. We fancy that a few illus- trations of the apparatus employed in bacteriological research would be acceptable, and we note that no men- tion is mide of Haff"kine's work in anti-choleraic vaccina- tion ; this might certainly have been included, notwith- standing the circumstance that a valuable piece of desiruciive criticism, emanating from Dr. Klein, has thrown considerable doubt upon the value of the method. The article which very appropriately follows upon the first is contributed by Dr. T. W. Thompson, upon the sub- ject of "The Natural History of Infectious Diseases"; it IS a careful and well-written article, leaving but little to be desired. The subject of the communicability of phthisis IS, however, worthy of a little more space than NO. 1265, VOL. 49] that allotted to it, more especially as during the past two years a conviction has established itself among health officers that there is at present an enormous amount of preventible mortality from that disease, by reason of the fact that the malady is frequently traceable to infection from a pre-existing case ; and there is every prospect, in the near future, of phthisis being brought more directly under the control of preventive measures. Article 3, by Dr. J. C. McVail, gives an excellent summary of the work that has resulted in our present system of vaccination, and deals fully enough with the subject of anti-vaccination. The article contains many useful diagrammatic expressions of the deaths from small-pox, and the general incidence, age and sex incidence, types, &c. of the disease among both the vaccinated and the unvaccinated. The subject of vital statistics has been entrusted to Dr. Ransome for treatment. It is, of course, a good article, but rather short, and hardly explanatory enough in some respects for the purpose of those who will doubt- less consult the volume upon points which they have either not been able to understand or to gather from the perusal of the smaller works upon public health. The main scope of Article 5 is the hygiene of those who live at sea, in ships as their houses, and with the sea and air as their environments. It is appropriate, there- fore, that under the heading of "Marine Hygiene" the writer should treat of sea-water in its chemical and physical aspects ; the various kinds of ships, and the material used in their construction ; shipping and pas- senger statistics ; the cubic space, ventilation, and tempera- ture of cabins and bunks ; the water supply of ships ; and the sailor, his food and its preservation, his clothing, and the diseases to which he is especially subject. The best feature, and the most useful, of this admirable article is that bearing upon port sanitation, and Dr. H. E. Armstrong is to be congratulated upon a careful and valuable contribution. The sixth article, upon military hygiene, is by Prof. J. L. Notter. It is substantially that which appears in the same writer's edition of Edmund Parke's work upon practical hygiene. It is well written and sufficiently exhaustive. The article which deals with disposal of the dead consists of two parts. Part i. is contributed by Sir T. Spencer Wells, and treats of the various methods employed by different sects and nationalities. It is ad- mirably written, extremely interesting, and is a powerful vindication of cremation. The second part is written by Mr. Frederick Walter Lowndes, who, while he discusses the question in a spirit of impartiality, maintains that there need be no difficulties and dangers in the prevailing method of disposing of the dead, if proper care be exer- cised in the selection of the site of the burial-ground and its subsequent management. The volume is concludedbyan excellent article upon the medical officer of health, by Dr. Ashby ; and we are glad to find the writer advocating whole time service, though deprecating the altogether inadequate emoluments which are offered in return. This will be found one of the most valuable contributions in the whole volume for those who, having secured an appointment as medical officer of health, wish to have brought before them the whole O 286 NA TURE [January 25. 1894 requirements, duties, and routine work appertaining to that office. All those interested in public health can but be grateful for the opportunity, which this valuable and well-bound volume affords, of gaining an excellent and reliable knowledge of the many subjects which it embraces. The second volume, of which the title is given at the head of this notice, is a third edition, considerably enlarged and improved, of the " Principles of Hygiene," — a small handbook written by Dr. Willoughby, for the special use of the students of hygiene in the Science and Art Department, South Kensington. The author very justly infers that with a material increase in its bulk, the scope of its utility has been extended, and that it will now meet the requirements of the medical man, the student, and the teacher. We do not, however, quite agree with the author in his assertion that the contents will be found almost if not quite sufficient for most examinations in public health. The book undoubtedly deals fully enough with the principles of hygiene, but the student for diplomas in public health will find it necessary to consult other works upon special subjects— such as Water, Air, and Food Analysis, Offensive Trades, and Sanitary Legislation. We do not wish it to be inferred, however, that Dr. Wil- loughby's book is inferior in any way to most of the other small manuals dealing with the same subject, neither of which is sufficient in itself to meet the requirements of those seeking public health diplomas. The present volume is well adapted to rank with others of its kind as a very useful manual, and its appearance adds to the difficulty which teachers already experience of concluding as to which is the best all-round book for students bent upon securing a degree in hygiene. This difficulty ex- perienced by teachers arises from the fact that all such manuals are, of necessity from their small bulk, somewhat unequal ; in all it is easy to lay one's finger upon some important points which are dismissed far too cursorily. The present volume is no exception in this respect ; the chapters on food, school hygiene, and demography are excellent, and probably the best that have yet found their way into any of the smaller public health pub- lications ; but, on the other hand, there is practically nothing about offensive trades, with reference to the nature and source of the various nuisances which each gives rise to, and the means by which these can be abated ; the subject of the collection, storage, and distribution of water for town supplies might be amplified with ad- vantage ; and if it is necessary to introduce the examin- ation of air, surely its importance justifies the author in giving at least two full pages to it. The manual suffers somewhat from a dearth of illus- trations ; these are prized highly by the student who comes green to the subject, and Dr. Willoughby would have done well to give more than thirty-nine illustrations in his manual of nearly 500 pages. In the preface the author writes : " Some of my state- ments, especially as to cholera, diphtheria, and the influence of small-pox hospitals, may appear somewhat dogmatic and opposed to traditional teaching." But we do not think that the bulk of sanitarians will differ from Dr. Willoughby in the] views which he holds upon either NO. 1265, VOL. 49] of these subjects, and we commend his opposition ta traditional teaching when this teaching is not in accord- \ ance with more recently acquired knowledge. The work: ■ is for the most part very well done, and those interested ■ in the study of public health matters will do well to read it. Mr. Crookes can be congratulated in so far as he has well translated a work which serves to give us an insight into the German methods of practical hygiene. These methods are for the most part similar to those in vogue in this country, but in many important respects we differ from our neighbours ; and it is mainly on this account that the work will not become the text-book for English students of practical hygiene, valuable as it undoubtedly must be to German students. The book is characterised by what appears to be almost a studied ostracism of everything British. The methods selected and advocated are almost exclusively German, and with very rare exceptions (possibly half a dozen m the two volumes) continental views and opinions are alone given. In view of the fact that in the preface the author writes : " Thus I handover my book to the nation which has taken the lead of all modern civilised peoples in the sphere of practical hygiene," it is strange that he should have so persistently ignored everything English in the work. Surely in water-analysis we might reasonably expect to find some mention made of Wanklyn's, Frank- land's, or Tidy's processes ; and a perusal of the section upon the hygienic examination of dwelling-houses dis- closes several discrepancies which exist between English and German views on house sanitation Such a sentence, for instance, as " The overflow pipes of cisterns should not open into the soil-pipe of a w.c. without the inter- vention of a siphon," would certainly not find its way into our sanitary literature. The use throughout the work of the term "typhus " for " typhoid " or " enteric," and the fact that the " degrees " of hardness are always i German degrees, will certainly create a little confusion \ among English readers ; and here and there are instances where the information is either imperfect or misleading when viewed from the English standpoint. One such instance has already been given, and we now furnish a few others : — The author writes : " The danger of chronic poison- ing by drinking water has probably never existed." He I estimates the ammonia by adding the Nessler reagent to the original water, and does not appear to attach sufficient importance to its presence ; the indigo process is the only one given for estimating the nitric acid in water ; the organic matter in water is alone determined by the amount of oxygen which it will consume, accord- ing to Kubel-Tiemann. The microscopical examination of foreign matter in water occupies about a page, and no illustrations are given save of the ova of the more common intestinal parasites. Organic matter in the air is dealt with very cursorily and unsatisfactorily, and the only means of estimating it is by the oxygen which it will absorb from permanganate, which, the writer is at pains to point out, suffers from grave defects. The micro- scopical characters of the dift'erent starch grains are treated in a very poor and insufficient manner. The January 25, 1894] NA TURE 287 tract of the ether vapours in the Soxhlet apparatus is wrongly described, and the treatment of the subject of soil examination is crude. Although it is not difficult to thus indicate many points with which a critic in this country may find fault, the work may with profit be consulted on many subjects, and none with greater advantage than that of Food. The book is capitally printed and bound in two handy- sized volumes. THE LATEST TEXT-BOOK OF GEOLOGY. Text-Book of Geology. By Sir Archibald Geikie, Director- General of the Geological Survey of Great Britain and Ireland. Third Edition, revised and enlarged. (Lon- don : Macmillan and Co., 1893.) T T goes very much against the grain, for it savours of ingratitude, to begin by picking holes in a book that has been a trusted companion, that has proved itself worthy of trust, and to which I have been so largely in- debted, as the volume before me. But the strictures I feel bound to make are not very severe, and the blots I cannot help noticing do not impair seriously the value of the work- -do not, indeed, detract at all from its use- fulness in the case of a large number of readers. The first point on which I have always differed from the author is this. In Book i., which deals with the cosmical aspects of geology, we are introduced to some of the darkest and most unsettled problems that arise when we concern ourselves with the earth's history ; the stability of its axis, the degree of its rigidity, the causes of the changes of climate which have occurred in bygone days. Besides their obscurity these points have not a little in common, and much may be said in favour of grouping them together. But when we find it stated in the preface that the method of treatment adopted is one which the author has found, while conducting his geo- logical class, to afford the student a good grasp of the general principles of the science, it is hardly possible to avoid doubting the wisdom of bringing them in at so early a stage. To do this is to run counter to that prime canon of teaching, which bids us start with the concrete, simple, and known, and lead thence up to the abstract, complex, and hypothetical. To the advanced student, who has already made the acquaintance of these un- settled points, such a summary as we have here of what has been done towards their solution is most valuable ; but it is rather strong meat for the beginner. On just the same grounds I would object to putting in the fore- front speculations as to the state of the earth's interior or her age. Something may be said in favour of an early notice of the nebular hypothesis, for it looks like beginning at the beginning. But to do this successfully we must have some certain knowledge of what the beginning was, and this we assuredly have not in the case of the earth. So greatly do I differ from the author's view as expressed in the preface that I always recom- mend students to omit large portions of Books i. and ii. on their first reading. In the same connection one may note that, on the principle that the father comes before the children, hypogene action precedes epigene action in Book iii. But on grounds already stated, I should be inclined to reverse the order. NO. 1265, VOL. 49] Further, while all that style could do to render the work attractive has been done, I have found that the arrangement of its matter tends to render it at times rather hard reading. It is somewhat irritating, when you have begun to grow warm on some subject and want to know everything that is known about it, to be told that no more can be said here, but that some information has been given in a previous book, and that the subject is further discussed in a subsequent book. It is no great hardship to have to turn backwards or forwards, though a little hunting may be required to find the exact passage sought ; yet these cross references do act as a check on the even flow of one's thought, and they occur pretty frequently. A little more elasticity and a little less con- sistency may be desiderated. Take the case of metamor- phism. In Book ii. part 7, section iii. we have a descrip- tion of the chief varieties of metamorphic rocks ; then, under the head of Dynamical Geology, in Book iii., instances of the changes produced by metamorphism ; lastly, in Book iv., which treats of the architecture of the earth's crust, we are told of some additional meta- morphic changes and of the processes by which meta- morphism is brought about. It is difficult to see why the last two sections should have been so widely separated for the process of metamorphism, specially of regional metamorphism, is a dynamical operation. It would have been a convenience and would have saved some repeti- tion, to have had all these sections in continuous sequence ; and it is instructive to notice how impossible is rigid adherence to systematic arrangement, for even in the descriptive section there are constant anticipations of the dynamical problems which are treated more fully later on. There are other cases in which, for a similar reason, it will be found troublesome to gather into a connected whole all that the book has to tell on a specific subject ; but the trouble will be well repaid, for it is a book almost exhaustive in its fulness, copiously illustrated, lucid in its descriptions, and a model of English in style. As an illustration of its thoroughly practical character, we may point to the minute directions on the subject of fossil- collecting at the end of Book v. On some of the more recondite and obscure problems of geology, the author has wisely refrained from attempting to decide between rival hypotheses ; but he has summarised the more im- portant speculative solutions that have been put forward, and has given such full references to the papers in which these appear, that the reader, who is so minded, can easily follow out the questions for himself. Indeed, throughout what may be called the physical side of geology, the book is a most exhaustive and trust- worthy compendium, such as could be produced only by one who has a wide acquaintance with the literature of the subject, and who has also been brought face to face with what he describes by life-long and varied work in the field. When we come to stratigraphical geology, it behoves the critic to be wary in his judgments. To treat this satisfactorily seems to me to be the most trying ordeal to which the writer of a text-book can be subjected. At the very threshold we are met with one of the most perple.x- ing of geological problems, when we are called upon to decide between the rival claims of contemporaneity and homotaxis. The subject is discussed at some length by 288 NATURE [January 25, 1894 our author. A reference to Prof. Huxley's Anniversary Address [Q. J. Geol. Soc. xxvi. [1870] p. 43) might be usefully added to the note on p. 658. And when we pass from theoretical questions to matters of actual fact, the treatment of this branch of geology is no less difficult. Mow often does it consist of little else but tables of names of formations (comparative or otherwise), lists of fossils, and other statistical information, that make it about as lively as a parish register or a regimental roll-list. How often do we ungratefully curse for its dismalness a book of this kind, to which we are glad enough to turn for reference. And at first it looks as if this could not be helped, for if we are to give within reasonable compass only a summary of what is known of the stratigraphy of the world, what space is left for more than dreary statistics ? Fortunately there are two matters directly arising out of the bare facts of stratigraphy, which give life to its dry bones ; the light which the rocks of a region throw on its physical geography at the time they were formed, and the connection between the fossils of geological epochs and the general evolution of life on the earth. For these space must be found, because without these our narrative is no more geology than a list of dates is history. These points have not been lost sight of in the present text-book. The oldest rocks of the earth's crust are in the present edition prudently grouped together under the head of pre- Cambrian. Of the many names given to these rocks all but this have involved more or less of unjustifiable as- sumption ; but in this there is comparative safety, for what- ever difference of opinion there may be about the upper limit of the Cambrian, there is a fairly general provisional agreement as to where its base is to be placed. The account of the pre-Cambrian rocks has been recast and amplified ; the term is not used as a "dumping ground for everything of unknown age," but the claims of the rock groups described under this head to the antiquity which the name implies are canvassed. Additional de- tails as to the recent work of the Geological Survey in the North-west Highlands are introduced. Attention is also called to the fact that portions of the Archaean schists have in more than one locality been shown to be intrusive, and that the amount of the Archaean has thereby been materially reduced. But it must not be overlooked in this connection that the pebbles in the conglomerates of the Torridian and other pre-Cambrian clastic rocks prove the existence of crystalline schists of Archaean type before these beds were deposited, and so leave a residue of Archaean rocks that no future dis- coveries can abolish. Further additions in the present edition deal with the rocks of the Central Highlands pro- visionally classed as Dalradian, and the researches of American geologists among their Fundamental Complex and Algonkian. The amount of new matter in this part of the book makes it practically a new work. Within the space of this article it will not be possible to do more than glance at the many subsequent improve- ments. The account of the Silurian Rocks of North Wales is hardly up to date, and specially the treatment of the May Hill Beds leaves somewhat to be desired. The insertion of a table giving the results of Prof. Lap- worth's work in the Southern Uplands of Scotland is a recognition that all geologists will welcome. The De- NO. 1265, VOL 49] vonian section is enriched by an account of the re- searches of Mr. Usher and Prof. Kayser. Under the head of the Carboniferous System the account of the distribution of the fossils of the English coal measures is hardly up to the mark. It is scarcely brought out with sufficient distinctness that the marine shells are found only in a few thin bands, and that these are by no means confined to the Canister Beds. It is questionable, too, whether it was worth devoting so much space to the attempts of Grand'Eury and others to zone the carboni- ferous rocks by means of their plants. There are those among us who yet recollect Hooker's warning as to the value of specific distinctions between fossil plants, which has been since enforced by the discovery that two genera so seemingly distinct as Lepidodendron and Halonia are really difTerent parts of the same plant. A most im- portant addition to the Permian section is an account of the marine type of the Permian rocks, which, if I mistake not, now finds for the first time a place in an English text- book. Under the Jurassic section attention is called to Neumayr's speculations as to the climatic belts of that period. Among the Cretaceous deposits due notice is taken of the work of Mr. Lamplugh and Prof. Pavlow on the Specton Clay. The treatment of the Gault and Upper Greensand is hardly satisfactory. The views as to the relationship of these two groups, by no means new but largely enforced by the work of Mr. Jukes-Browne, are only indicated ; and the reader will hardly gather that, as is stated so unhesitatingly in the last report of the Director-General of the Geological Survey, the two groups really constitute one formation. Have red-tape regula- tions here forbidden the author to give to the public the benefit of survey discoveries till they have been announced in an official form ? This seems a pity, but red-tape is hardly likely to see it in this light. In the Gossau Beds we find a striking instance of the difficulty of keeping a book up to date ; not many weeks have passed since a paper was read before the Geological Society, which will probably largely increase our know- ledge of this somewhat exceptional formation. One very useful addition among the Tertiary Rocks is a fuller notice of Mr.Clement Reid's studies of the Cromer section. The last book, on Physiographical Geology, is a little disappointing. The author has made earth-sculpture and other branches of this division of geology so specially his own, that we could have wished for more under this- head than the concise summary he has given. True^ he would have been repeating what he has said often- times before ; but his contributions to this most fascinat- ing subject are rather scattered, and a full summary would have been very welcome. The above notes, which are not the result of a system- atic collation of this and the previous edition, but have been culled at random, suffice to show that no pains have been spared to bring before the reader the latest results of geological inquiry. In a rapidly growing science the task of keeping edition after edition of a text-book up to date must be toilsome ; it is fortunate when we have an author who has the courage to stick to the work, and power to carry it out with success. It is a welcome fact that this third edition, in spite of its 150 additional pages, is less bulky than the second. A. H. Green. January 25, 1894] NATURE 289 THE CHEMISTRY OF THE BLOOD. On the Chemistry of the Blood, atid other Scientific Papers. By the late L. C. Wooldridge, M.D., D.Sc, Assistant Physician to, and co-Lecturer on Physiology at Guy's Hospital. Arranged by Victor Horsley, F.R.S., and Ernest Starling, M.D., with an introduction by Victor Horsley (London : Kegan Paul, Trench, Triibner, and Co., Ltd., 1893.) TO all who are interested in the progress of medical science and of physiology, the publication of the scientific papers of the late Dr. Wooldridge will be very welcome. Dr. Wooldridge always impressed those who knew him well as possessing many of the attributes of genius. Full of ideas in connection with the subject he chose for his work (chemical physiology), he was not con- tent to limit himself to the expression of ideas simply, but resorted to experiment to test the accuracy of his conceptions. The experiments and observations which he made, it may be said, dealt with one of the most com- plicated subjects in physiology, viz. the chemistry of the substances (proteids) closely related to the life of the cell and of the organism. A man of Dr. Wooldridge' s capacity and origmality could not long remain trammelled by the traditions of academic science. Although he received a very full academic training (and his early original work on the blood bears the impress of this training), he soon dis- covered new paths of research, and elucidated facts combating old ideas, and shedding light on the pheno- mena of life. It was perhaps inevitable that so original a man should come into conflict with what may be called the " academic mind " ; the man of great originality always does. What happened to Dr. Wooldridge in this respect is stated very clearly, and not too forcibly, in the excellent introduction to this volume by Prof. Victor Horslej\ It is only necessary here to state that although Wooldridge's work was appreciated on the continent, his Croonian lecture, embodying his views on the coagula- tion of the blood, was refused publication by the Royal Society. It is not wise, perhaps, to lay too much stress on this error of judgment, but it may be said that Wooldridge did not publish papers containing visionary ideas, but all his conclusions were based on well-con- ducted experiments, and that he was a modest and sincere seeker after truth. His work, in spite of the drawbacks and disappointments of his short life, is now beginning to be appreciated, and in two or three directions he led the way to discoveries which are of great importance to physiological and pathological science. It would be out of place here to give anything like a full synopsis of the scientific work done by Wooldridge. It may be said that his chief work dealt with the pheno- mena of the coagulation of the blood : phenomena clearly showing the passage of a living tissue into a dead. The investigation of such phenomena is in many respects more difficult and complicated than a purely physical or chemical research ; for in a chemical study of so compli- cated a liquid as the living blood, the mere separation of one of its constituents may so alter its nature as to lead to a misapprehension of its real properties. This was clear to Wooldridge during the whole course of his work. The phenomena of the coagulation of the blood NO. 1265, VOL. 49] was explained by Alexander Schmidt and his pupils of the Dorpat school, as consisting in the action of a " fer- ment" on a proteid body called fibrinogen; the chief change in the blood preceding the formation of fibrin being a destruction of the white corpuscles. This theory was taught in the schools, and accepted not as a final explanation, but as a very probable explanation, the chief idea being that a "ferment" was essential to pro- duce coagulation. Now Wooldridge showed conclusively by his experiments that a ferment is not necessary to co- agulation ; he, in fact, separated from the blood plasma a fibrinogen which became transformed into fibrin with- out the aid of a ferment. This change he found in many cases was accelerated by lecithin. Wooldridge viewed coagulation as a change occurring in the plasma of the blood, and not so much in the white corpuscles ; his ideas, therefore, were in direct opposition to those of the Dorpat school, and have been in part confirmed by sub- sequent researches. For all the details of his work in this respect, his papers must be consulted ; mention must, however, be made of his brilliant discovery of a means of causing intra-vascular coagulation. It was known that by injecting a solution of peptone into the circulation of certain animals the coagulation of the blood was prevented when drawn from the body. No method was known by which the blood could be made to coagulate in the vessels during life. Wooldridge dis- covered that the injection of an extract of certain parts of the body, e.g. the thymus gland, the testis, and lymphatic glands, produced this. It isimpossible to overestimate this result, since it throws light on the phenomena of coagula- tion occurring in the vessels in many cases of disease. The body producing this effect is a proteid and called " tissue-fibrinogen." His study of this body, or bodies (for there may be several closely allied), induced Wooldridge, when he began to do work for the Medical Officer of the Local Government Board, to see whether it possessed any immunizing properties ; whether, in fact, the profound change it produced in the blood was unfavourable to the development of bacteria invading the body. He found that in the case of the bacillus anthracis that it had this property ; that in rabbits injected with this tissue fibrinogen the death from anthrax (inoculated at the same time) was delayed. Moreover, he found that he could produce a better result if the bacilli were grown for a short time in a solution of tissue fibrinogen. There is no doubt that Wooldridge, in these experiments, was the first worker who clearly showed the possibility of chemical vaccination for infective disorders ; and there is but little doubt that if he had lived to continue this work, he would have clearly demonstrated what others have since shown, viz. vaccination against a bacterial disease by means of the chemical products of the specific micro-organism. Sufficient has been said to show what the well-arranged volume under consideration demonstrates at length — that Wooldridge's work was of the highest order ; and it was fitting that his scientific papers should be arranged by Prof. Victor Horsley, who was Professor-Superintendent of the Brown Institution when Wooldridge did much of his work there, and by Dr. Ernest Starling, who succeeded him as co-Lecturer at Guy's Hospital. 290 NATURE [January 25, 1894 AGRICULTURAL BOTANY FOR EXTEN- SION ISTS. An Ele'i'eiitary Text-Book on Agricultural Botany. By M. C. Potter, M.A. Small 8vo. Pp. 250, with ninety- nine illustrations in the text. (London: Methuen and Co., 1893-) THIS is a very good little book up to a certain point, but it is neither better nor worse than the general run of elementary works on botany, in which there is an attempt lo cover the whole field. The physiological and anatomical parts are the best ; yet we see no reason why the title should be "Agricultural Botany." Indeed, we fear the author has been a little too ambitious ; laudably ambitious, perhaps, though wanting the practical know- ledge necessary to achieve his object — not that it is one within easy reach. This is an extract from his preface : " My aim in these few pages has been to lay a foundation which may serve to guide the future operations in the field, and form a basis for intelligent trial and experiment. In these days of competition and struggle for existence, every little tells, and the farmer who, understanding, can apply his knowledge, is more likely to succeed than one who labours without the advantage of this knowledge." No doubt a man would not necessarily be a worse farmer because he possessed some knowledge of vegetable physiology, nutrition, or even classification, and he might possibly derive a more intelligent enjoyment — if there be any left — from his occupation ; but if he knew all the botany in Mr. Potter's book, and all that is not in his book, we doubt whether he would be any nearer making farming pay, which is the main object, after all, of the majority of those who engage in the pursuit. Success in farming does not depend so much on scientific knowledge as on practical knowledge. Science has doubtless done much to advance farming — especially mechanical science ; and we should be the last to dis- courage making botany a subject of study for the budding farmer. But we think the macroscopic side is too much neglected in favour of the microscopic side. For in- stance, we sought the distinctions between rye {Secale) and barley {Hordcum) ; but although the anatomical structure of the stem of the former is described and illustrated in some detail, it is not included in the chapter on grasses where the floral structure is described. In the description of the natural order Leguminoste, it is stated that the fruit is always composed of a single carple ; that the leaves are never opposite ; and that the seeds are always destitute of endosperm. It is unnecessary to give examples disproving these statements. On the next page the flowers of the sub-order Coesalpineee {sic) are said to resemble the Papilionaceas, but to differ in having the standard inside the wings. There is one element of truth in this. The nature and extent of the information given under some of the genera of Leguminosje may be gathered from the following : Sarothamnus—thQ broom is common on sandy waste lands. Ononis— 2, small plant with pink flower, commonly known as the rest harrow. There are two species, one with spines and one without. Looking under Pisum, we discover that P. arvense, the field pea, is not mentioned. Under Vicia, the tare, V. sativa, is described as having a weak stem, partly erect, and purple flowers, often in pairs ; with the NO. 1265, VOL. 49] further information that it is often cultivated. In short,, this part of the book needs thorough revision before it can be considered as useful or satisfactory. At half a dozen other places where we opened the pages, we noticed the same incompleteness and want of precision. THE PRINCIPLES OF HOSPITAL CON- STRUCTION. Healthy Hospitals : Observations on some Points con- nected with Hospital Constrtection. By Sir Douglas Galton, K.C B., F.R.S., &c. (Oxford: The Clarendon Press.) THE object of this book, as its author, Sir Douglas Galton, tells us, is to bring together the principles of hospital construction which now lie scattered through various publications, and to show what points are essen- tial to health in hospital establishments. This task has been admirably fulfilled by the author, and we cannot but recognise the skilful manner in which jfrom chaos he has brought together and condensed in the small compass of 282 pages such a vast amount of useful information. Sir Douglas Galton has already a high reputation for the application of scientific methods to the construction of barracks and hospitals. Few men have had larger opportunities of acquiring such knowledge in the public service, and very few have been able to investigate the questions involved so thoroughly as the author of " Healthy Hospitals," whose zeal has induced him to visit every place, as well in America as on the conti- nent, where he could obtain sound practical knowledge on the subject by personal observation and inquiry. We therefore gladly welcome this book, which is the outcome of his great experience. In the preliminary chapter Sir Douglas Galton enters very briefly into the historical part of his subject, and dates the great improvement in the construction of hos- pitals from the close of the Crimean War, the American War of Secession, and the Franco-German War of 1870-71. He subsequently lays down the first principles on which the successful treatment of disease depends, the selection of site, the conditions of air supply, of warming, lighting, and water supply. Many of the rules laid down are of course not new, but they are nevertheless valuable, and bear to be repeated and emphasised. The rules to be followed are defined so clearly and concisely, that it becomes a simple matter to apply them in a practical form. The chapter on site is one that will at a glance show the importance of the subject, and at the same time the difficulties it often has to contend with. Many errors are pointed out which have been committed in the selection of plans for some of the large hospitals in England and on the continent. This is one of the most important and best chapters in the work before us. In the chapters on the constitution and movements of the ail", and on ventilation and warming, which are dependent in a great degree on these changes, the author enters very fully into the consideration of these important subjects. He accepts De Chaumont's standard as the January 25, 1894] NA TURE 291 best guarantee for keeping an air space pure and whole- some—a point of no small importance, since latterly a lower standard has been advocated. He recognises the importance of investigating the micro-organisms in air, but states " that our knowledge of this science and of the nature of the organisms is too recent to allow us to lay down any fixed rules for judging of what are dangerous characteristics of air in wards measured by this stan- dard." This is no doubt true up to a certain point, but the Ratio ^^^*^"^ as pointed out bv Carnelly and Moulds Haldane {Philosophical Transactions of the Royal Society, 1887), should not be overlooked in investigations on this point. The chapters on warming and lighting are complete monographs on these subjects, as we might expect from the distinguished author who has made them his special study. In discussing the various methods of ventilation which have been applied to hospitals, is mentioned the mechan- ical extraction of air as practised by propulsion. This plan has never found favour in England, but has been introduced into some continental hospitals. We note that on several occasions when three of the most im- portant hospitals were visited in Europe and the United States, in which ventilation depended on propulsion, on every occasion the propulsion happened to be out of use for the time ; in some cases evidently with the object of saving the expense of fuel V The latter chapters are devoted to the consideration of the ward unit and the administration buildings. Every detail has been most carefully noted, and the closest criticism fails to find an omission. The rules are laid down with a simplicity and clearness which render it very difficult to notice them without quoting them in detail, and the plans which accompany the letter-press show at a glance the principles which should be followed. We regret that the writer has not entered more fully into the question connected with isolation hospitals for infectious diseases. No plan is given of any such hospital, although mention is made of the Local Govern- ment Board rules for the London fever hospitals. The isolation pavilion of the Johns Hopkins' Hospital seems to be so admirably constructed, and the structural details so carefully carried out, that the plan would be a valuable addition to the present work. In infectious hospitals, the position of the administration block to the wards would also diiTer to the plan usually adopted for general hospitals. Sir Douglas Galton is opposed to the expense which some of the costly and palatial hospitals of the present day have entailed, and advocates simplicity of design and economy in construction as leading conditions to be observed in building hospitals for the future. If the rules he has so clearly given throughout his work be attended to, these important qualities will naturally follow. We commend this book not only to the architect and sanitarian, but to all interested in hospital work. It is eminently practical, and its author must be congratu- lated on the completion of a work of no ordinary merit and one which is a fitting companion volume to his •" Healthy Homes.' NO. T265, VOL. 49] OUR BOOK SHELF. The Vault of Heaven. By Richard A. Gregory, F.R.A.S. (London : Methuen and Co., 1893.) The aim of this volume of the University Extension Series of text-books is to give " an elementary account of some of the marvels that have been revealed by the use of the telescope and two of itsmost indispensable adjuncts, — the spectroscope and the photographic camera." In the space of about 180 pages the author contrives to give an admirable introduction to the study of modern physical astronomy, and the whole is set forth in a manner calculated to awaken a permanent interest in this most fascinating subject. The book is eminently readable, and contains none of the mathematical expres- sions which are so liable to arrest the progress of the general reader. Astronomical telescopes, including equatorials and meridian instruments, form the subject of the first chapter. Then follow two chapters giving an excellent account of the sun and of the various methods by which our knowledge of that luminary has been gradu- ally accumulated. The reader is next presented with bright and brief pictures of the moon and planets, comets and shooting-stars, and of the various bodies which are met with as we proceed further outwards into " boundless space." The " Chemistry of Stars and Nebulas," and " Celes- tial Photography," define the scope of the final chapters. Many novel illustrations are given to assist the reader in comprehending the significance of astronomical data. The subject-matter is quite up-to-date, and in matters not yet quite clear the author has wisely refrained from taking sides in controversies. The historical references are fairly complete, and space is found for some most interesting extracts and diagrams from Galileo's "Sidereal Messenger," published in 1610. Where all the various parts of the subject are so well explained, it is difficult to single out points for special mention, but we may say that the author is particularly successful in his treatment of celestial photography, though we cannot help regretting that more is not said about the immense gain to astronomy which has followed from the application of photography to the study of the spectra of the heavenly bodies. We are glad to see, however, that he says (p. 33) with regard to the Car- rington-Hodgson observation of 1859, "the statement that the outburst was iimnediately {oWov^^^ by a magnetic storm does not appear to be founded on fact. From an examination of the magnetic records kept at Kew, it appears that at the time of the observation the needles were unaffected, and it was not until fifteen hours after that a magnetic storm occurred." A word of praise is due to the author for the careful preparation and selection of diagrams and photographs, all of which are excellently reproduced ; many of them make their first appearance in this volume. There are a few misprints — as, for instance, on p. 113, where 14 times 60,000 is given as 84,000 ; but they are not so serious as to be misleading. A classified list of astro- nomical books for the use of those desiring to extend their reading beyond the limits of an introductory text- book, concludes a volume which is well adapted to impart the preliminary knowledge essential for a proper understanding and appreciation of the fresh results which are constantly being obtained in the various observatories throughout the world. A J our ney through theYemen, and some General Remarks upon that Country. By Walter B. Harris, F.R.G.S. (Edinburgh and London : William Blackwood and Sons, 1893.) The Yemen is an indefinite tract stretching inland from the south-western corner of Arabia, and the "general remarks" upon its geography and history are placed first in this volume, the personal narrative of the author's 292 NATURE [January 25, 1894 journey, in which alone is there any original information, occupying the second place. From Aden Mr. Harris started inland and crossed the Turkish frontier under the pretence of being a Greek shopkeeper from Port Said. In this way he obtained access to the disaffected province of Yemen during the progress of a rebellion, reached 3auaa, and was naturally imprisoned by the Turkish officials there, who refused to recognise his English pass- port. The author finds fault with the Foreign Office for not coming to his rescue, apparently forgetful that he wilfully concealed his nationality at the outset, and so gave use to suspicion, and forfeited any privileges to which it might entitle him. From Sanaa he was sent under escort to Hodeida. The illustrations are interest- ing as types of the scenery and people of the Yemen, but the book has no other claim to scientific notice. LETTERS TO THE EDITOR. [ The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected ■manuscripts intended for this or any other part ^/Nature. No notice is taken of anonymous communications. '\ The Directorship of the British Institute of Preventive Medicine. We observe in your issue of the i8lh inst. a letter, signed by Prof. Roy, respecting the appointment of a "Director" to the Institute of Preventive Medicine, and purporting to recount what occurred at the meetings of the Council. As Prof, Roy has misstated the principal facts, and has with- held others which are fatal to his allegations, it is possible that some of your readers may be misled, and it is there- fore advisable that the real state of the matter should be published. (i) The present appointment being one of a purely temporary nature (for three years only) and at a nominal salary, is not, as Prof. Roy implies, equal to that of Dr. Koch, neither is it to that of M. Pasteur, who, by the way, is not, as Prof. Roy implies, the Director of the Pasteur Institute. (2) The qualifications necessary for the office were fully con- sidered by the Council, and by committees of the Council, and consequently Prof. Roy's statements to the contrary are not correct. (3) Prof. Roy's statement that he initiated the idea of the In- stitute is not according to the fact. He was entrusted with moving the resolution proposing the establishment, at the meeting where the matter was first publicly discussed, but the founding of the Institute had been in the minds of the members of the Mansion House Committee and discussed among them long before. (4) Prof Roy implies that he resigned his position as secretary to the Council {sic) as a kind of protest against the latter's mode of transacting business. This statement is incorrect. In the first place. Prof. Roy was one of the secretaries to the Executive Committee, and not to the Council. In the second place. Prof. Roy resigned that position without making any protest whatever to the committee, by whom his resignation was at once and unconditionally accepted. (5) The subject of the temporary directorship was discussed by ''gentlemen who are" or have been "directors of labora- tories." Prof. Roy implies it was not so discussed by experts. The error of this allegation is probably due to the fact that he was absent from the Council meeting at which the question was first brought up, and that he was not a member of any com- mittee. It may be noted that Prof. Roy complains of non- attendances. On this point his statement may at once be conceded so far as he personally is concerned, since in 1893 he attended but three meetings. (6) The question of appointment of a temporary Director was stated on December 13 to be urgent, and the urgency was ad- mitted by the whole Council with the exception of Prof. Roy. Prof. Roy tells your readers that the statement "carried no weight with him." Possibly this may have been because he was absent from the previous Council NO. 1265, VOL. 49] meeting when the point of urgency was fully discussed ; but such ignorance, even if admitted to be an excuse, does not account for Prof. Roy now withholding the fact that when he was present on the 13th ult. the reason of the urgency was fully communicated to him. Also, it is not right for him to withhold, as he does, the fact that the acceptance of the report of the sub-committee, which was wholly conditioned by that urgency, was agreed to by the Council neni. con. (7) Prof. Roy speaks as though the Council strongly objected to the resolutions laid before it. He ignores the fact that on the 13th it was but two members, including himself, and on the 19th only himself, who so objected. (8) Prof. Roy suppresses the fact that a special meeting of the Council was held on December 19 to reexamine the whole question, and to confirm or reject the minutes of the meeting of December 13, and that those minutes were circulated to every member of the Council, and that the meet- ings of the 13th and 19th were well attended. He omits to mention that he circulated beforehand, and produced at the meeting on the 19th, a document which he termed a " protest," and that, as it contained offensive statements plainly contrary to fact, the Council declined to proceed with the business of the meeting until Prof. Roy withdrew his "protest" unconditionally. He also suppresses the fact that he did so, and that this preliminary having been executed, the minutes of December 13 were then put and confirmed nem. con. If any of your readers, after this historical statement, con- sider that Prof. Roy's letter is justified in any sense, further information can be supplied. In conclusion, it may perhaps be interesting to note the names of those present on December 19. These were, for the ap- pointment of the temporary Director — Sir Joseph Lister (chair- man), Sir Henry Roscoe, Sir Joseph Fayrer, Prof Burdon Sanderson, Prof. Michael Foster, Prof. Victor Plorsley, Mr. Watson Cheyne ; while there was opposed to the appointment — Prof Roy. J. Fayrer, Victor Horsley, Mover and seconder of the motion for confirmation of the minutes of December 13. The Origin of Rock Basins. In my previous letter I confined myself to one aspect of the controversy relative to the origin of rock basins now occupied by lakes, as all the other arguments adduced by Dr. Wallace-*- with one exception, of which more hereafter — have already been answered, and the case on either side so fully presented that each one may draw his own conclusions as to which is right. The particular confusion of argument I referred to has not been so fully dealt with, and Dr. Wallace's letter shows that it was one which required to be met, for the heading of his letter itself shows that he has not fully appreciated the particular point at issue, which is the cause of origin of rock basins irrespective of whether they are or have ever been occupied by lakes. Leaving out of question the opinions of other opponents of the glacial erosion theory of the origin of lakes, as this would introduce too^ large a subject for the correspondence columns of Nature, and confining myself to the defence of the views put forth in my former letter, I may point out that the preglacial origin of rock basins by deformation is by no means the strongest form of the alternative explanation ; on the contrary, it appears to me to be subject to nearly as many objections as the hypothesis of glacial erosion of rock basins. If a rock basin is produced by deformation in a region where the valleys are not filled by glaciers, the ordinary action of the streams will usually be able to prevent a lake from being produced by the erosion of the barrier, the filling up of the hollow, or both combined. When, however, a rock basm is formed by differential movements in a glacier filled valley, it would be filled with ice, and so protected from sedimentation, and on the retreat of the glacier would at first be filled with water, and only gradually filled with solid matter, while the stream, having deposited its solid burden in the lake, would be unable to exert any erosive action on the barrier. From this it appears that there is a probability that rock basins formed beneath the glaciers during their extension in the glacial period should remain to the present day as lakes only partially filled up by solid debris. Seeing then that there is an inherent probability that rock basins formed in non-glaciated regions would never become January 25, 1894-] NA TURE 29; lakes, except when the movements were unusually rapid or ex- tensive, the argument from geographical distribution fails ; for we have no evidence to show whether rock basins are more or less abundant in regions that have been glaciated, than in those that have not ; and seeing, further, that differential movements are known to take place, while it has never been proved that a glacier is physically capable of excavating a rock basin, the onus prohandi rests with the advocates of the glacial theory ; and until they have shown that rock basins are less com- mon in regions that have been glaciated than in those that have not, this argument is not logically admissible. Observations on this point are very desirable, but it must be remembered that filled up lake basins are not the only thing to be looked for ; what is desired is evidence of the production of rock basins, or of such differential movements as would have led to their formation, had the erosion of the barrier been less rapid. In the Himalayas such rock basins appear to have been formed in quite as great abundance as in the mountains of Europe, and to correspond with them in position and form ; but the elevation of the mountains has been so recent, and the rainfall is so great, that the processes of nature are more rapid than in Europe, and the rock basins have consequently not only been filled up, but the barrier has afterwards in many cases been destroyed, and the deposits largely removed by erosion, so that the fact of their having originally been accumulated in a rock basin is not always easily recog- nisable. The one new argument of Dr. Wallace's is that derived from .he supposed difference between the outlines of existing lakes and those that would result from the submergence of river valleyb. In the selected instances, however, he has com- pared mountain lakes with submerged lowland valleys instead of with mountain valleys. In the latter, long stretches are frequently found where the slopes of the beds of the side streams are much steeper than that of the main valley ; these valleys if submerged would give rise to lakes of great length in comparison with their breadth, and without the numerous deep embayments of the shore line which would be usually found in a submerged lowland valley. As a single easily verified instance to show that a submerged mountain valley need not have numerous deep bays, I may instance the Pangong lake in the Himalayas, which will be found on any good map of India, and is nothing more than a submerged subaerially formed river valley; on a smaller scale the Malwa Tal near Naini Tal and the Pil lake in the hills east of Quetta, both of which are river valleys dammed by landslips, have simple outlines without any embayments. The instances I have chosen are from regions where there has not been a great extension of the glaciers, and where the form of the valley before its submergence was entirely produced by subaerial denudation. R. D. Oldham. On the Change of Superficial Tension of Solid-Liquid Surfaces with Temperature. In a recent very interesting communication to the Birming- ham Phil. Soc. {Bir. Phil. Soc. Proc, vol. ix. part i, 1893), upon the effect of a solid in concentrating a substance out of a solution into the superficial film in accordance with Prof. J. J. Thomson's investigation ("Applications of Dynamics to Physics," p. 191), Dr. Gore has quoted an observation of Pouillet's {Annales de Chemie, 1822, vol. xx. pp. 141-162), that when inert powders like silica are mixed with liquids that do not act on them heat is evolved. On the other hand, when the superficial area of contact between a liquid and its gas is increased heat is absorbed. This latter is known to be the case because the superficial tension diminishes with rise of temperature. In the case of the solid-liquid surface being pro- duced, it would appear at first sight to follow that the super- ficial tension should increase with increased temperature. The matter is, however, somewhat more complicated. When a dry solid is mixed with a liquid we are substituting a solid-liquid surface for a solid-air surface, and from the fact that most liquids soak up into a mass of dry powder, we may conclude that the superficial potential energy of the solid-liquid is less than that of the solid-air surface, i.e. that more work must be done to separate the liquid from the solid than is developed by the air getting at the solid. If these actions are reversible, we may apply the laws of thermodynamics, and conclude that as heat is evolved when the system does work, i.e. when the solid-liquid surface is increased, that it must require more work NO. 1265, VOL. 49] to separate the solid from the liquid at high temperatures than at low ones, and in the case of silica and water, for instance, that is very much what one would expect from the action of water at very high temperatures on silica. If we could assume that the superficial tension of air-solid were zero, it would follow from this that the superficial tension of a solid-liquid surface is negative, i.e. that there is a superficial pressure, and that the liquid has more attraction for the solid than for its own particles, and that this difference increases with increased temperature, i.e. the superficial pressure increases. The whole subject deserves careful investigation and quanti- tative treatment, but the difficulty of measuring the superficial tensions of solid-liquid surfaces seems almost insurmountable, so that it would be very difficult to verify the theory. Perhaps something might be done with finely divided liquids that did not mix, and whose superficial tensions might be measured. Trinity College, Dublin. Geo. Eras. Fitzgerald. A Lecture Experiment. When charcoal, which has been allowed to absorb as much sulphuretted hydrogen as it can take up, is introduced into oxygen gas, the charcoal will burst into flame owing to the energy of the action of the oxygen upon the sulphuretted hydrogen. This fact is stated in most text-books on chemistry, but no description that I have ever seen of this experiment is calculated to bring about the effect with certainty. The following is a simple method for illustrating this reaction upon the lecture table, which I have never found to fail : — ■ A few grammes (from five to ten) of powdered charcoal are introduced into a bulb which is blown in the middle of a piece of combustion tube about twenty-five centimetres long. A gentle stream of coal gas is then passed over the charcoal, which is heated by means of a bunsen lamp until it is perfectly dry. This point may be ascertained by allowing the issuing gas to impinge upon a small piece of mirror, and when no further deposition of moisture takes place the charcoal may be con- ! sidered to be dry, and the heating may be stopped. The char- i coal is then allowed to cool in the stream of coal gas until its temperature is so far reduced that the bulb can just be grasped by the hand, when the coal gas is replaced by a stream of sul- phuretted hydrogen. The sulphuretted hydrogen should be passed over the charcoal for not less than fifteen minutes, by which time the bulb and its contents will be perfectly cold, and the charcoal will have saturated itself with the gas. (In practice it will be found convenient to prepare the experiment to this stage, and allow a very slow stream of sulphuretted hydrogen to continue passing through the apparatus until the experiment is to be performed. ) The supply of sulphuretted hydrogen is then cut off, and a stream of oxygen passed through the tube. Almost immediately the charcoal will become hot, and moisture will be deposited upon the glass. The supply of oxygen should be sufficiently brisk to carry the moisture forward from the charcoal, but not so rapid as to prevent it from condensing on the glass tube beyond the bulb. In a few moments the temperature of the charcoal will rise to the ignition point, when it will inflame and continue to burn in the supply of oxygen. G. S. Newth. Royal College of Science, London. PIERRE JOSEPH VAN BEN EDEN. THIS distinguished Belgian zoologist was born on December 19, 1809, at Malines, in the province of Antwerp, a town once well known for its extensive manu- facture of lace. He received an excellent education, and early showed a decided taste for natural history ; his native town being built on the borders of a tidal river, his attention was soon called to the examination of the littoral fauna of Belgium, though it will be remembered that Belgium only evolved itself into a kingdom in the year 1830, when Beneden came of age. His first promotion was to the keepership of the Natural History Collections at Louvain, and in 1835 he was made an assistant professor in the University of Gand, a post which he appears to have held for only one Term, as we find him in the same 294 NATURE [January 25, 1894 year professor of the Catholic University at Louvain, which professorship he continued to fill for more than half a century. Van Beneden belonged to a generation of zoologists that connected Cuvier with the present age, and followed so far in this great master's steps, that they worked at almost all the branches of the animal kingdom. If we were to give a summary of the very ex- tensive writings of van Beneden we should begin with his memoirs on apes, seals, whales, and so through the various classes, with perhaps the exception of the birds and reptiles, to the gregarines. Circumstances made him devote a great deal of attention to the groups of parasitic worms and Annelides. Most of his papers on these forms were communicated to the Brussels Academy of Sciences or to the Paris Academy ; the latter we find reported on by Ouatrefages. He took a leading part in the, at one time, exciting controversy about the "alter- nation of generations," with the elder Sars, D'Udekem, and others. Among the more important works of Beneden may be mentioned " The Natural History of the Fresh-water Polyzoa," in collaboration with Du Mortier, published in 1850, which obtained the Grand Prize of the Paris Academy ; the " Zoologie Medicale," in 1859, of which Paul Gervais was joint author ; the " Recherches sur la Faune Littorale de Belgique " (Polypes), in 1866! In connection with this work it may be mentioned that Beneden's artistic powers were quite remarkable, and that many of his memoirs owe a great deal to his excel- lent illustrations. A good correspondent, he kept him- self acquainted with the work of most of his contem- poraries, and he was the writer of many of the short biographical sketches referring to zoologists that ap- peared from year to year in the Reports of the Brussels Academy. Some of our readers may remember what an active part he took in the Liverpool (1870) meeting of the British Association ; Rolleston was president of the biological section, and gave a morning to the discus- sion of the subject of " commensalism," which at that time Beneden's mind was occupied with, and about which he afterwards (1875) published a volume in the " Bibliotheque Scientifique Internationale," that has been translated into German and English. Peradventure some too may remember how delighted Beneden, with Strieker, Dohrn, and some of the other " foreigners " present at that meeting were, to find that a little nucleus of the great body combined to make the " Association Sunday" as little sad as possible by the practice of a proper commensalism. Full of honour after a long life well and usefully spent, Beneden had the additional reward of seeing his son Edward take a high rank in the modern biological school, in this resembling his great contemporary Henri Milne Edwards. Beneden was a member of very many of the Academies and Societies of Europe, and was an honorary LL.D. of the University of Edinburgh. He died at Louvain on January 8, 1894. THE GREAT GALE OF NOVEMBER 16-20. TTHE past autumn and early winter were especially ■*■ characterised by a mild and humid atmosphere, due to the very marked prevalence of south-westerly winds which have blown with great persistence from the Atlantic. These conditions are without doubt intimately associated with the frequency with which gales have occurred. The violent storm which was experienced over the entire area of the United Kingdom, as well as over the sea and the parts of the continent adjacent to our islands, from November 16 to 20, was more severe than the other gales which have recently occurred, and it is necessary NO. 1265, VOL. 4q] to refer back many years before a storm so violent and so destructive can be found to have traversed the country. Prior to the advent o^f the storm an anticyclonic area, with fairly high barometer readings, was situated over our islands, and north-easterly winds were prevalent. On November 14 and 15 a small cyclonic disturbance travelled over the south-western portion of the kingdom, and caused a general giving way in the area of high barometer readings, while the large anticyclone over Europe also materially decreased in its energy. At this time a large cyclonic disturbance was out in the Atlantic, and was rapidly approaching our western coasts ; the first intimation of a renewal of bad weather was shown by a fresh fall of the barometer which set in at Valencia at 4 p.m. 15th, and an hour or so later the wind was freshening from the south-east. On November 16 the conditions had so far changed that at eight o'clock in the morning the weather chart prepared by the Meteorological Office gave unmistakable indications of an important disturbance at no great dis- tance from the Irish coast, and the Official Weather Report has the following remark : — " A large depression is approaching our western coasts from the south-west- ward, and is likely to cause rough wet weather over the kingdom generally, especially in the west and north." At this time a strong south-easterly wind was blowing in the south-west, but the force of the wind had not attained to that of a fresh gale (force eight of Beaufort notation) in any part of the United Kingdom, although the wind, which on the previous day had been north-easterly, was now everywhere southerly. The self-recording barograph at Valencia shows that the lowest barometer occurred at 7 p.m. i6th, and between eight and nine in the evening the wind shifted from east by south to west-south-west. The central area of the storm was not far distant from Valencia at this time, and during the succeeding night it traversed Ireland in a direction from south-west to north-east, the whole storm-system progress- ing at the rate of of about twenty-five geographical miles an hour. By the morning of November 17 the heart of the storm had reached the west of Scotland, the lowest barometer reading reported to the Meteorological Office being 28'53 iris, at Ardrossan. Strong gales had blown during the preceding night in the north and west, and the force of a gale was still reported at many places on our coasts, while the wind had shifted to the north-westward over Ireland. The weather information for the evening of the 17th shows that the storm had continued its course to the north-eastward, and at six o'clock the centre of the disturbance was not far from Wick, where the barometer was 28'57 ins. The north-westerly gale was still blowing over the western portion of the kingdom, but there was a decided lull in the strength of the wind in the east and south-east of England. It was shortly after this time that the greatest violence of the storm burst suddenly over the northern part of the country, and at Deerness, in the Orkneys, the wind at 6 p.m. shifted suddenly from east by north to north by east. The subsequent tiack of the storm had a most impor- tant influence on the increased violence of the wind, and there seems no reason to suppose that if the disturbance had continued its north-easterly track the gales ex- perienced would have been at all unusual. A very important change in the distribution of atmospheric pressure was in progress over Western Europe, and the change of track and subsequent violence is clearly to be traced to these barometer changes. The anticyclone over Central Russia, which had given way for the small disturbance which first traversed the southern portion of England on the 14th and 15th, was now reasserting itself, and this formed a most effectual barrier to the further north-easterly progress of the storm. In addition to January' 25, 1894J NATURE 295 this, the "ridge" of high barometer which was following the storm was of a very pronounced character, and caused a rapid recovery of pressure in the rear of the dis- turbance. As the result of these two regions of high barometer, or anticyclones, between which the storm system, or cyclone, was situated, the central area of the storm was brought to bay, and abruptly struck out on a path to the south-eastward, in which direction there was the least resistance to its progress. This halting and indecision and abrupt change of path on the part of the storm area caused the high pressure system in the rear to considerably gain on it, with the result that exceptionally steep gradients were caused for northerly gales, which continued to blow for a period of two or three days over our islands. The diagram showing the barometer and wind for 8 a.m. November i8, indicates a decided change in the course of the disturbance, and at that hour the lowest November i6, 10 a.m., to November 20, 9 p.m.—At\ Days. Station. Maximum velocity. Hours with velocity 45 miles and above. Force 8 of Beaufort notation. Mean hourly velocity for i,\ days. Miles. Direction. Rate. Valencia Scilly Holyhead Orkney North Shields Yarmouth Kew 60 66 89 96 69 64 33 N.N.W. N.W. N.W.b.N. N.b.W. N. N. N.E.b.N. N.N.W. iS 4 a.m. „f 2 a.m. '^i 6 a.m. 18 II a.m. 17 9 p.m. \ 10 a.m. 20 5 a,m. 18 7 p.m 31 } '■ 76 40 1 '" 31 0 33 41 54 39 33 33 23 BAROMETER AND WIND. Friday, 17 th November. Saturday, 18 th November. 8 a.m. 8 a.m. li'^n:-r r~ BcnUllsc. Diagram to illustrate the storm during the period of its greatest violence on November 17 and 10. The barometer is expressed by isobars, the pressure corresponding to each line being given in inches and tenths. The winds are shown by arrows which are drawn flying with the wind. © = a calm ; ** = a light or moderate wind ; > = a fresh or stormy breeze ; > > = a gale. barometer was 28-99 inches at Spurn Head, the centre of the disturbance being situated about 50 miles to the east of Scarborough, and travelling south-eastwards down our east coast. On the 19th the disturbance had reached Cuxhaven, where the barometer was reading 29-10 inches, and on the 20th it was passing away over central Europe, but gales were still blowing in the south-east of England and in parts of the North Sea. The following table shows the strength of the wind in miles per hour as recorded by the velocity anemo- meters under the supervision of the Meteorological Council, who have kindly allowed access to the anemo- graphs and tabulations : — NO. 1265, VOL. 49] The factor 3 is used with all the anemometers for ob- taining the velocity of the wind. The hourly velocity at Orkney was 90 miles or above for 5 consecutive hours — from 9 p.m. 17th, to i a.m. iSth — and both this and the maximum velocity of 96 miles in the hour is in excess of any previous record in this country, the highest velocity in the hour previously recorded being 91 miles at Fleetwood in a gale which occurred on May 20, 1887. At Holyhead the wind was 65 miles or above, force 10 of Beaufort's notation, for 31 hours, and was 85 miles an hour or above for 4 hours. The storm appears to have originated on November 7 to the east of the Florida coast, near the Bahamas, and 296 NATURE [January 25, 1894 it can be tracked completely across the Atlantic to our islands, and eventually to central Europe on November 20. Several vessels keeping logs for the Meteorological Office, with standard instruments on board, have re- corded observations on the storm during its passage across the Atlantic, and the Cunard steamship Lucania was under the influence of the disturbance during the whole of her passage from America to England. During the storm no fewer than 335 lives were reported as lost ■on or near our own coasts, this number being the result of reports received during the four weeks subsequent to the storm. Chas. Harding. PA UL HENRI FISCHER. THE Museum of Natural History of Paris has suffered a great loss in the person of Dr. Paul Henri Fischer, the well-known zoologist and palaeontolo- gist, who died on November 29, after a long and painful illness. Born at Paris, on July 7, 1835, he received his early classical and medical education at Bordeau.K. He became Interne des Hopitaux of Paris in 1859, and obtained his degree of Doctor of Medicine in 1S63. The study of medicine did not prevent him from devoting himself also to that of the natural sciences ; for in 1 86 1 he entered as Demonstrator in the Labora- tory of Palaeontology of the Museum of Paris, under the direction of M. d'Archiac. His researches chiefly concerned the living and fossil mollusca, and from 1856 he edited the Joiir7ial de Conchyliologie in col- laboration with M. Crosse. From the position of Demonstrator he rose to be aide-natiiralisie (assistant), and studied with great success the marine animals of the coasts of France, their geographical and bathymetric distribution. He indicated the depths at which a large number of foraminifera, ccElenterata, echinodemata, mollusca, bryozoa, &c. can be collected on the coasts of the west of France. In collaboration with the Marquis de Folin he undertook the study of the animals dredged in the extremely interesting region of the Gulf of Gascony, to which the nam.e " Fosse du Cap Breton " has been given. The two savants discovered a large number of forms hitherto unknown, and many which recalled species only known in the fossil condition. With M. Delesse he made researches on the submarine sediments of the French shores. He was elected member of the Commission of Dredging, and took part from 1880 to 1S83, on board the Travailleur 3.nd the Talisman, in the celebrated expeditions directed by Prof. Milne Edwards. In the course of these expeditions he noted the enormous extension of a cold fauna characterised by boreal and arctic species, and reaching as far as Senegal, where it lives beneath a superficial fauna with intertropical characters. Among the writings of Dr. Fischer, which number not less than 300 titles, including books, pam- phlets and memoirs, we may cite : " Paleontologie de TAsie mineure " (in collaboration with MM. d'Archiac and de Verneuil) ; " Mollusques de Mexique et de I'Amerique Centrale"; "Species general et iconographie des coquilles vivantes " ; " Animaux fossiles du Mont Leberon" (in collaboration with MM. Gaudry and Tournouer) ; " Paleontologie de Tile de Rhodes "; "Cetacds du Sud-Ouest de la France " ; " Catalogue et distribution geographique des mollusques terrestres, fluviatiles et marins d'unepartie de I'lndo-Chine ; " Sur les caracteres de la faune conchyliologique terrestre et fluviatile recemment eteinte du Sahara " ; " Sur la faune conchylio- logique de I'ile d'Hainan"; numerous memoirs on the mala- cological fauna of Lord Hudson Island (Pacific Ocean), of Cambodge, of the islands of the Caledonian Archi- pelago, of Aleutian islands, of the Bay of Suez, &c. In collaboration with M. E. L. Bouvier he published papers on the anatomical peculiarities of certain groups of NO. 1265, VOL. 49] molluscs. Finally, he wrote a remarkable treatise on conchology which has become classical (" Manuel de Conchyliologie et de paleontologie conchyliologique ou histoire naturelle des mollusques vivants et fossiles, suivi d'un appendice sur les Brachiopodes par CEhlert." In this manual the author showed that the classification of molluscs ought to be based not alone on the form of the shell, but primarily on the anatomical characters. Dr. Fischer was Chei'alier de la Legion d'Hdnneur and Officier de V Instruction piiblique. He obtained several prizes at the Paris Academy of Sciences, and had been President of the Zoological and Geological Societies of France. He possessed deep erudition, was a charming conversationalist, and after having treated a subject belonging to the domain of the natural sciences or of medicine, he was far from embarrassed if he had to discuss philosophy, literature, or sesthetics. The death of this savant, who was as affable as he was modest, has been a cause for general regret and for deep mourning among his large circle of friends. Edmond Bordage. NOTES. The Academy of Natural Sciences of Philadelphia has awarded the Hayden Medal to Prof. Huxley. The medal is of bronze, and, with the balance of the interest arising from a sum of 2,500 dollars given to the Academy by the widow of the late Prof F. V. Hayden, is awarded annually "for the best publi- cation, exploration, discovery, or research in the sciences of geology and palaeontology, or in such particular branches thereof as may be designated." The recipient in 1892 was Prof E. Suess, and in 1891, Prof. E. D. Cope. Prof. J. Hall had the distinction of receiving the first award of the medal in 1890. Sir Henry Roscoe has been appointed to the vacancy in the Senate of London University caused by the death of Sir WiUiam Smith. An Elliott Cresson Medal has been awarded to Mr. Nikola Tesia, by the Franklin Institute, for his researches in high frequency phenomena. M. GuYON has been elected a member of the Section de Geographie et Navigation of the Paris Academy of Sciences, in the place of the late Admiral Paris. Dr. E. Zacharius, Extraordinary Professor of Botany in Strasburg University, has been appointed Director of the Ham- burg Botanical Gardens. Dr. J. K. Hasskarl, who introduced the cinchona plant into Java, died at Cleves, Germany, on January 5, at the age of eighty-two. In 1852 he was sent by the Dutch Government to South America to collect cinchona seeds and plants. He did not confine himself to collecting Calisaya, but gathered seeds and plants of other varieties, some of which were new. In 1854 he successfully carried about four hundred Calisaya plants to Java, but two years later he left Java, owing to differences between Dr. Junghuhn and himself on many vital principles of the system of cinchona culture. It is a singular fact, remarks the Chemist and Druggist, that the most valuable of all cin- chonas, the Lea^eriana variety, was not introduced into the Indies by any of the collectors specially appointed by the British or Dutch Governments, but by a private trader in South America, the late Mr. Ledger. The annual general meeting of the Geologists' Association will be held at University College, London, on February 2. After the reading of the report and election of officers for the ensuing year, the President will deliver an address on " Geology in the Field and in the Study." January 25, 1894] NATURE 297 The twenty-first annual dinner of the old students of t he Royal School of Mines will be held on January 29. Among those who have promised to attend are Sir Lowthian Bell, F.R.S., Prof. Roberts Austen, C.B., F.R.S., Prof. Le Neve Foster, F.R.S., Prof. Thorpe, F.R.S., Prof. RUcker, F.R.S., Mr. P. C. Gilchrist, F.R.S., Mr. W. Topley, F.R.S., and other well-known authorities in the mining and metallurgical world. Ir succeeding numbers of the Psychological Review are of the same high character as the first, there is little doubt that the journal will meet with the success it deserves. The presidential address, delivered by Prof. Ladd, in December last, before the American Psychological Association, is included in this new Jiez'irw, and several interesting contributions from the Harvard Psychological Laboratory. Among the latter is a paper in which an account is given of an experimental study of memory. The results show that, when isolated, the visual memory surpasses by far the aural, but when combined the aural excels the visual — -in other words, in the united action of the senses of sight and hearing, their relative strength is just the reverse of what it is when they act independently. Another contribution from the Harvard Laboratory deals with the intensifying effect of attention. It is usually held that when the attention is directed to an object, the impressions received are intensified. The experiments at Harvard lead, however, to the remarkable result that all stimuli appear relatively less when the attention is from the outset directed to them. In addition to these original papers, the Review contains discussions of psychological subjects, and a survey of recent literature upon the subject. Writing in the U.S. Monthly Weather Revieiv, Mr. Mark W. Harrington remarks that the influences of the wind and tide, and possibly the low barometric pressure of a storm area, in causing an unusual rise of water, is the occasion of much of the damage and loss of life that attends the storms of the Atlantic and Gulf coasts. Observations tending to fix the extent of this high water, and the special causes that produce it are, therefore, always desirable. Mr. Harrington has brought together the records of water, wind, and pressure for two storms, viz. June 4-5, 1891, at Galveston, and October 12-13, 1893, at South Island, Winyah Bay, S.C. The results show that in Winyah Bay, under the influence of winds that were estimated at 90 miles, although doubtless the maximum velocity of the open sea exceeded this, the actual height of the- water exceeded that due to the natural tide by 7 or 8 feet. At Galveston, under the influence of easterly winds, whose measured velocity attained 44 miles, the maximum gauge reading was less than 4 feet above the slight natural tide. At these two stations, therefore, the rise in the water surface attributable to the winds is in both cases about twenty times greater than the height of a column of water that can be sustained by such winds in statical equilibrium, as in the Lind anemometer, and this factor is only slightly diminished by making some allowance for the rise of water due to the diminished barometric pressure. Dr. S. C. Hepites has published, in the Analele of the Meteorological Institute of Roumania, a -valuable resume of the climate of Sulina from observations taken during fifteen years, 1876-90. The meteorological station is situated on the left bank of the Danube, very near to the sea, and was estab- lished by the European Commission of the Danube. The mean annual temperature is 5i°'6, the mean difference between the hottest month, July, and the coldest month, January, being ! 43°'2. The absolute maximum observed was 98° '4, and the ' minimum -ii°'2, which gives an extreme range of I09°'6. I The mean relative humidity of the air is 76*5 per cent.; the autumn is damper than the spring. The annual amount of arainfall is only 17*3 inches, on sixty-four days; the wettest NO. 1265, VOL. 49] month being June, and the dryest, February. The greatest fall in twenty-four hours was 2-59 inches. The prevalent wind is from north-east, the relative frequency from this direction being 20 per cent. Thunderstorms are not of frequent occurrence ; they occur mostly in June and July, and not at all in winter. Fog occurs on about twenty-five days in the year; considering the position of the town, we should have expected a more frequent occurrence of this phenomenon. Falls of dust have several times been noted ; they apparently come from the Russian Steppes. Mr. J. Glaisher, F.R.S,, contributes to the Quarterly Statement just issued by the Palestine Exploration Fund, a paper on the fall of rain at Jerusalem in the thirty-two years from 1861 to 1892. The average annual rainfall is 25*23 inches, that s, very nearly the same as the mean for London, though the fall is very differently distributed throughout the year. A somewhat remarkable point brought out in the discussion is an evident increase of the fall of rain in the later years of the series of observations. The mean annual fall in the sixteen years from 1861 to 1876 is 22"26 inches, whereas in the sixteen years from 1877 to 1892 the mean is 28 "20 ; therefore the mean annual fall in the second half of the series is 5 "94 inches greater than in the first half. The honour of being the " oldest fossiliferous rock in Europe " has been claimed for certain strata in Bohemia. Barrande first worked out the Silurian and Cam.brian basin in Bohemia, and described a "primordial fauna" at the base of the Cambrian slates near Skrej. Some time later. Prof. Kusta, of Rakonitz, found fossils in the strata below, which had been ranked as pre-Cambrian or Azoic by Barrande. Great interest naturally attached to this discovery of a so-called "ante-primordial fauna," and Prof. Kusta and others wrote several papers upon the fossils. Dr. Jahn, of the Austrian Survey, went for three weeks last summer to the same district, and found that many of the fossils occurred in strata interbedded with the Cambrian series, and had no right to be called " ante-primordial." In a short preliminary note sent to the Verhandluugen der k. k. geol. Reichsanstalt, September 30, 1893, he writes that the oldest of the " ante-primordial" horizons of Kusta rests above Cambrian shales and interbedded with them, while the so-called " youngest ante-primordial horizon " is in reality the oldest, resting immediately below the Cambrian of Barrande, and con- taining a similar fauna. As Dr. Jahn's statements rest on good stratigraphical evidence, we can only conclude that the "oldest fossiliferous rocks in Europe" have yet to be found. The Geological Commission of the Natural Science Society of Switzerland has just published vol. xxi. part i. of the "Con- tributions to the Geological Map of Switzerland" ("Beitrage zur Geol. Karte der Schweiz." Bern, 1893.) This part em- braces the wide district of the Bernese Oberland Alps. The author. Dr. Edmund von Fellenberg, was always an enthusi- astic mountain climber, and between the years 1862-1872 dis- tinguished himself as a pioneer of some of the most difficult ascents in the Bernese group. He was asked, in 1872, by the Geological Commission to make a systematic geological survey of the district, and now gives in this volume of the "Beitrage'' the complete result of his scientific labours. The maps which he used in surveying were on the scale of i : 50,000 ; those have been reduced to the scale of the Dufour map, i : 100,000. The value of the work is greatly enhanced by an elaborate " Atlas," containing eighteen plates and a map showing the routes under- taken by the author. The plates include an important series of coloured geological sections through the Breithorn, the Aletsch- horn, the Jungfrau and the Finsteraarhorn mountains, a great number of sketches from nature illustrating in detail the geo- logical features of the landscape, and several prints from photo 298 NA TURE [January 25, 1894 graphs taken mainly for the purpose of demonstrating the intri- cate folding of the rocks and the varied effects of weathering in those glaciated Alpine areas. The "Atlas" merits a wider circle of admirers than merely the students of geology, for it reveals in the most effective manner the structure of one of the 'grandest regions of the Alps, a region which must be familiar to ail English lovers of the Swiss lakes, Grindelwald, and the Rhoue Valley. The Electrician of January 19 contains an interesting coloured map showing; the electric-lighting districts of London. Our contemporary says that the chief alteration in the map, as com- pared with the one of last year, is the extension of the city mains. The Chelsea Company has run down the King's Road, but the London Company has followed it, and is in active com- petition. The Metropolitan Company and St. Pancras Vestry have thrown out a branch or two, but the additions to the mains have, on the whole, been made by " drawing in " additional conductors rather than by advance into new streets. In another place we read that the Owens College Physical Laboratory is prepared to test a limited number of electrical instruments free of charge. The testing will be carried out by qualified assistants, the electrical standards will be compared from time to time with those of the Board of Trade, and every effort will be made to ensure accuracy. All enquiries should be addressed to Prof. Arthur Schuster, Owens College, and headed "Physical Laboratory Testing Department.'" The recently published report of the Magnetic Observatory of Copenhagen for 1892 contains a description of the work which has been carried on in the " field," as well as tables con- taining the results of the observations made at the observatory. The tables given include the values of the declination, hori- zontal force, and vertical force for every hour for each day of the year (1892) as obtained from the self-recording instruments, the absolute value of the readings having been determined on five or six days in each month. There are also tables giving the diurnal variations which have been derived from measurements made on selected quiet days. Observations made in the island of Bornholm show that there exists considerable magnetic dis- turbance, for while if there were no disturbance the declination would vary between 9° 11' on the east _side and 9° 29' on the west, it is found that at some places on the east shore the de- clination is 11°, and at one spot near the middle of the west shore values as low as 7° have been obtained. Observations which had been made in 1892 showed that the true lines of equal declination were in many cases closed curves, and thus the dis- turbances must extend to the surrounding water. With a view to tracing the isogonals after they leave the land, M. Hammer has made a series of declination observations on a raft which had been made without any iron, and a map showing the isogonals obtained is published in the report. The greater part of the island consists of granite containing iron, and a small piece of the rock when brought near the box containing the declination needle is found to give a deflection of from a few minutes to two degrees. A map showing by means of arrows the disturbances in horizontal force, indicates in a very clear and striking manner that there exists a strong centre of force a little to the north of the middle of the island. A special series of observations have enabled the magnetic effect of a number of dykes consisting of diabase 'to be shown and measured, a full account of v/hich will be published in the Bulletin de I'Acadimie Koyale de Danc- mar/c. The occurrence of true dropsical diseases of plants, not due to the activity of micro-organisms, has been placed beyond doubt by Mr. G. F. Atkinson, of Cornell University. Such a disease was noticed, as we read in a paper on the subject contributed to Science, in some tomatoes grown in the forcing-houses of NO. 1265, VOL. 49] the University. The leaves were strongly curled, and the veins- on the under side were swollen and whitened. The cells in the affected areas were stretched radially to an enormous extent. Finally they burst, giving out a large quantity of water, and leaving elongated, depressed, and blackened areas in various stages of decomposition. Inoculations of healthy plants with cultures from the diseased areas gave no result, and no fungi of ordinary dimensions could be discovered microscopically in the early stages of the trouble. The disease was purely physio- logical, and 'due to the preponderance of root-pressure over transpiration in the moist and warm atmosphere of the forcing - house, the leaves not being able to give out the moisture absorbed by the roots. The disease could be brought on arti- ficially by subjecting healthy plants to pressure. Apple trees subjected to severe pruning during the winter suffered from a similar disease when growth began in the spring. The second part of vol. i. of "Contributions from the Botanical Laboratory of the University of Pennsylvania" is entirely occupied by a paper by Dr. J- W. Harshberger, entitled "Maize: a botanical and economic study." After a description of the anatomical and histological characters of Zea Mays, its origin is discussed at length, and this is followed by a treatise on its geographical distribution, and on its agriculture and economic value. The evidence appears to point, beyond a doubt, to the original home of the maize being Central Mexico, and not Asia, as some have supposed. The difficulty of satisfactorily differentiating between the typhoid bacillus and its constant companion the B. coli communis still remains, although numerous devices have from time to time been introduced, which have materially assisted in the separate diagnosis of these two bacilli. One of the most recent is that lately described by Dr. Schild {Centralblatt f. Bakterio- logie, vol, xiv. p. 717), and is based upon the greater sensitive- ness exhibited by the typhoid bacillus over the colon bacillus to the action of formalin vapour. Thus, whilst well-developed gelatine-cultures of the typhoid bacillus were destroyed when exposed for seventy-five minutes to the vapour derived from 5 c.c. of formalin, the B. coli communis was usually still alive after being similarly treated for two hours. The difference in this respect between these two organisms was still more strik- ingly brought out in their behaviour in broth to which formalin had been added, the typhoid bacillus being unable to grow in the presence of i : 15,000 parts of formalin, whilst the colon bacillus developed vigorously in broth containing i : 3000 parts. In order to turn this characteristic to practical account in the separate identification of the typhoid bacillus, Dr. Schild recom- mends that test-tubes containing 7 c.c. of sterile neutral broth- should each receive o'l c.c of a i per cent, solution of formalin, so that the formalin is present in the proportion of I : 7000 ; the inoculations are then made, and the tubes kept at 37° C. If typhoid bacilli are present, the solutions remain quite clear ; but if the colon bacillus has been introduced, turbidity is apparent in twenty-four hours. By this method Dr. Schild states that he was able to separately identify the typhoid and colon bacilli in a sample of well water sent to him from a place where an epidemic of typhoid fever was prevailing. A LARGE portion of the Bulletin of the Royal Gardens, Kew, Nos. 82 and 83, is occupied by an interesting report from Dr. King, of Calcutta, of a botanical exploration of the Sikkim- Tibet frontier, undertaken by Mr. G. A. Gammie. Other papers are on " Poling in Agave Plants," " Coffee Cultivation in the New World," and "The Resources of British Honduras. " A CATALOGUE has been issued showing the works on natural history, mathematical, and physical sciences, offered for sale by Mr. Bernard Quaritch. January 25, 1894] NATURE 299 The number of the Victorian Naturalist iorViecemhtx, 1893, affords evidence of the activity of the study of various branches of natural history in that colony. We have received a paper, reprinted from the Canadiaii Record of Science, October, 1893, in which Mr. J. F. Whiteaves gives descriptions of two new species of ammonites from the Cretaceous rocks of the Queen Charlotte Islands. Dr. J. Bergeohm has sent us apamphlet entitled " Entwurf einer neuen Integral-rechnung," Heft ii., in which he develops a new method for the calculation of integrals, and deals with irrationals, exponentials, logarithmic and cyclometric integrals, using his system. Messrs. C. Griffix and Co. have 'published a "Pocket- Book of Marine Engineering Rules and Tables, " for the use of all engaged in the design and construction of marine machinery, naval and mercantile. The authors of the book are Mr. A. E. Seaton and Mr. H. M. Rounthwaite. To those who purpose a tour in the Bernese Oberland, we can specially recommend a series of papers published in the re- cent numbers (211-214) of Eiiropdische Wanderbilder (Zurich, 1893.) They are written by F. Ebersold, and give a general sketch of the country, as well as information about the new mountain-railways. Bulletin No. 46 of the U.S. National Museum contains the collected writings, both published and unpublished, of the late Mr. C. H. BoUman, on the Myriapoda of North America. The papers have been edited by Prof. L. M. Underwood, who has added some notes and an introductory review of the literature of the North American Myriapods. We are pleased to see that the Yorkshire Weekly Post is now publishing weekly a well-written and accurate article dealing with the different branches of natural history, and in which the subject of ornithology and entomology in relation to agriculture is dealt with in a practical manner ; miscellaneous science notes are also included, and their sources properly acknowledged. The "School Calendar and Handbook of Examinations and Open Scholarships,'' published by Messrs. Whittaker and Co., is now in its eighth year of issue. The book contains a mass of information concerning the conditions of entrance scholarships and fees in all our Public Schools, Universities, and educational institutions, and is invaluable to the schoolmaster and teacher. A SECOND edition, revised and enlarged, has been issued of the Guide to Museum No. IH. of Economic Botany at the Royal Gardens, Kew. The collection in this museum chiefly consists of specimens of timber, arranged in groups according to the countries producing them. The Guide contains much usetul information with regard to the scientific character and economic value of the specimens. Messrs. Macmillan and Co. hope to publish in a few days " The Theory of Heat," by Mr. Thomas Preston, Professor of Natural Philosophy, University College, Dublin. In this volume the science of heat is treated in a comprehensive manner, both in its experimental and theoretical aspects. The whole subject has been kept in view rather than the require- ments of a particular examination, and the method of exposition is such that the general reader will be interested as well as the specialist. TwE. nvivahtr oi A}imiario publicaJo pelo Observatorio do Rio de Janeiro, which we have recently received, is the ninth that has been published, and is for the year 1893. In addition to various ephemerides and astronomical data, the volume contains some useful metereological tables with data relating to the climatology and physics of the globe, tables for calculating altitudes from barometric observations, vapour tension, and several others for the use of physicists and those engaged in NO. 1265, VOL. 49] chemistry. The fifth and concluding part gives the latitude and longtitude of the chief places in Brazil, with the heights in metres of the chief cities above the sea-level, terminating with a brief sketch of the climate of Brazil in general. The tables seem all to have been carefully constructed and brought up to date. "A History of Scandinavian Fishes," by B. Fries, C. U. Ekstrom, and C. Sundevall, with coloured plates by W. von Wright, made its first appearance in 1836, and though it was issued in an incomplete form, it gained a wide reputation. As several unpublished paintings by v. Wright were preserved in the archives of the Royal Swedish Academy of Science, and the text of the work could be brought up to date with comparatively slight alterations, Messrs. Sampson Low, Marston, and Co. have decided to issue a new edition. The work of revision and enlargement has been entrusted to Prof. F. A. Smitt, the present occupier of Sundevall's post at the Royal Zoological Museum. The former edition contained descriptions and figures of 64 species ; the new one will comprise about 220 Scandina- vian species, besides several forms from neighbouring parts, and of special interest to the Scandinavian faunist. Thus the great majority of the fishes of Europe as well as of the Arctic piscine species will be represented in the work, and the new edition will be about four times as comprehensive as the former one. The interesting di-nitro derivative of marsh gas, CH2(N02)2 has been isolated in the pure state by Dr. Paul Duden, in the chemical laboratory of the University of Jena. As might be ex- pected, it is a substance of little stability, and many of its metallic derivatives or salts, for the parent substance is endowed with acid properties, are dangerously explosive. The compound itself cannot be preserved, even in sealed tubes, for many hours, becoming converted into gaseous products of decomposi- tion, but its potassium salt, CHK(N02)2, is much more stable, and may be kept unchanged for months. The preparation of the acid is best achieved from this potassium salt, by decompos- ing it at a low temperature with dilute sulphuric acid. The potassium salt may be readily obtained by reducing the di- bromine derivative of dinitromethane by means of an alkaline solution of arsenious oxide. The di-bromine derivative is a substance obtained by distilling tribromaniline with nitric acid. It is added in small portions at a time to the strongly-cooled aqueous solution of the alkaline arsenite, in order to mitigate the violence of the reaction. After the completion of the change the potassium salt is deposited in small bright yellow crystals, which by recrystallisation from hot water yield the salt in perfectly pure large monoclinic prisms. The aqueous solu- tion of these crystals is neutral to litmus, the strong acid being neutralised by the introduction of one atom of potassium. At a temperature near 205° the crystals detonate loudly, evolving a mixture of nitrogen, nitric oxide, and carbon dioxide. Concen- trated acids violently decompose the crystals with evolution of red nitrous fumes, but if they are suspended in iced water, and a layer of ether is spread over the surface, they are quietly acted upon by dilute sulphuric acid with liberation of free dinitro- methane, as above mentioned. The latter substance is dissolved by the ether, and the dried ethereal solution yields it after evapora- tion of tha ether as a yellowish liquid of peculiar acid odour, and which soon begins to effervesce, owing to the elimination of products of decomposition. The free compound may be pre- served much longer in ethereal or benzene solution. The silver salt, CHAg(N02)2, is the most remarkable of its salts. It crystal- lises in bright green tabular crystals, which are extremely sensi- tive to light. Mere boiling of their aqueous solution is suffi- cient to produce deposition of metallic silver. Either upon warming or by contact with a drop of hydrochloric acid, the crystals explode with great violence. Upon reduction of the iced solution of the potassium salt by sodium amalgam, a curious 300 NA TURE [January 25, 1894 substance of the composition CHoNoO is produced, which ex- plodes below the temperature of boiling water. An account of the work is contributed to the current Bcrichte. A NEW mode of preparing methylamine and ethylamine, based upon the reduction of the remarkable ammoniacal com- ivcands of formaldehyde and acetaldehyde, is described by MM. Trillat and FayoUat in the current issue of the Bulletin de la Societe Chimique. When aqueous solutions of formal- dehyde and ammonia are mixed, a vigorous reaction occurs with considerable rise of temperature, and the evaporated liquid deposits hexagonal needles of the ammoniacal compound, the composition of which has been given by several chemists as N4(CH.,)g. It is now shown that the reaction can be much more simply explained in the light of the behaviour of the com- pound upon reduction, by accepting the simpler formula N2(CH2)3. By the direct union of equal molecules of formal- dehyde and ammonia, the substance CHg : NH, methylene imide, is supposed to be produced, two molecules of which then combine with another molecule of formaldehyde to pro- /N : CH2 duce the compound in question CHj^ with elimina- \N:CH2 tion of a molecule of water. This substance is rapidly broken up upon treatment with zinc dust and hydrochloric acid, and subsequent addition of caustic alkali, with liberation of methyl- amine. It is probable that four atoms of hydrogen are taken up during the reduction, thus fully saturating the molecule and .NH -CHa forming the compound CHo<^ ; this latter substance NH • CHs then becomes converted into formaldehyde and methylamine by assimilation of water during the saponification with alkali. In order to prepare methylamine it is unnecessary to isolate the i ammoniacal compound ; formaldehyde and ammonia are simply ] mixed and immediately treated with zinc dust and dilute hydro- i chloric acid. The liquid is then saturated with caustic alkali, and the methylamine, together with excess of ammonia, ex- pelled by a current of steam and received in dilute hydrochloric acid. Upon evaporation of the acid solution, a mixture of sal- ammoniac and methylamine hydrochloride is left, and the latter may readily be extracted by absolute alcohol. A second dis- tillation of the methylamine hydrochloride with caustic alkali yields pure methylamine. Ethylamine may be similarly pre- pared by reduction and saponification of the well-known com- pound of acetaldehyde and ammonia. The additions to the Zoological Society's Gardens during the past week include a Himalayan Monkey {Macacus assa- mensis, ? ) from Sikhim, presented by Capt. Edmund A. Grubbe ; a Bonnet Monkey {Macacus sinicus, 9 ) from India, presented by the Rev. Thomas Rickards ; two Japanese Pheasants {P/iasiamcs versicolor, $ ?) from Japan, presented by Mr. W. Rudge Rootes ; two Spanish Terrapins (C/^;«»?jj/^ leprosd) from Melilla, North Africa, presented by Mr. Bennet Burleigh ; a Dwarf Chameleon {Chamaleon pumi- lus) from South Africa, presented by Mr. E. Wingate ; five Gigantic Salamanders {Megalabatrachus maximus) from Japan, deposited ; a Cuvier's Podargus {Podargus cuvieri) from Australia, purchased. OUR ASTRONOMICAL COLUMN. Report of the Wolsingham Observatory. — The Rev. T. E. Espin is to be congratulated upon the large amount of good work he is carrying on at the Wolsingham Observatory. The system he adopts of sending out circulars announcing any new or strange phenomenon observed by him, is one that could be followed with advantage in many other observatories, for NO- 1265, VOL. 49] astronomers thus have their attention drawn to interesting objects that they might otherwise have overlooked. We have noted the contents of these circulars from time to time, and the report that has just been issued sums up the work done in 1893. Sweeps for stars with remarkable spectra were made on fifty- three nights during the year. The total number of stars detected was 578, of which 489 were found to be new to Argelander's Chart. A thorough examination was made of the Red Region in Cygnus, and several new objects detected. Many nebulous objects were also met with, fifteen of which are not contained in the New General Catalogue. The Compton 8-inch photo- graphic telescope was used during the year for photographing stars suspected of variation. The variability of four stars was confirmed, and three new variables were detected. Mr. Espia points out that it is much to be desired that the Compton instru- ment should be mounted separately, so that the large telescope could be devoted exclusively to spectroscopic work. During the latter part of the year photographic work was almost entirely discontinued, on account of the necessity of using the large telescope for spectroscopic observations. Early in last year the Observatory sustained a severe loss in the sudden death of Miss Brook, who equipped the Observatory with meteorological instruments, and generously defrayed all the incidental expenses. We hope a new benefactor will soon spring up and supply the much-needed mounting for the photographic telescope. Anomalous Appearance of Jupiter's First Satellite. — It will be remembered that in September 1890, Profs. Burn- ham and Barnard saw the first satellite of Jupiter, with the 12- inch telescope of the Lick Observatory, crossing the disc of the planet as a small dark double spot like a close double star [Astr. Nach. No. 2995). Various suggestions were made to account for this anamalous appearance, and it was even supposed for a time that the satellite was actually duplex. The explanation that found greatest favour in the eyes of astronomers, however, was that there was a permanent bright belt around the satellite, approximately parallel to Jupiter's belts, while the poles of this "Galilean star" are of a dusky hue. A repetition of the phenomenon was observed by Prof. Barnard, on September 25 of last year, with the 36-inch Lick telescope {Astr. Nach. No. 3206). The observations show that beyond doubt the second ex- planation is the true one. The satellite apparently rotates on an- axis nearly perpendicular to the plane of its orbit. When it is over a portion of the Jovian disc as dark as its own polar regions, it appears more or less elongated, and parallel to the belts of Jupiter. But when it is projected on a brighter region it appears double, with the components in a line nearly vertical to Jupiter's equator, the dusky polar regions alone being visible. The smaller size of the southern component is very probably a perspective effect produced by a tilt towards Jupiter of the satellite's south pole. Astronomy and Astro-Physics.— The January number of Astronomy and Astro- Physics maintains the high reputation of that journal. Prof. W. H. Pickering describes a number of different telescope mountings in use in England and France, and compares them with some of those employed on the other side of the Atlantic. The history and work of the National Argentine Observatory forms the subject of a paper by Mr. J. M. Thorne, the director. The immense number of observ- ations made in that Observatory testifies to the zeal of the astronomers as well as to the generally cloudless sky of Cordoba. Prof. S. W. Burnham gives a descriptive list of so- called double stars, of which the change of position is the result of proper motion. An important paper is contributed by Prof. F. H. Bigelow on the polar radiation from the sun, and its influence in forming the high and low atmospheric pressures of the United States. Prof. E. C. Pickering gives a brief account of the new star that appeared in the constellation Norma last summer, and was discovered by Mrs. Fleming on October 26, while examining a photograph of the spectra of the stars in its vicinity. An excellent plate accompanies the account, showing that the spectra of Nova Aurigje and Nova NormK were exactly alike, line for line. Among other articles of interest is one on Prof. Langley's recent progress in bolo- meter work at the Smithsonian Astro-Physical Observatory, and another on the object-glass grating, by Mr. L. E. Jewell. In the latter paper it is proposed to construct a photographic object-glass grating for use instead of the object-glass prism m obtaining photographs of stellar spectra. The plan suggested is to photograph a series of images of a long narrow slit. This January 25, 1894] NA TURE 301 can be done by having a slit and photographic lens fixed and placing the sensitised plate upon the carriage of a dividing engine. The plate is moved along with the carriage, and when it has been exposed to the slit a desired number of times it is developed and fixed, the result being a photographic grating. GEOGRAPHICAL NOTES. A TELEGRAM from Zanzibar, dated January l6, states that over a hundred deserters from Mr. Astor Chanler's expedition had reached the coast and reported that he was left with only eighteen men at Daicho. It has already been mentioned (Nature, vol. xlix. p. 112) that the expedition was deprived of Lieutenant von Hohnel's services, by an accident. We trust that Mr. Chanler may be able to reorganise his expedition, and push into the unknown country on the borders of which he has been so long detained. The Times correspondent at St. Petersburg states that Mr. F. G. Jackson, after testing his sledges and other appliances in the neighbourhood of the Yugor Strait, is returning 10 England via Lapland, and that he has not been in the Yalmal peninsula. The proposed North Polar expedition via Franz Josef Land, will be, if it starts, as is expected, this year, the fourth in the field. The others are the private American expedition under Mr. Peary, working from the north of Greenland ; the private Norwegian expedition of Mr. Ekroll, which left the north coast of Spitzbergen in summer, relying on a new convertible sledge- boat ; and Yir. Nansen's expedition, drifting northward from the neighbourhood of the New Siberian Islands. The death is announced, on January 20, of General SirC. P. Beauchamp Walker, the Foreign Secretary of the Royal Geo- graphical Society. The memory of Prince Henry the Navigator, to whose per- sistent efforts the modern revival of oceanic exploration was mainly due, is to be honoured by the celebration of the 500th anniversary of his birth, in March, with great festivities at Oporto. The proceedings will to a certain extent resemble the Columbus celebration recently held in Spain. The event they are to commemorate was even more important, since the Portuguese explorers, as a direct consequence of the encouragement of the half-English prince, discovered the ocean-road to India, and incidentally the coast of South America also, independently of the Spanish voyagers who followed in Columbus' track. Several recent experiments on oceanic currents by means of floats have been noticed in the newspapers within the last fort- night. Mr. J. E. Muddock states in the Times that a corked soda-water bottle containing an addressed slip of paper which was thrown overboard by him off the entrance to the Strait of Belleisle, on July 12, 1892, was picked up on November 28, 1893, on the Norwegian coast near Kvarno, in latitude 61° 4' N. The bottle was launched farther north than any of those placed in the water by the Prince of Monaco, but there is no clue to its course beyond that of the time elapsing before it was found, 485 days. Mr. Muddock assumes that the drift was 4000 miles, but the direct distance by sea is only 2500 miles, although it is probable that the bottle drifted south in the Labrador current before turning north-eastward with the Gulf Stream. Mr. Ballingall, of Largo, writes to the Scotsman that he launched a cork-covered bottle at Largo, on the Firth of Forth, on November 22, which was picked up at Akre, on the Norwegian coast (lat. 59° 19'), 460 miles distant, on December 29. Being only thirty-seven days in the water, the bottle must have drifted at the rate of not less than twelve miles a day. The bottle pro- bably floated high and was helped by westerly winds ; but in any case the rate of movement is rapid, and if the direction of the current was that usually assumed, first southward, then east, and finally north, the velocity is very remarkable. EARTH MOVEMENTS. T7 VERY year, every day, and possibly every hour, the physi- -^-^ cist and observer of nature discovers something which attracts attention, causes wonder, and aftords material for dis- cussion At one moment we are invited to see solidified air, at another to listen to telephonic messages that are being trans- mitted without a wire, or to pause with astonishment before a NO. 1265, VOL. 49] pen which is producing a fac-simile of the writing, the sketches, and the erasures of a person who may be in a distant city. Not a day passes without a new creation or discovery, and novelties for our edification and instruction are brought to our notice at the meetings of societies and conventions which from time to time are held in various parts of the world. At the last meeting of the British Association, held in Nottingham, the attention of members was called to the reports of two committees summaris- ing a series of facts which seem destined to open a new field in the science which treats of movements in the crust of our earth. For thirteen years one of these committees has devoted its attention to the volcanic and seismic phenomena of Japan, with the result that our knowledge of these subjects has been con- siderably extended. Now we observe that earthquakes, which are referred to as catastrophes in the processes of mountain formation and the elevation or depression along our coast-lines, are spoken of as "vulgar disturbances" which interfere with the observation of certain earth movements which are probably as common to England as they are to Japan. Earthquake observations, although still capable of yielding much that is new, are for the present relegated to a subordinate position, while the study of a tide-like movement of the surface of our earth, which has been observed in Germany and Japan, earth tremors, and a variety of other movements, which we are assured are continually happening beneath our feet, are to take their place. Only in a few countries do earthquakes occur with_ sufficient frequency to make them worthy of serious attention. The new movements to which we are introduced are occurring at all times and in all countries, and we are asked to picture our continents as surfaces with a configuration that is always changing. We are told that every twenty-four hours the ground on which we live is gently tilted, so that the buildings in our cities, and the tall chimneys in our manufacturing towns, are slightly inclined like stalks of corn bent over by a steady breeze. The greatest tilting takes place during the night ; in the morning all return to the vertical. Why such a movement should exist, we are not told. All that we hear, is that it is too large for a terrain tide produced by lunar attraction. In Japan it appears possible that it may prove to be a concertina-like opening and shutting of the crumpled strata forming a range of mountains. To determine whether this intermittent puckering of strata, which would mean a daily increase and decrease in the height of mountains, explains the variability in the level of districts where observations have been made, is a matter for future investigation. A problem which suggests itself in connection with this novel work will be to determine the limiting change in inclination, which we will assume means rock-bending, that culminates in sudden fracture and a jar, causing an earthquake. Earthquake prophets up to the present appear to have lived upon the reputation of a few correct guesses, the nonoccurrence of which would have been contrary to the laws of chance. As ob- servation has shown us that a very large proportion of our earth- quakes, like those which occur in the Himalayas and the Alps, and even those which occur in volcanic Japan, are produced by faulting or sudden breakages in crumpling strata, rather than by explosions at volcanic foci, it would seem that a study of the bending which leads to fracture would be a legitimate method to approach the vexed question of earthquake prediction. Another class of movements to which our attention is called are our old acquaintances, the microseismic or tremor storms, which are now defined as long flat waves which give to the surface of our earth a movement not unlike the swell we so often see upon an ocean. Such disturbances are particularly notice- able whenever a district is crossed by a steep barometrical gradient. It is not unlikely that these movements, which are appreciable at considerable depths, have an effect upon the escape of fire-damp at our collieries, that they may influence the accuracy of delicate weighing operations — as, for example, during the determination of standard weights — that they may interfere with gravitational observations, and that they are a neglected source of error in certain classes of astro- nomical work. Our attention is next directed to the bending effect produced in certain districts by the rise and fall of the barometer, certain areas under variations in atmospheric pres- sure behaving as if they were the vacuum chambers of an aneroid. Then there are the earthquakes of comparatively restful countries like our own. A large fault, by which mountains are suddenly lowered and va' leys compressed, takes place in a distant country 302 NA TURE [January 25, 1894 like Japan. Near the origin of the dislocation the shaking brings down forests from the mountain-sides, and the neighbour- ing district is devastated. As the waves spread they become less and less violent until, after radiating a few hundred miles, they are no longer appreciable to our senses. But the earth- quake has not ended. As long, flat, easy undulations it con- tinues on until it has spread over the whole surface of our globe. The waves passing under Asia and Europe reach England first, while those crossing the meridian of our Antipodes and North America arrive somewhat later. At Potsdam, Wilhelmshaven, and in Japan, waves of this order have often been recorded, but for the rest of the world they are thus far unrecognised. Great cities like London and New York are often rocked gently to and fro ; but these world-wide movements, which may be utilised in connection with the determination of physical con- stants relating to the rigidity of our planet's crust, because they are so gentle, have escaped attention. That the earth is breathing, that the tall buildings upon its surface are continually being moved to and fro, like the masts of ships upon an ocean, are at present facts which have received but little recognition. Spasmodic movements which ruin cities attract attention for the moment, but when the dead are buried, and the survivors have rebuilt their homes, all is soon forgotten. It seems desirable that more should be done to advance our knowledge of the exact nature of all earth-move- ments, by establishing seismological observatories, or at least •preventing those in existence from sinking to decay. J. Milne. THE CLIMATIC AND NATIONAL-ECONOMIC INFLUENCE OF FORESTS. i TT is to German scientific men that we owe the first steps taken 1 in order to ascertain data concerning the actual climatic effects of forests. Since then, however, most civilised countries, j except Britain, have been actively engaged in the collection of j accurate data concerning this very important subject. So far as . those data have yet been collated and compared they lead to the following results. It was not until the year 1867 that exact scientific observa- vations were undertaken on an extensive scale to determine the actual influence which forests have in modifying the temperature of the air and of the soil within their own areas and over the sur- rounding tracts of country, and the first results were published in Ebermayers celebrated work. Die pliysikalischeti Eimvirkitngen des IValdes aiif Liiftc mid Boden, 1873. I. As regJ.rds Atmospheric Temperature. — The average results of observations made during ten years (1876-85) throughout nearly the whole of Germany, and in parts of France and Switzerland, in different kinds of forest, at heights above the sea-level varying from 10 to 3C00 feet, and at latitudes varying from 472" to 55i^ prove conclusively that in general the annual average temperature within forests growing in closed canopy is lower than in the open, although the crowns of the trees are on the whole a little warmer in winter. The difference is greatest in summer, least in winter, and about midway between these extremes in spring and autumn ; the mean annual difference, however, seldom amounts to over i°Fahr. near the ground, and is scarcely V in the crowns. The prevention of insolation of the soil during the long hot days of summer, and the rapid transpiration taking place through the foliage, exert a greater influence on the atmospheric temperature than can be ascribed to shelter from wind and to decrease of nocturnal radiation. The ohservatioas recorded prove (i) that the variations between the temperatures of the trees themselves and the air in the open exceed those between the woodland air and the latter except during winter, (2) that they are largest during the most active period of vegetation in summer, and (3) that they are greater in spring, when the circulation of sap begins, than during the autumn months, when vitality becomes sluggish and dormant. In the crown of the trees, where insolation by day and radiation by night make their full influence felt, the difference in the daily average over the whole year is less than it is near the ground. In winter it averages little either above or below o' , and in summer usually about the half of the reading at 5 ft. above the ground. Observations made in Southern Germany establish the fact that in the forests it is cooler during the day and warmer during the night than in the open. During the night the trees interfere with the radiation of heat, and in the day-time the shade afforded by the crowns keeps the air from being rapidly warmed by the sun's rays. These influences are naturally strongest during spring, summer, and autumn, when foliage is most abundant, whilst in winter the coniferous forests with evergreen foliage are milder than deciduous forests. Owing to these differences in temperature, beneficial currents of air are induced between the forests and the open country, which follow the same law as obtains in regard to land and sea breezes. During the day the cooler and moister air of the forest sets outwards to take the place of the heated air ascending in the open ; at night the current sets in from the open, cooled by radiation, towards the forest. The statistics, upon which these deductions are based, prove that the immediate action of forests is to modify the daily maxima and minima of atmospheric temperature, whence it may be deduced that a comparison of the absolute ex- tremes of temperature during the year must exhibit definitely the sum total of the influence exerted by forests on the temperature of the atmosphere. This modification of the extremes of temperature, which are bad alike for man and beast, and also for agricultural operations, is of immense importance from a national-economic point of view, since many places that were once fertile are now little better than barren wastes in consequence of the reckless denudation of forest. In registering the data, however, it was observed that the geographical position, and the exposure of the forests to winds, exerted a certain amount of modifying influence in lessening the differences, and there are reasons to believe that towards the crown the forest temperature in winter is considerably higher than down nearer the ground. It was found, too, that certain forest trees exerted greater influence than others in consequence of the density of their foliage ; for beech forests in summer exert, through their dense foliage and complete canopy, a considerably greater influence in diminishing the extremes of temperature than forests of spruce or Scots pine, although after defoliation their influence is merely similar to that of the pine forest, and only half so great as that of the more densely foliaged spruce. 2. As regards Soil-Temperatitre. — The influence exerted on the soil temperature by forests growing in close canopy is of considerable importance, especially with regard to the soil- moisture. The observations made concerning this point seem to make it clear that the mean annual temperature of the soil in the forest is at all the above depths of observation cooler than in the open, and that the differences are greatest in summer, about the mean in spring and autumn, and very small in winter. In countries with warm summers this reduction of the soil-temperature over large areas by means of forest growth has a decidedly beneficial result. . According to observations made in Wiirtemberg, the difference between the maxima of soil-temperature in forests and in the open can extend so far as up to 14° Fahr. It was also found that the daily differences in soil-temperature varied according to the season of the year, but that throughout nearly the whole year the upper layers of soil in the open were warmer in the afternoon than in the forenoon, whereas in the forest the variations were inconsiderable. As with regard to the atmospheric temperature, the influence of the forest trees in equalising the soil-temperature throughout the year is greatest in the case of trees whose foliage is densest, spruce heading the list. 3. As regards the Degree of Atmospheric Humidity. — Ob- servations recorded throughout Central Germany show that as regards the absolute humidity of the air forests have no ap- preciable climatic effect, for the annual averages showed merely slight traces of differences at 5 feet above the soil. The differences between the relative humidity oj the air in forests and in the open are, as might be expected, greatest in summer, although very different results as regard variations are obtained with changes of altitude and of other physical conditions. The results of the various series of observations, corrected so as to eliminate, so far as possible, local differences due to altitude and other physical dissimilarities in the various meteoro- logical stations, show that the mean annual relative humidity 01 woodland air is from 32 to 10 per cent, greater than that of air in the open, but that the difference varies greatly according to the season of the year, being greatest in summer and autumn, and least in winter and spring. They show, too, that large NO. 1265, VOL. 49] January 25, 1894 J NA rURE 303 areas covered with spruce will be moister, as well as cooler, than those under woods of less densely foliaged species of trees. In Bavaria it was found that in summer, in consequence of the density of the foliage in beech forests during the most active period of growth, the difference even amounted to 13-6 per cent. of saturation over the relative humidity in the open. 4. As regards t/ie Pftripiiaiion of Aqueous Vapour. — It has been shown above, not only that the atmosphere within the forest is cooler than in the open, but also that the temperature of the trees themselves is lower, especially in sununer, than the air surrounding them ; hence, when a current of air is wafted from the open into the forest, and comes in contact with the cooler trees, its temperature is reduced, and it is brought nearer to the point of saturation, i.^. its relative humidity increases. But if this air was already in the open at, or near, the point of saturation, then the effect of the cooling process is that a certain amount of surplus moisture beyond the aqueous vapour that can be held by the air up to a point of saturation at its reduced temperature must be released and precipitated in the form of dew. Woodlands, therefore, act as condensers of atmospheric moisture, and decrease the absolute humidity of the air whilst increasing its relative humidity ; and in addition to this, they increase the humidity of the air by transpiration from the leaves, whilst the sap is being rendered available for structural pur- poses, and the work of assimilation is proceeding. Endeavours have been made to establish, by means of careful observations, the effect of forests in regard to the precipitation of aqueous vapour in the form of dew or rain, but the results are often of so conflicting a nature that, up till the present, safe deductions caiiDOt be drawn. In order to compare observa- tions made in the forests with those made at the usual meteoro- logical stations m the open, a correction would in each case be necessary to reduce the localities to the same sea-level, as air cools in rising and increases in relative humidity, i.e. it approaches the point at which it must precipitate some of the aqueous vapour held by it. Hence rainfall generally increases with the height of a locality above the sea-level, although no direct proportional increase can be proved. It fluctuates with the geographical position and the varying physical conditions of each point of observation, whilst variations in the direction of the moist winds of the locality also militate against the collection of reliable data for comparison with readings made in other localities. The mean of the readings at 192 points of observation in Germany, corrected as carefully as possible with reference to these causes of difference, do not seem capable of giving any more exact inference than the general statement, that at high altitudes large extents of forest may considerably increase the local rainfall. As regards the quantity of rainfall and snow- fall which is intercepted in forests by the leaves, branches, and stems of the trees, the observations made in Switzerland, Prussia, and Bavaria show that nearly one-fourth of all the precipitations of aqueous vapour is intercepted by the forest trees, and is given off again by evaporation, or is gradually conducted down the stems to the soil. In lofty forest-clad regions the mechanical action of the rains on the surface-soil is thus very much modified. By means of their lower temperature, their greater relative humidity, and the mechanical obstruction they offer to the movements of currents of air, extensive forests act decidedly as condensers of the aqueous vapour contained in the atmosphere, and their influence in this respect is more marked at high altitudes and in mountainous districts than on plains or near the sea-coast, where other physical factors come into competi- tion with and modify it. Further data are still requisite to enable us to determine with anything like certainty that forests directly cause increase of precipitations irrespective of such local considerations as the ruling direction of winds and pecu- liarities of situation ; the generally accepted dictum is, however, that in the vicinity of extensive forests the rainfall is greater than at other localities under otherwise similar physical conditions. In portions of the Russian Steppes, planted up nearly 50 years ago, the inhabitants assert that the summer rainfall has considerably increased, and that the danger to crops from drought is not so great as formerly, whilst the villages are also protected by the forest from the violence of the winter storms. In summarising and criticising this point Prof. Endres of Karlsruhe remarks as follows^ : — 'Conrad, Elster, Lexis, and Loening's wissenschafcen," 1S92, vol. iii. page 6oS. NO. 1265. VOL. 49] '■ Handworterbuch der Staats- " The data furnished from tropical countries must be accepted with the greatest caution, and in any case they afford no con- clusive deductions for European circumstances. Blandford reports from India (Meteorological Journal, 1888) that in an area ot 61,000 square miles, which was formerly denuded of woodlands, but has been planted up again from 1875, ^he rainfall has increased 12 percent, since then. But H. Gannet (ll'ealher, yo\. v.) arrives at exactly the opposite conclusions for America, as his observations in the prairie region and in Ohio go to prove that the re-wooding of a tract exerts no per- ceptible difference on the amount of the aqueous precipitations. Lendenfeld also tries to prove that the clearance of woodlands in Australia has resulted in a better climate and an increase in rainfall, as the soil under eucalyptus remains hard as stone and inabsorptive, whilst it is rendered lighter and more porous by grass. ( Peter/nanii' s Geog. Mittkeilungen, volxxxiv. )." 5. As regards Evaporation of Soil-RIoistiire. — The low tem- perature and the high relative humidity of the atmosphere in forests are unfavourable to rapid evaporation, which is still further reduced by the protection afforded to the soil against direct insolation and the action of winds. From observations extending over 10 years (1876-85) in various parts of Germany and Austria, the following relation is shown between evaporation in the forests and in the open in the vicinity of the forests : the differ- ences would probably be greater if comparisons had been made with places in the open that were far removed from the modify- ing influence of the woodlands : — Water evaporated. In the open In the forest 20 "9 inches 9-5 ., Lower in forest thani in open by . .•' 1 1 '4 inches Evaporation in forestl expressed in per-l, centage of that in: the open . J 46 per cent. The practical import- ance of this will be seen, when it is re- collected that the mineral food in the soil can be taken up by the rootlets only in the form of soluble salts. It was also found that the amount of evaporation depended on the class of forest, thus : — Percentage of Water. Species of Woodland. Evaporated in Remaining i the Forest. the Soil. Beech ... ... ... ... 40 ... 60 Spruce 45 ... 55 Scots pine... ... ... ... 42 ... 58 Clearing for reproduction ... 90 ... 10 In these statistics no account has been taken of the quantity of water given to the air by transpiration through the leaves ; but this is not of essential importance, as such supplies of moisture are drawn by trees, except during the earliest stages of growth, from the deeper layers of soil and subsoil not im- mediately and directly affected by the aqueous precipitations on the surface. This may be less true of spruce than of other trees. The action of forests, therefore, is to retain in the soil a large proportion of the rainfall or of the moisture arising from the melting of snows, which, by percolation to the lower layers and the subsoil, tends to feed the streams perennially, and to maintain a constant supply of moisture, without which trees could not derive their requisite food-supplies from the soil. The nature of the soil-covering below the forest trees exerts alsoconsiderable influence on the amount of moisture evaporated. From experiments conducted during five years in Bavaria it was found that a good layer of fallen leaves, and of hunm: or vege- table mould formed by their decay, is a powerful factor ; it diminishes the evaporation by more than half, or reduces it to less than one quarter of that in the open, and thus adds very considerably to the surplus amount of moisture retained in the soil. 6. As regards the Feeding of Streams and the Protection of the ;o4 NA TURE [January 25, 1894 Soil. — From the above data it seems evident that the eftect of extensive forests, more especially of those situated at high alti- tudes, is, by cooling the air and reducing its capacity for retain- ing aqueous vapour, to increase the precipitations SVhilst these precipitations are taking place the crowns of the trees intercept a large proportion of the total, and by breaking the violence of the rainfall protect the soil from the danger of being washed away during heavy storms. By the decomposition of fallen leaves and twigs a .-trongly hygroscopic soil-covering is formed, capable of imbibing and retaining moisture with sponge-like capacity. Rapid evaporation of the soil- moisture is counteracted through the protection afforded by the foliage against direct insolati->ii during the day, and by the mechanical hindrance offered to currents of wind. The crown of foliage likewise prevents the soil cooling rapidly at night by radiation. The hotter the summer, the more marked are these beneficial effects of the woodlands. When, therefore, large tracts of country are denuded of timber, increase of temperature during the days of summer, rapid radiation of soil-warmth by night, diminished precipita- tions (especially in the spring and summer), and unchecked evaporation of moisture, due to complete insolation of the soil by day and absence of any protection from winds, must be the inevitable consequences. Examples of such actual re- sults can be pointed out in many parts of continental Europe, in Western Asia, and throughout India. In Great Britain and Ireland the effects of the wholesale clearance of woodlands have not been so marked, in consequence of the favourable influences exerted on our climate by the Gulf Stream. In localities having no protective woodlandsheavy rains wash away the surface-soil, torrents and freshets rush down the water- courses with great violence, laden with detritus and discoloured with the soil held in mechanical solution, whilst streams and rivers often overflow their banks in consequence, devastating large areas of low-lying tracts under cultivation. Forests, on the other hand, tend to break the violence of the rainfall, and retain for the time being about one fourth of the total amount on the foliage and branches ; the roots of the trees and of the under- growth help to bind the soil firmly ; the rainfall is retained by the vegetable mould and by the spongy growth usually found on the surface-soil, and thence gradually percolates to the deeper layers, where it is held in reserve, to be finally parted with in being utilised for the feeding of perennial streams having their sources on the wooded slopes. Thus arose in the Alpine districts of Southern Europe the necessity for maintaining ban-forests as a protection against landslips, avalanches, &c. , and legal measures were early adopted for safeguarding them in order to protect the lower tracts from erosion of the soil when sodden with rainfall or melted snow. 7. As rega7-ds General Hygienic Effect on the Attnosphere. — It is well known that on the one hand when large tracts of forest are cleared for cultivation, especially in tropical and sub- tropical countries, fever and ague are frequently the consequence, and on the other that the planting up of notorious fever dis- tricts, such as the Campagna di Roma, the Tuscan marshes, and the Russian Steppes, has decidedly diminished the insalubrity of these localities. But the causes are very probably rather due to the degree of direct insolation of the soil, freely afforded in the one case, and counteracted in the other, than to any hygienic property inherent in tree-growth. In the latter case, too, stag- nating surplus of soil-moisture may have been got rid of by transpiration through the foliage, and this would of itself go far towards removing causes of insalubrity, and improving the climate. It is generally accepted that ozone kills miasma in the air, and purifies it — at any rale impure air contains little or no ozone ; the proportion of ozone is therefore usually taken as the measure of atmospheric quality. The belief that the woodland air is, like sea air, very rich in ozone has not yet been satisfactorily proved. Experiments in Bavaria showed that in the forests the percentage of ozone, though greater than that in the vicinity of towns, was slightly less than in the open in the vicinity of forests, and that there was no perceptible difference in this respect between coniferous and deciduous forests. The woodland air was found to contain most ozone in winter, which shows that its production could not be due to any chemical action of the foliage, for there are no leaves on decidu- ous trees at that season, whilst conifers transpire merely, and do not assimilate. Jt also indicates that the excess is probably due NO. 1265, VOL. 49] to the comparative freedom of air in the forest from the smoke, carbonic acid, and many other impurities with which air in the vicinity of towns is contaminated and defiled, and to the with- drawal of enormous supplies of oxygen from the air which takes place for the support of animal life at all populous centres. Thus whilst in general the quantity of carbonic acid in the atmosphere is somewhat under four volumes in 10,000, that is the normal amount in London air ; but in thick fogs this pro- portion is frequently doubled, and has been known to be more than trebled, or even to exceed 14 volumes in the city. Sunlight, however, has the power of decomposing carbonic acid in the presence of chlorophyll, the green colouring matter contained in foliage, the carbon being-absorbed by the plant for its growth, and the oxygen set free. During darkness a contrary action takes place, oxygen being consumed by the foliage, and carbonic acid given off. As, however, particularly in the case of deciduous trees which are in leaf only Irom April till October, the hours of light far exceed in number those of darkness, the general hygienic effect of trees in cities and towns — apart from their invaluable sesthetic influence — tends decidedly towards the purification of the atmosphere from excess of carbonic acid. Ozone again is an allotropic modification of oxygen obtainable by passing a series of electrical discharges through it; hence it is more than probable that in forests in exposed localities, more especially those at high altitudes, where storms and elec- trical disturbances of the air are most frequent, a greater quantity of ozone must be generated in the atmosphere than in localities less subject to such powerful ozonising influences. Ebermayer, undoubtedly one of the greatest authorities on this subject, says^ ; — " In the middle of the great 'ozone-factory,' which we must consider the forest to be, neither more oxygen nor less carbonic acid is off'ered to mankind for breathing than over large un- wooded areas." At another part of the same article he also adds- : — " From the hygienic standpoint it is worthy of notice that, according to my examinations, the air in and immediately above the crowns, then that in the immediate vicinity of the forests, has more ozone than that in the interior of the forests, where a portion of the ozone is consumed by the decomposing foliage lying on the ground." It appears, therefore, to be his matured opinion at present that whilst more ozone is found in forests than in the open — which the Austrian students of the subject deny, or at any rate are not yet prepared to admit without further observations and proofs — yet the decomposing matter covering the soil consumes the surplus, and often more than that, so that no difterence can be established in favour of the forest air. In this withdrawal of ozone in excessive quantities from the air by decomposing vegetable matter, the unhealthiness of tropical jungles, and the prevalence of malaria at all the lower elevations witnin the tropics usually covered by woodlands, seem easily explainable. According to Endres and to Fernow ^ it is claimed that forests tend to resist the spread of epidemics, and to offer a bar to the progress of diseases like cholera and yellow fever. Regarding the Sanitary Injltience of Forests, the latter states {op. cit. p, 21) as his summary that "(i) the claimed influence of greater purity of the air due to greater oxygen and ozone production does not seem to be significant ; (2) the protection against sun and wind, and consequent absence of extreme con- ditions, may be considered favourable ; (3) the soil connections of the lorest are unfavourable to the production and existence of pathogenic microbes, especially those of the cholera and yellow fever, and the comparative absence of wind and dust, in which such microbes are carried in the air, may be considered as the principal claim for the hygienic significance of the forest." Fortunately there are not many infectious diseases the germs of which can be carried by water ; as yet only two are known with certainty, cholera and enteric fever. When outbreaks of these diseases occur in tropical countries, the infectious power of the germs is favoured by warmth and moisture ; moreover, when epidemic, these diseases usually break out in thickly populated towns and similar localities, where it is impossible to submit 1 " Hygienische Bedeutung der Waldluft und des Waldbodens " in vol. xiii. of •' Forschungen auf dem Gebiete der Agricultur-Physik," edited by Prof. WoUny, 1890, p. 429. 2 Op. cit., p. 435. 3 " Forest Influences," p. 172, 1S93. January 25, 1894] NA TURE ;o5 the soil-moisture or the water-supply to the filtrating action of belts of woodland. S. As regards the A!;riatltural Productive Capacity of Neigh- bouring Tracts, and the National-Economic Eject on the Soil generally. - From an agricultural standpoint, a dry season is much preferable to a low temperature and excessive rainfall. In the former case the crops, although they may be somewhat scanty, are invariably of superior quality. A wet season may produce abundant crops, but they are generally of low quality. With regard to the influence of forests on the aqueous precipitations throughout central Europe, Prof, Endres makes the following remarks^ : — "The question whether woodlands can influence the rainfall is one of the most important from a national-economic point of view. Even if this could be distinctly aftirmed, the beneficial action of forests would only be established in the rarest cases, for throughout central Europe at present the number of too wet years exceeds that of dry years. In districts where the rainfall is over 40 inches, any increase is undesirable^' For agriculture very dry years are on the whole less disastrous than extremely wet years. The precipitations of any district are influenced mainly by the position of the mountain ranges with reference to the cardinal points of the compass, by its elevation above sea-level, and its distance from the sea." But, as the American investigations prove {idem. p. 13), "no influence upon the general climate which depends upon cosmic causes can in reason be expected from a forest cover. Only local modifications of climatic conditions may be antici- pated, but these modifications, if they exist, are of great prac- tical value, for upon them rest success or failure in agricultural pursuits, and comfort or discomfort of life, within the given cosmic climate. The same condition must be insisted upon with reference to forest influences upon waterflow, which can exist only as local modifications of water conditions, which are due in the first place to climatic, geologic, and topographic conditions." Even so early as in Roman tinies it was recognised that too great a clearance of woodland areas brought undesirable changes in the physical conditions of Italy, and affected the welfare of the inhabitants. That the destruction of the ancient forests throughout Great Britain and Ireland, to such an extent that only 38 per cent of the total area can now be classified as woodlands {vide Parliamentary Report on "Forestry," dated August 5, 18S7), was not followed by such disastrous climatic changes as were occasioned by similar causes throughout the Landes, Syria, Asia Minor, Greece, Russia, and many parts of India, we owe entirely to our insular position with its moist climate, and to the happy effects wrought by that portion of the Gulf Stream which reaches our western and southern shores. Early in the present century, for example, ihe Agricultural Society of Marseilles reported that in consequence of the reck- less destruction of the forests after the revolution of 1789 : — "The winters are colder,the summers hotter, and the bene- ficial spring and autumn showers no longer fall ; the Uveaune, flowing from east to west, rushes down in flood with the least rain, carrying away its banks and flooding the richest pasturage, while, for nine months of the year, its bed lies dry owing to the drying-up of the streams." To a similar cause also Prof. Geffcken (in The Speaker of January 6, 1893) attributes the Russian famine of 1892 in the following terms : — " We speak of the deficit (in the Russian Budget) of 1893 as certain, and it is easy to show that it will be so. The prin- cipal cause of the present dearth is the drought during the last spring and early summer, and this absence 0/ rain is greatly due to the devastation of the forests. The area formerly covered with timber was enormous, the woods belonging to the Crown, to the great landed proprietors, and to the village communities. But the means of transport were then so imperfect and costly that only in the neighbourhood of large rivers did the felling of timber pay. This changed with the construction of railways \ " Hygienische Bedeutung der Waldluft und des Waldbodens " in vol. xiii. of " Forschungen auf dem Geblete der Agricultur-Physik," edited by Prof. WoUny, iSgo. p. 607. - This is a point of very great importance with reference to the proposals of Mr. Munro Ferguson, M.P. {Contevipoarv Revieiu for October 1S92, pp.521, 522), for planting up the Highlandsof Scotland, and Dr. Macgregor's three ques'ionsin the House on the same subject on November 13, December :2, and December 19, 1893. For if 'here be already any tendency towards more rainfall during the summer months than is good for agricultural crops, an extensive increase in the acreage of woodlands in such vicinities is not desirable. and the abolition of serfdom ; the former gave the possibility of selling with profit, and the peasants abandoned their woods to speculators for what they thought a good price, little think- ing of the future ; the larger proprietors followed their example ; the purchase money was spent in drink and luxurious living, and no one thought of replanting. Too late has the Govern- ment issued a laut for the protection oj jorests. Such a devasta- tion going on for 20 years not only exhausts a source of zvcalth, but has also other bad consequences. When the country is de- prived of its trees, the earth is dried up and crumbles from the hills ; the water coming down from heaven cannot be kept back as is the case with the woods, which act as a sponge, but rushes in torrents into the rivers and disappears in the sea, and the consequence is a gradual diminution of the fertility of the soil and the disappearing of numerous brooklets and small rivers, to help the larger ones show a low water-mark, which proves prejudicial to the navigation." This view is confirmed by the special correspondent of the Times (vide article "Through Famine-stricken Russia" in issue of April 18, 1892), who writes : — "I have now travelled over most of the famine-stricken provinces, and I have been struck by the sameness of the picture. Everywhere reckless extravagance meets the eye, the forests have been cut away wantonly, the rivers are neglected, the climate is ruined." Such also appears to have been the opinion of Major Law, Commercial Attache to the British Embassy at St. Petersburg, as expressed in his " Report on Agriculture in the South-Eastern Provinces of European Russia," commented on in a leading article of the Times of September 17, 1892, in the following words : — " It is said that this gigantic natural tillage farm (i.e. the ' black-soil ' region) was formerly hedged in by belts of forest, which served the twofold purpose of sheltering it from the desert winds and of increasing the humidity of the climate. It is certain that these forests do not now exist, and that the black-soil country is often scourged by devastating blasts from the steppe, and not infrequently baked by prolonged droughts. The desert winds pile the snow in drifts into winter, which become the source of destructive torrents jin the spring. In summer the same winds are so fierce and arid that in the space of a few hours they wither the corn as it stands, while, when they are laden with sands, I hey smite the soil itself with perpetual barrenness." All writers, indeed, who have recently published views en this subject, seem agreed as to the main causes of the recent Russian famine.^ In order to obtain the full national-economic benefits that are derivable from woodlands, the areas reserved as forests or planted up should be scattered over the face of the country as equally as possible. In all countries where the population is thin, and primeval forest is siill to be found, measures with this end in view can easily be carried out without inflict- ing any apparent hardship on the existing community. But wherever danger from famine is apt to recur from time to time, it would at the same time seem to be worthy of consideration whether it would not be wise to expropriate tracts of the poorer and higher land here and there, and plant them up on a well- considered scheme lor the purpose of ameliorating the climatic conditions for man and beast in the future. J. NiSBET. SCIENTIFIC SERIALS. American fournal of Science, January. — Researches in acoustics. No. 9, by Alfred M. Mayer. This paper deals with the law connecting the pitch of a sound with the duration of its residual sensation, and with the smallest consonant intervals among simple tones. The residual sound, i.e. the sound per- ceived by the ear after the actual vibration has ceased, was in- vestigated by means of an apparatus consisting of a tuning-fork vibrating close to the opening of a resonator. The nipple of the resonator was placed opposite a hearing-tube leading to the ear, and the sound was interrupted by a rotating perforated disc inter- posed between the nipple and the opening of the tube. The discs, which were made of mahogany covered with cardboard, had several circles of holes, and intercepted the sound very 1 See also the article on " The Penury of Russia" mth.^ Edinburgh Review for January 1893 (pp. 17-19), which may be said to contain a summary of the best opinions on the matter. NO. 1265, VOL. 49] 3o6 NATURE [January 25, 1894 effectively. The discs were worked by a hand-pulley and fly- wheel, controlled by a clock beating seconds loudly. The residual sensations obtained, by noticing at what speed the sound became continuous, ranged fromoo23i sees, in the case of Uto, frequency 128, to 00049 sees, in the case of Ut,, frequency 1024. The smallest consonant intervals were de- termined by noticing when the beats coalesced into a smooth tone. The residual sensations deduced from these experiments wore found to be about one-third greater than those obtained by the former method. — Petroleum in its relations to asphaltic pavement, by S. F. Peckham. While it has been well known for years that bitumens occur in great variety, the selection of a proper material for softening the asphalt, to the exclusion of others less desirable or wholly unfit, appears to have escaped attention. A properly selected material should enter into chemical union with both the constituents of the bitumen in the asphalt, thereby increasing its adhesive and binding properties upon the other constituents of the mastic. The proportion of bitumen to sand and other non-bituminous ingredients should be as I : 9, a larger amount of bitumen making the pavement too soft, and a smaller amount giving too little stability. — The age of the extra-moraine fringe in Eastern Pennsylvania, by E. H. Williams, Junr. All observations tend to the conclusion that there was but one ice age in Pennsylvania, and that a short and recent one. — The internal work of the wind, by S. P. Langley (see Notes). — Post-glacial seolian action in Southern New England, by J. B. Wood worth. This paper treats mainly of the action of blown sand in carving rocks and boulders. In the Botanical Gazette for November, 1893, we find a paper on the Food of green plants, by Mr. C. R. Barnes, in which he proposes the term photo-syntax for the process of formation of complex carbon compounds out of simple ones under the influ- ence of light. — Mr. H. L. Russell continues his account of the Bacterial flora of the Atlantic Ocean in the vicinity of Woods Holl, Massachusetts ; and Miss F. D. Bergen, her useful Record of popular American plant names. The third and concluding part of vol. vi. of Cohn's Beitrage zur Biologie der Pflanzen contains three important papers. — Dr. M. Scholtz describes the changes in position which take place in the flower-stalk of Cobcea scandens before and after flowering. It affords the first recorded instance of an organ with complicated anisotropy. During the development of the bud the flower-stalk exhibits strong negativegeotropism and positivehelio- tropism. After the opening of the flower, which is strongly proterandrous, changes take place in the position of the stamens and style which bring the stigma nearly into the position pre- viously occupied by the anthers. — HerrG. Karsten gives further details of the embryology of Gnetiim ; the development of the male, of the imperfect female, and of the perfect female flowers being described in detail. In the perfect female flowers there are always at first several embryo-sacs ; and in some species two or three of these remain till the period of fertilisation, and are capable of impregnation. The actual process of impregna- tion presents some analogy, on the one hand, to that in the Coniferse, on the other hand to that in the Casuarineze. The generative nucleus of the pollen-grain divides within the pollen- tube, as in the Coniferje. The two portions of this nucleus enter the embryo-sac and coalesce with one of its nuclei. In some species secondary embryos are produced. — Pv. Hegler gives details of experiments on the influence of mechanical traction on the growth of plants. Bulletins de la Societe d Anthropologie dc Paris, Tome iv. (4e Serie), No. lo. — The greater part of this number of the Bulletins is occupied by the replies of M. J. M. van Baarda to the questions of the Anthropological Society with regard to the island of Halmaheira, or Gilolo, in the Moluccas. M. G. de Mortillet contributes some pal?eographical notes on the lower valley of the Seine ; and MM. E. Fournier and C. Riviere describe the discovery of objects of the Robenhausian period in the Grotto Loubiere, near Marseilles. SOCIETIES AND ACADEMIES. London. Royal Society, January 18.— " On the Transformation of Optical Wave-Surfaces by Homogeneous Strain." By Oliver Heaviside, F.R.S. "On the Reflection and Refraction of Light." By G. A. Schott, formerly Scholar of Trinity College, Cambridge. NO. 1265, "^'OL- 49] Chemical Society, December 21, 1893. — Dr. Armstrong, President, in the chair. — The following papers were read : — Corydaline. Part iii. : Oxidation with potassium permanganate, by J. J. Dobbie and A. Lauder. The authors have investigated corydalinic acid, CiiH5N(OMe)4(COOH)4, obtained by oxidis- ing corydaline with potassium permanganate. — The properties of o-benzaldoxime and some of its derivatives, by W. R. Dun- stan and C. M. Luxmore. Both a-benzaldoxime and its acetyl- derivative may be obtained in the solid state by cooling. The authors are at present examining a number of addition pro- ducts of the former substance with the halogen acids. — The interaction of acid chlorides and nitrates, by H. E. Armstrong and A. Lapworth. — The freezing points of triple alloys, by C. T. Heycock and F. H. Neville. The existence of a compound of silver and cadmium of the composition 2AgCd seems probable from the results of freezing point determinations of mixtures of these metals in tin, lead, or thallium solution. The behaviour of solutions of silver and cadmium in bismuth points to the formation of the compound 4AgCd. Aluminium and gold appear to form the compound AuAL when dissolved to- gether in molten tin. — Synthesis of pentamethylenecarboxylic acid, hexamethylenecarboxylic acid, hexhydrobenzoic acid, and azelaic acid, by E. Haworth and W. H. Perkin, jun. The authors have prepared the acids mentioned above from the pro- ducts of interaction of a mixture of tetra- and penta-methylene bromides and ethylic sodiomalonate. — The conversion of ortho- into para- and of para- into ortho-quinone derivatives : I. The condensation of aldehydes with /8-hydroxy-a-naphthylamine, by S. C. Hooker and W. C. Carnell. — The synthesis of lapachol, by S, C. Hooker. An isomeride of lapachol is ob- tained by heating an acetic acid solution of hydroxynaphtha- quinone with valeric aldehyde and hydrochloric acid. Geological Society, January 10. — W, H.Hudleston, F.R.S. , President, in the chair. — The following communications were read : — On the Rhstic and some Liassic Ostracoda of Britain, by Prof. T. Rupert Jones, F.R.S. The published observations on the occurrence of these Microzoa in the Rhsetic and Lower Liassic strata of England, chiefly in Gloucestershire and Somer- set, by the Rev. P. B. Brodie, H. E. Strickland, C. Moore, and others, were given ; and the various notices of the so-called Cypris liassica in various palseontological works were con- sidered. Numerous specimens submitted by the Rev. P. B. Brodie, the Rev. H. H. Winwood, and Mr. E. Wilson, and some few examined in the Geological Society's collection, have been studied, with the result of determining the characters and alliances of Darwinula liassica (Brodie) and of six or seven other species found in the same and the associated series of strata. The Dar-wimda globosa (Duff), from Linksfield, Moray- shire, was also critically re-examined as one of this interesting series of Rhsetic Ostracoda. The other species belong for the most part to Cytheridea ; thus most of them probably lived in brackish or estuarine waters. The President and Dr. Henry Wood- ward spoke on the subject of the paper, and the author replied. — Leigh Creek Jurassic Coal-Measures of South Australia : their origin, composition, physical, and chemical characters ; and recent subatirial metamorphism of local superficial drift, by '. James Parkinson. This paper dealt with the lignitic coal of i Leigh Creek and associated rocks. Analyses were given, as ; illustrating comparisons between the Leigh Creek coal and I Jurassic and other coal-bearing rocks found elsewhere. The | author discussed the origin of the Leigh Creek deposits, and described certain peculiarities noticeable in the superficial materials. The President and Mr. Browne made a few remarks upon the subject of the paper. — Physical and chemical geology ; of the interior of Australia : recent subaerial metamorphism of Eolian sand at ordinary atmospheric temperature into quartz, quartzite, and other stones, by James Parkinson. South of the Flinders Range fragments of stone of all sizes are found on the ground, the origin of which the author discussed. He main- tained that they were formed by subaerial metamorphism of Eolian deposits. A discussion followed, in which the President, Mr. R. D. Oldham, Prof. T. Rupert Jones, Dr. H. Woodward, Mr. Marr, Dr. G. J. Hinde, and Mr. E. T. Newton took part.. Zoological Society, January 16.— Sir W. H. Flower, K.C.B., F.R.S., President, in the chair.— The Secretary read a report on the additions that had been made to the Society s menagerie during the month of December, 1893. — Mr. Sclater exhibited and made remarks on a drawing of the head of a monkey {Cercopithecus erythrogaster) in the Paris Museum, for-' warded to him by M. Pousargues, of that institution. — An extract! January 25, 1894] NATURE 307 was read from a letter received from Mr. C. B. Mitford, de- scribing an invasion of locusts observed at Free Town, Sierra Leone. Mr. C. O. Waterhouse had referred the specimens of these insects sent home to Pachytylus migratoroides. A further extract from the same letter gave an account of the occurrence of the elephant in the district of Sierra Leone. — Mr. R. Lydek- ker gave an account of some of the principal objects observed during his recent visit to the La Plata Museum, calling special attention to the splendid series of remains of Dinosaurian reptiles, of Cetaceans, and of Ungulates of three different sub- orders. Mr. Lydekker also made remarks on some of the specimens of Edentates, and of the gigantic birds of the genus Brontornis. — Mr. Lydekker also exhibited a painting of the head of a wild goat {Capra agagrus) of unusual size. — On behalf of Mr. J. Tenner Weir, a specimen of the Tsetse Fly {Glossina THorsitatis) from the Transvaal was exhibited. — Mr Tegetmeier exhibited a curiously barred variety of the common pheasant.— A communication was read from Prof. W. N. Parker, contain- ing remarks on some points in the structure of the young of the Australian Echidna. — A communication was read from Mr. Roland Trimen, F. R. S., giving an account of a collection of butterflies made in Manica, Tropical South-east Africa, by Mr. F. C. Selous in the year 1892. Of 166 species represented in the series, 44 were stated to be of general distribution, and of the remainder (amongst which were nine apparently new to science) 26 were peculiar to the South-Tropical area of Africa. — A communication received from Dr. A. B. Meyer contained remarks on a rare African monkey {Cercopitheciis wolfi), accom- panied by a coloured drawing. — Dr. A. Giiniher, F.R.S., gave an account of a collection of reptiles and fishes made by Dr. J. W. Gregory during his expedition to Mount Kenia. The col- lection contained examples of 37 species of reptiles, 9 of Batra- chians, and 13 of fishes. Several species of reptiles were new to science, amongst which were two new lizards — Bunocneinis nto- desta, g. et sp. n., of the family Geckotidae, with imbricate scales and large scattered conical tubercles on the hinder part of the hind limbs ; and Agama gregorii, allied to A. cyanogastcr, but with lateral, not tubular nostrils. Six new fishes were also charac- terised and named : — Chromis niger, Chromis spihmis, Alestes affinis, Labeo gregorii, Barbns tanensis, and Barbtis taitensis. Royal Meteorological Society, January 17. — Dr. C. Theodore Williams, President, in the chair. —The council in their report stated that the Society had made steady and unin- terrupted progress during the year, there being an increase in the number of Fellows, and the balance of income over expenditure being greater than in 1892. They also reported that Dr. C. Theodore Williams, previous to vacating the office of President, had expressed a desire for the formation of a fund for carrying out experiments and observations in meteorology, and that he had generously presented to the Society the sum of ;^ioo to form the nucleus of a research fund. — The President, Dr. C. Theodore Williams, in his valedictory address gave an account of the climate of Southern California, which he made most in- teresting by exhibiting a number of lantern slides. In the autumn of 1892 Dr. Williams visited this favoured region, chiefly with a view of investigating its present and future resources, and its suitability for invalids. After describing the entrance into Cali- fornia from Utah and Nevada, the general geography, and the mountain ranges, he pointed out that the mountain shelter is tolerably complete, and that the protected area consists of (i) valleys, chiefly running into the coast range from the sea, and rising to various elevations, such as the fertile San Fernando and San Gabriel valleys, or else (2) more or less extensive plains, as those of Santa Ana and San Jacinto. Southern California is subdivided into two portions, eastern and western, by the Sierra Nevada, and its spurs, the San Gabriel and San Bernadino mountains. The climate of the eastern portion, which is an arid region, is very dry, very hot in summer, and moderate in winter The climate of the western portion has three important factors, viz. (i) its southern latitude, (2) the influence of the Pacific Ocean, and especially of the Kuro Suvo current, which exercises a similar warming and equalising influence on the Pacific coast of North America as the Gulf Stream does on the western coasts of the British Isles and Norway ; and (3) the influence of mountain ranges, these affording protection from northerly and easterly blasts, and also condensing the moisture from the vapour- laden winds blowing from the Pacific. Dr. Williams then gave particulars as to the temperature and rainfall at Los Angeles, San Diego, Santa Barbara, and Riverside. From these it ap- pears that the climate of Southern California is warm and NO. 1265, VOL. 49] temperate, and on the whole equable, with more moisture than that of Colorado, and that it is a climate which would allow of much outdoor life all the year round. The President next described 'he eff"ect of the climate on vegetation, and showed what results had been obtained by diligent watering and gar- dening in this beautiful region. Wine and brandy are made in South California, but oranges and lemons are the leading crops, varied with guava-, pineapples, dates, almonds, figs, olives, apricots, plums and vegetables. On higher land, apples, pears and cherries bear well, and our English summer small fruit is also grown; while strawberries ripen all the year round, and are plentiful except in July and August. Dr. Williams concluded by saying that many an invalid has regained vigour and health, as well as secured a competence, in the sunny atmosphere of Southern California. — Mr. R. Inwards was elected President for the ensuing year. Linnean Society,January 18. — Mr. W. Carruthers, F.R.S., Vice President, in the chair. — Messrs. T. B. Cato, W. Elborne, and R. E. Leuch were admitted, and the following were elected : — Sir Hugh Law, Messrs. G. B. Rothera and Thomas Sim. — The chairman, before proceeding to the business of the evening, referred to the loss which the Society had sustained by the recent death of Mr. Richard Spruce, who had travelled and collected much in South America, and who was the re- cognised authority on Hepatica:. It was much to be regretted that, having but lately presented to the Society a valuable paper on this subject, containing descriptions of a great number of new species, and illustrated with careful and beautiful drawings, he had not lived to see the published result of his labours. The chairman also feelingly referred to the death of Mr. Algernon Peckover, of Wisbech, who had been a Fellow since 1827, and who by his will had bequeathed to the Society a legacy of £100. — Mr. E. M. Holmes exhibited a flowering specimen of a new species of Cascarilla (C. Thomsoni), and the bark of the tree from New Granada ; also two new foreign seaweeds, Gelidhim Beckii from South Africa, and Leptocladia Binghamitz from California, and three new British marine algae, viz. Entophy- salis granulosa and Symploca atlaniica from Swanage, collected by himself; and Vaucheria coronata from Arbroath, collected by Mr. J. Jack. — Mr. Thomas Christy exhibited and made ob- servations upon some remarkably long tendrils of Landolphia Kirkii, which served as an illustration to a paper subsequently read by Mr. Henslow. — Mr. J. E. Harting exhibited and made some remarks upon the plant debris ejected in the form of "pellets" or "castings" by rooks, and stated that a number of these pellets which had been examined were composed of the cuticles of the succulent root of the couch grass Triticum repens, commonly called "scutch," "squitch," and "twitch" grass, a most troublesome weed to the farmer. ]\Ir. Harting also exhibited a rare Australian duck, Stictonettancszosa (Gould), which had been obtained at Gippsland Lakes, Victoria, and of which very few examples were to be found in collections. — A paper was then read by the Rev. G. Henslow, on the origin of the structural peculiarities of climbing stems by self-adaptation in response to external mechanical forces. The purport of this paper was to prove, by an appeal to facts and experiments, the existence of the power in living protoplasms of responding to external and purely mechanical forces by enveloping supportive tissues, by means of which the plant is enabled to resist the eff'ects of gravity, tensions, pressures, &c. In the case of climbers, not only is this principle illustrated wherever a force is felt, but whenever a strain is relieved of a force atrophy, or arrest of mechanical tissues lakes place, supplemented, however, by an increase in the number and size of vessels. The con- clusion arrived at was that while, on the one hand, the peculiar structures of climbers are all the outcome of a response to the external mechanical forces actirg directly upon the stems, such structures are precisely those which are most admirably suited to the requirements of the stems themselves. The variations of structure characteristic of species, genera, and orders of climbing plants have been thus acquired in a definite direction, viz. of direct adaptability, this being effected, according to Mr. Darwin's statement, "without the aid of natural selection." The paper was criticised by Dr. D. H. Scott, Prof. Reynolds Green, and Mr G. Murray, who, while testifying to the number of interesting facts brought forward by Mr. Henslow to sup- port his views, were yet unable to agree with him in several of his conclusions. The paper was illustrated by a great variety of specimens and drawings, and was listened to with consider- able interest by a very full meeting. 3oS NA rURE [January 25, 1894 Paris. Academy of Sciences, January 15. — M. Loewy in the chair. — The death of M. P. J. van Beneden was announced, and a short account of his scientific career given by M. Emile Blanchard. — On the theory of the photography of simple and compound colours by the interference method, by M. G. Lipp- mann. The mathematical theory of the action of light on the phr.tographic film is developed at length. — On a problem in mechanics, by M. A. Potier. The author gives a simple solu- tion of the problem proposed by M. J. Bertrand concerning the law of the forces for a point describing a conic section. — Studies on the formation of carbonic acid and the absorption of oxygen by the detached leaves of plants. Experiments made at the ordinary temperature with the concurrence of biological activity, by MM. Berthelot and G. Andre. The results for wheat, Coryliis avellana and Sedum maxinuini, are compared with the results, previously obtained and described, of strictly chemical character, and hence the results of the biological activity of the living matter of the leaves are deduced. — On a method for the study of gaseous exchanges between living things and the atmosphere which surrounds them, by M. Ber- thelot. A method is indicated whereby, by means of periodical analyses of an atmosphere, which is large compared to the respiratory needs of the living specimen, the changes caused by the organism can be examined while it is living in the normal manner. — On the chronostylographic method, and its appli- cations to the study of the transmission of waves in tubes, by M. A. Chauveau. A description of the use of some improved instruments such as might be used for the study of the movements of all kinds occurring in the animal economy. — Observations on the Aipyornis of Madagascar, by MM. A. Milne-Edwards and Allred Grandidier. A quantity of new material from Madagascar has been examined with the result that the remains have been classed in two main divisions, .(Epyornis and Mullerornis, each with several described species. — Generalisation of some theorems in mechanics, by M. A. Kotelnikoff. — On the pendulum of varying length, by M. L. Lecornu. A mathematical study of the conditions during the oscillation of a pendulum of which the length varies in a definite manner. — Emission of sounds, by M. Henri Gilbault. It is shown that, in the ordinary case of vibrating bodies of three dimensions, the time occupied in communicating its energy to the air varies with the nature of the surface of each particular body. — Is there oxygen in the atmosphere of the sun ? A note by M. Arthur Schuster. Attention is directed to a letter by the author published in Nature (December 20, 1877) in connection with M. Duners recent communication on this subject. — On the magnetisation of soft iron, by M. P. Joubin. The characteristic equation deduced from Rowland's experimental results is x = \ + o'33 (i -j) ± i*3 sl^-y I K — K where x = — andj = — ; I is the intensity of magnetisa- \c Kc— K" tion, and K the susceptibility of the material. — The relation of storms at Pare de Saint-Maur to the position of the moon, by M. E. Renou. The author believes that he has shown that, in this district, storms are more frequent with a northern than with a southern declinatinn of the moon — On the combination of hydrogen and selenium in an unequally heated space, by M. H. Pelahon. A thermodynamical study of the reaction, showing that the experimemal results agree with the predictions. — Ceric bichromate and the separation of cerium from lanthanum and didymium, by M. G. Bricout. A crystalline bichromate is deposited electrolytically from a solution of cerous carbonate in chromic acid, lanthanum and didymium give no deposit on the positive pole from chromic solution, hence a method for the separation of cerium as a pure soluble sal'.- Researches on the desiccation of starchy matters, by MM. Bloch. — On the liquid fr >m albuminous perio-titis, by M. L. Hutjounenq. Analyses show that the periostiiial exudation resemtJes that of " hydar- thio-e" most nearly — Influence of atmospheric agencies, par- ticularly light and cold, on the pyocyan^genous bacillus, by MM. (.rAr.sonval and Charrin. — On th.- amihocytes, the oogt-riesis and the ovi-deposition of Mioonereis variegata, by M. Emile G. Racovitz^. — On the syochr )nism of the coal basins of Commentry and St. Etienne and its consequences, by M. A. Julien. — On the epidermis of the egg-bearing peduncles and seeds of Benncttites Morierei, by M. O. Lignier. BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books —The Fauna of the Deep Sea : Dr. S. J. Hickson (Kegan Paul).— The Technique of Post-Mortem Examination: Dr. L. Hektoen (Chicago, Keener and Co.).— Climates of the United States, in Colors : Dr. C. Deni- son (Chicago, Keener and Co.). — Physiology Practicums : Dr. B. G. Wilder (the Author, Ithaca) —Biologischer Atlas der Botanilc, Serie " Iris," Erlau- tetnderText: Dr A. Dodel.— Ditto, Tafel i to 7 (Ziirich, Schmidt).— The Royal Natural History, Vol. i. Part 3 (Warne).— Ninth Annual Report of the BureauofEthnology(Washington).— Annals of the Astronomical Observatory of Harvard College, Vol xxix., Miscellaneous Researches made during the Years 188:1-93 (Camb.. Mass.).— Ditto, Vol. .xxv., Comparison of Positions of Stars &c., &.C. : W. A. Rogers (Waterville, Me ).— Ditto, Vol. xl. Part 2, Observations made at the Blue Hill Meteorological Observatory, Mass., U S.A,, in the year 1892 : A. L. Rotch (Camb., Mass.).— Ditto, Vol. xx.\i. Part 2, Investigaiions of the New England Meteorological Society for the year 1891 (Camb., Mass.).— Heat, an Elementary Text-book, Theoretical and Practical: R T. Glazebrook 1 Cambridge University Press).— The Yoruba-Speaking Peoples of the Slave Coast of West Africa; A. B. Ellis (Chapman and Hall).— Congres International de Zoologie. Deux. Session a Moscou, Deux. Partie (Moscou). Pamphlets.— Sugar Maples, and Maples in Winter: W. Trelease (St. Louis, Mo). — Royal Gardens, Kew, Official Guide to the Museums of Economic Botany, No. 3, limbers, 2nd ediiion (Eyre and Spottiswoode). — Notes of Research on the New York Obelisk : A. A. Julien. — Some Ancient Relics in Japan : R Hitchcock (Wa5hingion).^The Ancient Burial Mounds of Japan : R. Hitchcock (Washington) — Sninto, or the Mythology of the Japanese: R. Hitchcock (Washingt .n).— The Ainos of Zezo, Japan: R. Hitchcock (Washington).— The Ancient Pit Dwellers of Zezo, Japan : R. Hitchcock, Washington). — Bibliography of the Salishan Languages: J. C. Pilling (Washington). — The New Naii nality of the N le : Drs. Sarruf and Nimr (Cairo). — Report of the Superintt-ndent of the U.S. Naval Observatory for the Year ending June 30. 1893 (Washington). — The Cincinnati Southern Railway : J. J. Hollander (Biltimore). Serials. — Zeitschrift fiir Wissenschaftliche Zoologie, Ivii. Band, 2 Heft (Williams and Norgate). — The Psychological Review, No. i (Macmillan). — The Botanical Gazette, December (Blooming ton). — Ga'zetiaChimtca Italiana, Vol. 2, fasc. 12 (Palermo).- Palestine Exploration Fund, Quarterly State- ment, January (Watt). — The Quarterly Journal of Microscopical Science, January (Churchill). — Quarterly Review, January (Murray). — Zeitschrift fiir Physikalische Chemie, xiii. Band, i Heft (Leipzig).— Journal of the Franklin Institute, January (Philadelphia). — Journal oe Phy.-.ique, January (Paris) — Proceedings of the Academy of Natural Sc ences of Philadelphia, 1893, Part 2 (Philadelphia). — Bulletin of the US. National Museum, No. 46 — The Mariapoda ot North America : C. H. Bollman (Washington). — Rendiconto dell' Accademia delle Scienze Fisiche e Matemaiiche, Serie 2, Vol. 7, fasc. 8 and 12 (Napoli). — Astronomy and Astro-Physics, January (Wesley). — Nucvo Giornale Botanico Italiano. N uova Serie (Vol. i. No. r (Firenze). CONTENTS. Recent Public Health Works TheLatestText-Bookof Geology. By Prof. A, H. Green, F.R.S The Chemistry of the Blood Agricultural Botany for Extensionists The Principles of Hospital Construction Our Book Shelf:— Gregory: " The Vault of Heaven " Harris : " A Journey through the Yemen, and .some ■ General Remarks upon that Country" . ... Letters to the Editor :— The Directorshipof the British Institute of Preventive Medicine.— Sir J. Fayrer, K C.S.I., F.R.S.; Prof. Victor Horslcy, F.R.S The Origin of Rock Basins. — R. D. Oldham ... On the Change of Superficial Tension ol Solid-Liquid Surfaces with Temperature. — Prof. G. F. Fitz- gerald, F.R.S. . ... A Lecture Experiment. — G. S. Newth Pierre Joseph van Beneden . ....... The Great Gale of November 16-20. {With Dia- gram.) By Chas. Harding Paul Henri Fi&cher. By Dr. Edmond Bordage . . Notes Our Astronomical Column . — Report of the Wolsingham Observatory ...... Anomalous Appearance of Jupiter's First Satellite Astionomv and Astro-Physics Geographical Notes ... Earth Movements. By Prof. John Milne, F.R.S. . The Climatic and National-tconomic Influence of Forests. By Dr. J. Nisbet Scientific Serials ... S lCletle^ and Academies . ... Books, Pamphlets, and Serials Received PAGE 28s 287 289 290 290 291 291 292 292 293 293 293 294 296 296 300 300 300 301 301 302 305 306 '•;o8 NO. I 2 56, VOL. 49I NA TURE 309 THURSDAY, FEBRUARY i, 1894. CHINESE CENTRAL ASIA. Russian Central Asia : a Ride to Little Tibet. By Henry Lansdell, D.D., M.R.A S., F.R.G.S., Author of "Through S.iberia,"" Russian Central Asia," "Through Central Asia," &c. Two Vols. (London : Sampson Low, 1893.) THERE are i^w, if any, men who have travelled so extensively throughout the length and breadth of Asia as Dr. Lansdell, and in the work before us he has given an interesting account of his last great journey of 50,000 miles, which occupied " two years and seven months, of which 525 were travelling; and 425 were stationary days. The regions visited comprised five of the kingdoms of Europe, four of Africa, and every king- dom of Asia. The methods of travel were 18,000 miles by railway, 25,000 by water, and 7,000 by driving and riding on the backs of horses, camels, donkeys, yaks, elephants, mules, and men." Dr. Lansdell is a privileged person, high in favour with influential men in Russia, as well as in England, and has always been permitted to travel freely in all parts of Russia, without let or hindrance, to an extent which would probably hardly be allowed to anyone else. He speaks with high praise of the civility and courtesy with which he was everywhere received, by officials and others ; but apart from this, we are glad to find that now that the Russians have consolidated their power in Central Asia, they are gradually giving up their old exclusiveness, as witness the recent experiences of Lieut. Coningham. Dr. Lansdell's primary objects, as before, were chiefly missionary. He distributed copies of the Scriptures in the various languages of the countries through which he passed ; visited mission stations, and prisons, and noted everything likely to be useful for directing future efforts in the same direction. But he has avoided making this feature too prominent a part of his book ; and we are glad to see that there is scarcely a word in reference to other religions which could give offence to the most fastidious, except, perhaps, in his sometimes speaking of Mo- hammed as " the false prophet." One object which Dr. Lansdell set before him was to penetrate to Lassa ; but, unfortunately, the difficulties which have baffled every recent traveller happened to be increased at the time by a war on the Indian frontier ; and it is needless to say that he did not succeed. It is to be inferred from his historical notes that Tibet was originally closed against foreigners by the Chinese, and that the custom has since been maintained by the Tibetans The greater portion of the book is taken up with the personal narrative of the author's journey. He started from London to St. Petersburg, and thence to Baku, and "via the Transcaspian Railway to ninety-one miles beyond Bokhara, where the line then terminated, though it was being pushed forward at the rate of three miles per day. Thence he proceeded to Issik-Kul, Vierny, Kuldja, Aksu, Yarkand, and over the Karakorum to India, China, Japan, &c., and then back to London via the Suez Canal, visiting many more countries on the way. It is, NTO. 1266, VOL. 49] however, only the early part of the journey, as far as India, which is described in detail. The Transcaspian Railway was not in existence at the time of Dr. Lansdell's previous journey in Russian Cen- tral Asia in 1882 ; but as far as Kuldja the journey of 1888 frequently intersected and sometimes coincided with that of 1882, and the author observed and notes many changes which had taken place in Bokhara, Sam- arcand, Tashkend, &c., since his former visit. At Issik- Kul, and still more beyond Kuldja, he began to break entirely new ground, and it is here that the most interesting part of his narrative begins. We may note incidentally that he obtained a new fish {Diptychtis Lans- delli, Giinther) at Lake Issik-Kul. It was not to be expected that during so long and difficult a journey the author should have been able to give attention to every possible subject of interest, but he succeeded in obtaining a large series of photographs of views and natives. Many of these photographs were used to illustrate magazine articles, and have been re- produced in this book. The author, therefore, apologises for the unfinished state of some of his illustrations, on the score of their having been originally prepared for the exigencies of rapid newspaper printing. The numerous types of races figured should make the book very useful to anthropologists ; and the natural history appendices and lists of birds, insects, fish, &c., in which the author had the assistance of various eminent naturalists, will appeal to zoologists. Other matters worth noticing, from a literary and scientific point of view, are the maps, the bibliography and chronology (compiled by Mrs. Lansdell), and the geographical and historical information scattered through the book. To travellers about to set out for the same countries, the account of the author's personal ex- periences cannot but be of much value, though others can hardly expect to be so exceptionally fortunate as Dr. Lansdell. Things are greatly changed for the better in Central Asia since the Russian occupation, and Dr. Lansdell was everywhere received as a guest, and treated with the utmost hospitality during the greater part of his journey. It was only between the Russian and British frontiers that he appears to have encountered any very serious hard- ships, and even these were in large measure due to the difficult nature of the country to be traversed. Among the Kirghese tribes, near Issik-Kul, the idea of sympathetic cures is firmly fixed. " Thus for an obstinate attack of yellow jaundice, they wear on the forehead a piece of gold, or better, cause the patient to look at it for a whole day, or if a piece of gold be lacking, which is generally the case, they substitute a glass basin." At Vierny, Dr. Lansdell found many traces of the great earthquake which had devastated the town in the year pre- vious to his visit. We believe that it is somewhat unusual for countries so far inland to be liable to earthquakes, and that Central Asia is exceptional in this particular. At Kuldja, the author put up at "the best inn in the town ; above the average of Chinese inns elsewhere." " This was my first experience of a Chinese inn, and it made my flesh creep. Passing through a wide door- way, we entered a square courtyard, with rooms on two sides, and occupied in the centre and on a third side by 3IO NA TURE [February i, 1894 horses, carts, and drivers. The removal of such trifles as foul straw and manure was deemed superfluous, and through this I had to wade towards the door of a room, and there wait till the coal in it was swept into a corner, and what looked like a brewing apparatus removed. " There was no flooring, not even of bricks, and no furniture, but at the end of the room was a kang, or platform of loose boards, over what appeared to be an ash-pit, though the cinders, no doubt, represented the remains of fires for winter heating. Over this receptacle for rubbish of various kinds I was to sleep and eat." Besides this, there was an intrusive crowd at the door and window, a flour-mill at work, and the jingling of horse and mule bells in the yard. " This went on all day ; and what with the stench of manure, distracting noises, windows unglazed, and inquisitive visitors, my lodging proved to ht the worst I had ever had." One man defended his intrusion on the traveller's privacy by ask- ing, " Cannot I come into a room in my own country ? " Here the author was invited to breakfast with Kab-i- chang, the Commissary of Russo-Chinese affairs, where he found a variety of dishes, including black putrid eggs, a special delicacy in China. After leaving China, Dr. Lansdell crossed the Tian Shan into Chinese Turkestan by the Muzart Pass, at a height of 11,000 or 12,000 feet. Here the Chinese picket did their best to smooth the way by laying boughs of trees across crevasses, and covering them with blocks of ice, for the men and horses to cross to the crest of the pass, a nearly perpendicular ice clifif with steps cut in it, down which horses are sometimes lowered by ropes ; but in this case, one man took a horse's head, and another hung on by the tail, and thus, wonderful to relate, they con- trived to descend in safety. This formidable pass has, it appears, never been crossed before by any European ; and from this point Dr. Lansdell proceeded to Aksu, the most important place on the way to Kashgar and Yarkand, where he found much to interest him, including criminals wearing the cangue, or wooden frame round the neck, a familiar punishment in China. Thence he travelled to Kashgar, passing, on the way, through a place called Maralbashi, where the chief mandarin has a drum before his door, and if this is struck, he is bound to attend at once to the appeal of any suppliant. But, to avoid any trouble, if the drum is struck, the mandarin orders the disturber of his peace one hundred lashes, and then asks his business. From Kashgar Dr. Lansdell proceeded to Yarkand and Khotan, and at the latter place he witnessed a dance of dervishes, of which he gives an illustration. He was anxious, at Khotan, as well as elsewhere, to take photo- graphs of some of the native beauties, but having no opportunity of seeing them unveiled, he was advised to tell his landlord that he wanted a pretty wife, and to ask him to bring him half a dozen on approval. Here and there v?e meet with occasional natural history notes on collecting butterflies, or on birds, &c. observed. For example, we read (vol. ii. p 270) : — " Of aquatic birds I obtained specimens of the white-bellied dipper {Cinclus leucogaster) at Ak- Shor, and afterwards at Tribhun. We often noticed this little fisher boldly plunging into the swiftest torrents, seeking insects in a stream the half of which was con- gealed to solid ice." On the Kilian Pass, about the NO. I 266, VOL. 49] height of Mont Blanc, Dr. Lansdell had his first experi- ence of mountain sickness. He slid off his yak, and' attempted to run up a hill to shoot partridges, but was seized with palpitation of the heart, and was forced to sit down to rest immediately. He appears to have suffered more here than even on the great Karakorum Pass further south (18,800 feet instead of 16,000). Thus our author gradually made his way to India, where we will now leave him. There are so many de- tached points of interest mentioned in his work, that our limited space has only permitted us to select a fev/, here and there, to show its interesting and varied character. The book is dedicated " To his August and Imperial Majesty, the Emperor of China, &c., &c., &c." W. F. KiRBY. HUXLEY'S COLLECTED ESSAYS. Collected Essays. By T. H. Huxley. Vol. I. " Methods and Results." (London : Macmillan and Co., 1893.) T^HERE is probably no lover of apt discourse, of keen criticism, or of scientific doctrine who will not welcome the issue of Prof. Huxley's essays in the present convenient shape. For my own part I know of no writing which by its mere form, even apart from the supreme interest of the matters with which it mostly deals, gives me so much pleasure as that of the author of these essays. In his case more than in that of his con- temporaries it is strictly true that the style is the man. Some authors we may admire for the consummate skill with which they transfer to the reader their thought without allowing him, even for a moment, to be con- scious of their personality. In Prof. Huxley's work, on the other hand, we never miss his fascinating presence : now he is gravely shaking his head, now compressing the lips with emphasis, and from time to time with a quiet twinkle of the eye making unexpected apologies or protesting that he is of a modest and peace-loving nature. At the same time one becomes accustomed to a rare and delightful phenomenon. Everything which has entered the author's brain by eye or ear, whether of recondite philosophy, biological fact or political programme, comes out again to us —clarified, sifted, arranged, and vivified by its passage through the logical machine of his strong individuality. These essays were, he says in preface, " written for the most part in the scant leisure of pressing occupations, or in the intervals of ill-health." Though the oldest bears the date of 1866, he finds, so far as their substance goes, nothing to alter in them. " Whether," he concludes, "that is evidence of the soundness of my opinions or of my having made no progress in wisdom for the last quarter of a century, must be left to the courteous reader to decide." The first volume of the nine, which are to be issued monthly, owes its title to the inclusion therein of the famous essay " On Descartes' Discourse touching the method of using one's reason rightly," and of samples of the application of that method in various fields. Amongst the latter are the essays on the physical basis of life, on the hypothesis that animals are automata, on adminis- trative nihilism, and on the natural inequality of men. February i, 1894] NA TURE 311 The essay on animal automatism was delivered as an evening address at the meeting of the British Associ- ation at Belfast, when Tyndall was president. It was a truly marvellous performance, for it occupied nearly an hour and a half, and was delivered with an appearance of complete spontaneity and ease in the very words which are here printed, without a note or reference of any kind, by a man who, when he first attempted it, " disliked public speaking " and, as he tells us, had a firm con- viction that he should break down every time he opened his mouth. To some readers, as to myself, the short *' autobiography," with which the volume commences, will be new, and owing to its charming frankness and graceful reticence the most delightful chapter in it. Prof. Huxley, doubtless for good reasons, does not tell us where and under what circumstances each of these essays first saw the light, but the autobiography was apparently published with a photograph not many years ago. It is full of good things. The author confesses to having inherited from his father, as well as an inborn faculty for drawing, " a hot temper, and that amount of tenacity of purpose which unfriendly observers sometimes call obstinacy.'' He remembers preaching to his mother's maids intht kitchen, with his pinafore turned wrong side forwards in order to represent a surplice—" the earliest indication I can call to mind of the strong clerical affini- ties which my friend Mr. Herbert Spencer has always ascribed to me ! " Of his schoolmasters he has nothing good to say — they " cared about as much for our intel- lectual and moral welfare as if they were baby-farmers." His great desire on leaving school was to be a mechanical engineer ; but the fates were against this, and he com- menced the study of medicine. It is very interesting to those who know the value and range of his original researches in comparative anatomy to read the statement — " I am afraid there is very little of the genuine natur- alist about me. I never collected anything, and species work was always a burden to me ; what I cared for was the architectural and engineering part of the business, the working out the wonderful unity of plan in the thou- sands and thousands of diverse living constructions and the modifications of similar apparatuses to serve diverse ends." I venture to think that it is not only as a mechanical engineer in par it bus infidelium, as he says of himself, that Prof Huxley has dealt with organic form, but also as an artist, a born lover of form, a character which others recognise in him though he does not himself set it down in his analysis. Some day, it is to be hoped, Prof. Huxley will fill in the outlines of this autobiography, and especially give us an account of those long years of arduous work, of discoveries, struggles, triumphs, and friendships from the time when he succeeded his friend Edward Forbes in 1854 to the present day. No better introduction can be given to Prof. Huxley's collected essays than his own statement of the objects which he has had in view during the years in which, whilst producing also educational books and many larger and strictly scientific works addressed to the limited circle of biological experts, he has by these occasional addresses and articles taught a vast number NO. I 266, VOL. 49] of his fellow-countrymen the value of scientific ways of thinking, and freed them from the fetters of orthodox superstition. These objects have been, he says — " To promote the increase of natural knowledge and to forward the application of scientific methods of investi- gation to all the problems of life to the best of my ability, in the conviction which has grown with my growth and strengthened with my strength that there is no alleviation for the sufferings of mankind except veracity of thought and of action, and the resolute facing of the world as it is when the garment of make-believe by which pious hands have hidden its uglier features is stripped off. It is with this intent that I have subordinated any reason- able, or unreasonable, ambition for scientific fame, which I may have permitted myself to entertain, to other ends ; to the popularisation of science ; to the development and organisation of scientific education ; to the endless series of battles and skirmishes over evolution ; and to untiring opposition to that ecclesiastical spirit, that clericalism, which in England, as everywhere else, and to whatever denomination it may belong, is the deadly enemy of science. In striving for the attainment of these objects, I have been but one among many, and I shall be well content to be remembered, or even not remembered, as such." E. Ray Lankester. A THE PSYCHOLOGY OF TO-DAY. G^'undziigc der PJiysiologischen Psychologie. Von Wilhelm Wundt. 4te Auflage. (Leipzig: Wm. Engel- mann, 1893.) NEW edition of this well-known work will be welcomed by all interested in this developing branch of science, and the author is to be congratulated on the fact that a work of this magnitude should reach its fourth edition in nineteen years. The general plan of the work and the general opinions are unaltered, but there has been much revision and addition of detail throughout. The most extensive altera- tion consists in the much more detailed description of experimental methods, especially in the chapters on the intensity of sensation, and on Time problems. The descriptions are admirably clear, and their value is greatly increased by the addition of numerous woodcuts illustrating the apparatus employed. In the first half of the book, which deals with the anatomy and physiology of the nervous system, one turns with interest to learn what the author has to say on the subject of cerebral locahsation. Wundt opposes the notion that the physiological substrata of complex mental processes can be localised in a limited area of the brain, though he appears later to disregard this when he suggests that his process of apperception is localised in the prajfrontal lobes. While accepting, however, the localisation of motor and sensory processes in a more or lessgeneral way, he hesitates to accept that definitelocalisa- tion which the facts now at our disposal seem to justify, ai any rate so far as concerns the so-called motor area. His attitude on this question is influenced by the fact that he regards the prevailing view as an outgrowth from the doctrine of specific nerve energy, of which he is a deter- mined opponent. One of his chief arguments is derived from the phenomena of compensation when a part of the brain has been destroyed. Wundt's view of this process is that the functions of the destroyed part are taken on 312 NA TURE [February i, 1894 by another part which had previously had a different function ; thus he speaks of an element, which under normal conditions gives rise to a visual sensation, be- coming the seat of a tactile or muscular sensation. It seems much more likely that the new function in such a case is taken on by elements of the cortex previously un- developed, and the fact that compensation occurs so much more readily in the young is in favour of the latter view. On the question which is at present so much debated among English neurologists, viz. whether the Rolandic area of the cortex is to be regarded as motor or sensory (kintesthetic), Wundt does not express a very definite opinion ; he speaks of this area generally as centro-motor, but does not exclude the presence of sen- sory elements, though of a tactile rather than kina^sthetic nature. In the second half of this volume, dealing with sensa- tion, the section on what is usually called the mus- cular sense has been considerably modified. The im- portance of the part taken by impressions arising in the joints is fully recognised, and in the case of passive movement, Wundt agrees with Goldscheider in ascribing to them a very preponderant role, but insists on the addition of elements from the muscles and tendons in the case of active movements. Sensations of innervation are also called in to explain active movement, though Wundt now recommends that this name should be given up, and that this component of the sensation-complex should be called central as distinguished from the peri- pheral components arising in the joints, muscles, tendons, and skin. The author, however, states, as indeed he did in the last edition, that such central components probably have their source in memory-images of movements previously carried out. The theory of colour vision in another section of this part does not differ materially from that brought for- ward in the last edition, and in the fourth volume of " Philosophische Studien," though several matters, and especially the phenomena of contrast, which are referred to central conditions, are more fully considered. A new section has been added on the physical accom- paniments of pleasurable and painful feeling, in which re- cent work on the subject, and especially that of Lehmann, has been embodied. Wundt supposes that the circula- tory and respiratory changes which accompany pleasure and pain are the results of central innervations concomi- tant with the feelings ; pleasurable feelings being asso- ciated with increased rapidity, and painful with inhibition, of the central processes. In the first part of the second volume, in which per- ( eption is dealt with, there is little new ; the most noticeable addition is on the subject of geometric optical liusions. Such illusions are regarded as mainly de- pendent on sensations arising from movements of the eyes. The author does not altogether exclude the influ- ence of association to which some psychologists would refer them, but he objects strongly to the way in which Lipps has explained them by " introducing indefinite aesthetic notions into psychology, instead of referring esthetic effects to definite psychological factors." We have already mentioned the improvements made in the chapter on Time by the description of apparatus and methods. In considering the estimation of time- NO. I 266, VOL. 49] intervals, the work and theories of Miinsterberg and Schumann are adversely criticised, and Wundt takes this opportunity to make a hit at the former psycholo- gist for the large amount of work which he imposes on the muscle sensations in making them responsible for estimation of time and space, as well as for attention and the intensity of sensations. A section is devoted to Hypnotism, in which the views recently advanced by the author are shortly expressed. The hypnotic condition is regarded as dependent on in- hibition of active apperception, i.e. of will and voluntary attention. The explanation of the hallucinations and analogous phenomena of hypnotism is referred to a general law that when the greater part of the brain is out of action, the sensitiveness of the active remainder is increased ; a law which also applies to the explanation of dreams. The doctrine of Apperception, which is the most characteristic feature of Wundt's system, does not appear to have suffered any material change. Apperception, as used by the author, corresponds very closely to the atten- tion of many English psychologists, and Wundt himself occasionally seems to use the terms " apperception" and "aufmerksamkeit" indifferently. The book combines the qualities of a text-book and of a philosophical treatise. It may be used with the greatest advantage as a means of learning the way in which the methods of experimental psychology are employed, and as an account of what we have learnt thereby ; but it is also an able attempt to treat the whole subject of the connection between Mind and Body philosophically. RAILWAY WORKS. Roufid the Works of our Great Railways. By various Authors. (London: Edward Arnold, 1893.) THIS volume consists of a reprint of a very interesting series of articles which appeared some i&'w months ago in the English Illustrated Magazi7te, the authors in most cases being intimately connected with the railway companies' works they describe. Taken as a whole, this book is very readable, and contains much useful in- formation. The London and North-Western Works at Crewe are first described by Mr. C. J. Bowen Cooke, of the loco- motive department. The Crewe Works have been so often described by many people, that the present author ran the risk of being unfavourably compared with the others ; there is, however, no need to fear the comparison, for the article is well done. It is a pity that anything was written on the subject of building an engine in twenty- five hours ; and the author of the article on the Great Eastern Works at Stratford does the same thing on p. 128, although in this case the time is reduced to ten hours. No doubt the statements are wonderful to the general public, but to locomotive builders they merely go to show how railway sliareholders' money is sometimes wasted. Chapter ii. (written by Mr. C. H. Jones, of the locomotive department) describes the Derby Works of the Midland Railway Company. In orderto show the sizeof the staff on this railway in the locomotive department only, the fol- lowing figures are of interest : — There are 13,150 men, February i, 1S94] NA TURE Z^Z 232S locomotives, 302 stationary engines, 267 stationary boilers, 1023 hydraulic machines, and 416 cranes of every kind, besides many other mechanical appliance?, the super- vision of which come under the locomotive department. Mr. A. J. Brickwell, of the surveyors' department of the Great Northern Railway, is the author of Chapter iii. describing the locomotive work of that company at Doncaster. High speed has always been associated with the Great Northern, and very properly so, for this company has always held the palm in this respect, thanks to the magnificent engines designed by Mr. Stirling, the locomotive engineer. A passable illustration of Xo. 776 engine, built in 1S87, gives some idea of the bold outline of the " flyers " that daily tackle the " Scotchman " express, and seldom drop a minute on the road. What locomotive engineer, besides Mr. Stirling, of Doncaster, can point to engines like these, designed twenty-three years ago, and can still claim that the engines are able to hold their own with their present-day rivals, be they compound or otherwise ? Chapter iv., by Mr. Wilson Worsdell, the locomotive superintendent of the North-Eastern Railway, deals with the works of that company, and we naturally read a good deal about the virtues of the two-cylinder com- pound locomotive, besides the excellent description of the works. As this company is building some very powerful non-compound express engines, it would appear that compounding is not the source of economy hitherto claimed for this system. The Great Eastern Railway Works at Stratford are described by the secretary to the locomotive superinten- dent, Mr. Alex. P. Parker. The article is well written and interesting, notwithstanding the absurdity of claim- ing credit for throwing an engine together in ten hours. Everything at Stratford is certainly on the most modern system of management and manufacture, and those responsible may well take credit for being "up to date." Chapter vi. is of much interest, because it deals with the Great Western Railway Company's works at Swindon, and particularly so because of the now defunct broad- gauge system with Sir Daniel Gooch's noble engines. These are well illustrated in the text, and some exciting runs on the engine of the " Dutchman " are described. The following chapter deals with the new narrow-gauge engines built to take the place of the veterans when the line was converted to the narrow gauge. The last chapter in the book is on the Cowlairs Works of the North British Railway, the only Scotch railway described, the author being Mr. A, E. Lockyer, of the locomotive department. This article is interesting, but it appears to be unduly curtailed, and has fewer illus- trations than the other chapters ; the illustrations that are included, however, are certainly the clearest in the book. The unique part of this chapter is the description of the working of the trains up the incline at Cowlairs from the Glasgow terminus at Queen Street, by means of a stationary engine and endless wire rope. The descrip- tion of the works is good. Altogether the volume is most interesting, and should be read by all connected with, or travelling by, the rail- ways of this country, containing, as it does, much unique information on a subject little thought of outside the railway circle. N. J. Lockyer. NO. 1266, VOL. 4q] ESSENTIALS OF CHEMICAL PHYSIOLOGY. The Essentials of Chemical Physiology. By Prof. W. D. Halliburton. (London : Longmans, Green, and Co 1893-) T^HERE is no doubt that this elementary text-book -»- by Prof. Halliburton will be welcomed by students of chemical physiology. The teaching of physiology has come to be so much a matter of laboratory instruction that the demand for carefully written text-books dealing with the practical parts of the science, has become a very pressing one. This book is a companion volume to Prof. Schafer's "Essentials of Histology." It is constructed on the plan originally adopted in the syllabus of lectures by Prof. Burdon Sanderson. At the beginning of each chapter there is a series of exercises which form practical illustrations of the subject with which the chapter deals. The exposition which follows the list of exercises is mani- festly the work of one who is a master in the modern methods of teaching, and the frequent references to recent research give to these chapters an interest which is unfortunately sometimes absent from text-books. The elementary is followed by an advanced course, in which are given the more elaborate exercises on the subjects of the earlier chapters. In this course perhaps too little attention is paid to experiments on the living organism. The exercises given are concerned chiefly with those substances which can be extracted from the organism by some means or other. We have, for example, a chapter on hccmoglobin, in which we get instruction in regard to substances such as alkaline ha^matin, hasmochromogen, haematoporphyrin. There are no exercises on oxygen or carbonic acid, and yet the relation of these gases to the organism is surely of vastly greater importance in physio- logy than haemochromogen. Similarly we have the analysis of urine considered even so far as to include the estimation of creatinine, while there are no exercises showing how the constituents are related to physiological conditions. The function of such instruction as we find in this book is not only to bring physiology to practical expression, but to show its relation to the questions of practical medicine ; and exercises, with this in view, are more to be desired than the estimation of creatinine. The diffi- culties in the way are not such as to prevent the intro- duction of experiments of the kind suggested. In the appendix the author describes one or two examples of complicated apparatus, and gives some chemical tests. Apparatus in the complicated forms is always a burden to the physiologist, and any allusion to it should appear in an appendix, if at all. It is difficult to see why the author has placed Kjeldahl's method for estimating nitrogen in the appendix. The method is an easy one and is in universal use, and should be familiar to advanced students. It would also be well to present it to beginners in some simpler form than that which is given here. i\part from its relation to experimental work the book is of interest in so far as it gives indication of a new de- parture in physiology. We are told that " the chemist cannot, at present, state anything positive about living matter." So far as we know apparently, we cannot say that there are any chemical changes in living cells. 314 NATURE [February i, 1894 The author also discards any physical or chemical account of absorption. The cells absorb in virtue of their " vital activity." Finally, in describing the process of respiration, he states his position generally in the following sentence : — " Much recent physiological re- search has shown that we must largely abandon physical theories for what are called vitalistic theories ; in other words, the vital processes of selection possessed by the cell may counteract or supplement physical processes." It is probably significant, as it is new for vitalism, as a theory of life, to put forward a claim to recognition in the name of " recent research " We are accustomed to the theory being classed among things which are not only characterised by the flavour of antiquity, but are familiar to those only who shun all kinds of experimental investigation. If vitalism be adopted as the true point of view in biology, it will clearly be necessary to recon- sider the position of physiological chemistry as a science. OUR BOOK SHELF. The Sacred City of the Ethiopians. By J. T. Bent. (London: Longmans, 1893.) In the interesting volume before us, Mr. Bent gives us a very readable account of the journey to Ethiopia which he and his wife undertook in the year 1893. The work contains twelve chapters by Mr. Bent, a chapter of rather more than fifty pages by Prof. David Heinrich Miiller, of Vienna, upon the inscriptions at Yeha and Aksum, an appendix on the morphological characteristics of the Abyssinians, by Dr. J. G. Garson ; and a map of the country, showing Mr. Bents route. Mr. Bent's purpose in visiting Ethiopia was archaeological, and he took con- siderable pains to visit all the sites of ancient cities, some- times even seeming to carry his life in his hands in so doing. The principal sitesexaminedbyhim were Asmara, Keren, Adoua, Yeha, and Aksum, and he made pilgrim- ages to the famous monasteries of Bizen and Debra Sina, into which last religious house Mrs. Bent succeeded in gaining admittance by assuming male attire. Through- out his travels Mr. Bent was shown the greatest courtesy by the Italians, and although many parts of the country were convulsed by civil war, yet under their direction Mr. Bent made his way in comparative security. Mr. Bent has noted many particulars of interest, and the illustrations made from photographs taken by Mrs. Bent give additional interest to his narrative ; but the most important part of the book for the Orientalist are the translations of the Himyaritic and Ethiopic texts which Prof. D. H. Miiller has made from Mr. Bent's excellent squeezes. These show that the Sabeans migrated into Ethiopia at a much earlier date than is usually supposed, and they are full of historical and archaeological interest. It is true that some of the texts have been copied and published before, but the new critical investigation by such a competent scholar as Prof. Miiller has resulted in the elucidation of many important details. If Mr. Bent's book runs into a second edition, he will do well in re- vising his account of the Mohammedan conquest of Ethiopia to note several facts given in the account of the invasion, written in Ethiopic by a monk, the text of which has recently been published in Berlin by Dr. A. W. Schleicher, entitled " Geschichteder Galla." Meanwhile we thank Mr. Bent for the squeezes and the labour which he undertook to obtain them. Era i Batacchi indipoideiiti. Viaggio di Elio Modigliani, publicato a cura della Societa Geografica Italiana. (Rome, 1892.) SiGNOR Modigliani communicated an account of his journey through Sumatra in 1890-91, to the Genoa Geo- NO. 1266, VOL. 49] graphical Congress of 1892, and it is now published in book form, enriched with many excellent illustrations. He describes in some detail the Battak people of Central Sumatra, one of the most remarkable remnants of primi- tive culture in all Asia, as they retain their own forms of architecture, industry, and writing, together with their primitive religion and their political independence, although surrounded on every side by Mohammedan tribes and Dutch supremacy. The headquarters of the shrunken remnants of the Battaks is round the great lake of Toba, of the western side of which Signor Modigliani has made a large scale map, published in the book. The scenery of this lake is very fine, and a long panoramic view goes far to justify the enthusiasm of the author's description. The main object of the journey was to make ethnographical collections, and some excellent photo- graphs of the Battak physical type are reproduced, to- gether with examples of native art, architecture, and industry. Incidentally a good many adventures befelthe author, and these he does not minimise. While there is little in these pages of real importance that has escaped the careful observation of the Dutch and German observers, who have made an almost exhaustive study of the Battaks, the narrative is interesting, and the col- lections should be very useful to students in Europe. A short meterological appendix gives observations of tem- perature, pressure (aneroid), humidity, and rainfall from October, 1890, to April, 1891. Romance of the Insect World. By L. N. Badenoch, (London : Macmillan and Co., 1893.) This is a pleasantly written little book, which contains much interesting information on insect life and habit. The metamorphoses of insects, their food, hermit homes, social homes, defences and protection through adaptation are successively considered. Although there is not much evidence of individual observation, the author has been careful in his selection of authorities. The book is intentionally descriptive rather than explanatory, and, since the descriptions are picturesque without inaccuracy, may be safely recommended to those who seek, for in- formation in one of the most fascinating departments of natural history. LETTERS TO THE EDITOR. The Editor does not hold himself responsible for opinions ex- pressed by Ids correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part at the lake margin, found to be over 400 feet above the deepest point of the lake. There are three possible explanations of this phenomenon : either (l) the rivers had a fall of over 400 feet in less than a mile, while above this the slope was only very slight, or (2) the lake valley has subsided 400 feet, or (3) it has been deepened by ice eroion. Few will, I think, consider the first two to be possible, and there is evidence that they are not. For fuller details reference may be made to my forthcoming paper. It seems to me that we have here a reasonable and possible method of testing the value of the rock basin theory, and I believe that its application in other regions will show that ice can, where conditions were favourable, excavate lake basins of large size, and has done so. This conviction comes to me in spite of distinct preconception and prejudice against the theory. R. S. Tarr. Cornell University, Ithaca, New York, January 15. Glacial Erosion in Alaska. References in your recent correspondence to my estimate of the rate of erosion by the Muir Glacier in Alaska, call for a supplementary statement. The estimate was made in 1886 by determining the amount of sediment per gallon brought down by one of the sub-glacial streams, and calculating as best I could the area of the glacial basin, the amount of annual rain- fall, and the probable waste by evaporation and by the formation of icebergs. The result obtained was the removal of one-third of an inch of rock per annum over the glaciated area. Since my visit to the Muir Glacier, Prof. H. F. Reid has spent two summers on the same ground with more ample pre- parations for collecting the facts. His report may be found in the National Geop-aphic Magazine (Washington), vol. iv. p. 51. According to his calculation, the erosion amounts to three- quarters of an inch, or nearly three times as much as I had estimated. I have little question that Prof Reid's estimate is more nearly correct than mine, since my calculation was based upon the removal of sediment from the entire drainage area of the glacial amphitheatre. Prof Reid, however, rightly con- cludes that this is full twice as large as the actual t)ed of the glacier to which the glacial erosion was practically limited. Making that correction, our estimates are in close agreement. It should be observed, however, that these observations do not bear directly upon the question of the erosion of lake basins by glaciers ; for the Muir Glacier, whose sediment was estimated as above, is moving down a slope of about 100 feet per mile. The erosion over this slope, therefore, may be quite different from that at the foot of the glacier as it descends below the water-level into the head of the tidal inlet, where, I should presume, the erosive power would be soon reduced to a small quantity. Still, the mechanical problem involved in calculating the distribution of the force of a descending glacier as it reaches the foot of the incline is too complicated for ready solution. That there is some scooping out of a rocky basin in such cases seems amply proved by the facts which I have quoted in my " Ice Age "(pp. 237-239), from Prof. I. C. Russell, concerning the formation of cirques in the Sierra Nevada Mountains. In my own observations two or three years ago, however, upon Lake Geneva in Switzerland, I was led to believe that whatever might be true of glacial erosion, attention enough had not been given to the theory of a possible buried outlet leading past Mount Sion and Frangy to Seyssel. Certainly the course of the Rhone across the spur of the Jura Mountains at Fort De I'Ecluse is very suggestive of recent occupancy. Among the great lakes of America there can be but little doubt that Lake Erie and some others owe their existence almost wholly to the choking up of preglacial outlets of the valleys by glacial debris. The great depth of Lake Geneva, however, would render it improbable that it was wholly due to such a cause, and I dp not NO. 1266, VOL, 49] know that the conditions are such as to permit the supposition made above. I distinctly remember, however, that from the vicinity of Seyssel there was an unobstructed view between the mountains towards Geneva, and that the gravel deposits extend from Geneva far down towards those which appear a^iout the head-waters of the small tributary to the Rhone which joins it at Seyssel. Perhaps this theory has been fully considered and refuted ; if so, I have not seen the refutation. G. Frederick Wright. Oberlin, Ohio, January 17. On the Equilibrium of Vapour Pressure inside Foam. It is known that the vapour pressure near a curved liquid surface is different from that near a flat surface, being less near a concave surface and greater near a convex surface than near a flat one. Now, inside foam bubbles the surfaces are approxi- mately flat, except where three bubbles join to form an edge, and along these edges the surface inside any bubble is concave with a very small curvature. How does it happen that equilibrium caft exist with the small pressure in these corners, and a larger pressure required near the flat surfaces? In the first place it maybe that equilibrium cannot exist, and that all foam is essentially unstable ; and it would be almost impossible to disprove this by a direct experiment. If, however, foam can be stable, it seems as if the only conclusion possible were that the flat surfaces will evaporate and thin down, the liquid condensing in the corners, until the flat parts are so thin that they are in equilibrium with a smaller vapour pressure than a thick liquid surface would require. In other words, that the vapour pressure near a very thin film may be less than it can be near a thick one at the same temperature. It is evident that inside or out- side a solid box stability must be possible, so that the second alternative is the only solution. We see a phenomenon of this latter kind in the hygroscopic films that cover glass. Being due to an attraction of the glass for water there results what I am describing, namely, that in an atmosphere incompletely saturated a film of such a thickness can exist that the vapour pressure near it is such as corresponds to the existing vapour pressure in the surrounding atmosphere. If we knew the connection between the thickness of a film and the vapour pressure near it, it would be possible to calculate the shape of a bubble near a corner. The pressure at any point being that due to the thickness diminished by an amount proportional to the curvature. So that \{ f {y) be the pressure due to a film of thickness y and r be the radius of curvature of the surface of the liquid near a corner, we get as the equation of the surface T /O') - ,s, = constant, r(5 - a) when T is the superficial tension which may be a function o\ y and 5 the density of the liquid and a of the vapour of the liquid, which latter will depend on the vapour pressure inside the bubble. To determine this and the constant we should [ know how much liquid we have at our disposal (V = \ydx) to lie round the bubble and to supply vapour inside, and it would appear that inside a cubical box falling freely, for instance, I a bubble would always be spherical unless the quantity of liquid were sufficiently small to require the sides of the bubble to be flattened against the sides of the box ; i.e. unless the volume of liquid were less than i - 7r/6 times the volume of the box. In connection with my letter in last week's Nature, I may suggest that a possible cause of warming of solid powders when mixed with liquids, is that the solids have already got a film of water over their surfaces, which being on the outside in contact with air, is at least on its outer surface in tension, and that this enormous area of air-liquid film disappears when the solid is immersed in liquid, and that the heat is due to the extinction of this great film. It would require very careful measurements of the heat evolved and estimates of the area of the film con- cerned, to decide whether this would account for the heating: observed. In my former letter I assumed that liquids would soak up into dry powders, and that these latter warmed liquids when mixed with them. The suggestion I am now making, would account for a warming being produced by damp powders^ or by spray or cloud falling into a liquid. G. F. Fitzgerald. Trinity College, Dublin, January 29. February i, 1894] NATURE Ty^^l A Liquid Commutator for Sinusoidal Currents. My attention has been drawn to a note in Nature of January ii (p. 253) which quotes from the Electrical World of New Yorlc "a novel method of obtaining sinusoidal alternating currents of very low frequency," described by Lieutenant F. Jarvis Patten. The method is to make a pair of conducting plates revolve in a vessel of liquid which also contains a pair of lixed plates. This liquid commutator, however, is not new. It was the subject of a joint patent taken out by Mr. C. G. Lamb and myself a year and a half ago, and it was used in connection with the magnetic curve-tracer in my British Association lec- ture at Edinburgh on " Magnetic Induction,"' and again at the Royal Society soiree last May. It has been, in fact, for some time an item in Messrs. Nalder's catalogue of scientific appar- atus. A description of it was published in the Electrician of November 18, 1892. J. A. EwiNG. Engineering Laboratory, Cambridge, January 26. A Curiosity in Eggs. A COMMON "barn-door" hen, belonging to a neighbouring farmer, recently laid an egg measuring 4^ inches in length by 7 inches in circumference ; weight 6 ounces. On this egg being carefully broken a second perfect egg, with hard shell of ordinary size (3 inches by 5i in circumference), was found float- ing in the contents of the outer one. The contents of both eggs appeared to be normal and healthy. This is surely a very unusual occurrence. E. Brown. Further Barton, Cirencester, January 16. RICHARD SPRUCE, Ph.D., F.R.G.S. ALTHOUGH little known beyond a limited circle of botanists and South American explorers, the sub- ject of this notice was in many respects a remarkable man, who, under more favourable circumstances, would have acquired a wider reputation. He was the son of a schoolmaster at the village of Ganthorpe, Yorkshire, and at an early age showed a taste for botany, having compiled a '' List of the Flora of the Malton District " in 1837, when he was just twenty years old. For some years he was teacher of mathematics at the Collegiate School, York ; and during his holidays he explored Esk- dale, Teesdale, Killarney, and other districts, paying special attention to the mosses and hepatics, among which he discovered many new species, which he de- scribed in the Phytologist, the Transactions of the Botani- cal Society of Edinburgh, and in the London Journal of Botany. In 1845 he went to the Pyrenees, where he spent ten months, chiefly devoted to his favourite groups of plants, among which he discovered a large number of new or rare species. These were fully described in a paper published in the Annals and Magasi?te of Natural History in 1849. The delicate state of his health requiring a warmer and more equable climate than that of his native York- shire, he decided, by the advice and with the assistance of the late Sir William Hooker, to visit the Amazon valley as a botanical collector, with the object, if possible, of reaching the head waters of the Orinooko and the eastern valleys of the Andes, districts whose riches had been indicated by the explorations of Humboldt and Bonpland at the beginning of the century, but which no experienced botanical collector had since visited. In- valuable assistance was also given by the late Mr. Ben- tham, who undertook the great labour of dividing and distributing the dried plants as they arrived in England, and sending sets to those who subscribed for them, thus 'acting as an unpaid but most efficient agent. The same eminent botanist described most of the new species of flowering plants as they arrived, thus making known the value of the collections, and ensuring the sale of the whole of the specimens. In July, 1849, Mr. Spruce arrived at Para (where the NO. 1266, VOL. 49] present writer first made his acquaintance), and during the succeeding fifteen years carried out successfully a series of voyages and explorations in equatorial South America, surpassing in extent, probably, those of any other scientific traveller. A mere enumeration of these journeys can alone be given here, in order to show how much was accomplished amidst all the difficulties due to climate, scarcity of food, scanty means, and imperfect means of transportation, aggravated by solitude and i ill-health. After a few months in Para and its vicinity, he moved to Santarem, at the mouth of the Tapajoz River. Here he remained for a year, collecting and studying the remarkable shrubby vegetation which surrounds the town, consisting largely of species then entirely new to botanists. During this time he made an exploration up the river Trombetas and its tributary the Aripecuru to the limit of canoe navigation. The following year was spent at Manaos (Barra do Rio Negro) exploring the surrounding forests and streams. He next ascended the Rio Negro in a large boat of his own, so as to be able to collect and preserve plants during the voyage. Two. months were occupied in ascending the river as far as San Gabriel, situated on the cataracts of the Rio Negro, where he rested seven months, making numerous canoe excur- sions across the river to the various islands and to tributary streams, not without danger amid the roaring waters produced by the granite rocks and reefs which for some miles here fill the broad river-bed. Spruce next ascended the Uaupes River as far as the first cataract at Panure or San Jeronymo, which he made his headquarters for another seven months. Here he was delighted by the richness and novelty of the forest vegetation, which was almost wholly new in species, and even in some of the genera, .Many of the loftiest trees had flowers of extreme beauty, especially those of the natural orders VochysiaceJe, Tiliaccri?, Bombaceee, Lecythideae, Rhizoboleae, and Rubiacea;, and to add to the botanical interest of the district, when the rainy season brought the flowering of the forest trees to a close, the ground beneath them became ornamented with thousands of curious herbaceous plants, mostly leafless but adorned with delicate or brilliantly coloured flowers. These belonged mainly to the genera \'oyria, Burman- nia, Ptychomeria, and the TriuridccC. Here also fungi were more abundant than in any other locality visited, and about 200 species were collected, many of which were as varied and brilliant in colouring as the flowers them- selves. Leaving the Uaupes the traveller made his next head- quarters at San Carlos, the first village in Venezuela situated on the north bank of the Rio Negro, not far from the entrance of the Cassiquiare. From this station excursions were made up the Rio Negro and many of its tributaries, and also through the entire length of the Cassi- quiare to Esmeralda on the Upper Orinooko. He was now in the country explored by Humboldt and Bonp- land nearly a century before, and collected hosts of plants, which were known only from the specimens sent home by those botanists, together with considerable numbers of new genera and species. In order to procure food in this notoriously hungry region, he made a special journey from San Carlos to the cattle district of the cataracts of Maypures on the Orinooko, travelling over the portage of Pimichin which forms a narrow water- shed between the two great river systems. After twenty months in this district he descended again to Manaos,. from which he had been absent three years, and pre- pared for his great journey to the Andes. Ascending the main stream of the Upper Amazon, and entering its great southern tributary, the Huallaga, he passed beyond its first rapids, and by means of a small western affluent and a day's journey overland, reached Tarapoto. This is a town of about 7000 inhabitants,. NATURE [February I, 1894 beautifully situated in a level plain about 1200 feet above the sea, and almost entirely surrounded by forest-clad mountains of moderate height, from which abundant streams descend through narrow ravines, offering in every direction a rich harvest for the enthusiastic botanist. Here Spruce remained for nearly two years, exploring the country for twenty op thirty miles in every direction, occasionally remaining weeks at a time in the more pro- mising mountain localities. Rich collections of all orders of plants were here obtained, especially of ferns and of his favourite groups the mosses and hepatics, while on the mountains — though only 5000 to 6000 feet in eleva- tion, many north-temperate genera, such as Ranunculus, Rubus, Stellaria, and many others, made their first appearance. In March, 1857, he left Tarapoto for the Andes of Ecuador by way of the Upper Amazon and its tributary, the Pastasa, reaching Canelos by a northern branch, the Bobonasa, and thence through the forest to Banos. On the way he had to cross the river Topo by bamboo bridges, constructed afresh by every traveller from rock to rock across the broad mountain torrent. The stream, however, was in flood, and he had to wait four days before the bridge could be constructed, and then the water was so high and the passage so dangerous that most of his baggage — books, manuscripts, micro- scope, &c. — had to be left behind under a thatch of leaves till they could be sent for, his party of sixteen per- sons being in danger of starvation had they waited longer. After reaching Banos, the packages were sent for, and recovered without injury. During his enforced stay on the banks of the Topo, he had found the forest so rich in plants — especially in his favourite hepatics — that after some weeks he returned there in order to obtain a more complete series of its botanical treasures, and again had the greatest difficulty and risk in passing the flooded river, of which he declares that the only pleasant recol- lection he retains is of the new and strange hepaticae which he collected on its banks. After some months at Baiios, he devoted more than three years to the continuous exploration of the forests and higher mountains of Ecuador, visiting in turn Tun- guragua. El Altar, Guayrapata, Azuay, Pichincha, and Chimborazo, but devoting most time to the first named. In the year i860 he was commissioned by Mr. Clement Markham, on behalf of the Indian Government, to procure seeds and young plants of the Cinchona sticdrudra, one of the species which produces the best quinine, in order to establish plantations of this precious tree in the Nilghiries. For this pur- pose he settled himself in the forests on the western slope of Chimborazo, where this species is found between the heights of 3500 and 7000 feet above the sea-level. Assisted by Mr. Robert Cross, a gardener sent for the purpose of taking charge of the plants on the voyage to India, he collected abundance of ripe seeds and raised a quantity of young plants, all of which arrived safely, and helped to form those fine plantations which now supply an abundance of the valuable drug. He also wrote an elaborate report on the Cinchona forests, their vegetation, and the mode of collection and preparation of the bark, which is considered to be one of the best works of its kind that has ever appeared. This expedition, undertaken and completed under the pressure of almost continual suffering, was the conclu- sion of Spruce's labours in South America. So long as he had remained in the warm equable climate of the equatorial plains his health had been better than when in England, and appeared to be fairly re-established, notwithstanding much privation and occasional attacks of fever. He suffered, however, from chronic diarrhoea ; and the extremes of temperature and of moisture in the forests and mountains, having frequently to wade for hours in ice-cold water, and exposure to the severe and change- NO. 1266, VOL. 49] able climate of the high Andes, which, as Mr. Whymper assures us, is the most detestable in the world, brought on an attack of some obscure malarial disease which rendered all further exertion impossible, and led to com- plications which rendered the remainder of his life that of a confirmed invalid. Under medical advice he re- moved to the hot and dry sea coast, remaining there for two years in the vain expectation of a recovery sufficient to enable him to extend yet further his botanical ex- plorations. All hope of renewed health being given up, he re- turned to England in 1864. After a few months in London, he went to live at Hurstpierpoint, Sussex, in order to be near his correspondent, Mr. William Mitten, who had undertaken to describe the whole of his new South American mosses. After remaining there two or three years, in varying conditions of health, he deter- mined to remove to Yorkshire, where a cottage was offered him on the Castle Howard estate, and where his slender means would enable him to command greater comforts than elsewhere. This was rendered necessary by the loss of a large part of the money derived from the sales of his collections, owing to his having placed it at interest in a commercial house in Ecuador, which, un- fortunately, became bankrupt. He was granted a small Government pension in recognition of his services in regard to the establishment of the Indian Cinchona plantations and his complete incapacity for any further remunerative work, and on this and the small remnant of his property he was able to live in some com- fort, though with the very greatest economy. He resided first at Welburn and afterwards at Coneysthorpe, both small villages situated near Malton and in the immediate vicinity of the noble park of Castle Howard. Here he lived the life of a confirmed invalid, rarely of late years leaving the house, keeping in a room of uniform warmth and subjecting himself to a rigid system of diet. By these precautions he prolonged his life to the ripe age of seventy-six, and then only succumbed to an attack of influenza, from which his much enfeebled system was unable to rally. During the twenty-five years of his secluded life in Yorkshire he was always occupied with some botanical work, although for much of the time he could only write or use his microscrope while reclining on a couch. His more important works during this period were his " Palmas Amazonics," forming vol. xi. of the botanical series of the Journal of the Linnean Society, and his " Hepaticce Amazonicae et Andinse," in the Transactions of the Botanical Society of Edinburgh, 1885. During the last few years he published many papers on new Hepa- ticae, both American and European, and carried on a considerable correspondence with students of that group in all parts of the world, by whom he was looked up to as one of the greatest, if not the greatest, of living authori- ties in their favourite study. Having had the pleasure of Dr. Spruce's acquaintance from the time when he reached Para in 1849— an acquain- tance whichsoon ripened into friendship during the many days spent together in various parts of the Amazon and Rio Negro, in London, at Hurstpierpoint, and during several visits to him at Welburn and Coneysthorpe— a few words descriptive of his appearance and character may not be out of place. Richard Spruce was tall and dark, with fine features of a somewhat southern cast, courteous and dignified in manner, but with a fund of quiet humour which made him a most delightful com- panion. He possessed in a marked degree the faculty of order, which manifested itself in the unvarying neatness of his dress, his beautifully regular handwriting, and the orderly arrangement of all his surroundings. W^hether in a native hut on the Rio Negro, or in his little cottage in Yorkshire, his writing materials, his books, his micro- scope, his herbaria, his stores of food and clothing, all February i, 1894] NA TURE 319 had their appointed places in which they were always to be found. This habit of order made him an admirable collector, and I well remember, on visiting Kew after my return from the Amazon, the late Sir William Hooker took out some bundles of plants collected by Dr. Spruce and pointed out to me how well chosen and beautifully preserved they were, notwithstanding that they had been collected in one of the very moistest climates in the world, in which the care and labour required to produce such a result was very great. He was quick at languages ; spoke and wrote French with ease ; and in South America rapidly acquired the Portuguese and Spanish languages, for the latter of which he had a great admira- tion. He had literary tastes, and was fond of the old poets ; he was full of anecdote, and even when suffering from illness an hour would rarely pass without some humorous remark or pleasant recollection of old times. He was an advanced Liberal in politics, a true lover of the working classes, and nothing more excited his indig- nant wrath than to hear of the petty, but cruel, per- secutions to which they are often subjected. In all his words and ways he was a perfect gentleman, and to possess his personal friendship was a privilege and a pleasure. Of his merits as a botanist it must be left to experts to speak ; but his writings show that he had great powers of observation, and that nothing escaped him that could throw light on the peculiarities of the grand and luxuriant vegetation among which the best years of his life were passed. His papers and letters sufficiently prove that he possessed a clear and picturesque style of writing, and it is to be hoped that the journals kept during his fifteen years' exploration, which he was himself unable to prepare for publication but which must be full of interesting matter, may soon be given to the world. His sole executor is his old friend and neighbour, Mr. Matthew B. Slater, of Malton. A. R. W. PRECIOUS STONES. /^NLY twenty-five years have elapsed since the exist- ^^ ence of diamonds in South Africa was first made known, and during that period the diamond trade of the world has undergone a complete revolution. The work- ing of diamond gravels in Brazil has been almost entirely abandoned, while the search for the gem in India, Borneo, and other districts has been seriously dis- couraged. The export of rough diamonds from South Africa rose gradually from 200 carats in 1867-68 to 3,841,937 carats in 1888, when it attained a maximum: since that date, however, there has been a slight decline in the output of the mines. The annual value of the diamonds raised in South Africa now exceeds ^^4,000,000. Strange to say, the discovery of the new and abundant source of diamonds has not had any serious effect in diminishing the market value of the gem. When the diamond was first discovered in South Africa, the esti- mated value per carat of the rough stones was about ^i lay.; in 1890 the price had risen to £\ i^s. 2,d., and last year it declined to /i 5^-. 8^. The foregoing particulars are taken from a recently published book which gives an admirable account of the origin of the diamond industry in South Africa, and of the successive changes made in the method of mining and washing the " blue-earth " which yields the gems.i This work originally appeared as a guide to the Kimberley exhibition of 1892, and contains so much valuable information in a small compass, that the author has been well-advised in issuing it in its present more permanent form. 1 "Diamonds and Gold in South Africa." By Theodore Reunert, M.Inst.M.E., Assoc. M.Inst.C.E., with Maps and Illustrations. (London : E. Stanford; and Capetown, Port Elizabeth, and lohannesburg : I. C. Juta and Co., 1893.) NO. 1266, VOL. 49] The working of the celebrated mines about Kimber- ley was commenced by adventurers working indepen- dently in their claims. But as the mining was carried to greater and greater depths, combined action became necessary, and gradually the claims were amalgamated and bought up by large companies. Up to the year 1872 the working of the claims in the South African mines was carried on by a system of road- ways, which were laid out when the concessions were first granted. About the date named, the use of these roads had to be abandoned in favour of a system of haulage by wire ropes — these making a network over the whole of the mines. The appearance of the mines under these two systems of working is admirably illustrated by photo- graphs in the work before us. By the year 18S4, the mine at Kimberley having been carried to a depth of 40a Exact size and shape of a diamond found in the De Beers Mine, and exhi- bited at the Paris Exposition, 1889. Weight, before cutting, 428^ carats, after cutting, 228^ carats. Diamond found in Jagersfontein Mine in June 1S93. Length (a) ai in.; greatest width (b) 2 in. ; smallest width (c) ij in. Thickness at {b) end ij in.; thickness at (c) end 5 in. Extreme girth in width (taken from e to d) 5g in. Extreme girth in length (taken from y to g) 6| in. Gross weight 969J carats. feet, and heavy falls of material having produced serious loss and inconvenience, it was felt that the time had come for carrying out a totally different system of mining there. Accordingly, in that year, inclined shafts, starting from the surface, outside the limits of the mine, were put down, and these inclined shafts have been since superseded by vertical ones. The changes in the working of the Kimberley Mine have been followed by similar alterations in the nature of the operations carried on in the three other great mines in its immediate neighbourhood — De Beers, Bultfontein, and Dutoitspan. These four mines are in the vicinity of the townships of Kimberley and Beaconsfield in the British colony of Griqualand West. The only other im- 320 NATURE [February i, 1894 portant diamond mine in South Africa is that of Jagers- fontein, situated in the Orange Free State, about eighty miles to the south-east of Kimberley. The diamond mines of South Africa are not less remarkable for the size of the individual stones that they have yielded, than for the vast amount of the precious material with which tiiey have flooded the markets of the world. The "Braganza" diamond, which belonged to the Emperor of Brazil, is said to weigh 1680 carats, but it has never been subjected to the inspection of experts, and there is every reason to believe that it is nothing but a colourless topaz. In the same way the reputed diamond of the Rajah of Matan in Borneo (367 carats) has been recently shown to be only a piece of quartz. The " Great Mogul," the Regent or Pitt diamond, and the Koh-i-nur, the finest productions of the Indian mines, are said to have originally weighed 787I, 410, and 193 carats re- spectively, but were reduced by cutting to 279/,.;, 136^-, and \02\ carats. The Brazilian mines have yielded the Portuguese Regent and the Star of the South, the former of which, on cutting, yielding a gem of 215 carats, while the latter weighed 254^ carats in the rough. The South African 'mines have, however, produced stones surpassing in size all those hitherto obtained either from India or Brazil. Some of these stones are, it is true, of a yellow colour, and therefore of comparatively small value ; but others, like the Porter- Rhodes diamond (150 carats), the De Beers diamond (428A carats), and the Jagersfontein diamond (969^ carats) — the last-men- tioned having been discovered as recently as June 30, 1893 — are remarkable for their freedom from any trace \ of yellow tint, and for the perfect whiteness or even blue-whiteness of their colour. We are able to give outlines drawn to the true scale of the two largest South ', African diamonds, the one characterised by its crystalline ' form (a regular octahedron), the other by its irregularity of shape. These are taken from Mr. Reunert's book. Another book on precious stones that has recently appeared is of a very different character, and deals not only with the diamond, but with all the other materials held in esteem ^by jewellers.^ The two works are, how- ever, equally entitled to praise for the accuracy and fulness of the information they supply, and for the manner in which the latest sources of information have been utilised. The distinguishing feature of Dr. Doelter's book upon precious and ornamental stones is the care which has been bestowed upon the directions for their easy and certain discrimination. In the earlier chapters, the descriptions of the various methods for determining and accurately defining the specific gravity, cleavage, hard- ness, refractive index and double refraction, as well as the colour, pleochroism, and absorption of minerals, are very full and entirely satisfactory. The second part of the work contains systematic descriptions of the minerals employed for purposes of ornament ; and these, as might be expected from a mineralogist of Dr. Doelter's position, leave nothing to be desired in the way of completeness and accuracy. No less admirable are the accounts given of the artificial production of these minerals, of the materials made to imitate them, and of the value of gems and the modes of cutting them. Details of this kind are of much practical v^alue, and add greatly to the usefulness of the book as a work of reference. The position of certain minerals in the estimation of jewellers is liable to vari- ation as the popular taste changes, and it is certainly not the same in different countries. Dr. Doelter's classi- fication will, however, we think be generally accepted as a judicious one. Of precious stones proper he admits 1 " Edelsteinkunde ; Bestimmung und Unterscheldung der Edelsteine und Schmucksteine. Die Kiinustliche Darstellung der Edelsteine. " Voq Dr.C. J)oeker, o " Prof, der Mineralogie an der K.K. Univer^itat Graz. (Leipzig : V^eit and Co., 1393.) NO. T 266, VOL. 49] three classes, in the highest of which he places only the diamond, the various forms of corundum, the emerald, and the spinel, though possible exception may be taken to the high position allowed to the last of these. The second-class contains euclase, chrysoberyll, zircon, phenacite, topaz, the noble opal, garnet and tourmaline. To the third class are relegated the turquoise, olivine, cordierite, kyanite, andalusite, staurolite, hiddenite, axinite, vesuvian, and diopside. The " semi-noble stones" fall into two classes, in the higher of which are placed quartz, chalcedony, agate, felspars, lapis lazuli, and rhodonite, while the lower contains amber, fluor- spar, nephrite, agalmatolite, malachite, and serpentine. It is doubtful whether some of the forms of quartz, like amethyst and cat's-eye, are not deserving of a place among the noble stones proper. The third part of the work contains a series of tables for the determination of the minerals which are employed as precious stones. These tables have been drawn up with great care, and cannot fail to prove of very great service to those studying gems and similar materials, either from the scientific or the commercial point of view. The table showing the trade names, and the scientific designations of the several gems, is very complete ; and the whole work may be commended for its union of scientific accuracy with practical usefulness. NOTES. The International Sanitary Conference, which was to have opened at Paris on January 24, has been postponed to February 7. We learn that President Cleveland has appointed Dr. Edward S. Shakespeare, of Philadelphia, Dr. Stephen Smith, of New York, and Dr. Preston H. Bailhache, of the United States Marine Hospital Service, delegates to represent the United States at the Congress. A SLIGHT earthquake visited North Devon about 9 a.m. on Tuesday, January 23. The shock seems to have been felt over the whole of Exmoor as far as South Molton. We regret to note the death of Prof. A. Hirsch ; he died at Berlin on January 28, at the age of seventy-six. We have also to announce the death of Dr. G. Adler, Professor of Mathematical Physics in Vienna University. Dr. K. von Zittel, Professor of Geology in Munich Uni- versity, has been made a member of the German Privy Council. At a public meeting held at Shrewsbury on Tuesday, it was resolved to raise a memorial to Charles Darwin, who was a native of that town. Another public meeting will be held to consider the best method of carrying out the proposal. The Mayor of Shrewsbury, in commenting upon the proposal, rightly remarked that in doing honour to one who had shed an im- perishable lustre on his native town they were doing honour to themselves. In addition to the suggestion that a bronze statue of Darwin should be erected in front of the old Grammar School, now the public library and museum, it was proposed to found a scholarship to his memory in connection with Shrewsbury School. Another suggestion was that the memorial should take the form of a hall of science to be erected in Shrewsbury for the purposes of scientific and technical instruction. It is reported that a sum approaching ^^50,000 has been be- queathed by the late Mr. T. H. Adam, of Newport, for the purposes of technical instruction. The money is to be devoted to teaching practical and theoretical agriculture to men and youths, and a knowledge of dairying, housekeeping, and other subjects to women and girls, either by means of lectures or the establishment of a school or schools of agriculture at Edgmond or Woodseaves, in Shropshire, or Chadwell, in Staffordshire, or elsewhere ; or by such other means as the trustees shall think fit. February i, 1894J NATURE 321 Through the liberality of Mr. J. H. Veitch (says the Km.' Bulletin), the Museum of the Royal Gardens at Kew has recently been enriched by the whole of the fine and extensive collection of vegetable products made by him during his recent travels in Japan. The collection is not only very extensive, but it is also very varied, and contains many things quite new to the Museum. The Rev. C. W. Langmore sends us a description of a fine lunar rainbow observed by him at Bracknell, Berks, about nine o'clock on the evening of Wednesday, January 17. At a dis- tance of about four or five times the moon's apparent diameter a circle of brilliant white was seen. This was surrounded by a broad band of brown-orange of several gradations. Next came a narrow band of violet, followed by a broader band of green, and a narrower one of yellow. The whole series was encircled by a broad band of brown-orange. A MEETING was held at the Society of Arts on Friday last for the purpose of formally constituting an Association of Tech- nical Institutions. Representatives of almost every technical institution in the country attended the meeting. Principal F. G. Ogilvie, Edinburgh, presided, and it was agreed that the objects of the association should be {a) to provide a medium for the interchange of ideas amongst its members ; {b) to influence, by combined action, where desirable, Parliament, County Councils, and other bodies concerned in promoting technical education ; and (c) to promote the efficient organisation and management of technical institutions, and to facilitate concor- dant action among governing bodies, and aid the development of technical education throughout the United Kingdom. The council and officers of the association were elected, and a Par- liamentary committee was appointed to take such steps as may be necessary to secure due representation for technical schools on the Commission for dealing with secondary education, and to watch the progress of legislation affecting such schools. The twenty-first annual dinner of old students of the Royal School of Mines was held on Monday. More than 150 guests were present, among them being Profs. W. C. Roberts Austen, Le Neve Foster, T. E. Thorpe, A. W. RUcker, and G. B. Howes, Sir H. Trueman Wood, Sir Lowthian Bell, Captain Abney, Mr. Bennett H. Brough, Mr. W. Topley, Mr. P. C. •Gilchrist, Mr. R. D. Oldham, Dr. E. J. Ball, and Dr. Wynne. The weather has recently been very unsettled over the British Islands, owing to the influence of a succession of great atmo- spheric disturbances passing from the Atlantic to the north- ward of Scotland ; strong gales have occurred in some parts daily for more than a week, accompanied at times with thunder- storms and snow or hail. During the latter part of last week reports from the Azores showed that the barometer there was two inches higher than in Scandinavia, and the steel barometric gradients over this country caused the wind to blow with the force of 10 of the Beaufort scale (o- 12) in the north and west, both on Saturday and Monday. Although rain has fallen every day, the amount has only been heavy in exceptional cases; an inch and upwards in twenty-four hours was measured both in the north and south towards the close of the week. In the north of Scotland the fall for the week ended January 27 was much above the average. Dr. J. Hanx has just communicated to the Academy of Sciences at Vienna a paper entitled " Contribution to the daily range of the meteorological elements in the higher strata of the atmosphere," containing (l) the calculation of the two-hourly observations of all the meterorological elements on the summit ■of the Ontake in Japan (10,023 feet), from August i to Sep- tember 12, 1891, and at two base stations, with a thorough investigation of the results by harmonic analysis, by which means some interesting differences in the daily range are ex- bibited between the upper and lower stations; (2) the calcu- NO. 1266, VOL. 49] lation and discussion of the observations made by self-recording instruments established by M. J. Vallot on Mont Blanc (15,770 feet), from July to September, 1887, together with observations at Grand Mulcts (9875 feet) and Chamounix (3396 feet). The maximum temperature on Mont Blanc occurred at ih. 30m. p.m., and at the other stations at ih. p.m., but at Geneva it occurred at 2h. 30m. p m. The mean temperature on Mont Blanc from July 18 to August 14 was 20 "5, and at Geneva 69°"8. The average decrease with height was therefore i^'i F. for each 100 metres (328 feet) ; the maximum decrease was i°'3 at 3h. p.m., and the minimum nearly i°"o at 4h. a.m. The daily range of atmospheric pressure shows that notwithstanding the enormous height the double daily period still occurred. The author then discussed, with the aid of the Bavarian stations, the modifications to which the single daily barometric oscillation with increasing altitude is subject. The analysis shows that the amplitudes first decrease with height, and then increase, from about the height above sea at which the times of the phases begin to run in an opposite way to those at the surface of the earth. The influence of the daily variation of temperature in the strata of air below the mountain summit, is thoroughly discussed on the basis of these results. Dr. Hann points out that it is one of the most interesting results of barometric observations on high mountain peaks, that they show us that daily temperature oscillations in free air are much smaller than those shown by thermometers at stations, even those on the peaks. Meteoro- logical science is much indebted to Dr. Hann for this valuable and laborious investigation. Two ways of producing "artificial glaciers" are described by K. R. Koch in Wiedmanns Annaleit. The yellow kinds of pitch resembling colophony, which can be commercially obained, exhibit the plasticity with regard to pressure, and biittleness with regard to tension, that ice possesses, or at least the surface layers do after some exposure to the air. Herr Koch takes a square tray provided with a slanting gutter, down which the pitch is allowed slowly to descend. To prevent its rolling down, the gutter is first lined with a layer of very hot pitch. As the mass descends, fissures are produced in the surface, which show a great resemblance to those observed in ice, though not so deep as the latter. Cracks proceed from the edges towards the middle at an angle of forty- five degrees to the edges, and join the transverse fissures in the centre. Where the bed widens, longitudinal crevices are produced. The black fissures show well in the brown surface. Another method is to coat the pitch with a layer of some white paint, when the cracks appear black on white. It can thus be easily shown that particular forms of cracks always appear at particular parts of the bed. The motion, sometimes uniformly progressive, sometimes pausing, and sometimes directed upwards, can be well studied with a microscope. Those who have had occasion to measure an electric current by the deposition of silver on a platinum bowl as kathode, have probably occasionally noticed the very regular manner in which the silver is deposited in radial lines. This appear- ance is particularly noticeable on the sides of the bowl, and when a somewhat strong solution of silver nitrate is employed. Herr U. Behn has conducted an elaborate series of experiments with a view to ascertaining the cause of this regular deposi- tion, and has examined the effect on the deposit produced by the concentration of the solution, the current density, and the potential difference between the anode and kathode. He finds that in the electrolysis of silver nitrate, the effect is best obtained with a concentrated solution of the salt, and when the current density at the kathode is small. An in- crease in the temperature of the voltameter is found to facilitate the formation of the ridges, while, on the other hand, the value of the electromotive force employed seems to e.xert no influence. .22 NATURE [February i, 1894 The author has succeeded in obtaining the same effect with solu- tions of copper sulphate, and finds that the chief condition which must in this case be fulfilled is that the current density should be small. The concentration of the solution affects the deposit in the same manner as with silver nitrate, though to a smaller ex- '.eiit. Much smaller ridges were obtained with solutions of lead acetate and of zinc sulphate. The author considers that the ridges are in all cases caused by the effect of convection currents set up in the electrolyte owing to the changes in concentration which go on in the liquid during the passage of the current. The F^per ""^ which these results are given is published in Wiedetnann's Annalen for January. In the January number oi ZeifscJwift f/ir prahtische Geologie a brief historical account may be read of the Geological Survey Departments of Bavaria and of Alsace-Lorraine. Bavaria was the first among German States to found a Government Geo- logical Survey. That was more than forty years ago, and ever since its commencement it has been under the able guidance of Oberberg Direktor von Giimbel. To his tireless zeal is largely due the enormous amount of work accomplished by the Survey. The mountains on the borderland of Bohemia and the Austrian Tyrol have been mapped in detail, Franconia was completed in 1891, and there still remain Rhenish Bavaria, the Danube districts, and certain parts in the north-west of Bavaria. The Alsace-Lorraine Survey, instituted in 1873 under the manage- ment of Profs. Benecke and Rosenbusch, was handicapped at its commencement by the want of detailed topographical maps. Rapid strides are now being made, and a series of geological I sheets of Northern Lorraine have been published since 1887. The long southern strip of Alsace is scarcely begun. National rivalry makes itself felt along the French frontier. The German geologists complain that it is made practically impossible for them to carry their work over the frontier, whereas the French geologists have had the advantage of free access into Alsatian territory. Modern geology entered on a new period of progress when it realised some of the results of horizontal rock movement. Heim, Lapworth, Bertrand, and others proved beyond dispute that rock masses could be displaced and carried many miles over the surfaces of underlying rock. A Swiss geologist has just proposed a movement of this kind, but on a gigantic scale, as an explanation of the Chablais mountains which extend on both sides of Lake Geneva. He imagines that the upper part of an immense fold of rock was carried from the districts south of Mont Blanc and Mont Rosa, to the northern slopes of the Alps, and that this movement was not limited to the Swiss areas, but could be traced eastwards at least into the Engadine. The Chablais mountains and frag- mentary portions all along the northern edge of the Swiss and Bavarian highlands are thought to be the remaining traces of the carried rocks, and to be, in short, geologically misplaced mountains. Should this theory prove to be correct, it will be of the highest importance ; at the same time, the evidence in its favour does not yet profess to be entirely conclusive. {Arch, des Sc. Phys. etnattir., December, 1893, Geneva, " Surl'origine des Prealpes Romandes," by Hans Schardt.) The statistics of the cases treated for hydrophobia during the month of November at th t Pasteur Institute in Paris appear in the December number of the Annates de V Institiit Pasteur. No less than 129 persons underwent this treatment, and of these ninety-four were bitten by undoubtedly rabid animals, the remainder having been attacked by animals suspected of suffering from rabies at the time, but in which the actual proof of this being the case, such as a veterinary examination and com- munication of the disease to other animals, was wanting. Of these persons 109 were bitten by dogs, seventeen by cats, one by a horse, one by a sheep, and one by a pig. In October 127, NO. 1266, VOL. 49] in September 108, and in August 135 persons were treated for hydrophobia in Paris. The establishment of similar institutes in so many other parts of the world, naturally tends to reduce the number of foreigners attending the Pasteur Institute in Paris ; last year's statistics, however, showed that England still furnished a considerable proportion of the strangers at the Institute, and this state of things is unfortunately likely to continue as long as we are obliged to depend upon other countries for the treatment of this terrible disease. We published a few years ago a review of an elaborate work on the chemical and bacteriological examination of potable waters by Salazar and Newman ; these authors have recently communicated a paper on the ice consumed in Valparaiso to the " Actes de la Societe Scientifique du Chili," 1893. The inconsistency of people taking elaborate precautions to ensure the purity of their drinking water, whilst ice is used without any consideration of its source, is pointed out. In one of the samples examined, and taken from some of the ice supplied to the city, as many as 15,300 micro-organisms were found in a cubic centimetre of melted ice. Following in the footsteps of other investigators, the authors insist upon all ice used for consump- tion being prepared from water rendered above suspicion by being either previously distilled or passed through Chamberland filters. A CATALOGUE of meteorological, magnetic, and physical instruments has been received from E. A. Zichau, Hamburg. The December number of Dr. Braithwaite's " British Moss Flora " has been received. It deals with Bryacese and Bar- tramiacese. We have received several supplements to the Queensland Government Gazette, containing the statistics of meteorological observations made in Queensland during 1893. The January number of the Essex Review contains an obituary notice of the late Mr. E. Charlesworth, and an article on tech- nical instruction in Essex, by Mr. J. H. Nicholas. By far the best description that we have seen of the Man- chester Ship Canal, both as regards text and illustration, appears in Engineering for January 26. The work is traced from its beginning, eleven and a half years ago, and all the details of construction are dealt with in a very exhaustive manner. We have received from Messrs. Williams and Norgate a work entitled "Descriptive Biography Columns," by Mr. Nasarvanji Jivanji Readymoney. The work is designed toreceive records of the events that make up one's life, and is therefore similar to Mr. Gallon's life-history album, with the addition of a few novel features. The second edition of Clowes' and Coleman's " Quantitative Chemical Analysis " (J. and A. Churchill) has just appeared. The original edition was reviewed in these columns in April, 1892. Several important alterations and additions have since been made, thereby increasing the value of a book that has been found useful to both teachers and students. Bulletin No. 41 of the Experimental Station of the Kansas State Agricultural College, Manhattan, is devoted to a report from the Botanical Department on the effect of fungicides on the germination of corn. The Monatsschrift fur Kakteenkicnde, a monthly journal devoted entirely to the cultivation of Cacti and other succulent plants, has now entered on the fourth year of its existence. It is edited by Prof. Schumann, of Berlin, and published by Neumann, at Neudamm, in Brandenburg. February i, 1894] NA TURE 123 We have received the Agricultural Gazette of New South Wales for October, 1893, containing, among other papers, an elaborate one by Mr. N. A. Cobb, on "Plant Diseases and their Remedies." The present instalment is entirely devoted to the very numerous diseases which attack the sugar-cane ; copious illustrations are given of its animal and vegetable parasites. Mr. W. Trelease reprints, from the fifth annual Report of the Missouri Botanical Garden, an elaborate illustrated paper on sugar maples. He recognises ten species of Acer natives of the United States, and classifies them under five groups — the bush maples, vine maples, sycamore maples, soft maples, and hard or sugar maples. The sugar maples are Acer grandiJentatum, sacchariim, and Floridanutn. Linnaeus's Acer saccharinum is not a sugar maple at all, but is the silver maple belonging to the group of soft maples. A NEW method of preparing phosphorus is described by Messrs. Rossel and Frank in the current issue of the Berichte. By the use of aluminium as reducing agent it is shown that phosphorus may be directly obtained from any mineral phos- phate, and the method lends itself admirably to lecture-table demonstration. When ordinary microcosmic salt, hydrogen ammonium sodium phosphate, is fused in a porcelain crucible until it is converted into sodium metaphosphate, and aluminium turnings are dropped into the liquid, the flame of burning phosphorus at once appears. If the experiment is conducted in a glass tube in a slow current of dry hydrogen the phos- phorus distils into the cooler part and without the formation of any phosphoretted hydrogen. The residue consists of alumina, sodium aluminate, and a phosphide of aluminium of the com- position AI3PJ. This latter substance may be isolated as a grey crystalline powder by leading phosphorus vapour over aluminium heated in a combustion tube ; it is unchanged by further heating, but is decomposed by water with formation of aluminium hydrate, phosphoric acid, and phosphoretted hydrogen. In the preparation of phosphorus by the method above described it is consequently impossible to obtain more than thirty per cent, of the phosphorus contained in the mineral phosphate employed. But it is found that the phosphide is totally decomposed by heating with silica, and hence if the mineral phosphate is previously mixed with some form of silica the whole of the -phosphorus is liberated, and the reaction proceeds in a regular and readily controllable manner. Bone meal, powdered phosphorite or fossil phos- phate, magnesium pyrophosphate, calcium metaphosphate, or any ordinary available phosphate, may be employed. Care must be taken, however, not to employ superphosphates con- taining admixed calcium sulphate, such as are commonly ob- tained for agricultural purposes by treatment with sulphuric acid without separation of the sulphate, for the sulphate is sud- denly decomposed by the aluminium when a certain temperature is attained, with explosive force. Superphosphates obtained by treatment with hydrochloric instead of sulphuric acid may be em- ployed with perfect safety, as chlorides are not explosively decomposed by aluminium. The new mode of preparing phos- phorus may be conveniently illustrated upon the lecture-table by placing in a combustion tube a yard long, traversed by a slow current of hydrogen, a mixture of two and a half parts of aluminium, six parts of sodium metaphosphate, obtained by heating microcosmic salt, and two parts of finely divided pre- pared silica, and heating until the reaction commences. This is notified by a sudden brilliant incandescence, and phosphorus is observed to rapidly condense in globules in the cooler portion of the tube, at the end nearest the draught-hole into which the escaping hydrogen is led. NO. 12 56, VOL. 49] An interesting paper upon the interaction between oxygen and phosphoretted hydrogen is contributed to the Zeitschrijtjiir Physikalische Chemie by Dr. Van de Stadt. It is shown that the two gases instantly combine, with the appearance of flame, when they are allowed to mix under diminished pressure. The combination occurs under these circumstances in the proportions of two volumes of hydrogen phosphide to three volumes of oxygen, the product being phosphorous acid. When, however, the oxygen is admitted very slowly, or the two gases are allowed to mix by diffusion under a pressure not exceeding 50 mm. equal volumes appear to react with production of a greenish flame, liberation of hydrogen, and formation of a crystalline deposit on the walls of the vessel. The crystals melt at about 80°, and appear to consist of the little-known metaphosphorous acid HPO2 ; they are deliquescent, but after combination with sufficient water vapour to produce ordinary orthophosphorous acid the substance solidifies again. If the pressure is greater than 50 mm. both the meta and ortho acid are produced together with more or less free hydrogen. When the pressure is gradually reduced the gases combine at a certain low pressure with explosion. It is somewhat remarkable that the influence of moisture is directly opposite to that usually observed, for instead of facilitating the combination it greatly retards it. Notes from the Marine Biological Station, Plymouth. — Recent captures include two specimens of a small well-marked species of Doris, new to Britain, and probably to science. The tow-nets, on the other hand, have not yielded much of unusual interest lately, the chief contents being Copepods, Sagitta, Cirrhipede Naiiplii, Polychsete larvae, and Teleostean ova. The breeding season of a large number of both Fishes and Invertebrates has, however, recently commenced, including the Nemertine Lineus obscurus, the Polychaste Phyllodoce, the MoUusca Purpura laplllus and Acanthodoris pilosa, the Crus- tacea Cravgon vulgaris zx^A Eurynome aspera, and the Ascidian Botryllus violaceus. The Anthozoa Alcyonium digitatum and Cereus pedunculatus are still breeding. The additions to the Zoological Society's Gardens during the past week include two Black-eared Marmosets {Hapale penicillata) from South-east Brazil, presented by Mrs. G. E. Russell ; two Weka Rails (Ocydromus anst rails) from New Zealand, presented by the Hon. Lancelot Lowther ; a Cross- bill Loxia curvirostra) British, presented by Mr. W. S. Berridge ; a King Snake {Coluber geiulus) from Florida, pre- sented by Mr. Lawson Reuss ; a Rose-ringed Parrakeet {Paler ornis docilis) from West Africa, presented by Mr. J. Hickman ; a Ring-tailed Coati {Nasua rufa) from South America, deposited ; two Abyssinian Guinea Fowls {Nutnida ptilorhyncha) from Somaliland, two Burrowing Owls {Speotyto cunicularia) from America, eight Undulated Grass Parrakeets {Melopsittacus undnlatus) from Australia, purchased. OUR ASTRONOMICAL COLUMN. Jupiter's Satellites in 1664. — In the New York Nation, Mr. D. C. Oilman calls attention to an interesting letter of John Winthrop, written in 1664 to Sir Robert Moray. The letter is printed in the Proceedings of the Massachusetts Historical Society, June, 1878, and the following is an extract from it : — ' ' Havinge looked upon Jupiter with a Telescope, upon the 6th of August last, I saw 5 (?) Satellytes very distinctly about that Planet : I observed it with the best curiosity I could, taking very distinct notice of the number of them, by several! aspects with some convenient tyme of intermission ; & though I was not without some consideration whether that fifth might not be some fixt star with which Jupiter might at that tyme be in neare conjunction, yet that consideration made me the more ,24 NATURE [February i, 1894 carefully to take notice whether I could discerne any such difference of one of them from the other foure, that might by the more twinckling light of it or any other appearance give ground to believe that it might be a fixt starr, but I could discerne nothing of that nature : and I consider that the tube with which I looked upon them, though so good as to shew very clearely 'he Satellytes, yet was but of 3 foote and halfe with a concave ey-glasse ; and I question whether by a farre better tube a fixt star can be discerned so near the body of that planet when in the ever bright activity of its light, for, if so, why are there not often if not alwayes scene with the best tubes the like or more." The fifth body ob^^erved by Winthrop was probably a small star, but though it cannot definitely be said what the body was, every one will agree that it was not the fifth satellite discovered by Prof Barnard. Even at the present time it is not uncommon for an astronomical tyro to believe he has seen the moons of Mars by means of an opera-glass, being deceived by the appearance of small stars in the vicinity of the planet, and there is httle doubt that Winthrop was misled in a similar manner. The U.S. Naval Observatory. — The report of Captain F. V. McNair, superintendent of the U.S. Naval Observatory, for the year ending June 30, 1893, has just been issued. We extract from it a few points of interest. On May 15, 1893, the old Naval Observatory was formally abandoned as an observa- tory, and the new site on Georgetown Heights, Washington, officially occupied. Owing to this change, few observations of the heavenly bodies have been made since the last report. Prof. Eastman has determined the position of the new observatory with reference to the old one. Assuming the adopted latitude and longitude of the old observatory to be correct, the position of the new is lat. 38° 55' i4"-68, and long. 5h. 8m. 1571s. west of Greenwich. Prof. Eastman has been relieved of the charge of the transit circle, and is now chief of the department of fun- damental observations. The new office is one that many astronomers would consider of doubtful advantage, for we learn that the department consists of one computor to assist in com- piling the results of twenty-three years' observations of stars with the transit circle. Prof. Harkness has been chiefly en- gaged in overlooking the remounting of the equatorials and the prime vertical transit instrument. Into the mountings of the 12 and 26-inch equatorials he has introduced a pair of dials for in- dicating the right ascension and declination of the point of the heavens to which the telescope is directed. The dials face the observer when his hands are upon the right ascension and de- clination quick motions, they are brightly illuminated, they give the same degree of accuracy as the old-fashioned coarse circles, and as the right-ascension dial is moved by clockwork it shows the apparent right ascension of the telescope, together with its hour angle, and the right ascension of the meridian. Having the right ascension and declination of any visible object, the observer can instantly bring it into the field of the finder by set- ting these coordinates upon the dials. All the movements of the instrument are controlled, and all the readings of the dials, and circles are made, either from the floor of the dome or from the eye end of the main telescope, thus enabling an observer to work alone without the aid of an assistant. For greater con- venience in observing the sun and moon, supplementary gearing has been introduced into the driving clock, by means of which the spet d of the telescope can be instantly changed from sidereal to mean solar or mean lunar. Prof. Harkness' arrangement is extremely ingenious, and should be adopted in all observatories in which ihe aim is to minimise inconveniences. Prof. Frisby reports that, with the assistance of Prof. Brown, the catalogue of 17,000 stars observed by the late Captain Gilliss, at Santiago, has been completed, and is now ready for publication. These facts suffice to show that though the observatory was in an un- settled condition during the year covered by the report, a large amount of good work was accomplished. The Satellite of Neptune. — Prof. Struve recently com- municated to the St. Petersburg Academy of Sciences a discus^ sion of the observations of the satellite of Neptune made with the 30-inch refractor at Pulkova from 1885 to 1893. A com- parison of the four orbits calculated for four different epochs has clearly established the existence of the p'ogressive move- ment of the pole of the orbit suspected by Mr. Marth some years ago. An acceleration of the motion of the satellite has been detected, the cause of which is unknown. The value obtained for the mass of Neptune is 1/19396, the sun's mass being unity. NO, 1266, VOL. 49] GEOGRAPHICAL NOTES. Prof. Marcel Dubois publishes in the last number of the Annales de Geographic an epitome of his address on the inauguration of the Chair of Colonial Geography in the Faciilte des Lettres at Paris. He proposes to treat the subject of colonial geography on widely philosophical lines, and repudiates the suggestion that it is synonymous with the history of French colonisation or the topographical description of French colonies. M. Dubois is one of the leading exponents in France of the modern conception of geography as a science involving the application of the results of many sciences to the central problem of the relation of Man to the earth. The new number of Petermamis Mitteihmgen contains the first instalment of a paper by Count Joachim Pfeil on South- west Africa, illustrated by an excellent map of the region bor- dering 20° E., showing the routes of all travellers who have crossed it, and a series of valuable sections from Count Pfeil's own determinations of altitude. The number also contains an account of the Adelsberg Grotto, by Herr Kraus, referring spe- cially to the explorations of MM. Martel and Putick, mentioned in Nature, vol. xlix. p. 256. Prince Constantine Wiazemski has completed a very ex- tensive journey through Asia, of which he will soon give an account to the Paris Geographical Society. Leaving St. Petersburg in 1892, he travelled to China by Siberia, and continued thence though Tonkin to Annam, Cambodia, Cochin-China, Siam, the Laos country, Burma, Manipur, Kashmir, Tibet, Bokhara, and Persia, arriving at Tiflis in November last. In this great land journey he made extensive scientific collections, which were unfortunately nearly all lost on account of attacks by natives when passing through the Chin country. THE LARGE FIREBALL OF JANUARY 2$. A LARGE detonating fireball was observed over a large ■^ district at ten o'clock on the evening of Thursday, January 25. Mr. W. F. Denning has sent us the following detailed description of the phenomenon : — " A slow-moving fireball of the most brilliant kind was seen at Bristol on January 25, at loh. im. Clouds covered the sky at the time, but the planet Jupiter and a few of the brighter stars were dimly visible. " A sudden and vivid illumination of the firmament caused me to look upwards, without, however, seeing anything. A second flash prompted me to turn round, when I immediately saw, in the north-northeast, the expiring splendours of a large double-headed fireball. No stars could be distinguished in the vicinity, but the point of disappearance was afterwards carefully determmed as in azimuth 206° west of south, and altitude 20°. It was slightly descending, and the backward prolongation of its track indicates the radiant as near a Cephei. "The fireball appears to have been seen with startling effect at many places in Worcestershire. At Alvechurch, Redditch, a loud report similar to a clap of thunder was heard after the dis- ruption of the meteor, and there was a perceptible oscillation, supposed to be due to a slight shock of earthquake. At Worces- ter, Droitwich, and other places in the locality, windows were violently rattled and houses shaken, so that people rushed out of doors in a terrified state. I "The meteor was well seen at Birmingham, and the deton- I ation followed the explosion in three minutes, according to the ; testimony of two trustworthy observers. " From a discussion of the various observations, the disap- pearance of the meteor is well indicated at a height of only sixteen miles above a point of the earth's surface, four miles north of Ash- church, near Tewkesbury. Its direction was from north-north- west to south-south-east, and the earth point at Swindon, thirty- five miles from the place of disappearance. The descriptions are somewhat conflicting as to the early stages of the meteor's flight, but it probably passed over Chester at an elevation of fifty-eight miles. At the time of its disappearance near Ash- church it was forty-seven miles from Bristol, and thirty-six from Birmingham." Mr. Lloyd Bozward writes to us as follows : — "At about ten on Thursday night a meteor of enormous size passed over Wor- cester. The night here was densely overcast. For all that, the brilliance was so intense as to dim the light of the street lamps. Even when first manifest the radiance was exceedingly bright^ February i, 1894] NA TURE 325 and as the phenomenon passed onwards the light grew in bright- ness until it equalled the lustre of the electric arc, and has been compared to the glow of a great electric search-light. The emitted light lasted at least 30 seconds. Apparently the path was from the north-west. Two minutes after disappearance three detonations were heard, the last being of exceptional violence, shaking buildings, and causing the earth to vibrate. Here at Henwick, the- head of the meteor, though visible at other places, was invisible, but a magnificent long luminous trail was apparent. At Hallow, hence three miles north, and at Clifton-on-Teme, hence twelve miles north-west, the light was seen, and the effects of the terrific explosion were ex- perienced. At the former place the crockery-ware was jarred off the shelves of cottages. A loud rumbling noise was also heard, some persons describing it as like the prolonged roar of distant thunder. At the Wych Malvern, slates were displaced from house-roofs. A gentleman who observed the meteor at Mold, North Wales, says that, if anything, it appeared to him to be larger than the moon. The colour ' was blue in the centre, and had yellow fire round the edges." No explosion was heard there. The meteor, it is supposed, broke up near Clifton-on-Teme, but no trace of its debris has hitherto been found. At Droitwich, hence seven miles nortb-east, it was thought that the Evesham gas works, twelve miles away, had blown up. At Pershore the head of the meteor was seen, and its buisting, which it is said was ac- companied by the flashing of a dull red light, was witnessed. At Malvern, eight miles westward, the terrific effects of the occur- rence were apparent. Here there is no previous record of a meteor on so grand, prolonged, and terrific a scale." Several letters describing the meteor have appeared in the Times. Air. W. H. Lloyd observed the phenomenon from the top of the Cotswolds, about half a mile north of Minchin Hampton. He saw a ball of fire pass rapidly from north to south, and disappear in one or two seconds. About a minute or a minute and a half afterwards a series of explosions was heard. A de- tonating sound was also heard at Cheltenham, but at some other places no peculiar sound was noticed. A loud rumbling noise like an explosion was heard near Ross, Herefordshire, and ascribed to an earthquake shock. Mr. J. G. Wood remarks in yesterday's Tirnes that there is possibly a connection between earthquakes and meteoric phenomena. He points out that the North Devon disturbance of January 23 (see p. 320) was fol- lowed by the meteor of January 25, and that both an earthquake and a bright light was observed at i\os«, though the observer did not actually see a meteor. The light of the meteor is variously stated, but the majority of observers describe it as in- tensely bright and bluish, similar to the light of the electric arc. Mr. J. D. La Touche, writing from Stokesay Vicarage, Shrop- shire, says that the phenomenon continued for certainly more than half a minute ; but at Brixworth, Northampton, the dura- tion is said to have been about seven or eight seconds. All agree, however, that the meteor was of a brilliancy so great that the whole sky was illuminated, and Venus and Jupiter paled into insignificance before it. time since, about two miles south of the one sent you some time ago. I can have it sent to you by train from Hyrock." Various delays occurred, and I did not get it until September 5. The meteor had been very carefully packed, and had not suffered much loss on the journey, although, like the previous one from this locality, it is much cracked, and many parts of the surface are ready to crumble away. All the parts together weigh 74^ lbs., and its specific gravity as a whole is 3757. The No. i Gilgoin meteor weighs 67.2 lbs. and its specific gravity is 3'857. They are so much alike that it strengthens the probability arising from external similarity and nearness of the localities in which they were found that they are parts of one much larger. It is but right, however, to add that if so, they must have travelled through the atmosphere together a sufficient distance to cause the usual melted surface, which, although in parts lost by subsequent slow effect of oxidation, is yet too extensive to admit the alternative that they divided as they fell. ON A METEORITE FROM STATION} GILGOIN TT will be remembered that at the June (1889) meeting of the Society I exhibited a meteor weighing 67^ lbs. sent to me by Mr. J. F. Yeomons, of Gilgoin Station, situated forty miles towards east south-east from Brewarrina. (This meteorite is the left-hand one shown in the accompanying figure.) It had been long exposed to the weather, and the chemical action of air and rain had broken up the surface of it to such an extent that pieces fell off each time it was handled. On February 8, 1893, Mr. Yeomons again wrote to me and said : — " We have in our possession an aerolite, found, a short 1 Read -at the Royal Society, Sydney, November i, 1S93. NO. 1266, VOL. 49] This recently-found No. 2 Gilgoin meteor is, roughly, double convex, and measures 7 inches through the thickest part, and 14 X 15 inches diameter. The surface has been melted, but is not so smooth and glossy as others I have seen ; when a part of it which has not been oxidised is broken, it is dark grey in colour, and shows a great abundance of fine bright, white metallic particles. The rule is laid in a space left by some pieces missing. The meteorite has not yet been analysed, but I hope Prof. Liversidge will undertake that work. H. C. Russell. MODERN MATHEMATICAL THOUGHT} /^NE who, like myself, is not a mathematician in the modern ^^ sense naturally feels that some apology is due for accept- ing the invitation with which this society has honoured me, to address it on a mathematical subject. Possibly an adequate apology may be found in the reflection that one who has not gone deeply into any of the contemporaneous problems of mathematics, but who, as a student, has had a sufficient fond- ness for the subject to keep himself informed of the general course of thought in it, may be able to take such a general review as is appropriate to the present occasion. I shall there- fore ask your consideration of some comparisons between tlie mode of thinking on mathematical subjects at the present time, and those methods which have come down to us from the past, with a view of pointing out in what direction progress lies, and what is the significance of mathematical investigation at the present day. Among the miscellaneous reading of my youth was a history of modern Europe, which concluded with a general survey and attempted forecast of progress in arts, science, and literature. So far as I can judge, this work was written about the time of 1 Address delivered before the New York Mathematical Society at the annual meeting, December 28, 1S93, by Prof. Simon Newcomb. 126 NATURE [February i, 1894 Euler or Lagrange. On the subject of mathematics the writer's conclusion was that fruitful investigation seemed at an end, and that there was little prospect of brilliant discoveries in the future. To us, a century later, this judgment might seem to illustrate the danger of prophesying, and lead us to look upon I the author as one who must have been too prone to hasty con- [ 'ilusions. I am not sure that careful analysis would not show j the P.uthor's view to be less rash than it may now appear. May i we iiot say that in the special direction and along the special lines which mathematical research was following a century ago no very brilliant discoveries have been made? Can we really say that Euler's field of work has been greatly widened since | his time? Of the great problems which baffled the skill of the | ancient geometers, including the quadrature of the circle, the ! duplication of the cube, and the trisection of the angle, we have j not solved one. Our only advance in treating them has been i to show that they are insoluble. To the problem of three bodies we have not added one of the integrals necessary to the i complete solution. Our elementary integral calculus is two centuries old. For the general equation of the fifth degree we ! have only shown that no solution exists. We should, doubt- less, solve many of the problems which the Bernoullis and their j contemporaries amused themselves by putting to each other, rather better than they did ; but, after all, could we get any solution which was beyond their powers? I speak with some j diffidence on such a point as this ; but it seems to me that pro- \ gress has been made by going back to elementary principles, and starting out to survey the whole field of mathematical in- vestigation from a higher plane than that on which our pre- \ decessors stood, rather than by continuing on their lines. : We may illustrate this passage to new modes of thought by comparing Euclid's doctrine of ratio and proportion with our own. No one questions the beauty or rigour of the process by which Euclid developed this doctrine in his fifth book, and applied it to the theory of numbers in his seventh book. But | can we help pitying our forefathers who had to learn the 1 complex propositions and ponderous demonstrations of the fifth book, all the processes and results of which we could now write on a single sheet of paper ? As a mental discipline the study was excellent ; but it seems hardly possible that one could have remembered the propositions or the methods i of demonstrating them if he had no other knowledge of them than that derived from the work itself. When we care- fully examine these propositions, we find that while Euclid recognised the fact that one of two ratios might be greater than, equal to, or less than another, yet he never regarded them as mere quantities which could be treated as such. From his standpoint a ratio was always a relation, and a relation cannot exist without two terms. In pointing out this complexity of Euclid's doctrine, I must not be taken to endorse the very loose way in which the doctrine in question is usually treated in our modern text- books. What we should aim at is to replace Euclid's methods by those which pertain to modern mathematics. At the present time we conceive that a relation between any two concepts of the same kind may always be reduced to a single term by substituting for it an operator whose function it is to change one of these concepts into the other. In the case of the relation between two lines, considered simply as one dimensional quantities, which relation is called a ratio, we regard the ratio as a numerical factor or multiple, which, oper- ating on one line, changes it into the other. For example, that relation which Euclid would have expressed by saying that two lines were to each other as 5 to 2, or that twice one line was equal to five times the other, we should now express by saying that if we multiplied one of the lines by two and one half, we should produce the other. This might seem to be simple difference of words, but it is much more. It is a simpli- fication of ideas ; a substitution of one conception for two. Euclid needed two terms to express a relation ; we need but one. But this is not the only simplification. A peculiarity of our modern mathematics is that operators themselves are regarded as independent objects of reasoning ; susceptible of becoming operands, without specification of their particular qualities as operators. 'J'hus, instead of considering the ratio which I have just mentioned as an operation of multiplying a line by two and one half, we finally reduce it to the simple quantity two and one half, which we may conceive to remain inert until we bring it into activity as a multiplier. It thus assumes a concrete form, capable of being carried about in thought, and operated upon as if it were a single thing. This example may afford us a starting-point for a farther illustration of the way in which we have broadened the con- ceptions which lie at the basis of mathematical thought. Let us reflect upon the relation between a straight line going out from a certain point, and another line of equal length going out from the same point at right angles to the first. Had this relation been presented to Euclid as a subject for study, he would pro- bably have replied that though much simpler than those he was studying, he could see nothing fruitful in it, and would have drawn no conclusions from it. But if we trace up the thought we shall find a wide field before us, embracing the first conception of groups, and with it an important part of our modern mathematics. In accordance with the principle already set forth, we replace the relation between these two lines by an operator which will change the first into the second. We define this operator by saying that its function is to turn a line through a right angle in a fixed plane containing the line. This definition permits of the operator in question being applied to any line in the plane. Then let us apply it twice in succession to the same line. The result will be a line pointing in the opposite direc- tion from the original one. A third operation will bring it again to a right angle on the opposite side from the second position ; and a fourth will restore the line to its original position, the result being to carry it through a complete circle. If we now consider the operations which would have been equivalent to these one, two, three, and four revolutions through a right angle as four separate operators, we see that their results will be either to leave the line in its original position, or to move it into one of three definite positions. If we then repeat one of these four operations as often as we please, or in any order we please, we shall only bring the line to one of the four positions in question. We thus have a group of the fourth order, possessing the property that the repetition of any two operations of the group is equivalent to some single operation of it. I scarcely need call attention to the familiar homology between these operations and successive multiplications by the imaginary unit \'-i. This last concept, considered as a multiplier, has the same properties as our rotating operator. Repeated twice, it changes the sign or direction of the quantity on which ; operates ; repeated four times, it restores it to its original value. Let us extend this idea a little. Instead of taking two lines at right angles to each other, let us con- sider two which form an angle of 40°. As already re- marked, this relation is homologous with an operator which will turn a single line through that angle. If we continually rep eat this operation, we .^hall bring the line into thirty-five different positions, the thirty-sixth position being identical with the original one. Thus we should have thirty-six positions in all, expressed by that number of lines radiating from a single centre, and making angles of 10 with each other. Now let us imagine thirty-six operators whose function it is to turn a line, no matter what, successively through an arc of 10", 20°, 30°, &c. up to 360°, the last being equivalent to an operator which simply does nothing. These thirty-six operators will form a group which we know to be strictly homologous with multiplication by the thirty-six expressions e^'^, «-', £"', . ''■(^ = e" — \, NO. 1266, VOL. 49] where <^ is the arc of 10" in circular measure. So far we have only considered operations formed by the continual repetition of a single one ; in the language of the subject, all our groups are constructed from powers of a single operator. Now let us extend our process by substituting a cube for our straight line. Through this cube we have an axis parallel to four of its plane sides. By rotating the cube through any multiples of 90° around this axis we effect an inter- change of position between four of its sides. This process of interchanging is homologous with rotation through 90°, being in fact equivalent to it, and therefore it is also homologous with multiplication by the imaginary unit. But there is also another homology. Let us designate the four sides of the cube parallel to the axis of rotation as A, B, C, D. Then our group of rotations will be homologous with the powers of a cyclic substitution between the four letters A, B, C, D. Let us next introduce a new operator, namely, rotation around an axis at right angles to the first one, but always February i, 1894] NATURE 327 through an arc of 90°. This introduces a new element into the problem, and enables us to change the cube from any one position to any other position, that is, to effect any interchange among the sides which would be consistent with their remain- ing sides of the same cube. Here we have a series of rota- tions which, in the case of the cube, are homologous with certain linear transformations which have been developed by Klein in his very beautiful book on the Icosahedron. But it is also obvious that in introducing these rotations we are practically operating with quaternions, the operator being a unit vector. Thus we have a homology between certain forms of quaternion multiplication and linear transformations involving the imaginary unit. Moreover, since these rotations are also homologous with substitutions, performed on six sym- bols representing the six sides of the cube, it follows that there is also a homology between certain groups of substitutions and certain linear transformations involving two quantities, a numerator and a denominator, and quaternion multiplication by unit vectors. I have taken a cube as the simplest illustration. Evidently we can construct a great number of groups of substitutions of the same sort between the sides of any regular solid, as Klein has done in the work I have already cited. The relation be- tween the linear substitutions thus found and the solution of corresponding algebraic equations forms one of the most beautiful branches of our modern mathematics. We have in all these cases a very simple illustration of a law of thought, the application of which forms the basis of an im- portant part of modern mathematical research. We may call it the law of homology. I am not sure of my ability to define it rigorously, but I think we may express it in some such form as this : If we have two sets of concepts, say A and B, such that to every concept of the one set shall correspond a concept of the other, and to every relation between any two of one set a cor- responding relation between the corresponding two of the other, then all language, reasoning, and conclusions as to the one set may be applied to the other set^ We may, of course, extend the law to a correspondence between things or concepts, and symbols, or other forms of language. This law is, I think, more universal than might at first sight appear. Not only the progress, but the very existence of our race depends upon that coordination between our mental processes and the processes of the external universe, which has gradually been brought about by the attrition between man and nature through unnumbered generations. A man is perfect, powerful, and effective 'in proportion as his thoughts of nature coincide with the processes of nature herself ; each process of nature having its image in his thought, and vice versa. Now, language consists in coordination oetween words and conceptions. Thus we pass from nature to what corresponds to it in thought, and from thought to what corresponds to it in language, and thus bring about a correspondence between language and nature. Modern scientific research affords many examoles of the application of this law, which would be very marvellous if they were not so familiar. We are so accustomed to the prediction of an eclipse that we see no philosophy in it. And yet might not a very intellectual being from another sphere see something wonderful in the fact that by a process of making symbols with pen and ink upon sheets of paper, and combining them accord- ing to certain simple rules, it is possible to predict with un- erring certainty that the shadow of the moon, on a given day and at a given hour and minute, will pass over a certain place on the earth's surface? Surely the being might ask with surprise how such aresult could be attained. Our reply would be simply this : There is a one-to-one correspondence between the sym- bols which the mathematician makes on his paper, and the laws of motion of the heavenly bodies. His symbols embody the methods of nature itself. The introduction and application of homologies such as 1 have pointed out have, perhaps, their greatest value as thought- savers. In the field of mathematical thought they bear some resemblance to labour-saving machines in the field of economics. They enable the results of ratiocination to be reached without going through the process of reasoning in the particular case. Much that I have said illustrates this use of the method, but there is yet another case which has been so fruitful as to be worthy of special mention : I mean the general theory of functions of an imaginary variable. We may regard such functions as being in reality representative of a pair of functions NO, 1266, VOL. 49J of a certain class involving a pair of real variables ; but the difficulty of conceiving the various ways in which the two variables might be related, and the results of the changes which they might go through, in such a way as to clearly follow out all possible results, would have rendered their direct study impos- sible. But when Gauss and Cauchy conceived the happy idea of representing two such variables, the real and the imaginary one, by the rectangular coordinates of a point in a plane, those relations which before taxed the powers of conception became comparatively simple. Considered as a magnitude, the com- plex variable, or the sum of a real quantity and a purely imaginary one, the latter being considered as one measured in imaginary units, was represented by the length and position of a straight line drawn from an origin of coordinates to the point whose coordinates were represented by the values of the variable. Such a line, when both length and direction are considered, is now familiarly known as a vector. Theconceptionof the vector would, however, in many cases be laborious. But the vector is completely determined by its terminal point ; to every vector corresponds one and only one terminal point, and to every ter- minal point one and only one vector. Hence we may make abstraction of the vector entirely, and in thought attend only to the terminal point. Since for every pair of values we assign to our original variables there is one point, and only one, we may in thought make abstraction of both of these variables, and of the vectors which they represent, and consider only the point whose coordinates they are. Thus the continuous variation of the two quantities, how complex soever it may be, is repre- sented by a motion of the point. Now such a motion is very easy to conceive. We may consider it as performing a number of revolutions around some fixed position without the slightest difficulty, whereas to conceive the corresponding variations in the algebraic variables themselves would need considerable mental effort. Thus, and thus alone, has the beautiful theory, first largely developed by Cauchy, and afterward continued by Riemann, been brought to its present state of perfection. Another example of the principle in question, where the two objections of reasoning are so nearly of a kind that no thought is saved, is afforded by the principle of duality in projective geo- metry. Here a one-to-one correspondence is established be- tween the mutual relations of points and lines, with the result that in demonstrating any proposition relating to these concepts we at the same time demonstrate a correlative proposition formed from the original one by simply interchanging the words " point " and " line." The subjects of which I have heretofore spoken belong [con- jointly to algebra and geometry. Indeed, one of the great results of bringing homologous interpretation into modern mathematics has been to unify the treatment of algebra and geometry, and almost fuse them into a single science. To a large class of theorems of algebra belong corresponding theo- rems of geometry, each of one class proving one of the other class. Thus the two sciences become mutually helpful. In geometry we have a visible representation of algebraic theorems; by algebraic operations we reach geometrical conclusions which it might be much more difficult to reach by direct reasoning. A remarkable example is afforded by the geometrical application of the theory of invariants. These are perhaps the last kind of algebraic conclusion which the student, when they are first presented to his attention, would conceive to have a geometrical application, yet a very litl le study suffices to establish a complete homology between them and the distribution of points upon a straight line. This use of homologies does not mark the only line by which we have advanced beyond our predecessors. Progress has been possible only by emancipating ourselves from certain of the con- ceptions of ancient geometry which are still uppermost in all our elementary teaching. The illustration I have already given is here much to the point. The expression of a relation between two straight lines by the multiplier which would change one into the other is now familiar to every schoolboy, and the rela- tion itself was familiar to Euclid. But the yet simpler relation of a line to another of equal length standing at right angles to it, and the corresponding operator which will change one into the other, was never thought of by Euclid, and is unfamiliar in our schools. Why is this ? It seems to me that it grows out of the ancestral idea that mathematics concerns itself with measurement and that the object of measurement is to express all magnitudes in one-dimensional measure. So completely has 328 NA TURE [February i, 1894 this idea directed language, that we stillextend the useof the word " equal " to all cases of this particular kind of linear equality : we say that a circle is equal to the rectangle contained by its radius and half its circumference. We have therefore been obliged to invent the word "congruent " for absolute equality in all points, or to qualify the adjective "equal " by " identical," aying "identically equal." There is of course no objection to the comparison of magnitudes in this way by reference to one dimensional measures, or by presupposing that the change which one magnitude must undergo in order to be transformed into the other is to be expressed by a single parameter, but changes involving two or any number of parameters, are just as important as those involving one, and the attempt to express all metric relations by referring them to a single parameter has placed such restrictions on thought that it seems to me appropriate to apply the term emancipation to our act in freeing ourselves from them. With us mathematics is no longer the science of quan- tity. But even if we consider that the ultimate object of mathe- matics is relations between quantities, we have reaped a rich reward by the emancipation, for we are enabled by the use of our broader ideas to reach new conclusions as to metric relations. The idea of groups of operations, as I have tried to develop it, has in recent years been so extended as to cover a large part of the fields of algebra and geometry. Among the leaders in this extension has been Sophus Lie. Considered from the alge- braic point of view, his idea in its simplest form may be ex- pressed thus : We have a certain quantity, say x. We have also an operation of any sort which we may perform upon this quantity. Let this operation depend on a certain quantity, a, which necessarily enters into it. As one of the simplest possible examples, we may consider the operation to be that of adding a to ,r. As the quantity a may take an infinity of values, it follows that there will be an infinity of operations all belonging to one class, which operations will be distinguished by the par- ticular value of a in each case. We thus operate on ,v with one of these operators, and get a certain result, say v'. We operate on ,1' with a second operator, of the i-ame class, and get a second result, say .\". If whatever operators we choose from the class, the result i" could have been obtained from the original quantity r by some operation of the class, then these operations are sucti that the product of any two is equivalent to the per- formance of some one of them. Thus, by repealing them for ever, we could get no results except such as could be obtained by some one operator. To illustrate by one simple example : if our operation consists in the addition of an arbitrary quantity to V, then we change .\ into v' by adding a certain quantity a and ,v' into x" by adding a second quantity /'. The result of these two additions is the same as if we had added in the first place the quantity a -f h. It need hardly be said that the mul- tiplication by v of any quantity would be another example of the same kind. The perlormance of any number of successive multiplications on a quantity is always equal to a single multi- plication by the product of all the factors of the separate multiplications. These operations are not confined to single quantities. We may consider the operation to be performed upon a system of quantities, which are thus transformed into an equal number of different quantities, each of these new quantities corresponding to one of the first system. If a repetition of the operation upon the second system of quantities gives rise to a third system, which could have been formed from the first system by an operation of the same class, then all these possible operations form a group. The idea of such systems of operations is by no means new. It has always been obvious, since the general theory of algebraic operations has been studied, that any com- bination of the operations of addition, multiplication, and division could always be reduced to a system in which there would be only a single operation of division necessary — just as in arithmetic a complex fraction, no matter what the order of complexity of its terms, can always be reduced to a single simple fraction, that is, to a ratio of two integers, but cannot, in general, be reduced to an integer. Abel made use of this theorem in his celebrated Memoir on the impossibility of solving the general equation of the fifth degree. Another field of mathematical thought, quite distinct from that at which we have just glanced, may be called the fairy- land of geometry. To make a mathematician, we must have a higher development of his special power than falls to the lot of other men. When he enters fairyland he must, to do himself justice, take wings which will carry him far above the flights, and even above the sight, of ordinary mortals. To the most imaginative of the latter, a being enclosed in a sphere, the surface of which was absolutely impenetrable, would be so securely imprisoned that not even a spirit could escape ex- cept by being so ethereal that it could pass through the substance of the sphere. But the mathematical spirit, in four-dimensional space, could step out without even touching any part of the globe. Taking his stand at a short distance from the earth, he could with his telescope scan every particle of it, from centre to surface, without any necessity that the light should pass through any part of the substance of the earth. If a practised gymnast, he could turn a somersault and come down right side left, just as he looks to our eyes when seen by reflection in a mirror, and that without suffering any distortion or injury whatever. A straight line, or a line which to all our examination would appear straight, if followed far enough, might return into itself. Sp.ace itself may have a boundary, or, rather, there may be only a certain quantity of it ; go on for ever, and we would find our- selves always coming back to the starting-point. All these re- sult^, too, are reached not merely by facetious forms, but by rigorous geometrical demonstration. The considerations which lead to the study of these forms of space are so simple that they can be traced without difficulty. When the youth begins the study of plane geometry his attention is devoted entirely to figures lying in a plane. For him space has only two dimensions. To a given point on a straight line only one perpendicular can be drawn. By moving a line of any sort in the plane he can describe a surface, but a solid is wholly without his field. He cannot draw a line from the outside to the inside of a circle without intersecting it. On a given base only two triangles with given sides can be erected, one being on one side of the base, the other on the other. When he reaches solid geometry his conceptions are greatly extended. He can draw any number of perpendiculars to the same point of a straight line. If he has two straight lines perpendicular to each other, he can draw a third straight line which shall be perpendicular to both. A plane surface is not confined to its own plane, but can be moved up and down in such a way as to describe a solid. The characteristic of this motion is that it constantly carries every part of the plane to a position which no part occupied before. Now, it is a fundamental principle of pure science that the liberty of making hypotheses is unlimited. It is not necessary that we shall prove the hypothesis to be a reality before we are allowed to make it. It is legitimate to anticipate all the possi- bilities. It is, therefore, a perfectly legitimate exercise of thought to imagine what would result if we should not stop at three dimensions in geometry, but construct one for space having four. As the boy, at a certain stage in his studies, passes from two to three dimensions, so may the mathematician pass from three to four dimensions with equal facility. He does indeed meet with the obstacle that he cannot draw figures in four dimensions, and his faculties are so limited that he can- not construct in his own mind an image of things as they would look in space of four dimensions. But this need not prevent his reasoning on the subject, and one of the most ob- vious conclusions he would reach is this : As in space of two dimensions one line can be drawn perpendicular to another at a given point, and by adding another dimension to space a third line can be drawn perpendicular to these two ; so in a fourth dimension we can draw a line which shall be perpen- dicular to all three. True, we cannot imagine how the line would look, or where it would be placed, but this is merely because of the limitations of our faculties. As a surface de- scribes a solid by continually leaving the space in which it lies at the moment, so a four-dimensional solid will be generated by a three-dimensional one by a continuous motion which shall constantly be directed outside of this three-dimensional space in which our universe appears to exist. As the man confined in a circle can evade it by stepping over it, so the mathematician, if placed inside a sphere in four-dimensional space, would simply step over it as easily as we should over a circle drawn on the floor. Add a fourth dimension to space, and there is room for an indefinite number of universes, all alongside of each other, as there is for an indefinite number of sheets of paper when we pile them upon each other. From this point of view of physical science, the question whether the actuality of a fourth dimension can be considered admissible is a very interesting one. All we can say is that, NO. 1266, VOL 49] February i, 1894] NA TURE 329 so far as observation goes, all legitimate conclusions seem to be against it. No induction of physical science is more uni- versal or complete than that three conditions fix the position of a point. The phenomena of light shows that no vibrations go outside of three-dimensional space, even in the luminiferous ether. If there is another universe, or a great number of other universes, outside of our own, we can only say that we have no evidence of their e.\erting any action upon our own. True, those who are fond of explaining anomalous occurrences, by the action of beings that we otherwise know nothing about, have here a very easy field for their imagination. The question of the sufiSciency of the laws of nature to account for all pheno- mena is, however, too wide a one to be discussed at present. As illustrating the limitation of our faculties in this direction, it is remarkable that we are unable to conceive of a space of two dimensions otherwise than as contained in one of three. A mere plane, with nothing on each side of it, is to us incon- ceivable. We are thus compelled, so far as our conceptions go, to accept three dimensions and no more. We have in this a legitimate result of the universal experience through all genera- tions being that of a triply extended space. Intimately associated with this is the concept of what is some- times called curved space. I confess that I do not like this expression, as I do not see how space itself can be regarded as curved. Geometry is not the science of space, but the science of figures in space, possessing the properties of extension and mobility which we find to be common to all material bodies. The question raised here is a very old one, and in a general way its history is familiar. Mathematicians have often attempted to construct geometry without the use of what is commonly called the ninth axiom of Euclid, which seems to me best expressed by saying that in a plane only one line can be drawn which shall be parallel to another line in the plane in the sense of never meeting it in either direction. Yet every attempt to construct an elementary geometry without this axiom has been proved to involve a fallacy in some point of the reasoning. This consideration led Lobatchewsky, and independently of him, I believe, Gauss, to inquire whether a geometry might not be constructed in which this axiom did not hold ; in which, in fact, it was pos- sible that if we had two parallel lines in a plane, one of them might turn through a very minute angle without thereby meet- ing the other line in either direction. The possibility of this was soon shown, and a system of geometry was thus constructed in which the sum of the angles of a plane triangle might be less than two right angles. Afterward the opposite hypothesis was also introduced. It was found that, given two parallel lines in a plane, it might be supposeJ that they would ultimately meet in both directions. This hypothesis might even be made without there being more than one point of intersection, each straight line returning into itself. The geometry arising from these two hypotheses has been reduced to a rigorous system by Klein. To guess the future of mathematical science would be a rash attempt. If made it might seem that, in view of what has been accomplished during our time, the safest course would be to predict great discoveries in this and all other branches of science. The question is sometimes asked whether a mathematical method may not yet be invented which shall be as great an advance on the infinitesimal calculus as the latter was on the methods of Euclid and Diaphuntus. So far as solving problems which now confront us is concerned, I am not sure that the safest course would not be to answer such questions in the negative. Is it 1 not true in physics as in mathematics that great discoveries have I been made on unexpected lines, and that the proiilems which perplexed our ancestors now baffle our own efforts? We must jalso remember that the discovery of what could not be done I has been an important element in progress. We are met at jevery step by the iron law of the conservation of energy: in ■ every direction we see the limits of the possible. The mathe- matics of the twenty-first century may be very different from jur own ; perhaps the schoolboy will begin algebra with the heory of substitution-groups, as he might now but for inherited abits. Bat we may well doubt whether our posterity will jiolve many problems which we cannot, or invent an algorithm jnore powerful than the calculus. The first principles of all our (uathemaical methods are as old as Euclid, and we cannot ex- pect that the future will do more than apply them to new roblems. NO. T266, VOL. 49] UNIVERSITY AND EDUCATIONAL INTELLIGENCE. Oxford. — At a meeting of the Junior Scientific Club, held on Friday, January 26, Mr. Pycraft exhibited a restoration of the wing of archoeopteryx ; Mr. F. A. Hillard read a paper on carborundum, and other substances, prepared by means of the electric arc ; and Mr. H. M. Vernon read a paper on the activity of the cardiac centre under varying conditions. It was agreed at the meeting that the annual Boyle lecture, which will be given this year by Frof. Macalister, should be held early in .May, and that a conversazione should be given on another day in the sum- mer term. Cambridge.— Mr. J. W. Capstick, Fellow of Trinity, has been appointed an Assistant Demonstrator in Physics at the Cavendish Laboratory, in the room of Mr. Whetham, who has been elected to the Clerk Maxwell Scholarship. A course of lectures with demonstrations in elementary phy- siology for students of agriculture will be given this teim by Mr. Eichholz, Fellow of Emmanuel College, on Mondays and Saturdays, at nine. Baron Anatole von Hiigel, Curator of the Museum of Archaeology and Ethnology, will this term give two courses of lectures on the collections in the Museum. A syndicate, consisting of the Vice-Chancellor, the Master of Peterhouse, the Master of Christ's, Prof. Thomson, F.R.S., Prof. Liveing, F.R.S., Mr. Glazebrook, F.R.S., and Mr. Shaw, F.R. S., is about to be appointed to consider the best means of extending the Cavendish Laboratory. A site for the extension is reserved, but the standing difficulty of funds is likely to prove a serious one unless outside help can be obtained. Dr. P. W. Latham has resigned the Downing Professorship of Medicine, which he has held since 1874. The appointment is made by a special board of electors. Mr. J. R. Green, of Trinity College, Professor of Botany to the Royal Pharmaceu- tical Society of Great Britain, has been approved by the General Board of Studies for the degree of Doctor of Science. It is proposed to admit to the privileges of affiliated students, matriculated members of the University of Adelaide who have studied there for two years in arts, law, science, or medicine, and have passed certain specified examinations. Such affiliated students are exempted from the Previous Examination and from one year of residence for the B.A. degree. SCIENTIFIC SERIALS. American Meteorological Journal, ]z.nViZ.xy. — History of the Weather Map, by M. W. Harrington. Simultaneous observ- ations, which form the basis of weather charts, were made in Virginia from 1772 to 1777; about the same time Lavoisier proposed that such observations should be made in Europe, and referred to an earlier proposal by Borda. In 1842, Kreil, of Prague, proposed the use of an electromagnetic telegraph for the same purpose. The earliest proposal for a weather map was probably made by Brandes, in 1S16, but his plan seems never to have been carried out, and it was not until 1856 that current charts of the weather were made by the Smithsonian Insti- tution. In 1857, Le Verrier published an international bulletin, but his synoptic charts were not issued until 1863 ; and in this country Admiral FitzRoy commenced the publication of tele- graphic weather reports in i860; since this time such reports and charts became general.— The meteorological work of the Medical Department of the United States Army, by Major C. Smart. The earliest meteorological journal in the office of the Surgeon-General is from Cambridge, for July, 1816. The first results were published in the Meteorological Register for the years 1822-5.— The meteorological work of the Smithsonian Institution, by S. P. Langley. In December, 1847, Prof. J. Henry proposed a "system of extended meteorological observ- ations for solving the problem of American storms, and shortly afterwards the institution issued directions for meteoro- logical observations ; in 1849 elementary telegraphic weather reports were furnished to the institution daily.— Early indi- vidual observers in the United Slates, by A. J. Henry, A daily record of the weather was kept by the Rev. J. Campanius at Fort Christiania, near the present city of Wilmington, Dela- ware, during 1644-5, and at Boston, by the Hon. P. Dudley, in 330 NA TURE [February i, 1894 1729-30. The instrumental period bejjan with Dr. J. Lining's observations at Charleston, in 1738. The above, and articles on the storms of the Atlantic, and the creation of meteoro- logical observatories upon islands, are abstracts of papers prepared for the Chicago Congress of Meteorology. — The recurrence of hurricanes in the solar magnetic 26'68 day period, by F. H. Bigelow. The author compares the curves of hurri- cane recurrences with those of the solar magnetic period. An inspection of the curves shows that they have closely synchro- nous maxima and minima. Mr. Bigelow concludes that the intensifications of the polar magnetic field have much to do with the generation of West Indian tropical storms, but he admits that many points of the subject are as yet only partially under.-:tood. Bulletins dc la Societe d' AntJiropologie de Paris, Tome iv. (4e Serie), December 15, 1893. — M. Ch. Letourneau describes a stone cross, found at Carnac, with inscriptions. The two arms of this cross Are pal, 'c, like those of a Maltese cross, and the four faces of the quadrangular shaft are covered with in- scriptions which resemble in their general character those megalithic inscriptions which are so numerous in the neighbour- hood of Locmariaker. As these inscriptions must have been cut subsequently to the fashioning of the cross, we have a very different case to that in which a cross is found carved on a menhir. This cross, with two others of a similar character, are figured by Miln as tail-pieces in his work ' ' Fouilles de Carnac " (Paris, 1877), and he considers them to mark the transition period between Paganism and Christianity. There can be no doubt, however, that the men who chiseled the great menhir of Locmariaker and carved the inscriptions of Gavr Inis were capable of cutting a cross out of stone if they were disposed to do so ; afterwards these crosses might have been preserved by the Christians, and even, perhaps, restored by them. — Dr. Paul Raymond contributes a paper on the prehistoric period in the departments of Card and Ardeche ; and M. Desire Charnay describes the remains of the cliff-dwellers exhibited at the World's Fair at Chicago. — The colour of the eyes has long been looked upon as one of the most important race signs, and Dr. Harreaux proposes a systematic method of describing the iris, which, so far as one can judge without the assistance of plates, will enable qualified observers to record and recognise very minute differences ; the system, however, appears to be somewhat too complicated for general use and is surpassed in precision by the iridographic method of Bertillon. — Dr. Le- double contributes a valuable paper on the anomalies of the great dorsal muscle. — M, A. Pokrovsky describes four crania found by Prof. Obolonsky in the grotto of Sundurli-Koba, near the village of Ouzoundja, in the Crimea. Three out of the four are considerably plagiocephalic, the plagiocephaly being left in two cases and right in the third ; two of the crania are male, one is female, and the fourth is that of a child of about twelve years of age. — M. Adrien de Mortillet gives an account of the figures cut on the megalithic monuments near Paris ; these are three in number, one in the valley of the Seine, at Aubergenville ; the two others in the valley of the Epte, at Dampsmesniland at Boury. The dolmen at Aubergenville is known as the Trou-aux-Anglais, that at Dampsmesnil is called by the country people the Trou-aux-Loups, while the third is the Dolmen de la Bellehaye. Bulletin of the New York Mathematical Society, vol. iii. No. 3, December, 1893 (New York). — A doubly-infinite system of simple groups (pp. 73-78) is an abstract of a paper presented to the Congress of Mathematics at Chicago, by Prof. E. H. Moore. The paper is to be published in full in the Proceedings, and also in the Alathematische Annalen. Two notes follow, on monogenic functions of a single variable (pp. 78, 79), by Dr. Craig, and Lambert's non-Euclidean geometry (pp. 79, 80), by Prof. Halsted. This latter is very interesting, as it narrates the discovery of an old paper of Lambert's (Zur Theorie der Parallel- linien, 1766) on what was long after named the non-Euclidean geometry. Pages 80-88 are taken up with remarks on the teaching of mathematics at Gottingen. There are the usual "notes" and "new publications" (pp. 88-94). The number of the Joiu-iial of Botany for December, 1893, contains further Notes on the genus Fotamogeton, by Mr. A. Fryer, with illustrations ; Descriptions of three new African grasses, by Mr. A. B. Rendle ; the completion of Mr. E. G. Baker's Synopsis of genera and species of Malvece ; and Mr. NO. 1266, VOL. 49] Carruthers' Report of the Department of Botany in the British Museum for 1892. — The most important papers in the No. for January, 1894, are one on the Primary subdivisions in the genus Silene, by Mr. F. N. Williams ; and the late Prof. Asa Gray's Last words on nomenclature. SOCIETIES AND ACADEMIES. London. Entomological Society, January 17.— Sixty-first Annual Meeting. — Mr. Frederic Merrifield, Vice-President, in the chair. — An abstract of the treasurer's accounts, showing a balance in the Society's favour, having been read by Mr. J. Jenner Weir, one of the auditors, the secretary, Mr. H. Goss, read the report of the council. It was then announced that the follow- ing gentlemen had been elected as ofificers and council for 1894 : — President, Mr. Henry J. Elwes ; treasurer, Mr. Robert McLachlan, F. R.S. ; secretaries, Mr. Herbert Goss and the Rev. Canon Fowler ; librarian, Mr. George C. Champion ; and as other members of the council, Mr. Walter F. H. Blandford, Mr. Charles J. Gahan, Mr. Frederic Merrifield, Prof. Edward B. Poulton, F. R. S., Colonel Charles Swiuhoe, Mr. George H. Verrall, Mr. James J. Walker, R.N., and the Right Hon. Lord Walsingham, F.R.S. Mr. Merrifield then read the President's address, in which, after alluding to the principal events of the past year, and the prosperous condition of the Society, he referred to the additions which had been made in 1893 to the literature of entomology, calling attention to the "Butterflies of China and Japan," by Mr. J. H. Leech; the "Moths of India," by Mr. G. F. Hampson ; "Butterflies of North America," by Mr. W. H. Edwards; " Lepidoptera Indica," by Dr. F. Moore ; and the continuation of the " Biologia Centrali- Americana," by Messrs. F. D. Godman, F.R.S., and Osbert Salvin, F.R.S. He also commented on the recent publications of the Grand Duke Nicholas Mikhailovitch, M. Charles Oberthiir, and Dr. Staudinger, on the continent. The Presi- dent concluded by referring to the losses by death during the year of several Fellows of the Society and other entomologists, special mention being made of Prof. H. A. Hagen, the Rev. Leonard Blomefield, Mr. A. C. Horner, Prof. J. Wood-Mason, the Rev. Henry Burney, Mr. J. C. Bowring, the Rev. F. O- Morris, Mr. J. Batty, Mr. Francis P. Pascoe, Herr Eduard Honrath, and Dr. Adolph Speyer. A vote of thanks to the President was proposed by Colonel Swinhoe, seconded by Mr. Jenner Weir, and carried. Lord Walsingham proposed a vote of thanks to the officers of the Society ; this was seconded by Mr. Waterhouse, and carried. Mr. Merrifield, Mr. McLachlan, and Mr. Goss replied, and the proceedings terminated. Royal Microscopical Society, January 17. — Annual Meeting. — Mr. A. D. Michael, President, in the chair. — After the report of the council for the past year and the Treasurer's statement of accounts had been read and adopted, the President announced that the following were elected as officers and council for the ensuing year : — President : A. D. Michael ; Vice-Presidents: Prof L. S. Beale, F.R.S., Dr. R. Braith- waite, Frank Crisp, T. H. Powell ; Treasurer : W. T. Suffolk ; Secretaries : Prof. F. Jeff"rey Bell, Rev. Dr. W. H. Dallinger, F.R.S. ; Ordinary Members of Council : A. W. Bennett, Rev. E. Carr, E. Dadswell, C. H. Gill, Dr. R. G. Hebb, G. C. Karop, E. M. Nelson, Prof. Urban Pritchard, C. F. Rousselet, Prof. Charles Stewart, J. J. Vezey, and T. C. White.— The President then delivered the annual address. He took for his subject the growth and present state of our knowledge of the Acari. The name "Acarus" was probably first used by Aristotle ; it means uncuttable. But Aristotle did not antici- pate Cambridge rocking microtomes, and the President exhi- bited a set of over 120 serial sections cut from a far smaller Acarus than Aristotle could ever have seen. The President then described what an Acarus really is and in what respects it differs from other Arachnida, a distinction which is erroneously stated! in almost all text-books of zoology. The classification of the. group practically began with Linnseus ; it was shown how diffi- cult it is to identify a Linnean species, and the progress of classification was shortly traced from the single Linnean genuS| to the two hundred and twelve genera admitted by Trouessart, one of the latest writers on the subject. The President theni referred to the fact that many of the predatory Acari had not in I re m February i, 1894] NA rURE any special organs of vision, and yet that they were most active creatures, and would catch such agile insects as Thysanuridse without constructing any web or trap, and did not seem to suffer in the least Irom their eyeless condition ; he had seen small and weak Acari quietly waiting until larger ones had finished feeding before they ventured to attack the leavings, although both were blind. The various forms of acarine parasitism and commen- sualism were then described, including one where a parasite lives in the fur of the rabbit, not feeding on the host, but on other parasites which really do so, and the number of these which it will destroy is amazing. The President then illustrated the principal families of Acari by selecting one or two instances of each, which were specially interesting either from their habits, their anatomy, or otherwise. The Sarcoptidse, or bird parasites, were represented by a parasite of the cormorant, discovered by the President, in which the male has one leg much larger than the other, and the skeleton of the body is greatly modified to support it ; but the enlarged leg and modified skeleton are on the right side of the body in some specimens, and on the left in others. The so-called cheese-mites were referred to in order to describe the hypopus-stage in the life-history of many of them ; when the creature, which is originally soft and easily killed by heat or exposure, suddenly becomes hard and able to endure almost all vicissitudes, and also to live for a long period without eating : it is then provided with special organs for adhering to insects, and thus the species are widely distributed under cir- cumstances where they would otherwise perish. The President then spoke of his recent res- arches into the association between many Acari (Gamasids) and certain ants in whose nests they live, and of a still stranger and hitherto unrecorded case, even more lately observed by him, in which a species of Acarus {Bdelia) lives habitually in as pider's web in harmony with the otherwise most ferocious occupant. The speaker then shortly described his recent discovery of the extraordmary way in which female Gemasids are fertilised, a spermatic capsule being con- veyed to its destination by the mandibles of the male. Finally, the descent of the Acari was discussed. The discourse was illustrated by the lantern. Edinburgh. Royal Society, December 12, 1893. — The Rev. Prof. Duns in the chair. — Dr. George Berry read a note on the focus of concavo-convex lenses, the surfaces of which are of equal curva- ture. The effect of the thickness of the lens was specially con- sidered.— Dr. W. Peddie read a paper on torsional oscillations of wires. The law of decay of oscillations when the set is large was investigated experimentally, and a very accurate em- pirical formula was given for the representation of the results. A theory of the phenomenon was then investigated, and was shown to lead to the empirical formula as an approximation when the loss of energy per oscillation was not too large a frac- tion of the total energy of oscillation. The theory was also shown to lead to a relation between torsion and set, which, on application to Wiedemann's results, was found to be in practi- cally complete accordance with experiment. It was shown also to lead necessarily to Kelvin's well-known "law of compound- interest " for the decay of oscillations when these are very small. — Dr. C. G. Knott communicated a paper, by Mr. S. Kimura, on certain electrical properties of iron occluding gases. The gases used were carbonic acid, carbonic oxide, and hydro- gen. The paper dealt with the changes of thermo-electric power and of resistance. — Dr. Knott also read a paper, by Mr S. Tolver Preston, on the ether — an idea of Sir John Herschtl modernised. January 15. — Prof. Sir Douglas Maclagan, President, in the chair. — After the reading of two obituary notices. Prof. Crum Brown communicated a paper by Prof. Alexander Smith, Wa- bash College, Indiana, U.S.A., on two stereo-isomeric hydra- zones of benzoin. — Dr. Knott communicated a paper, by Prof. Tait, on the compression of fluids. In this paper Amagat's recently published results are applied to test the truth of the empirical formula 7J^-v _ e c',,/ ir -f /' where ir is the internal pressure and v^{\-e) is the ultimate volume under infinite pressure. Tests are made, at pressures of I, 1501, and 3001 atmospheres, for the substances ether, ethylic alcohol, methylic alcohol, propylic alcohol, carbon bisulphide, iodide of ethyl, chloride of phosphorus, acetone, and water. The quantity e is found to be nearly the same for all these sub- stances, and indicates an ultimate reduction of volume of about 30 per cenf. It increases as a rule with rise of temperature. In the case of water, -k increases steadily with rise of temperature up to about 40° C. In all other substances -k decreases steadily with rise of temperature. These facts correspond to the known changes of compressibility with temperature. An attempt is then made to see how far it may be possible to extend the formula to substances such as carbonic acid at ordinary tem- peratures, considerable pressure being required to keep the sub- stance in the liquid state. Consistent values of e and -k are obtained at temperatures and pressures both above and below the critical point. It is found that ir is positive, at volumes a little above the critical volume, over a considerable range of temperature. Hence the Laplace effect predominates over the kinetic repulsion In the other regions for which tests were made, -k is negative. It vanishes, at a temperature a little over 80° C, throughout the observed range of volumes. This vanish- ing of TT corresponds to the case of the ideally perfect gas. Paris. Academy of Sciences, January 22. — M. Lcewy in the chair. — Integration of the equation for sound in an indefinite fluid in one, two, or three dimensions, when resistances of various types introduce into this equation terms proportional respectively to the characteristic function of the movement or to its first derived partials, by M. J. Boussinesq. A solution of a problem in the propagation of sound-waves suggested by M. Poincare in a recent communication. — On the calculation of coefficients of self-induction in a particular case, by M. A. Potier. — Experiments on the histological mechanism of the secretion of granular glands, by M. L. Ranvier. An account of methods employed in observing the cell-activities of the sub- maxillary gland of the rat, — A study of the fauna of the Gulf of L>ons, by M. H. de Lacaze-Duthiers. — Report on the meteorological observatory established by M. Vallot, near the summit of Mont Blanc, and on the first volume of the annals of the work of this oWservatory, by the commissioners, MM. Mascart and Bouquet de la Grye. — On the solar phe- nomena observed at the observatory of the Roman Col- lege, during the first two quarters of the year 1893. A letter by M. P. Tacchini, giving details concerning protuberances, faculse, spots, and eruptions observed. All the phenomena were more frequent in the southern zones, the maximum numbers also were found in these zones. In the first quarter, eruptions were not observed. The maxima of faculse and spots were found in the same zones (± 10°, ± 20°), of protuberances in higher latitudes. — Note on equations and implicit functions, by M. A. Pellet. — On new ex- perimental studies concerning the form, pressures, and temperatures of a jet of vapour, by M H. Parenty. Diagrams are given showing the distribution of pressures in jets with apertures of different types. — Contribution to the study of the properties of the arc with alternating current, by M. G. Claude. — On the minimum electromotive force necessary for the electrol>sis of dissolved alkaline salts, by M. C. Nourris- son. From thermochemical data the E.M. F. necessary is for chlorides 2'02 volts, ' romides 175, iodides i-i6, sulphates 2'15, nitrates 2 07, and chlorates 2'07 volts. The experimental results for the halogen salts of the alkalies and alkaline earths agree with these numbers, but for the corresponding sulphates, nitrates, and chlorates somewhat higher values are obtained. The minimum E M.F. necessary for the electrolysis of a dis- solved alkaline salt is constant lor oxy-salts and is constant for the haloid salts of the same acid. — On an application of sodium silicate, by M. G. Geisenheimer. The application referred to is that ot being used to soften waters for laundry purposes. — On some phosphochromates, by M. Maurice Blondel. The forma- tion and pr perties are described of bodies having the formulas 3K2O.P2O38C1O3 and 2KoO.H20.P205.4Cr03, or 2K3PO4. SCrOj and 2K2H PO4 4Cr03. — Action of sulphuric acid on wood charcoal, by M. A. Verneuil Some of the secondary products have been isolated and identified, notably the penta- and hexa-carbo.\ylic acids, C6H(C02lI).5 and C6(C0oH)g. — Con- densation of isovaleraldehyde with acetone, by MM. Ph. Barbier and L. Bouveault. — Studies on the chemical properties of the alcoholic extract of yeast ; formation of carbonic acid and ab- sorption of oxygen, by M. J. de Rey-Pailhade. — On the sea bottom of the region of Banyuls and Cape Creux, by M. G. Pruvot. — A certain symptom of death, indicatedby the ophthal- NO, 1 266, VOL. 49] o •»' NA TURE [February i, 1894 motonometer. Laws of ocular tension. A note by M. W. Nicati. — Some observations on snake poisons, by M. S. Jour- dain. Remarks supplementary to MM. Bertrand and Phisalix s recent paper, — On the ichthyological fauna of the fresh waters of Borneo, by M, Leon Vaillant. — A method of assuring and promoting the germination of vines, by M. Gustave Chauveaud. — On the structure of the French Alps, by M. Marcel Bertrand. — On the laws of the contortions of the shell of the earth, by i\I. Ziircher. — The temperature of the upper atmosphere, by M. Gu-.tave Hermite. The author shows from the results of two balloon ascents in 1S93 ^^at the decrease of temperature with the height is much more rapid than is indicated by temperatures recorded at mountain observatories. Sydney. Royal Society of New South Wales, September 6, 1S93. — H. C. Russell, F.R.S., Vice-President, in the chair. — The following papers were read by Prof. Liversidge, F.R.S. ; {a) On the origin of moss gold ; (/') on the condition of gold in quartz and calcite veins ; (c) on the origin of gold nuggets ; i^d) on the crystallisation of gold in hexagonal forms ; {e) gold moire-melallique. Results of observations of Comet VI. (Brooks), 1892, at Windsor, New South Wales, by John Tebbutt. — Treatment of manufactured iron and steel for constructional purposes, by W. F. How. October 4. — Prof. T. P. Anderson Stuart, President, in the chair. — On rock paintings by ihe Aborigines in caves on Eulgar Creek, near Singleton, by R. H. Mathews. — Notes on artesian water in Australia, by Prof. T. W. E. David. November i.— Prof. T. P. Anderson Stuart, President, in the chair.— Artesian bores on Bundabunda Station in Queens- land, by Hon. W. H. Suttor. — On the probability (A extra- ordinarily high spring tides about the December solstice of 1893, by John Tebbutt— (a) On meteorite No. 2 from Gilgoin Station; {b) On different pictorial methods of showing rainfi^ll, by H. C. Russell, F.R.S. — On the occurrence of a new mineral " Will)amite" from Broken Hill, by E. F. Pittman. December 6.— Prof. T. P. Anderson Stuart, President, in the chair. — On the occurrence of Triassic plant remains in a shale bed near Manly, by B. Dunstan.— The orbit of the double star h 5014, by R. P. Sellors. — Occurrence of " Evansite " in Tasnnania, by H. G. Smith. — On the separation of gold, silver, and iodine from sea-water by Muntz metal sheathing, by Prof. Liversidge, F.R.S. — Notes on the Cremorne bore, by Prof. T. W. E. David and E. F. Pittman.— The progress and position of irrigation in New South Wales, by H. G. McKinney. Netherlands. Entomological Society, January 21.— P. C. T. Snellen, President, in the chair. — The President exhibited several specimens of Vanessa carditi from different regions, showing that it is a very common species, being disttibuted over nearly the whole world; he also showed specimens of Papilio cpiits and Papilio ajitimachus, both from Java. — Dr. J. Th. Oudemans announced that he was preparing a revision of Snellen van Vollenhoven'.s list of indigenous Tenthredins ; he also stated that on the pupse of Lepidoptera the sex can be recognised, and showed a remarkable nest of Vespa media. — Mr. A. B ants read an interesting paper on the caterpillar of Notodonta ziczac. — Mr. P. J. M. Schuyt proposed the preparing of lists lor exchange of indigenous Lepidoptera. — Mr. J. de Vries exhibited a variety of Xanthia gilvago. Dr. F, W. O. Kallen- bach, a specimen of the raie Cidaria unifasciata, and Dr. A. J. van Rossum, a peculiar variety of Deikphila euphorbia. — Mr. J. R. H. Neervoort van de Poll exhibited a rare variety of Ornithoptera Priamus, and a very fine and rich collection of the colepterous genus Haplosonyx. — Dr. Ed. Everts called attention to a third supplement of his enumeration of indigenous Coleoptera, and showed several species not yet found in the Nethtrlands, but collected in Belgium in the neighbourhood of the limits. — Dr. F. A. Jentink asked if any of ihe members present had observed cats hunting after butterflies, a fact which he had found meniioned in a British periodical, and which he could confirm with his own experience. Dr. H. J. Veth said he had noticed a similar behaviour of cats against Tineidse in a house where the latter were very abundant.— Dr. A. F. A. Lee.-berg called attention to Aleloc aiitumnalis, of which several specimens were captured at Mount St. Pieter, near Maastricht, though this species is extremely rare elsewhere. — Mr. W. G. Huet showed a peculiar nest of Vespa vulgaris and a web of spider, on which hung a long thread with a small stone at its end. — Finally, Mr. F. M. van der Wulp exhibited several indigenous and exotic species of Hippobosca, Olfersia, and Ornithomyia,and described the principal characters to distinguish these genera and their species. BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books. — Alembic Club Reprint^;. No. 5 — Extracts from Micrographia ; R. Hooke (Edinburgh, Clay). — EinfCihrung in das Studium der bakierio- logie : Dr. Carl Giinther (Leipzig, Thieme) — London Matriculation IJirectory, No. xv. January 1894 (University Correspondence C. liege). — Cungres International d'Archeologie et d' Anthropologic Pr^hist riques, ii-e lie Session, a Moscou, Tome 2 (Moscou). — Science and Christian Tradition : T. H. Huxley (Macmillan). — Ein Geologischer Querschnitt durch die Ost-Alpen : A. Rothpletz (Stuttgart, Schw izerbart). — Lectures on Mathematics : F Klein, reported by A. Ziwet (Macmillan). — B^)tanical Wall Diagrams (various) (S.P.C.K.). — Quantitative Chemical Analysis, Clowes and Coleman, 2nd Edition (Churchill). Pamphlets — Questions and Answers on Meteorology : R. H. Scott (Williams and Strahan). — Sulla DistribuzioneTipograficadei Terremoti : M. Baratta (Roma). — Carsosaurus Marchesettii, &c. : Ur. A. Kornhuber (Wien). — Ueber Partanosaurus Zitteli Skuphos und Microleptosaurus Schlosseri nov. gen., nov. spec. : Dr. T. G. Skuphos (Wien). Die Mittel- liasische Cephalopoden-Fauna des H inter- Schafberges in Oberosterreich : G. Geyer (Wien). SEtJiALS. — The British Moss-Flora, Part xv. : Dr. R. Braithwaite (the Author, Clapham Road). — Journal of the Chemical Society, Supplementary Number, December (Gurney and Jackson). — Ditto, January (Cjurney and Jackson). — NuovoGiornale Botanico Italiano, vol. xxv. No. 4 (Firenze). — BuUetino della Societa Botanica Italiana, 1893, Nos 8, 9. 10 (Firenze).— The Esse.v Review, January (Chelmsford, Currant). —Annalen des K. K. Naturhistorischen Hofmuseums, Band viii. Nos. 2, 3. 4 Wien). — Studies from the Yale Psychological Laboratory, 1892-93 (New Haven). —Jahrbuch der K. K. Geologischen Reichsanstalt, xliii. Band, 2 Heft (Wien). — The Geographical Journal, February (Stanford). CONTENTS. PAGE Chinese Central Asia. By W. F. Kirby 309 Huxley's Collected Essays. By Prof. E. Ray Lan- kester, F.R.S 310 The Psychology of To-day 311 Railway Works. By N. J. Lockyer 312 Essentials of Chemical Physiology 313 Our Book Shelf: — Bent: " The Sacred City of the Ethiopians " . . . 314 Modigliani : " Fra i Batacchi indipendenti " .... 314 Badenoch : " Romance of the Insect World " . . . 314 Letters to the Editor : — The Postal Transmission of Natural History Speci- mens.— Philip P. Calvert 314 The Origin of Lake Basins.— John Aitken, F.R.S. ; R. S. Tarr 315 Glacial Erosion in Alaska.— Prof. G. Frederick Wright 316 On the Equilibrium of Vapour Pressure inside Foam. — Prof. G. F, Fitzgerald, F.R.S 316 A Liquid Commutator for Sinusoidal Currents. — Prof. J. A. Ewing, F.R.S 317 A Curiosity in Eggs. — E. Brown 317 Richard Spruce, Ph.D., F.R.G.S. By A. R. W. . . 317 Precious Stones. ( With Diagrams.) 319 Notes 320 Our Astronomical Column . — Jupiter's Satellites in 1664 323 The U.S. Naval Observatory 324 The Satellite of Neptune 324 Geographical Notes 3^4 The Large Fireball of January 25 324 On a Meteorite from Gilgoin Station. {Illustrated.) By H. C. Russell, CM. G., F.R.S. . . ... 325 Modern Mathematical Thought. By Prof. Simon Newcomb, F R. S 325 University and Educational Intelligence 229 Scientific Serials 329 Societies and Academies .33° Books, Pamphlets, and Serials Received 332 NO. 1266, VOL. 49] I NA TURE zzi THURSDAY, FEBRUARY S, 1894. A CRITIC CRITICISED. Darwinianism : Workmen and Work. By James Hutchi- son Stirling, F.R.C.S., and LL.D. Edin. (Edinburgh : J. and J. Clark, 1S94.) DR. STIRLING begins his preface thus : "Perhaps it may be thought that, on the whole, I might very well have spared myself this small venture" ; and such of his readers as know anything of Darwin's theories and works will most cordially agree with him. It has been the present writer's business to read most of the anti-Darwinian literature that has appeared in this country, and though much of it has exhibited extreme ignorance of the whole subject and a total inability to understand the theories and the arguments discussed, in both these respects the present volume fully equals the worst of Its predecessors, while in the effort to belittle Darwin's intellect and to depreciate the value of his life's work it surpasses them all. Considerably more than one-third of the volume is occupied with the lives of the three generations of Dar- wins, and though the animus is carefully veiled, there is an unmistakable attempt to show that, while there is much to admire in the moral and social aspects of the whole family, yet intellectually they have been greatly overpraised. In the very first chapter a number of opinions are quoted adverse to Dr. Erasmus Darwin ; and after a chapter devoted to theglorification of Dr. Thomas Brown, the metaphysician, a third chapter is given up to his " Observations on Dr. Darwin's Zoonomia" and the correspondence between them, and we are led to under, stand that the young critic had by far the best of the argument, and that Dr. Darwin lost his temper. The seventh to the twelfth chapters are devoted to Charles Darwin ; and at the very commencement we find a passage that gives the keynote to the whole book. After saying that, of course, Mr. Charles Darwin will go down to posterity as one of the first of naturalists — an observer only to be classed with the Linnasuses and the Cuviers — we have this curious statement : " Mr. Francis Darwin — and in the circumstances it is not to disparage him to say so — will not, in all probability, precisely do that ; but, with perhaps a more vigorous or more comprehensive general intellect, he is otherwise, we make bold to say, just about as good a man as his father was, than whom, for genuine worth, it would not be easy to find a better." What does this imply, if not that Darwin, though a preeminently good man, was, intellectually, not remarkable? And the whole of the succeeding chapters show that this is its meaning. Darwin's observing powers are dwelt on, and how much he thinks of technical 7iames (p. 72). Then we are told that he was considered by all his masters and by his father to be below the common standard of intellect (p. 75), and this is repeated at p. 77, and again at p. 117. To enforce this, his own depreciatory phrases— that he learnt almost nothing at school and college, that he could never follow abstract trains of thought, that mathematics were repugnant to him, and that he was compelled to conclude that " his brain was never formed for much thinking" — are fully set NO. 1267, VOL. 49] forth. At the same time, Dr. Stirling reiterates, that though quite ordinary intellectually, he was " a very good young man," always trying to improve himself (p. T]) ; that at Cambridge he was " the steady well regulated young man " (p. 84) ; that he was " the good young man '' who, for self-improvement, has interest in, and would have a try at, everything that gives marks. He actually " paid some attention to metaphysical subjects " (p. 105) ; and again — " he was the exemplarily good young man that sought self-improvement in all that was ticketed in society as right." (p. 119.) While thus, with subtle ingenuity, " damning with faint praise " the man whose life-work he is striving to de- preciate. Dr. Stirling impresses upon us what, in his opinion, is the intellectual faculty to which Darwin owes his reputation. It is, the love of observing movement ! Thus — " The stir of a beetle in the dust was the first stir that arrested the interest of a Darwin : the convulsion of a continent was possibly the last." (p. 114.) "It was stir that alone claimed his attention, stir that alone woke his single natural life." (p. 113.) '"Observation is an affair of the eyes — ^shallow, so far, and on the surface ; but ideas and their expression no less, spring rather from the depth — the cerebral depth — of the ears." (p. 114.) Here, by the profound philosophy of a Stirling we are informed that because Darwin was an observer and was jiot a musician, therefore he was shallow and of few ideas ! And for several pages this notion is harped upon — stir, movement, watching birds, observing facts, his very soul was " captivated, fascinated, mesmerised, by the en- chantment of physical movement," the Journal shows that he was " only using his eyes there in every paragraph and almost every line"— and thus the general reader, for whom this book is clearly intended, will gain the idea that there is something trivial and weak in minute observ. ation, and that this was what specially characterised Darwin. Further matter for depreciation is found in Darwin's remarks on some of the eminent men with whom he associated. He thought Carlyle narrow, because he was utterly unable to appreciate science, and this evidently condemns Darwin in Dr. Stirling's opinion, who calls Mill " his shallow contemporary," and describes the group of eminent men who were more or less intimate with him in these terms : — " The truth is that a feebler general j public has seldom existed than what was atmosphere to Carlyle " — of which Mill and the two Darwins, Tyn- dall, Huxley, and other eminent men were an important part. And when Darwin says of him — " I never met a man with a mind so ill-adapted for scientific research" — Dr. Stirling remarks, with crushing sarcasm, " Scientific research meant for Mr. Darwin only the observation of movement, as in beetles, say ; and there was no such accomplishment in Carlyle." Darwin also knew Buckle, and read his books with great delight, though not accepting all his theoretical views ; but even this limited admiration is too much for Dr. Stirling^ who thereon pours out his wrath for seven pages on what he terms " the commonest, vulgarest, shallowest free- thinkingism." Having thus prepared his readers by this fancy picture of the extremely limited range of Darwin's intellect, Ur. Stirling proceeds to deal with the " Origin of Species" Q 3^4 NATURE [February 8, 1894 as illustrated by the " Life and Letters." And the first point he brings forward is that Darwin was a compiler — a " not very sceptical " compiler, an "easy" compiler — and this idea is enforced throughout the first chapter of this second part of the work. Again and again this is recurred to, as the following passages show : — " With all his experiences in pigeons, poultry, and seeds, Mr. Darwin supported his results mainly on a conipilation. Had the public but known that !" (p. 190). "That all that— of the Descent of Man, say — should be supported, not on thirty years' actual ob- servation, experiment, and insight — personally — of the greatest naturalist in existence, but only on little more than so many years' clippings and cuttings from articles in periodicals and other such, as — about ' Hearne the Hunter'!" (p. 212). "Now that is the pity of it! The success of the book depended on the belief of the public that it was the product of work at first hand, and not of compilation at second — work at first hand and of the greatest naturalist in existence A compilation is always a dressing of facts for a purpose ; and such a state of the case is simply glaring in every turn of the * Origin.' " (p. 179.) It is then clear that Dr. Stirling wishes to impress upon the public that Darwin's chief work was mainly a compilation, badly put together — for he tells us it is " dull " and " as he.ivy as lead " — put together to support a foregone conclusion, without caution or judgment, and yet so as to deceive the ignorant public and make them believe it was original work ! Surely here is a Daniel come to judgment — though rather late in the day. Pre- sently we shall have to inquire whether he who delivers this severe judgment is a competent as well as a just judge. The next point is to show how it was that this dull compilation created such an excitement in the literary and scientific world, and made so many converts. We are told this was all owing to Darwin's habit — partly un- conscious, partly designed — of thinking and speaking so highly of the work of his chief scientific corresponden ts — Hooker, Lyell, and Huxley. " Lyell is the biggest fish ; and it is the hooking of him that is wished, and watched, and waited for with the intensest interest." (p. 166.) And after giving nearly two pages of extracts from Darw in's letters, we have the remark — " I suppose no one in this world has been more liberally or more lavishly thanked, iiattered, and bepraised than the recipients of the above.'' (p. 169.) Referring to the preliminary papers read before the Linnean Society, Dr. Stirling remarks : — " The way being so conspicuously prepared for it, and its appearance ushered in and heralded by a trumpet- blowing so resonant and extraordinary, was it any won- der that the book itself was hailed with acclamation and received with even a rush of expectation ? And we have now only to see how the proceedings of Mr. Huxley at the very first could but beat the e.xcitement that, so to speak, already blazed into an absolute conflagration and a veritable fury." (p. 172.) "As we all know, all in England is done by parties, and everything that appears in England is of no use whatever until it is made an affair of party. It was not different with the origin of species.'' (p. 174.) " With all before it that has now been detailed what could the public be expected to think ? The most powerful scientific trumpets that, in these islands, could be blown, were blown— before the book. The most powerful popular trumpets that, in these islands, could NO. 1267, VOL. 49] be blown, were blown — after the book. . . . What could be expected for such a book, if not all but a universal rush to buy ? And how did the public find the book "■: I do not suppose that any one will pretend that it is read now ; and I do not suppose that any one will pretend that it was read ihroiigJi then — unless by those, the few friends of science and the author, whom, in both respects, of course, it immediately and specially concerned." (p. 176.) Dr. Stirling should, however, have explained to his readers how it was that a book which hardly anybody read should have gone through six editions in twelve years, have been translated into every European language, and should still be constantly quoted and referred to as the most classical and authoritative work on the subjects of which it treats. Half the volume having been thus occupied in the insinuation, and attempted proof, that Darwin was a mere compiler with little reasoning power, that there was nothing in his book that was not anticipated by his grand- father (pp. 43-49), and that the book itself owed its suc- cess to the carefully-prepared trumpet-blowing of a few influential friends, Dr. Stirling proceeds to demolish the whole theory in detail in order to justify the conclu- sion he has arrived at. And it is clear that the value to be attached to his judgment, in this matter, must depend upon whether he has taken the trouble, or has the capacity, to understand the theory, or has acquired an adequate knowledge of the facts on which the theory is founded. I propose therefore to show, by a rather full account of his work and by a sufficient number of extracts, the almost incredible state of ignorance and misapprehension everywhere displayed by it. Chapter v. deals wtih the Struggle for Existence, devot- ing to it twelve pages, and maintaining throughout that, in the sense in which Darwin and his followers understand it, there is no such thing ! If this can be proved Darwinians must indeed tremble. Let us then see how it is done. The tameness of animals in un- inhabited islands is first referred to, with the remark : " It is impossible to think of struggle and strife in such circumstances." Dr. Andrew Smith and Mr. Selous are quoted to show the vast profusion of life in South Africa, carnivora and herbivora — " Plentiful lion was not in- compatible with more plentiful antelope.'' Then the passenger pigeon of North America is referred to, as described in one of Cooper's novels ; and the conclusion after two pages of such facts is—" With nature so prolific of life, what call is there for a struggle? what need?" Then we have several pages given to descriptions of how animals enjoy their lives. Mark Twain is quoted for playful schools of whales ; Bret Harte for squirrels and jays ; Jules Verne for antelopes, zebras, buffaloes, and monkeys ; two articles in Temple Bar on birds and otters amusing themselves. Darwin himself testifies to " the positive pleasures of existence, to the actual joys of nature," and, " it is perfectly within the limits of truth to say that his entire Jourtial disproves the struggle ! " And this conclusion is reiterated to the end of the chapter : — " There is little sign of a struggle for life in such cases. These animals have evidently no need to struggle : they seem indifferent about their food, and can remove themselves carelessly from any supplies of it.' February 8, 1894] NA TURE 335 (p. 214.) The Journal says so little of] the struggle that Dr. Stirling believes the idea to have been only an after- thought, followingthe readingofMalthus,andheconcludes the chapter with the opinion of Goethe, that, "in whatever situation of life we are placed, and wherever we fall, we never want actual food"— and he adds— "This means, that however galling the straits of life may be, there is no struggle such that, failing to triumph, we must perish in defeat." The next chapter — on the Survival of the Fittest — is a short one ; and it might well have been shorter, since it begins thus : - '•As regards our other consideration at present, it is pretty evident that if struggle there is none, survival, in that it simply means result of foregone contest, can be, and must be, so far, only a dead letter." This, though forcible, is cautious, but the next para- graph sets the thing in a still clearer light. " But, just squarely to say it, the proposition itself, survival of the fittest, is as things are, preposterousness proper. It is simply absurdity's self — the absolutely false." And then follows, quite unnecessarily, a metaphysical and scriptural demonstration of the same thing, in which comets, tides, wind, the earthquake of Lisbon, the Black Hole of Calcutta, contingency, time, and physical neces- sity, with a host of other things, are all dragged in to enforce the argument. This abstract argument was, however, felt to need support by a concrete example, as follows : — " Survival of the Fittest ! Of two lions that fight, must the strongest win .'' How about a thorn, or a stone, or an unlucky miss, and an unfortunate grapple, and a fatal strain — to say nothing of infinite contingencies of rest and fatigue, of sleep, and food, and health, that precede ? " And after a few more such illustrations we have the conclusion, that — " The proposition, as we have seen in fact, is wholly false as it stands." And after some more vain attempts to arrive at any meaning in this "absurdity's self," the argument is clenched with what is evidently felt to be a t'eductio ad abstirdum, and which is indeed a very gem of logic, as follows : — " Is it possible in such a struggle — a struggle that just constitutes existence — is it possible in such a struggle for even a single competitor to survive him who is the fittest to survive .'' If individual with individual, species with species, genus with genus, must struggle, how is it that the infinitude of time has not already reduced all life to a single unit.^" (p. 222.) Every biologist, every reader of Nature, will now, I am sure, see that I was justified in speaking of the almost incredible ignorance and misapprehension ex- hibited in this book ; but we have yet to find still more glaring examples of it. Two chapters, entitled " Deter- mination of what the Darwinian Theory Is" and "Design,'' may be passed over, and then follow six chapters of " Natural Selection Criticised," from which a few Illustrations of the capacity of the critic must be given. N. . I 267, VOL. 49] After Dr. Stirling's confident assertion that there is no struggle and no survival, and that the very idea of there being any such phenomena is " absurdity's self,' we shall not be surprised to find that he prides himself on having cleared up a subject which Darwin left vague, indefinite, and obscure. He says : — " It is only through long, patient looking that the par- ticular moments in the theory have reached the clearness which we should be glad to think they will be found to possess in these pages." (p. 342.) This is in the last chapter, when the author can look back with satisfaction on his completed work. One of the difficulties he has cleared up is the meaning of the word origin, in " Origin of Species." He says there is never a moment's question of the origin of a single species : " There is not even a hint before us of such a thing as origin. Change there is, not origin. We have a middle, elastic enough it may be, but we have no beginning, no origin, no first." (p. 250.) And a little further on, having previously referred to small living armadillos and the gigantic extinct species, and having asserted that " It was the obvious resem- blance common to both that irresistibly convinced ]\Ir. Darwin of the indubitable descent of the one from the other"— a statement for which he gives usno authorit}-- for the good reason that none can be given — he deals with the question in the following brilliant style : — " Origin ! We are referred from the Galapagos to the South American Continent, and there again the problem stares us in the face, only harder than ever. What is the origin of these South Americans ? Again origin ! Wh::.!. is the origin of these pigmies .-' and you refer us to giants ! Good heavens ! To be contented that the whole problem of the pigmies was solved in the giants, and never once to have asked what of these ! Surely the giants at once suggest an infinitely more instant question as to origin than the pigmies. That pigmies, too, could come out ol giants — such pigmies out of such giants ! Was it selection, natural selection, condescended to such a feat as that.'' ... Is that what is meant by 'the preservation of favoured races in the struggle for existence'— these pigmies ? The nine-foot Glyptodon dies, the six-inch armadillo lives — is that the survival of the fittest .'"' (p. 251.) This may be called argument by exclamation and in- terrogation founded on misconception, and it goes on with wearisome monotony page after page. And at the very end of the book he still stumbles over the same difficulty : " This is strange, too — in the whole ' Origin of Species ' there is not a single word of origin ! The very species which is to originate never originates, but, on the con- trary, is always to the fore." And again : " It was only the word origin did all this ; and the word origin, strictly was a misnomer ; misleading, not novelists alone, but the general public as such, into antici- pations of a beginning and a first that was to be, as it were, a new creation of all things ; whereas Mr. Darwin himself exclaims, ' It is mere rubbish thinking at present of the origin of life ! ' Had Mr. Darwin but used. 1 '(A NA TURE [February 8, 1894 instead of the word origin, his own other word for the idea in his mind, ' modification ' namely — had his title- page ran 'The Modification of Species by Means of Natural Selection/ I question whether Mr. Murray, with all his experience, would, for each of the thousand copies he did sell, actually have sold ten." (Last page.) Poor novelists ! Poor general public ! For thirty- five years you have gone on reading and discussing this book, and helping to make it celebrated, and have only now found one candid and truthful friend to inform you that you have been flagitiously deceived by the title, with- out which you would never have read it, or made any fuss about it, or even have heard of it at all ! In order, perhaps, to enforce this conclusion— that it was the word origin that alone attracted readers. Dr. Stirling assures us that Lyell was too old a bird to be caught by such chaff. Huxley, he tells us, is in a state of doubt ; Carpenter and Gray were only half-converted ; Hooker is the only genuine convert ; but — " Lyell, from the moment he came properly to know the doctrine, was really, and in point of fact, that doc- trine's absolute opponent." It is to be supposed, of course, that Dr. Stirling believes this ; but then what of his knowledge ? In five long chapters of the last edition of the " Principles," Lyell expounds the whole theory in his own calm judicial style, and on every aspect of it pronounces in its favour. The passages we have marked in this volume as examples of misconception, misstatement, or ignorance, are so numerous that it is difficult to know where to choose. Here for example is the way the author deals with natural selection, as being neither a law nor a dis- covery. " But has there been a discovery ? and actually of a law? We have seen an hypothesis — a gourd, as it were, that came up in a night to be a shadow over the land — but a discovery ? Can what the Pampas suggested, or South America, or the Galapagos — can what the breeders or fanciers suggested, or what Malthus suggested, or what the split-up stock of horses suggested — can either or all of these suggestions be called a discovery ? That the similarities in species (as in the beetles, say) should have struck him, and that he should have then asked. What, if naturally varying in time, and so naturally variously applied, they were all just naturally out of each other? — that is a mere supposition, it is no discovery. Even as a supposition, is it a credible one, unless we remove it, far out of sight, into the dark ? Yes : variations, accidents, we know them well, we see them daily ; but they come and go, they appear and disappear, they are born and they die out — they really do nothing ; and as for forming new creatures, is not that an extraordinarily weighty complication to burden such simple, perishable, transitory accidents with?" (p. 284.) Here we have an interrogative show of argument and of superior knowledge on a subject as to which it is quite clear that the writer knows nothing whatever, but hides his ignorance in vague involved words, from which it is impossible to extract any definite meaning. And when he attempts to deal with any definite facts, the ignorance becomes more glaring and the flood of wordy interro- gations more ludicrous. One more quotation to show this, and we have done. He is attempting to deal with the theory of protective colouration, and after a couple NO. I 267, VOL. 49] of pages of misconception and interrogation, he thus proceeds : — " But, seriously, why are canaries yellow ? Why are larks and starlings spotted ? Why has the robin the red breast that gives him his name? Selection! There is actually no selection. Neither on the part of nature, nor on the part of sex itself, is there the slightest proof of the necessary limit of selection. For selection, in the very idea that constitutes it, means a limit. And limit there is none. Blacks, and whites, and blues, and reds, and greens, and yellows, are to be seen indiscriminately mingled, almost everywhere — blacks, and whites, and reds, and greens, &c., in almost every possible shading — nay, in almost every possible variegation, too ! All that pretty anecdotal rationalising — story-telling — in regard to the leopard, too (the grandfather has it), is it not of the same kind ? There are so many leopards in existence because their spots, confounded with the interstitial light and dark of the jungle, save them. But if that is so, why are there quite as many tigers, animals that are not spotted, but striped? Oh, the ghauts, the ghauts, you cry. Well, yes, the ghauts are defiles ; but how is a stripe like a defile, or how does it come from a defile, or as being like a defile how does it save them ? But admitting that, and saying that leopards are saved by spots, and tigers by stripes, what of the lions ? They can be saved by neither — neither by spots nor by stripes, and they are equally numerous, or sup- posably equally numerous — and snf>posably so is the vernacular of the region — why is there no call for either spots or stripes in their case? Or, after all, just as it is, spotless, stnpeless, is not the lion quite as likely to escape detection in the jungle as either of the others, let it be leopard, let it be tiger ? " How clever is the jingle of words and interrogatives, yet how crammed with blunders and how devoid of sense I The writer evidently thinks that Darwin, or some authoritative writer on Darwinism, has stated that the tigers' stripes imitate the defiles in which they live, which defiles are the "ghauts"! He also is of opinion that jeopards, tigers, and lions, all live together in the same " jungles," all have the same habits, and therefore all re- quire the same protective colouring. But they are not coloured alike ; therefore their colouring is not pro- tective ! That is a sample of Dr. Stirling's knowledge and of Dr. Stirling's argument. Readers of Nature may think that too much space has been given to so contemptible and worthless a book ; but it must be remembered that the author has a considerable reputation in philosophy and literature, has published over a dozen works of more or less importance, and was the first Gifford Lecturer at Edinburgh University in 1888-90. It is certain that many purely literary critics, as ignorant of biology as is the author, will declare the work to be an important adverse critique of Darwin and Darwinism. If it were the work of an unknown man, it would, so far as its matter is concerned, be beneath contempt. But when a writer of established reputation goes out of his way to discuss a subject of which he shows himself to be grossly ignorant, and puts forth all his literary skill to depreciate the mental power and the life- work of one of the greatest men of science of the century, it is necessary and right that, in the pages of one scien- tific journal at least, the ignorance, the fatuity, and the carping littleness of the whole performance should be fully and unflinchingly exposed. Alfred R. Wall.\ce. February 8, 1894] NATURE J/ DYNAMOS AND TRANSFORMERS. Dynamos, Alternators, atid Transformers. By Gisbert Kapp, M.Inst.C.E., M.Inst.E.E. (London: Biggs and Co.) THE author of this work is well known as a successful designer of dynamos and transformers. In his preface he states his object to be " to place before the reader an exposition of the general principles underlying the construction of dynamo-electric apparatus, and to do this without the use of high mathematics and complicated methods of investigation." He further says, on p. 26 : " In attempting to establish a working theory of dynamo- electric machinery, or rather in setting forth the rules and formute now used by the designers of such machines, we shall therefore not follow the lead of the pioneers in science so much as that of their more popular expounders, and that of practical experience. The treatment will thus necessarily lack that mathematical elegance of which the scholastic mind is so fond, but, on the other hand, it will be more easily grasped and adopted by the practical engineer who works as much by the aid of his mechanical instinct as by that of science." This is the promise, and we may say at once that in our opinion there is plenty of room for mathematical elegance on the lines laid down. If the results of difficult investigations be assumed, and correct deductions be made and set forth in exact language and in appropriate notation, as required for the particular practical applica- tion, the exposition will be both elegant and scientific. Practical experience also is On the same footing as any experimental result in physics, and deductions made therefrom may be scientific in the highest degree. From the extracts above quoted, one would not expect to find one-third of the book occupied with a theoretical ex- position of electro-magnetism on lines similar to those that may be found in a dozen or more existing works. But such is the case, and we regret to say that there is much in the exposition of the author that is open to severe criticism on the score of the inaccurate and frequently incorrect use of scientific and practical ex- pressions, whose meanings are thoroughly well-estab- lished and generally understood. The word " energy " is employed in a sense with which, we imagine, theoretical and practical men will be alike unfamiliar. " Work " and " rate of doing work " are throughout the book em- ployed as interchangeable expressions, the word "energy" having double duty thrust upon it. It is scarcely necessary to observe that " energy '' is expressed in units of work, and that it is improper to use it in the sense of "rate of doing work " or " power." This is all the more extraordinary for the reason that the author defines " power " or " activity," and in one part of the book freely uses these terms to denote what he calls " energy " in another part. More serious is the circumstance that the author thinks it proper to express "rate of doing work" in units of " work." On p. 42 we find the statement : " This is called the Watt, and is equivalent to 10,000,000 ergs." It is as if the distance between London and Brighton were described as being fifty miles per hour. In the same context the C.G.S. unit of power is termed the erg-second. We have heard of the Watt-second, the NO. 1267, VOL. 49] volt-ampere, the ampere-second, &c., but never before of the erg-second, which has no meaning whatever as a hyphened expression built up in the manner customary with electricians. On p. 141 electromotive force is under discussion by means of the well-known rail and slider ; and on p. 142 occurs the following passage, which may be said to fairly beat the record: — " It was shown in chapter iv. that the mechanical force, P, acting upon a conductor in a field of 13 lines per square centimetre is (C.G.S. measure) P = /^33 where / is the length of conductor and c the current. If we move the slider with a velocity of v centimetres per second the energy required will be Vv^lc J3 V ergs. The energy represented by the current is ec. if by e we denote the electromotive force expressed in a suitable measure. We have therefore the equation ec=lc'>^v (28) or, e = l^ V from which we find that the induced electromotive force is given by the product of length of conductor, strength of field and velocity, all in C.G.S. measure. Formula (28) gives the energy in ergs. To obtain it in Watts, we divide by 10,000,000, and have Watts = /6-B V 10-'." Herein we find almost every conceivable blunder. Power is termed " energy," and expressed in ergs ; formula (28) is said to give the energy in ergs, whereas, of course, it gives the power in ergs per second ; and to wind up the comedy of errors, an expression said to represent ergs is divided by the number 10", and, magi- cally, it appears as Watts. Was confusion ever worse confounded ? The practical man — whose intellect the author con- siders robust enough for the expression, '' line integral of magnetic force,'' and for the comprehension of the (freely employed) integral calculus — is very easily pleased if he finds this sort of information improving. Surely, above all things, he demands accurate statements, and resents having symbols thrown at his head in this contemptuous manner. On p. 27 the north pole of a bar magnet is described as " the end which, if the bar were freely suspended would point to the geographical north." Why the qualifying adjective " geographical " ? If the author desired to evade a definition of the magnetic meridian, he surely might have preferred a " suppressio veri " to a " suggestio falsi." Many examples might be given of the looseness of the language employed. We already possess a number of excellent books on electro-magnetism written by thoroughly practical men in precise and accurate lan- guage ; and we must enter, for the reasons above given, a strong protest against the theoretical portion of this book. It is a pleasure to turn to the really practical part of the work, where the reader will find valuable informa- tion concerning dynamo design. In the case of large machines, the author favours the multipolar type. He 33« NA TURE [February 8, 1894 gives a detailed comparison of two-pole and four-pole machines of a power of 25 kilo-watts, and shows, it seems conclusively, that the latter can be made lighter, and to run at a lower speed than the former. We find a dis- tinction made between the " static " and " dynamic " electromotive force of a dynamo ; the former is defined "> be the E.M.F. "generated in the armature, and directly measurable on the brushes if the machine is working on open circuit." This is always shown on the characteristic (volt and ampere) of a dynamo of what- ever nature, and as there is no discontinuity between it and "dynamic" E.M.F. it is difficult to see the neces- sity either for separate discussion or for special nomen- clature. The alternators chosen as examples are repre- sentative of the different systems in vogue. We find those of Siemens, Ferranti, Gulcher, Mordey, Kingdon, and also that of the author designed for Messrs. Johnson and Phillips. There is not much set down about alternating current transformers, but some good working diagrams are given. There is no information about multiphasers. We have noticed some typographical errors. A serious one occurs on p. 46. P. A. M. GOLF. Golf : a Royal and Ancient Game. Edited by Robert Clark, F.R.S.E., F.S.A. Scot. (London : Macmillan and Co.) PROF. TAIT has recently pointed out how many scientific problems are involved in the flight of a golf ball, and many men of science have learned to find in the game of golf a never-failing and unsurpassed means of recreation from their arduous labours. It is fitting, then, that Mr. Clark's new edition of a golf classic should be noticed in these pages. A writer, who was a famous cricketer, and is apparently a new humorist, has lately, in the pages of a serious Review, started a controversy on the question, "Is Golf a first-rate game ? " The question must be here dis- missed with the remark that it is absolutely irrelevant. Unless there is no grain of earnestness in his reasoning, internal evidence, often misleading, shows that the writer referred to is in the twilight of knowledge of his subject, and the twilight of the gloaming, not of the dawn. Let him hope that he may pass through the darkness, and that it may be as the brief gloom of a St. Andrews' summer night. Mere first-class games, like cricket and kindred, are light o' loves, who leave you the moment that you have lost your youth and your pace. Golf is like a mother — kind to you once; that is, all her life. In the year 1875, "Golf: a Royal and Ancient Game," was edited and privately printed for a small circle of subscribers. It has long been out of print, and a new and slightly enlarged edition has now been published for the benefit of the world at large. It is a delightful book, and the reading of it is a pleasure. In it is found in all its quaintness the dear old fast-dying dialect of the Lowlands of Scotland, and here and there bits of the delicate humour indigenous to the same region. The atmosphere of the book is as breezy as that of the links which now dot our East Coast from NO. 1267, VOL. 49] John o' Groat's to the South Foreland. To class the book as a history is not quite accurate, for it is more a collection of the materials for history than history itself; but to any one interested in the subject, that is no drawback. The introduction is excellent, and together with the old statutes bearing on the game, the extracts from burgh and parish records (much added to in the present edition), the extracts from private note-books and from old minutes, and the new notes, afford interesting glimpses of the social life of the kindly Scots of the olden time ; of the difficulties of " the powers that were" in weaning the people from the game, in order to lead them to the archery butts and to the kirk ; of the funeral ceremonies of a keen golfer, the father of the great Marquis of Montrose, lasting one month and nineteen days ; of the consumption of wine during that period of mourning being reckoned in puncheons, and of the buckets of Easter ale being as numerous as the tears that fell ; of Smollett's genial reflections upon seeing on Leith links a party of four playing Golf, the youngest of whom was turned of fourscore. Among those records are to be found also materials out of which a theory of the development of the Sabbatarianism peculiar to Scotland might be built, and of this something of interest might be said did space permit. The gossip part of the book is too short. The story of John Patersone might be passed as a variant of the old tale of the king and the cobbler. It was at all events sufficiently interesting to inspire the celebrated Dr. Pit- cairn to write for the mural tablet of John's new house — his reward from Royalty for his prowess at the Golf — four elegiac verses and a motto enigmatically telling to all time a tale and John Patersone's part therein. The verses and the motto may be worth quoting : — Cum victor ludo scotis qui proprius esset ter tres victores post redimitus avos patersonus humo tunc educebat in altum banc quse victores tot tulit una domum. I hate no persone. The motto " I hate no persone " being an anagramma- tical transposition of the letters in the words "John. Patersone." The verses in the book are not intended for criticism, but a " Ballade of Golf " and "A Voice from the Rhine" are welcome additions. The wood engravings and the plates appeal to the artist, and an addition to the num- ber of the latter in place of the photographs that were, apart from their interest to contemporaries, out of all keeping with the pictorial part of the first edition, is a step in the right direction. The only serious objections that can be taken to the present edition, and that only in a spirit of gentle remonstrance, are pointed out in the prefatory note' by the editor. Following the note in the order of its statements, it sets forth that since the pub- lication of the first edition. Golf has advanced by leaps and bounds, that it is now as popular in England as it is in Scotland, that it has taken deep root in Ireland, yet in the body of the book not a sentence is devoted to Golf clubs furth of Scotland. No doubt this is partly ex- plained by the fact that no existing club furth of Scot- land except Blackheath is old enough to have a history. At the same time a few pages recording the facts of the introduction of Golf in recent years, not only to England February S, 1894] NA TURE 139 and Ireland, but also to America, India, Australia, Canada, and other parts of the world where Scotsmen have congre- gated, must have added to the value of the book. But, in this connection, the grave omission is that there is no reference to the history and records of the Blackheath Club, the oldest club in the United Kingdom. This is all the more remarkable, that a bright de- scription of " Medal Day at Blackheath " has a place in the book. The most serious complaint is left to the last, and that is that the editor should say in the note referred to that he has abandoned his intention of writing his own reminiscences. The reason assigned, that the books of his friends are a bar, will not bear examination. These books, clever and able as they are, were born of the high spirits of the hour, and were never thought of by their authors as anything but ephemeral. They served and are serving a good purpose ; they amuse and instruct their generation, and it matters little that they have induced many to contort themselves into the oddest of attitudes. The editor and his friends might furnish an interesting chapter of the history of the game. They have seen the days, when the grand manner was not yet dead, when the style of the front rank Golfers was dis- tinguished by something more than force and mammoth driving, when it was as graceful as that of the play of fence of a first-rate swordsman ; the days when the social life of Golf was free from some of the irksome bonds which it now wears. How many now remember an incident that marked an epoch, the boys' tournament of the summer of i860, organ-ised at great expense of time and trouble by the late Sheriff Gordon ! How few know anything of him ! And yet he was as distinct a type of a Scotchman of a past generation as singing Jamie Balfour, whose effigy is one of the adornments of the book. It is to be hoped that the editor may reconsider his decision, and add a chapter on modern Golf, stopping short of the time when it became the fashion. As it stands, the book is the only book indispensable to the Golfer, and its wider circulation will no doubt lead many to the great house of Golf. There they will read, and feel the truth of, the legend inscribed in indehble letters upon the portals : lude Sains. Let the last words here on this subject be the words of an enthusiast : — " Plaudere, non jubeo" (you may do that at cricket) " sed magna voce frementes, Dicite : In eeternum tloreat alma domus. Floreat." W. Rutherford. OUR BOOK SHELF. Celestial Objects for Common Telescopes. Vol. i. Bvthe Rev. T. W. Webb. Fifth edition, revised and enlarged, by the Rev. T. E. Espin, M.A., F.R.A.S. (London : Longmans, Green & Co., 1893.) Since the original edition of Webb's " Celestial Objects" was published in 1859, no book has appeared which has found greater favour in the eyes of amateur astronomers. Written by one who had seen the wonders and glories of the heavens, the work has always been recognised as sounding the genuine ring that results from rich ex- .perience ; and by entrusting the editing of the fifth NO, 1267, VOL. 49] edition to the Rev. T. E. Espin, the publishers have acted wisely, for he is an observer versed in both the old and the new astronomy. The work has been divided into two volumes, the first of which is before us. This volume is concerned with the subjects of parts i. and ii. of the original work ; the second, which will probably be published shortly, covers part iii. and is the book for the observatory. In some respects, this division of matter is an improvement, for descriptions of astronomical phenomena can very well be kept apart from lists of celestial sights. Mr. Espin is wholly responsible for the volume as yet unpublished, and as it has been entirely rewritten, we may confidently expect many important innovations. In the volume under review, very few alterations of the original text have been made. To bring the book up to date, workers in different branches of astronomy have contributed additional matter on the subjects in which they are specialists. One of the results arising from this division of labour is that the chapters are extremely unequal. The new matter is added in foot-notes, but we think the book would have gained in value if it had been incorporated in the text. Among these notes is one on celestial photography, and another on spectro- scopy as applied to the telescope. In the latter we read that " Stellar spectra were divided by Secchi into five types," and closely following this remark is given a classification in which Type v. includes bright line stars and nebulas. But Secchi only distinguished four types of stellar spectra, and it was not until 1891 that Pickering proposed to add a fifth type to Secchi's classification. There is another matter that might be more clearly expressed. In the brief statement of the use of the objective-prism for obtaining photographs of the spectra of stars, it is not men- tioned that the prism must be fixed over the object-glass with its edges east and west. If the prism is arranged with its edges north and south, no amount of regulation of the driving-clock will expand the linear star-image into a band upon the photographic plate. These omissions are, however, very slight, and Mr. Espin will doubtless remedy them at the first opportunity. They certainly do not lessen the welcome we extend to this new edition of an excellent book. Plane Trigonotnetry. By S. L. Loney. (Cambridge : University Press, 1893.) In the 500 pages of which this volume consists, the author has placed before students of trigonometry an elementary text-book which only wants reading carefully to be thoroughly understood. One cannot do more than state in clear and plain language the various methods of expressing trigonometrical ratios, the applications of alge- braic signs, ratios of multiple and sub-multiple angles, &c. ; and this the author has done, interpolating neatly printed figures and concise explanations wherever they seem necessary for a clearer exposition. A great number of excellent examples is also given, the answers being collected at the end. No very marked deviations from the usual sequence of the subject-matter adopted in such text-books have been made, but it is noticeable that here and there are given at some length many pieces of book- work which are passed over in a few words in some books. The second of the two parts into which the book is divided deals more with the analytical side of trigono- metry, that is, with exponential and logarithmic series, expansions of trigonometrical quantities, summations of series, &c. In this part the treatment of complex quantities has been so handled as to lead the student up to the methods of the more advanced treatises. The concluding two chapters deal briefly with errors of ob- servations, some miscellaneous propositions, solution of a cubic equation, maximum and minimum values, &c. A very useful list of all the principal formute which the 340 NA TURE [February 8, 1894 student should commit to memory is separately printed, and precedes the first chapter. Beginners will find it better on their first reading to omit the articles specially^ marked for this end, and also to make selections from the examples. It would be hard to find a better intro- duction to plane trigonometry book. LETTERS TO THE EDITOR. The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part (j/Nature, No notice is taken of anonymous communications.'] Music, Rhythm, and Muscle. In your issue of January i8, you refer (on p. 271) to an article by Dr. Wilks in the Medical Magazine (which I have not seen), in which the learned author points out that music is not to be regarded in its origin as a purely spiritual faculty, but that it admits of a physiological explanation. This dis- cussion is in itself a most interesting one. Dr. Wallace, in his well-known discussion of the relations of music to the other faculties of man, has raised this very question, or one closely allied to it. Wallaschek, as quoted by Dr. Wilks and your- self, asserts that "rhythm, or keeping time, lies at the very foundation of the musical sense." Rhythm again, he says, "can be referred to muscular contraction and relaxation,'" the "muscular sense being the measure of time," so that the mus- cular sense is intimately bound up with the idea of music. " Not in the different passions of the mind, but in muscular action, therefore, music appears to have had its origin." My purpose in addressing you is to point out that these opinions receive a remarkable and very beautiful illustration in the history of Greek dance and rhythm, so far as these are known to us. We know but little of Greek music in the stricter sense of this word, and this perhaps for the very reason that music was not then separated from choral intonation and movement. The strophe and antistrophe of the Greek chorus, which terms we usually apply to the musical phrases sung during a movement, are primarily, of course, not these strains but the evolutions themselves, the dancing towards the one side of the orchestra or the other. No w we do know from the metrical analysis of Greek dramas and odes what these rhythms were, and we can thus probably infer the character of the music proper. By the study of Greek rhythms we shall thus find a method of tracing the genesis of music in its most elaborate modern forms from dancing and footing it in any kind of measure. Dr. Wilks well points out that muscular movement is essentially rhythmical : we may go farther and say that all movement, even the rush of falling water, is rhythmical. The monotony of the recurrence of identical periods or colons would soon be felt, and we find accordingly that efforts are made by all early people to vary the measures. The use of two and four simple feet would soon pall, and was accordingly broken up in the Greek drama by threefold and more complex metres, as, for instance, by Pindar in his Epinikian odes. This " threefold form," says a recent writer, finds an almost exact counterpart in most of the figures of Bach's " Wohltemperirtes Klavier," and the " modern sonata has the same form on a very extended scale," the first part and its repetition corresponding with the strophe and antistrophe of the Greeks, and the second part with the epode. These curious parallels and essential similarities may be traced much farther and into elaborate de- tail, as is shown in part by the writer I have quoted, Mr. Abdy Williams, in the Classical Revieiu for 1893 (p. 295). Mr. Williams's article, which well deserves a careful reading, is based upon the important discovery of a treatise on rhythm by Aristoxenus of Tarentum. Aristoxenus was a favourite pupil of Aristotle, and flourished about 300 is.C. ; he wrote also a treatise on harmony, which less concerns us here, and he was "not only a musician, but a man of the widest culture and knowledge." Soon after the time of Aristoxenus the depend- ence of music on metre, which in its turn is a notation of choral movement andbut a regulation of the rhythms of various muscular moveoaent— ihe dependence, I say, of music on metre gave way to the ascendancy of accent. Accent, and not quantity began to NO. 1267, VOL. 49] form the basis of the rhythm. Strict measure thus became less obviously the basis of music and poetical rhythm ; but, says Mr. Williams, "upon the ruins of the ancient measured music arose a new and magnificent art, now known as ' Plain Song' or ' Gregorian Music,' the rhythmical construction of which is based on the natural laws of phrasing. " (Compare strophe and antistrophe.) With the disuse of plain song arose again the old metrical rhythms, but now so dissociated from choral evolutions that we have forgotten their muscular origin. The early modern com- posers recovered the elaborate rhythms once founded on choric phrases, but under the name of "form," and "by following the instincts of their genius, unconsciously brought about a renaissance of the natural rhythms and musical forms known to the ancient Greeks, developing them by the aid of modern re- sources, while adhering to certain definite principles which on examination are found to agree with those enunciated 2000 years ago by Aristoxenus of Tarentum." These, I need not repeat, were almost directly based not upon rhetorical, but upon muscular rhythms. The simpler and ruder the musical sense, the more brief and simply bipartite, or two-legged, must be the recur- rent rhythms, as the popular tunes of our street organs and music halls tell us daily ; the more relieved and elaborated rhythms of Bach and Beethoven need a more sustained atten- tion and a more cultivated apprehension, while the rhythms of Wagner are so postponed in their resolutions, and so broken in their variety, that perhaps few even of good musicians can follow them with any consciousness of muscular measure, or even of "form." Therefore we call them " highly spiritualised," and forget whence they are originally derived. Cambridge, January 28. T. Clifford Allbutt. P.S. — Since writing this letter, Prof. Roy has drawn my attention to the stateoient that if a pencil be taken in the right hand, a sheet of paper placed below if, and the hand thrown into a rapid automatic dotting action, as the paper is drawn forward the resulting row of dots will be found to be a uniform number per second — five or seven, I forget which — and thus for all persons alike there is the basis of rhythm. The Cloudy Condensation of Steam. The publication in your pages ^ of Mr. Shelford Bidwell's lecture on " The Cloudy Condensation of Steam," at the Royal Institution in May last, calls for a few remarks from me. As the points I have to refer to are principally personal, I shall be as brief as possible. In discussing the effects of electrification on the condensation of a steam jet, Mr. Bidwell, after pointing out that though it has been shown that small particles of matter are thrown off by the electrical discharge, says that — "Yet it is remarkable that Mr. Aitken . . . gives no countenance to the nucleus theory." He then informs his hearers that he imagines I have abandoned my conclusions regarding the action of dust. It is very difficult to understand Mr. Bidwell's objection to me not countenancing the nucleus theory to explain the phenomena, as in the very next paragraph he shows I was correct in not ascribing the change in the jet when under electrification to dust particles, and gives an experiment to prove it. His experiment is dif- ferent from the one on which I founded my conclusion. In some experiments made when working at this subject there did not seem to be a possibility of the dust produced by the elec- trical discharge getting to the jet. Take, for example, the fol- lowing experiment : — The steam jet was allowed to issue from the side of a polished metal ball of about 3 cm. diameter. This arrangement was adopted to prevent any discharge of electricity from the nozzle. At one side of the jet was placed an electrified body at a distance of about 10 cm.; and at about the same distance on the other side of the jet was placed a flame. As no air passed either from the flame or from the elec- trified body to the jet, it seemed impossible the effect could be due either to particles of metal from the conductor or to par- ticles of dust from the flame. The conclusion, therefore, was that the effect on the jet could be produced by electricity without the aid of dust. It, however, seems highly probable that the dust produced by the discharge of electricity may have some effect in such experiments as those described by Prof. Barus, in which the air from the terminals from which the dis- charge is taking place is carried to the jet. Prof. J. J. Thomson 1 Nature, Decemler 20, 1S93, February 8, 1894] NATURE S41 has since shown ^ that the increased density of the jet on elec- trification is only partly due to the cause to which I attribute it, namely, the electrical repulsion preventing the coalescence of the drops, as he proves that the electrification of the jet over- powers the surface tension, and so promotes the formation of small drops, and in this way assists in increasing the density of the condensation. Mr. Bidwell's misunderstanding of my position is greatly due to an impression he seems to have that I attribute all cloudy condensation to the presence of dust particles. Now, if he will turn to my first paper on this subject,- he will find that the effect of the vapours of hydrochloric, sulphuric, and nitric acids, active vapours, mentioned in his lecture, have all been referred to, and experimented with, as well as many other substances, so that I was well aware of these causes of condensation. Further, he will find in the paper referred to, as well as in another of a later date,^ that it is possible to produce cloudy condensation without the presence either of dust or a vapour capable of forming a nucleus with water vapour, or even the abnormal condition due to electrification, all that is necessary being a sufficiently high degree of supersaturation. Darroch, Falkirk. JOHN AlTKEN. The Os Pedis in Ungulates. Prof. Ewart, in a recent paper,^ describes the os pedis or " coffin bone " of the horse as consisting to a large extent of a bony cap developed from connective tissue around, and quite independent of the terminal phalanx. This throws an entirely new light on one of the most remarkable bones of the horse's skeleton, and ic especially interesting to veterinarians. Having a foetal calf (about 6| months) in my possession, I was led, on reading Ewart's paper, to examine the digits, and wish now, in a word, to state the result. I found each digit provided with a bony cap similar to that figured by Ewart from his 35 cm. horse embryo. On making a longitudinal vertical section of one of the digits, the investing cap could easily be distinguished from the phalanx proper ; and, further, I noticed a large deposit of osseous matter in what may be termed the diaphysis (shaft) of the terminal phalanx, and an indication of a second ossific centre at its apex. This affords additional proof that the third phalanx in ungulates, as in man, consists partly of membrane bone and partly of cartilage bone, and that it in all probability develops from several centres. I hope soon to publish a number of observations on the structure and development of the digits in ungulates. A. E. Mettam. Royal Veterinary College, Edinburgh. A Brilliant Meteor. A METEOR of extraordinary splendour was seen here this even- ing at 7.45. It appeared vertically under the Pole star, at an elevation of 40^, and, after pursuing a path that sloped down to the west at an angle of 30°, disappeared silently under Cas- siopeia. The incandescent mass had an apparent volume equal to that of a good-sized orange. It gave out a bluish-white light that brilliantly lit up, for about four seconds, the grounds and build- ings of the College. The glowing mass was followed by a long, conical, crimson train ending in a wisp of condensed vapour resembling smoke. The sky was clear, starlit, and moonless at the time. M. F. O'Reilly. The Training College, Waterford, January 31. THE VA TIC AN OBSER VA TOR Y. T^HE report recently issued by the Vatican Observatory -*■ {Pubdlicasiom della Specola Vaticana, Fasciculus iii.) is the best that has been prepared by Father Denza, and in abundance of matter and fineness of execution, it compares favourably with that of any observatory. The i Phil. Mag-. October, 1893. 3 ''Dust, Fogs, and Clouds." {Trans. Roy. See. Edin., vol. xxx. part i.) 3 ' On the Numbers of Dust Particles in the Atmosphere." (Trans. V^oy- Soc. Edin. vol. .\xxv. part i.) 4 "The Development of the Skeleton of the Limbs of the Horse." {Journal of Atiatoviy atui Physiology, January, 1894.) NO. J 267, VOL. 49] first report was published in 1891, but neither that nor the one of 1892 contains so much evidence of work done as the bulky tome last issued. The observatory, as it is at present constituted, only dates back to 1889 ; but pre- vious to that, it passed through so many vicissitudes that a brief outline of its history may be of interest. It is recorded that an observatory tower was erected by Pope Gregory XIII. in connection with the reform of the calendar, some time previous to 1582. The tower was intended for astronomical observation, and there is every reason to suppose it was the first celestial watch- tower built in Rome. The following translation of an e.xtract from the Aateiica Mcditcrranea of B. Crescenzi, published in Rome in 1607, clearly shows that the room at the top of the tower was used for astronomical pur- poses :■ — " When the sun arrives at the tropic of Cancer its rays enter a little hole which Ignatius Danti has had made for that purpose in the roof of the apartment which Pope Gregory XIII. had erected upon the Belvedere Gal- lery, and the rays only enter the hole once a year, when the sun is furthest from the equinox, after which he turns and goes back." Danti appears to have marked a meridian line upon a marble table in the tower, and meridian observations were made until about 1644, but the observatory was afterwards neglected, and remained so for about a century and a half. It was only towards the end of the last century that an attempt was made to renew the astronomical work. Cardinal Zelada had a large meridian circle constructed, and fur- nished the observatory with some good astronomical instruments, among which was a telescope by DoUond. As the observatory was not available for public instruc- tion, it was decided to establish another at the Roman College, and the new observatory was erected in 1787, though observations had 'oeen carried on at the College long before. In 1789 the Vatican Observatory commenced a new epoch in its history. Philip Gili began his directorship in that year, and, in addition to making astronomical observations, initiated researches in magnetism and meteorology, and other branches of terrestrial physics. The observatory kept well apace with the times until the death of Gili in 1821, but after that it became quite dis- organised. All the instruments and records were dis- persed, and the observatory itself was entirely deserted until about 1870, when it was transformed into a residence. Before passing to the third epoch in the " eventful history " of the Vatican Observatory, a few remarks upon the Observatory of the Roman College may be of interest, especially as the relations between the two institutions are not generally well understood among astronomers. According to Father Cortie, who has kindly furnished most of the following information upon this matter, the Roman College Observatory dates back at least to 1572. It belonged to the Society of Jesus, and consisted in the beginning of a few rooms set aside for astronomical studies. Scheiner, of sun-spot fame, Clavius, the author of the Gregorian reform of the calendar and the observer of Tycho Brahe's Nova of 1572, de Gottingues, who ob- served Jupiter's spots and the comets of 1664, 1665, and 1668, Boscovich, and other renowned astronomers were connected with it. There still exists in the Kircher Museum of the College a meridian line traced by Boscovich, and the same astronomer drew up the plans for a new observatory, but they were never carried into effect, on account of the troubles in France and Spain, during which the Society of Jesus was suppressed. During the period of the suppression, the observatory was directed at first by J. Callandrelli, who in 1773 built a square tower at the eastern angle of the facade of the College, and placed in it a zenith-sector and a meridian circle, the gifts of Cardinal Zelada and Pope Pius VII. 542 NA TURE [February 8, 1894 Fig. I. — Aito-Cumulus ^ZSf Fig. ;. — Strato-Cumulus and Alto-Stratus J February 8, 1894.] NATURE O^J Fig. 3. — Cumulus ami btr.ito Cumulus. Fig. 4-— Nimbus. 144 NATURE [February 8, 1894 After the restoration of the Society, however, the Jesuits gained possession of this observatory in 1824, and placed it under the direction of Dumouchel. De Vico, whose cometary discoveries and observations of Venus are so well known, was the next director, but with the troubles of 1848 came the expulsion of the Society of Jesus from Rome. De Vico died in London. In 1849, how- ever, Secchi, who made his first observation when an exile ai Stonyhurst, commenced to carry out the learned Bosco- vich's plans. The observatory was rebuilt, endowed, and instruments furnished at the expense of the Society of Jesus, and with the generous aid of Pope Piux IX. At the next expulsion of the Society, in 1870, Secchi re- mained at the observatory at the express wish of the Italian Government. At his death he bequeathed the property of the Society to Father Ferrari, but the Government appropriated the observatory and every- thing connected with it. Fortunately for astronomy, how- ever, Signor Tacchini was appointed to the directorship of the observatory, and has well sustained its reputation. It may be added that the Observatory of the Capitol, in which Respighi did such good work, was founded by Leo XII., and attached to the University of Rome. After the Vatican Exposition in 1888, in commemora- tion of the fiftieth anniversary of the priesthood of Pope Leo XIII., all the instruments and apparatus given by members of the Roman Catholic Church inter- ested in celestial and terrestrial physics were brought together, and it occurred to the managers of the science sections of the Exposition that they would find a suitable home in the old Gregorian tower. The suggestion was warmly approved and carried into effect. Father Denza, a great friend of Secchi's, was appointed the director of the revived observatory, and he began his work in 1889 with a comprehensive programme, which he and his assistants Lais, Andreis, and Mannucci have well carried out. The investigations instituted relate to meteorology, terrestrial magnetism, geodynamics, and astronomy. The building is well situated for meteorological observa- tions ; it is equipped with instruments for the continuous record, as well as personal observation, of meteorological data. In terrestrial magnetism, also, instruments are pro- vided for the determination of absolute values and the registration of variations of the usual elements. The chief astronomical engine of research included in the observatory's outfit is a photographic equatorial of the Henry pattern and mounting, for use in connection with the construction of the photographic star-chart which the Vatican Observatory is helping to bring to a successful termination. Having now described the constitution of the observa- tory, it remains for us to state the nature of the work done, as evidenced by the reports. The first report contains a long article on the prmciples and progress of celestial photography, by Father Denza. Father Lais reports the details of stellar photography in connection with the chart, and the methods of obtaining photo- graphic stellar spectra and solar pictures. He also summarises the observations made in Italy during the Perseid shower of August 1890, and during the Leonid shower of the same year. Sig. Andreis describes the points to be investigated in the geodynamical work of the observatory, and there is a full account of the meteorological instruments and the observations made with them. When the second report of the observatory was issued, it was seen that Father Denza and his assistants had carried on some useful observations during 1891. The geographical position of the observatory, eclipses of the sun and meon, the Perseid and Leonid meteor showers of the year, formed the subjects of important articles by the Director, while Father Lais and Sig. Mannucci described the work that had been done in celestial photography. Marvellous results were obtained with NO. 1267, VOL. 49] the Henry equatorial from the very beginning, and no stronger witness of this is necessary than that afforded by the beautiful plates which embellish the second report. The picture of the Ring Nebula in Lyra is certainly one of the best yet obtained, and that of the star-cluster M 15 is equally good. Other bits of celestial scenery included in the same volume are the Pleiades and neighbourhood, and a cluster in Sagittarius, while individual occupants of the heavens are represented by three portraits of Jupiter and two views of the lunar surface. We pass now to the report issued in the latter half of last year, and which in point of excellence and abund- ance of matter even surpasses the one before it. Two remarkably fine portraits are given in this volume, one of Pope Leo XIII., the other of the late Admiral Mouchez ; and the astronomical views include the region of Nova Aurigje, that of the Praesepe cluster, the Orion nebula, and four sun-pictures. But none of these photo- graphs are so striking as the fourteen reproductions of cloud photographs obtained by Sig. Mannucci, and of which we are able to give four specimens. Meteorolo- gists will remember that a set of eighty cloud photo- graphs taken at the Vatican Observatory were shown at the Royal Meteorological Society's Exhibition in 1890. Sig. Mannucci's experience indicates that in cloud photography very short exposures do not give the best results. Plates of medium rapidity, having a thin film, seem to give the boldest contrast between the blue of the sky and the masses of diaphanous haze that are some- times projected upon it. Such plates also show the greatest amount of detail in large masses of cloud. Sig. Mannucci gives a brief account of systems of cloud classification in the volume to which reference has been made. He practically accepts the classification proposed by Abercromby and Hildebrandsson at the International Conference held in Munich in 1891, and set forth in the Cloud-Atlas of Hilderbrandsson, Koppen,and Neumayer. The classification recognises ten different species ar- ranged in five principal groups. The first group (A) comprises the highest clouds in our atmosphere ; the second group (B) includes clouds at a medium height, and the third (C) low clouds. In the fourth (D) we have clouds in ascending currents, and finally, (E) contains the masses of vapour changing in form. In the first four groups the letter (a) is used to distinguish the forms of cloud usually accompanied by fine weather, and {b) for those characteristic of bad weather. The following is the grouping as given by Sig. Mannucci : — ■ Group A. Clouds from medium altitudes up to an average of 9000 metres. 1. Cirrus {a) 2. Cirro-stratus {h) 3. Cirro-cumulus Group B. Clouds having altitudes from 3000 to 6000 metres. 4. Alto-cumulus {a 5. Alto-stratus {b) Group C. Clouds the bases of which have altitudes from looo to 2000 metres. 6. Strato-cumulus («) 7. Nimbus {b) Group D. Clouds on ascending columns of air, with bases about 1400 metres high, and summits from 3000 to 5000 metres. 8. Cumulus (rt) 9. Cumulo-nimbus {b) Group E. Fogbanks up to about 1,500 metres. 10. Stratus February 8, 1894J NA TURE ;45 We cannot conclude this account without referring to the magnetic work done at the observatory. Father Denza contributes to the third report a long discussion of '.he magnetic declination and inclination at Rome, and, \y a comparison of observations, finds the secular varia- tons. In the latter half of the seventeenth century, the d«clination was about two and one-half degrees West, and increasing. In 1806, Gili obtained a value of 17' 17', and in T 824 a maximum of 18' seems to have been reached. Th» declination then began to decrease, and its value at the md of 1891 was 10' 45''35. The first observation of the magietic inclination at the Vatican was made in 1891. This element had been previously determined, however, in other parts of Italy by several observers. From 1859, when Secchi observed the inclination at the Roman Col- lege, ip to the present time, the recorded values for various oarts of Italy have been fairly numerous. Before 1859, hovever, very few observations were made. In 1640 an observer gave 65^ 40' as the inclination at Rome, and Humboldi obtained a value of 61'' 57' in 1806. Father Denza gives 58' 4'"6 as the inclination at the Vatican Observator; in 1891. A number of other matters are discussed in the volumes under notice, and many observations are included, upon which we have not been able to comnent in this article. Enough has been said, however, to show that the observatory has furthered in- vestigations in many branches of physical science, and, from the energetic character of the workers, we may con- fidently expect many more contributions to scientific knowledge. R. A. Gregory. NOTES. The Bakerian lecture is to be delivered before the Royal Society by Prof. T. E. Thorpe, on the 22nd inst., the subject of the lecture being a research carried out by Mr. J. W. Rodger and himself on the relations between the viscosity (internal friction) of liquids and their chemical nature. We are requested to state that Mrs. Tyndall would be much indebted to any correspondents of the late Prof. Tyndall who have preserved his letters, if they would kindly lend them to her for use in the preparation of his biography. Any letters thus lent should be sent to her at Hind Head House, Haslemere, and would be returned safely to their owners. A HYGIENIC laboratory has been established in the University of Bonn. The new institution will be under the direction of Prof. Finkler. According to the British Medical Journal, there is now no university in Prussia without a hygienic labora- tory. From the same authority we learn that the Bengal branch of the Pasteur Institute was successfully inaugurated on January 30, in the presence of a large company. The Duke of York visited King's Lynn on Friday, and opened a new technical school built by the Corporation at a cost of ;i^3,ooo. The order of S.S. Maurice and Lazarus has been conferred upon Sir Joseph Lister, M. Pasteur, and Prof. Virchow, by the King of Italy. Mr. Henry O. Forbes has been selected by the Library Committee of the Liverpool Corporation for appointment as Director of the Liverpool Museums. The late Dr. J. K. Hasskarl, whose death we announced on January 25, has, says the Chemist and Driiggist, bequeathed his library to the University of Strassburg, and his herbarium to the University of Leyden. Prof. Billroth died at Abbazia, on February 6, at sixty-five years of age. He principally devoted his attention to military surgery, and published a number of valuable papers on that branch of his profession. It is .said that during the last few NO. 1267, VOL. 49] months of his life he was engaged in completing a work upon the physiology of music. We regret to announce the death of Mr. Peter Redpath, a generous benefactor to science in Canada. Mr. Redpath took an active interest in the McGill College and University, Mon- treal, and in 1880 built, at his sole expense, a museum in connec- tion with the University. This building, known as the Peter Redpath Museum, is used for the exhibition and study of speci- mens in geology, mineralogy, palaeontology, zoology, botany, and archaeology. In October last, a library, capable of holding 130,000 volumes, and added to the University buildings through the liberality of Mr. Redpath, was opened in the presence of a Targe and influential gathering. The sums spent in erecting the museum and library are said to amount to nearly ;^75)000. Mr. Redpath died at Chislehurst on February i, in his seventy-third year. Prof. Edmond Fremy died on Saturday, at Paris. We are indebted to the Times for the chief points in the following sketch of his career. The son of a professor of chemistry at St. Cyr, he was born at Versailles on February 28, 1814, and after studying with his father, became a teacher at the Ecole Polytechnique. In 1857 he was elected into the Paris Academy of Sciences as successor of Baron Thenard. The amount of Fremy's scientific work is enormous. His first publications date from 1835 ; they relate to the precious metals, and attracted the attention of the scientific world. His investigations on ozone (in conjunction with Becquerel), on the ammoniacal bases of chrome and cobalt, on fluor spar and the reproduction of minerals, will remain classical. In organic chemistry, also, he made numerous important researches, and as manager of the Saint Cobain Works he superintended the manufacture of soda and sulphuric acid, the tempering of glass and steel, the refin- ing of castings, &c. Not long ago he published, jointly with one of his pupils, M. Verneuil, a work, which was the fruit of years of study, on the artificial production of rubies. He was the author, with Pelouze, of a treatise on chemistry in six volumes, and in 1881 began the publication of a chemical encyclopaedia. In addition to the names we gave last week, the Lancet says that the following are some of the principal delegates who have been appointed to represent the various Governments at the International Sanitary Conference which opened in Paris yesterday. Great Britain : Mr. Constantine Phipps and Dr. Thorne Thorne, C.B., F. R. S. British India : Surgeon-General Cuningham. France : M, Barrere, M. Hanotaux,Prof. Brouardel, Prof Proust, and M. Monod. Germany ; Herr von Schoen and Herr Mordtmann. Holland : Dr. Ruysch and M. de Stuers. Russia : M. Michel de Giers, together with technical delegates. Austria-Hungary : Count Kuefstein, Dr. Hagel, and Dr. Karliuski. Greece : M. Criesis and M. Vafiades. Italy : the Marquis de Malaspina and Dr. Pagliani. Portugal : M. Navarro. Sweden and Norway : M. Due. Turkey : Tuskan Bey, Nouri Pasha, Boukowski Pasha, and Dr. Haindy Bey. Persia : A delegate yet to be appointed by the Persian Ministry in Paris. Egypt : Achmet Pasha Choukry, M. Mieville, and Sedky Pasha. The remaining countries — Belgium, Denmark, and Spain — have not yet announced their delegates. The Executive Committee of the City and Guilds of London Institute have changed the name of the Guilds Central Institu- tion, in Exhibition Road, South Kensington, to the Guilds Central Technical College. The gold medal of the Royal Astronomical Society has been awarded to Mr. S. W. Burnham for his discoveries of binary stars and researches in connection with them. At the annual general meeting of the society, to be held to-morrow, the pro- posal will be made that henceforth the meetings be held at ;46 NA TURE [February 8, 1894 4.30 p.m. instead of 8 p.m. At present the Royal Society is the only one that meets at 4.30 at Burlington House. The fourteenth general meeting of the Federated Institution of Mining Engineers will be held at Leeds on February 14, and a number of important papers will then be read. Arrange- ments have been made for visits to works, &c. on the follow- ing day. As an introduction to the summer excursions of the London Geological Field Class, Prof. H. G. Seeley, F. R.S., will deliver a course of four lectures on " The Shaping of the Earth;" at Wortley Hall, Seven Sisters Road, beginning on February 22. We learn from the Kew Bulletin that Mr, W. Lunt has been appointed botanical collector for Kew to Mr. Theodore Bent's expedition to the Hadramant Valley, in South Arabia. The flora is only conjecturally known, and no botanical collections appear ever to have been made in it. The expedition left London on November 24, and is expected to return about April. The number of the Keiv Bulletin for December, 1893, con- tains an important correspondence between the Colonial Office and the Directors of the Royal Gardens, Kew, on the root- disease of the sugar-cane ; and an interesting account, by two of the gardening staff at Kew, of the subtropical horticulture in various gardens in Cornwall. The Botanical Gazette says that Mr. O. F. Cook sailed on October 25 for Western Africa, to make further observations and collections of the plants of that region, especially of cryptogams. He will be gone a year or more. His former voyage resulted in securing a large amount of botanical material, and the present visit is expected to yield even greater results. At the monthly meeting of the Malacological Society of London on January 12, Mr. G. B. Sowerby described a new species of the genus Vcrticordia, to which he gave the name of V. optima. The shell, which far exceeds in size and beauty any hitherto known, was taken off Port Blair, at a depth of 188 fathoms. The description and figure will appear in the forth- coming number of the Proceedings of the Malacological Society of London. The vertical distribution of the British Lepidoptera forms the subject of an article by Mr. W. H. Bath in the January and February numbers of the Entomologist. Too little attention is usually given to this interesting branch of entomology, though as a matter of fact vertical distribution is as important as hori- zontal or geographical distribution, for, as Mr. Bath points out, it not only estimates the affinities existing between the lowland species occurring in this country, and their relations in more elevated areas in the South of Europe, but shows the relation- ships between our mountain forms and their representatives found at higher altitudes in Alpine regions, and lower in Arctic and sub-Arctic latitudes. And further, vertical distribution gives a better index as to the range of temperature and other climatic phenomena which each species can endure than mere geographical distribution is capable of doing in anything like the same area. Mr. Bath has prepared a list of vertical zones in the British Isles, taking as its basis the divisions defined by the Brothers Speyer in their work on the distribution of Swiss and German Lepidoptera. His proposed list contains five zones, viz. the South Coast zone, the Lower Hill zone, the Upper Hill zone, the Lower Alpine zone, and the Upper Alpine zone. The limitations of these zones are fully described, besides being presented in a tabular form, so that any entomologist who desires to take up this mountaineering branch of his science will find that Mr. Bath has considerably smoothed the way of observation. NO. 1267, VOL. 49] The Geographical Journal for February contains a note of a journey up the Cross River, made by Sir Claude Macdonald, the Commissioner for the Niger Coast Protectorate. Since 1842 no vessel larger than a canoe had gone up the river as fa? as the rapids, but the stern-wheeler Beecroft, navigated b/ Captain Dundas, met with no difficulty, and in her Sir Claure passed the rapids, and would have gone on to some high fals spoken of by natives, but the rainy reason was almost over, ind the river beginning to fall so rapidly that he had to return. The natives met with were friendly and anxious to have regular communication on the river. We have received a pamphlet from Mr. Robert Stein, setting forth his plan for the exploration of EUesmere Land in a concise and practical form. His expedition is undertaken vith the cordial approval of the National Geographic Society of Wash- ington and of many of the leading British and American Arctic explorers. Mr. Stein retains full liberty for Ms conduct of the expedition, but is aided in organising it by an advisory committee consisting of Commodore G. W. Mel'ille, Dr. T. C. Mendenhall, General Greely, and Mr. John Jo/ Edson, who acts as treasurer. The expedition is estimated to cost only 10,000 dollars, a large part of it being subscribed by the mem- bers already appointed, while the remainder was nearly made by private subscriptions. The proposed method jf working bears every mark of having been carefully thought Jut. Twenty-two men at most will take part in it, and they w-ll leave St. John's, Newfoundland, about May i, 1894, in a whaler, which will land them at Cape Tennyson, in EUesmere Land, or as near that point as possible. A house will be erected, provisioned for two years, and left in charge of four men. Eight men will follow the coast of EUesmere Land westward, and establish an advanced depot about 100 miles from fhe base, and then make an attempt to reach Hayes Sound. A thorough search will be made eastward along the coast by a party of six for the missing Swedish naturalists Bjorling and Kaistennius. The whole party intended to spend the winter of 1894 at the base, where con- tinuous meteorological observations will be carried on, and in the spring of 1895 they will endeavour to extend the explora- tion as far as Greely fjord, but will make their way by the end of September to Cape Warrender, on Lancaster Sound, where four men will be lefc at a depot in 1894 to await them. A whaler will meet them there by appointment, and bring the expedition back to Scotland or Newfoundland. Careful scientific observations will be made throughout, and collections in all departments of natural history are arranged for. Over sixty men had volun- teered for the expedition up to January 9 ; of these, thirty were found to be suitable, but only three had been definitely en- gaged. The estimate of 10,000 dollars provides only for a party of ten ; in order to establish the reserve station at Cape War- render, and to search properly for the lost Swedes, a further sum must be raised. Should the first ex pedition prove successful, Mr. Stein's larger scheme of Arctic exploration will probably be proceeded with on his return. In the Geological Alagazine for February, Miss M. M. Ogilvie continues her paper on "Coral in the 'Dolomites' of South Tyrol." The article is illustrated by a fine map and sections of the district discussed. Miss Ogilvies conclusioa with regard to coral foimations in the dolomites strengthens " the position of those authorities who have contended that the immense thicknesses of ' Schlern Dolomite ' rock were an ordinary marine deposit and not ' coral-reefs. The discovery of petroleum on the Mendip Hills has re- cently been announced. A well at Ashwick Court, two miles north of Shepton Mallet, has long been known to yield water slightly flavoured at times with petroleum. A considerable flow February 8, 1894J NATURE 347 of oil is said to have taken place in July, 1892, when the water- level was low, and this has continued at intervals, but in smaller quantities, since that date. Ashwick is shown on the Geological Survey map to stand at the northern edge of the carboniferous limestone : the beds have a high dip to the north, passing under the millstone grit and the coal-measures of the Radstock area. Indications of petroleum are also known in other wells and springs in the neighbourhood. The matter is now being inves- tigt.ted by Mr. Boverton Redwood and Mr. W. Topley, under whose directions further explorations will be made. The phosphatic marls of New Jersey have long been known ; they have been worked for fertilisers since 1768. Mr. W. Bullock Clark has published a paper •' On the Cretaceous and Tertiary Formations of New Jersey." (Ann. Rep. of the State Geologist, 1892.) The origin of a glauconitic greensand is fully discussed, and reference made to recent deep-sea research. Coloured reproductions are given of Murray and Renard's plates in the Chalkuger Expedition Report, exhibiting phases in the formation of glauconite. The greensands occur most commonly near the boundary lines between the shallow and deep-water zones, but not opposite the mouths of large rivers, nor where strong currents prevail. In making the detailed survey in New Jersey, a small boring apparatus has been used, which seems, from the description given, to be simpler and more portable than that employed on the Belgian and English surveys. It is made of half-inch gas-piping, in lengths of 10 feet. This giyes good results to a depth of 30 feet. Mr. Clark's paper is further illustrated by prints from photographs. Some of those, e.g. " View among the Navesink Highlands,"' suggest nothing so much as an ultra-" impres- sionist " daub, all blur and no colour I The professional photo- grapher complains of the hypercritical eye of his fair sex con- stituency ; one could wish that nature had a word to say for herself. The photographic camera is fast coming to be con- sidered part of the equipment of the geologist. If men, whose movements in the field are already well burdened by hammer, compass, knapsack, and specimens, are willing to add to those the inconvenience of a camera, there must be great advantage to be got from photography. But what advantage will be derived from an occasional lucky hit ? It would be difficult to name the science now that does not utilise photography. Clearly the time has come when another "optional" may be added to the subjects of the complete curriculum. At any rate, science must recognise photography at its professional value, and must refuse bad photographs and worse prints. For some time past the United States Hydrographic Office has been collecting information about jthe meteorology of the North Pacific Ocean, with the intention of utilising it for the benefit of seamen, and it has recently issued an advance Pilot Chart of that ocean for the month of January, 1894, on the same principle as the Pilot Chart for the North Atlantic Ocean, which has often been referred to in our columns. The hydrographer states that, if Congress grants the necessary funds, it is proposed to issue on the first day of each month a chart showing for the Succeeding month, by deduction from accumulated observations, the winds and currents to be expected, the regions of prevailing fog and rain, the most advantageous' routes to be followed by sail and by steam, &c. The amount of information available for the Pacific is greatly inferior to that for the Atlantic, but if the support and cooperation sought for are freely given by those in- terested in enhancing the safety of navigation, the undertaking will undoubtedly become a very valuable contribution to mari- time meteorology. M. H. Parentv has been investigating the forms of steam ijels from various orifices, and has published his results in the NO. 126;, VOL. 49] last number of the Cotnptes Rendus. The diagrams accom- panying the paper, in which regions of different pressures are shaded differently, exhibit some curious fluctuations, which may be described as a series of nodes and ventral segments proceed- ing outwards from the orifice. These fluctuations are due to the interference between the outgoing waves of steam pressure and those reflected back by the air. In the case of a con- vergent elliptical orifice of 13', three nodes were found with pressures of 1 15, 165 and 138 cm. respectively, that at the orifice being 285 cm. or 375 atmospheres. All the nodes occurred within 2 cm. of the orifice. They were found by means of an air-manometer provided with very finely-drawn glass tubes. It appears that the position and value of the nodes or condensa- tions depend upon the difference of pressure between the boiler and the atmosphere, and the form of the orifice. At very high pressures the jet assumes an approximately paraboloidal shape, such as would be assumed by a liquid jet falling upon a disc of the size of the orifice. A further conclusion reached by M. Parenty is that the highest attainable velocity of etillux is the limiting velocity of sound in the medium concerned. The curious polarisation phenomena obtained with very small electrodes in a sulphuric acid voltameter through which a strong current passes, accounts of which have appeared in Wiedernann s Annalen for the winter of 1892, suggested to Dr. L. Arons the question as to what would take place at a very thin and small metallic partition in a voltameter. Some preliminary observa- tions made by Dr. Arons showed that when a piece of gold-leaf was pasted over a hole 15 mm. in diameter bored through a glass partition in a voltameter, there was no visible development of gas at the partition ; while with platinum foil '02 mm. thick there was a profuse development of gas with the same current strength. A very thorough investigation of the polarisation phenomena upon thin metal partitions has been carried out by Mr. John Daniel, an account of which is published in the Philosophical Magazine for February. The author has examined partitions made of gold, platinum, silver, and aluminium, and finds that, in good conducting solutions of sulphuric acid, copper sulphate, and common salt, the critical thickness, below which there is no polarisation, is for gold between "00009 mm. and "0004 mm., while for plates more than '004 mm. thick the polarisation is as great as for very thick plates. The author finds that the polarisation of " thick ' plates is about the same for all currents between o"2 ampere and 0"0i ampere, provided time be allowed in each case for the current to become constant. With " thin " plates, however, the polarisation depends upon the current. By thick plates we mean those with a thickness greater than 0*004 mm., and by thin plates those having a thickness less than this quantity. The same number of the Philosophical Magazine contains a paper by Mr. W. H. Steele, on the thermoelectric diagram for some pure metals. From some thermoelectric observations he had made, the author was led to suspect that the lines given by Prof. Tait in his thermoelectric diagram were not quite accurate, and he has therefore undertaken the measurements necessary to construct a diagram, using metals in as great a state of purity as possible. The metals used are aluminium, tin, lead, zinc, thallium, silver, gold, copper, cadmium, and antimony. The electromotive force for a temperature difference of about 100' C. was in each case compared with that of a standard Clark cell made according to Lord Rayleigh's instructions. The distribution of zymotic disease by sewer air is a question still sub jndice, and in order to throw, if possible, some additional light on the subject the London County Council asked Mr. Laws to make some investigations on the air in some of the London sewers. The report has recently been presented and published. The principal experiments were made^in a sewer run- ;4S NA TURE [February 8, 1894 ning under the Green Park, and constructed some 120 years ago, and presumably having had ample opportunity for getting thoroughly contaminated. The percentage of carbonic acid gas present was estimated, and especial attention was given to the microbial contents of sewer air. For the detection of the latter Prof. Percy Frankland's method {Phil. Trans. 1887) was em- ployed, and it is to be regretted that as this process enables large volumes of air to be sifted for micro-organisms in a short time, Mr. Laws did not examine more than ten litres. The results recorded confirm those obtained by previous observers, i.e. that sewer air contains generally very few organisms, and, as a rale, less than the air outside. Dr. Petri's observations on sewer air are not mentioned, but they are worth quoting, for he examined 100 litres of air in a Berlin sewer, and found on one occasion no organisms at all ; and in another experiment only one bacterium and three moulds. It would appear, therefore, that drain air as regards freedom from microbes is very fre- I quently superior to that which we inhale in our houses, and | compares especially favourably in this respect with the air in ; crowded reception-rooms. Mr. Laws, however, concludes his report by remarking that although the organisms in sewer air do not probably constitute any source of danger, the latter may | contain some highly poisonous chemical substance which may } produce a profound effect upon the general vitality. But every- 1 one agrees that sewer air is not a desirable addition to the atmosphere either of our streets or houses. The Midland Naturalist has ceased publication, owing to lack of support, after sixteen years' existence. Among the papers in the Actes de la Sociele Scientifiqtie dii j Chili, vol. iii. 1893, is one on the Coleoptera of Chili, by M. P. Germain, and another containing a description of a new method of determining the orbits of planets and comets, by M. A. Obrecht. The University Correspondence College Calendar (1893-4) j has just been published. It contains answers to the questions set at the Matriculation Examination of last month, and articles on the special subjects for June, 1894, and January and June, 1895. Mr. R. H. Scott, F.R. S., has prepared an abridgment of his " Elementary Meteorology," in the form of a little book containing five hundred questions and answers on meteorology. The book, which is published by Messrs. Williams and Strahan, will be found useful to teachers and others. Another of the Alembic Club Reprints (No. 5) has been published by Mr. W. F, Clay, Edinburgh. The volume con- tains extracts from the Micrographia of Hooke (1665), and a specially interesting paper in which his views on combustion are explained. Messrs. Nalder Bros, and Co., Red Lion-street, Clerken- well, have issued a price list of electrical testing, mathematical, optical, and other scientific instruments manufactured by them. The catalogue is very well illustrated, and each article named in it is given a telegraphic code word, so that in ordering any piece of apparatus it is simply necessary to transmit to the makers the code word allotted to it. Three representatives of the Lancashire County Counci Technical Instruction Committee visited, last year, some of the chief continental schools which give technical instruction in horology, the silk industry, and mining. As a result of the inquiry a report has just been issued, in which the deputation recommends the establishment of schools in which all these subjects are thoroughly taught. The Quarterly /oiirnal of the Geological Society (No. 197) contains, in addition to eight papers, eight plates illustrating NO. 1267, VOL. 49] the work of Mr. Rutley on the " Sequence of Perlitic and Spherulitic Structure," of Mr. E. A. Walford on "Inferior Oolite Bryozoa from Shtpton Gorge, Dorset," and " Cheilos- tomatous Bryozoa from the Middle Lias," and of Dr. J. W. Evans on the " Geology of Matto Grosso, Brazil." An entirely new edition (the seventeenth) of "Johnston's Elements of Agricultural Chemistry " has been published by Messrs. W. Blackwood and Sons. Prof. C. M. Aikman has revised the whole of this well-known text-book, rewritten large portions of it, and added new matter, so as to bring the work up to the present position of agricultural chemistry. The fact that the book has survived unto the seventeenth edition is suffi- cient evidence of its usefulness. A series of coloured botanical diagrams, suited for class teaching, has been published by the Society for Promoting Christian Knowledge. The plants selected are chiefly in- digenous, and the leaf, blossom, parts of the blossom, husk, and seed of each are very clearly shown in a greatly enlarged form. The diagrams thus exhibit to students the characteristic parts of plants, and will doubtless facilitate the study of some common specimens. "A Text-Book of Solid or Descriptive Geometry," by Mr. A. B. Dobbie (Blackie and Son), is a little book possessing many good points, and one upon which great pains have evidently been spent. There are about 350 diagrams in the book, all of which have been carefully designed by the author. The diagrams and explanatory text are both extremely clear, and the problems well arranged. Elementary courses in plane geometry and graphic arithmetic are included, and add to the value of a book which we confidently recommend to the notice of teachers. The first part of the volume of the Proceedings of the Congres International de Zoologie, held at Moscow during August, 1892, was reviewed in Nature of January 5, 1893. The second part has just been published, and is of equal excel- lence with the one that preceded it. The volume contains thirty memoirs, occupying 287 pages altogether, and a supple- [ ment of 83 pages is devoted to the second report of Prof. Blanchard on the nomenclature of organisms. Prof. Blanchard presented his first report upon this subject to the International Zoological Congress that met at Paris in 1889. The first edition of "Electricity in the Service of Man" (Cassell and Co.) was published in 1888. Two years later a second edition appeared, and the third is now before us. The work has been revised and enlarged by Dr. R. M. Walmsley, and it has certainly benefited by his changes. Some 120 pages of the second edition have been excised, and new matter cover- ing more than 200 pages has been inserted. It would be tedious to enumerate the numerous additions that have been made, both in the theoretical and technical sections of the subject. Suffice it to say that Dr. Walmsley has brought the book well up to date, and has largely increased its value by a thorough revision. The Irish Naturalist for February contains a list of all the known additions to the flora of the north-east of Ireland (except Musci and Hepatic*) since the publication in 1888 of Stewart and Corry's work upon that subject. The list also embodies ; additional localities for many of the rarer species. Dr. Scharft \ concludes a paper on the Irish wood-lice, in which he gives descriptions of all the British species. Miss S. M. Thompson sets up a plea for Irish glaciology, and the Rev. Hilderis Friend describes a new Irish earthworm. An admirable review of the rapid progress which has been made during the last few years in the new domain of stereo- 1 chemistry, which deals with the spacial arrangement of the February 8, 1894] NA TURE ;49 atoms which compose a chemical molecule, is contributed to the Chemiker Zeittiiig by Prof. Victor Meyer. The literature of this most interesting branch of chemical study has so rapidly ac- cumulated since the theory of Le Bel and Van't Iloff was pro- mulgated in the year 1874, that a concise account of the im- portant stages of progress which have led up to the present state of our knowledge is particularly welcome. The earlier portion of the memoir is devoted to the development of the idea of the asymmetric carbon atom, and the growth of the conviction that the occurrence of isomeric compounds represented by the same constitutional formula — which differ only in their action upon polarised light, and very slightly in other physical properties, such, for instance, as the three lactic acids — -could only be ac- counted for by the different spacial arrangement of the atoms in the molecule. The fundamental assumptions of Van't Hoff are very clearly expressed, and the possibilities of isomerism by change in the relative positions of the various groups attached at the four corners of the hypothetical carbon tetrahedron are fully illustrated. A striking example is afforded in this connec- tion by one of the results of the brilliant researches of Emil Fischer in the sugar group, whereby we are made acquainted with no Jess than thirteen distinct sugars, all of which are represented by the same constitutional formulae CH20H.(CHOH)4.CH20H. The second section is devoted to the stereo-isomerism of the derivatives of ethylene, so ably worked out by Wislicenus. The simple expIanaMon of the remarkable and long-discussed case of the isomeric acids, maleic and fumaric, upon the lines of the new theory, is referred to, and a similar explanation extended to numerous other and more complicated of the derivatives of ethylene. The third section deals with the peculiar nature of the stereo-isomerism of closed-chain compounds, such as the polymerised tri-aldehydes. It is then shown in a further section that carbon is by no means peculiar in lending itself to stereo- isomerism, but that the pentavalent nitrogen atom is likewise t capable of furnishing isomers which differ structurally merely in the relative positions occupied by the five attached atoms or groups. The stereo-isomerism of nitrogen compounds is shown, however, to be largely influenced by the weight and complexity of the five attached groups. The interesting discovery of a second di-oxim of benzil by Goldschmidt in Prof. Meyer's \ laboratory, gave a great impulse to the study of nitrogen com- pounds containing the group C = N, termed oxims, and the j number of stereo-isomeric oxims which have subsequently been isolated bear remarkable testimony to the use of a theory in stimulating research. The additions to the Zoological Society's Gardens during the past week include two Swainson's Lorikeets {Trichoglosstis novcT-hollandia) from Australia, presented by Mr. John Biehl ; a Chilian Conure {Coiiiirus smaragdinus) horn Chili, presented by Mrs. Gibney ; two Eyed Liza'ds (Za^^r/a ocellata) twenty European Tree Frogs {Hyia arborea) South European, pre- sented by Mr. T. Keen ; a Madagascar Porphyrio {Porphyria madagascariensis) from Madagascar, a Waxwing {A?)ipelis garruhis), two Long-tailed Tits {Parus caudaius) European, purchased ; a Hog Deer {Cervus porcintis) born in the Gardens OUR ASTRONOMICAL COLUMN. Eclipse Meteorology. — A very extensive series of meteor- ological observations was made during the total eclipse of the sun on January i, 1889, at Willows, California. It appears that the temperature fell 6^ F. from the commencement of totality to ten minutes after, while the variation of the baro- meter was so nearly identical with the daily fluctuation that no effect could with certainty be ascribed to the eclipse. The influence on the wind, however, was very marked, its previous velocity of twelve miles per hour being reduced almost to that NO. 1267, VOL. 49] of a calm. Observations with the solar radiation thermometer showed that some heat was received throughout totality. An attempt was also made to secure concerted observations of the so-called " shadow bands " — the long dark bands separated by white spaces which are seen in rapid motion on the ground and sides of buildings just before and after totality. The observa- tions collected seem to give decisive evidence against the view that the bands are diffraction fringes in the shadow of the moon, the observed velocities being far less than that of the shadow ; the fact that they were prominently seen at some stations, while at others they were hardly visible, indicates a local origin (Ann. Harvard. Coll. Obs. vol. xxix.). In the same volume, Mr. Parkhurst gives an account of his photometric observations of some of the asteroids, and confirms the previous conclusion that there is a phase correction over and above that for the defect of illuminated surface, and that this correction is different for different asteroids ; the idea that large errors may be introduced by rotation, however, is not con- firmed. The same writer also gives the individual observations of a large number of variable stars, which furnish valuable data for the construction of light-curves. A Remarkable Cometary Collision. — Two striking photographs are reproduced in the February number of Know- ledge, in illustration of an article, by Prof. E. E. Barnard, on the probable encounter of Brooks' Comet with a disturbing medium on October 21, 1893. The comet was discovered by Mr. Brooks, on October 16, but though it was kept under obser- vation at the Lick Observatory, no phenomena of an extraordinary kind were observed until the 21st of that month. A photo- graph, then taken with a Willard photographic lens, presented a remarkable appearance, the tail appearing, to use Prof. Barnard's analogy, like a torch streaming in the wind. The reproductions of the photographs give the impression that the comet's tail swept into some dense medium, and was broken up by the encounter. Indeed, Prof. Barnard thinks it impossible to escape the conclusion that the tail did actually enter a dis- turbing medium which shattered it. This theory is supported by the photograph taken on October 22, where the tail is seen to hang in irregular cloudy masses, and a large fragment appears to be entirely separated from the main part. There is little doubt that the tail met a mass of meteoritic matter, and so had its symmetry destroyed ; at any rate, this supposition must be accepted until a simpler and better one can supplant it. What we have to do, as Mr. Cowper Ranyard remarks in an article on the irregularities of comets' tails, is diligently to collect facts. The multiplication of such photographs as those obtained of Brooks' Comet, and of Swifi's Comet (1892), by Prof Barnard, will certainly revolutionise current opinion as to the develop- ment, and the types, of comets' tails, MiRA Ceti. — According tothe Co7npanion to the Observatory, this famous variable star will reach a maximum about the 17th inst. At the time of writing (February 3), the star is of a reddish tinge, and faintly visible to the naked eye ; but, un- fortunately, it is too near the sun to permit of long-continued observations on the same evenmg. The magnitude at maximum is very inconstant, and varies between i"7 and 50 (Gore). Spectroscopic observations of the star are of the highest importance, and it is to be hoped that a satisfactory record of its phases will be secured. The general spectrum is one of Group II., but near a former maximum, Pickering photo- graphed a number of bright lines, chiefly of hydrogen. Among the points on which information is desirable are : (i; at what phase of the variation the bright lines of hydrogen make their appearance ; (2) the fluctuations in the bright flutings of carbon observed by Mr. Lockyer at the maximum of 1888 (Nature, vol. xxxviii. p. 621). Proper Motions of Stars. — The recently published volume (xxv.) of the Annals of the Harvard College Observa- tory contains values for the proper motions of a large number of stars in the zone 50° — 55° north, the adopted values, how- ever, being only at present regarded as provisional. The results are derived by Prof. Rogers from the comparison of his own positions for the stars in this zone, obtained with the meridian circle, with the positions given for corresponding stars by earlier catalogues. One section of the volume gives the values of a and 5, referred to the system of the Astronomische Gesellschaft, for the stars included in the zone in question. The System of Algol — An elaborate discussion of the in- equalities in the period of Algol recently led Mr. Chandler to 350 NA JURE [February 8, 1894 conclude that there is a distant dark body around which the bright star and the dark companion producing echpses revolve in a period of 130 years (Nature, vol. xlv. p. 446). This con- clusion has been greatly strengthened by recent investigation by Mr. Searle, of the relative places of Algol and comparison stars from observations made with the meridian circle at Harvard College [Annals, vol. xxix. 1S93). The right ascension of the star appears to be increasing in general conformity with Chandler's prediction. THE INSTITUTION OF MECHANICAL ENGINEERS. THE forty-seventh annual general meeting of the Institution of Mechanical Engineers was held on the evenings of Thursday and Friday of last week, in the theatre of the Institu- tion of Civil Engineers. There were two papers down for reading, as follows : — " Research Committee on Marine Engine Trials. Abstract of results and experiments on six steamers, and conclusions drawn therefrom in regard to the efficiency of marine engines and boilers," by Prof. T. Hudson Beare. "Description of the Grafton High Speed Steam Engine," by Edward W. Anderson, of Erith. The reading and discussion of Prof. Beare's paper, together with the introductory proceedings, occupied both evenings, so Mr. Anderson's paper had to be adjourned until next meeting. Upon the members assembling on Thursday evening, the ist inst., the President, Dr. William Anderson, took the chair. Mr. Bache, the secretary, then read the annual report of the council, by which it appeared that the Institution continues to flourish, the i income and membership having increased during the past year. After the reading of the report Dr. Anderson vacated the chair, his term of office of two year? having expired, and the new ' President, Prof. Alexander B. W. Kennedy, F.R.S., was duly installed. After the usual votes of thanks, and a few compli- mentary speeches, the reading of Prof. Beare's paper was pro- ceeded with. As our readers are aware, the Research Committee on marine engine trials of this Instiiution has been for some time past en- gaged in making trials with different steam vessels. The reports of the committee on these trials have already been re- ferred to in our accounts of former meetings of the Institution at which they have been read. Six vessels have been experi- mented upon altogether since the committee was formed. These ships have consisted of channel passenger vessels and cargo boats, the committee not having had yet an opportunity of experimenting upon an important ship of the ocean liner type. The labours of the committee have been brought to a con- clusion, for the present at any rate ; and the paper of Prof. Hudson Beare was intended to give a summary of the results, and afford a basis of discussion thereupon. We are at a loss how to condense within the compass of space at our disposal the mass of data dealt with by the author of the paper. Perhaps the most lasting impression on one's mind, after going through the subject, is that no general conclusions, that can be compactly expressed, are to be drawn from the trials. The conditions of work required from marine engines in ships of different classes are so various that what is paramount virtue in one case becomes an unnecessary refine- ment in another. Thus in the cargo boats the first consider- ation is economy in fuel, to which nearly every other feature in the machinery is usually saciificed. In order to carry cargo at a rate sufficiently low to enable the shipowner to compete, the coal bill must be light, and therefore we find in these vessels boilers lightly worked and speeds low. On the other hand, vessels that have to convey passengers must be speedy, and general economy has to be sacrificed to this end, the model of the vessels themselves being formed with the same purpose in view. Perhaps we cannot do better than quote some of the elements of design of the machinery, and some of the re- sults attained during llie trials, in order to illustrate these leading facts. We will take two of the ships tried — the loiia, a large cargo boat, and the Ville de Dojcussion of Sir Henry Howorth's "Glacial Night- mare" appears in the (quarterly Revieii) (No. 355)- -^"^ Q.ox\.- clusion the reviewer remarks: "We venture to record the opinion that in his treatment of the rival claims of iceand of water, as to which was the chief factor in producing the great Drift at the close of the Pleistocene epoch, our author has succeeded in shifting the balance of probability, and transferring it to the action of the latter." Among other contributions of scientific interest in the magazines received by us is an interview with Dr. A. R. Wallace, F.R. S., on "Heredity and Pre-natal Influence," pub- lished in the Humanitarian ; an article in Longman s, in which Mr. J. G. McPherson brings together a number of elementary facts relating to "Colour," and a paper on "Vegetable Monsters," by Mr. Edward Step, in Good Words. Mr. Step describes the current fictions concerning the so-called Devil-tree, the Upas-tree, the manchineel {Hippomane mancinella), and the Scythian Lamb {Agnus Scythicus). We have received the Contemporaiy, but it does not contain any articles on scientific topics. UNIVERSITY AND EDUCATIONAL INTELLIGENCE. Oxford. — The voting for the board of the Faculty of Natural Science last week resulted in the election of Messrs. J. E. Marsh, H. Balfour, A. G. Vernon Harcourt, W^. Esson, G. C. Bourne, and R. E. Baynes. Mr. R. H. Bremridge has been elected to a Senior Demyship at Magdalen College. Mr. Bremridge obtained a first class in the Honour School of Natural Science (Physiology) last year. Mr. Rj. T. Giinther has been chosen as science tutor at Magdalen College, to succeed Mr. E. Chapman, who is leaving Oxford at the end of the Summer Term. Professor Ray Lankester is issuing a volume of studies made in the Linacre Department since his election to the Professorship. The volume, which bears on its cover a medal- lion with a likeness of Linacre, contains papers by Dr. W. B. Benham, and Messrs. Minchin, R. T. Giinther, Goodrich, Pycraft, and others. Cambridge. — The electors to the Downing Professorship of Medicine, vacant by Dr. Latham's resignation, will meet for the purpose of electing his successor on March 3. Candidates are to send twelve copies of their testimonials (if any) to the vice-chancellor (the Rev. A. Austen Leigh, Provost of King's) by Monday, February 26. The Council of the Senate have published, in the Uni- February 8, 1894] NA TURE o:io versify Reporter for February 6, a very important proposal, which may lead to a considerable increase in the number of students resorting to Cambridge for advanced study or research. The Council recommends that statutory powers be obtained for the establishment of two new degrees, Bachelor of Science and Bachelor of Letters, to be conferred on graduates only, whether of Cambridge or of some recogni'^ed University, British or foreign. The conditions suggested are (i) matriculation, (2) residence for one academical year (three terms), {3) evidence of advanced study or research in Cambridge, (4) an original dissertation on some subject, literary or scientific, coming under the cognisance of one of the Special Boards of Studies. Hitherto only graduates of the Universities of Oxford and Dublin, who have fulfilled conditions as to residence equivalent to those in force at Cambridge, have been admissible to ad eiDidem degrees. The new proposal is much more liberal, and is calculated to attract some of those maturer students who now, after graduating in their own University, seek op- portunities for higher work in the continental school^. As Cambridge graduates can qualify for the B. Sc. and B. Litt. degrees only if they have passed one of the higher Honours Examinations, and then only on submitting an approved original dissertation, it is plainly intended that these degrees shall imply a real distinction. It is interesting to note that literary or scientific research, and not the faculty of passing examinations, is a condition for the new " post-gnduate " degree. At Oxford similar proposals are said to be afoot, and if the two older Universities carry through their scheme, a great step will have been taken towards making them once more the resort of scholars from all parts of the world. The Times published on Tuesday a summary of the recom- mendations of the Gresham Commission on a Teaching Univer- sity for London, embodying a scheme for its constitution, with visitor, chancellor, vice-chancellor, senate, academic council, convocation, and schooU, and regulations as to examinations, faculties, boards of studies, and degrees. SOCIETIES AND ACADEMIES. London. Royal Society, December 14. — " x\ction of Light on Bacteria. — Bacterial Photographs of the Solar and Electric Spectra." By Prof. H. M. Ward, F.R.S. A thin film of gelatine or agar, in which spores or bacteria are evenly distributed, is spread over the flat bottom of a shallow glass dish. The lid of the dish is a plate of ground- glass, in which one or more slots, about 5 inch wide and 2^ inches long, are pierced. The spectrum is so arranged that the light-rays fall perpendicularly on the film carrying the spores &c. , and can only reach the latter through the slots, all other parts of the plate being covered by tin foil and black paper. When the film has been thus locally exposed for a certain number of hours to the spectral rays, the culture is put into the incubator. All those parts protected from the light entirely, behave as in any ordinary culture — the spores germinate out and develop colonies, and the previou--ly transparent film (transparent because the spores are too minute to afi'ect it) becomes opaque. Under the slot, however, the spores were exposed to the various rays of the successive regions of the spectrum. On one part of the exposed area the infra-red rays fall ; on another the red ; on another the orange ; and so on with the yellow, green, blue, violet and ultra-violet rays. If any of these rays kill or injure the spores they fall on, obviously the latter will show the effect by not germinating at all in the incubator, after exposure, or by germinating more or less slowly and feeby in comparison with the uninjured spores. Wherever the spores do not germinate at all, the gelatine remains transparent ; where they only germinate and develop into slowly growing, feeble colonies, the transparency of the gelatine film is merely clouded more or less ; whereas, where they germinate and develop as vigorously as on the unexposed parts of the film, the latter is rendered quite opaque. Obviously these diii'erences, or contrast effects, can be photographed, and the following is a photograph of a jilale treated as described. ■vr.-Uv m NO I 267, VOL. 40] In all cases so far examined, both the solar and electric spectra show that no action whatever is perceptible in the infra- red, red, orange, or yellow region, while all are injured or destroyed in the blue and violet regions. The exact point when the action begins and ends is not the same in all the experiments, though very nearly so, but it must be reserved for the detailed memoir to discuss the various cases. Broadly speaking, the action begins at the blue end of the green, rises to a maximum as we pass to the violet end of the blue, and diminishes as we proceed in the violet to the ultra- violet regions. Some especially interesting results were obtained with the electric spectrum. In the first place, the results with glass prisms, lenses, &c. , were so feeble that it was necessary to employ quartz throughout. Secondly, the bactericidal effect is found to extend far into the ultra-violet. The intervention of a thin piece of glass results in the cutting off" of a large proportion of effective rays. These results suggest evidently that the naked arc light may prove to be a very efficient disinfecting agent in hospital wards, railway carriages, or anywhere where the rays can be projected directly on to the organism. January 25. — "The Effect produced upon Respiration by Faradic Excitation of the Cerebrum in the Monkej% Dog, Cat, and Rabbit." By W. G. Spencer. The effect upon respiration of exciting the cerebrum in a non- ancesthetised animal is probably a complex one, yet, by careful regulation of the anaesthetic state, four constant effects can be obtained upon respiration by stimulation of the cortex, and these can be traced down each in a course of its own from the cortex to the medulla oblongata. A. Diminution of Action. I. Slowing and Arrest oj the Respiratory Hhy thin. — The cor- tical area where this result was obtained is situated just outside the olfactory tract in front of the point where the tract joins the temporosphenoidal lobe. On exposing successive and vertical sectional surfaces of the hemisphere the same result was obtained by exciting in the line of the strand of fibres known as the olfac- tory limb of the anterior commissure. After decussating at the ;54 NA TURE [February 8, 1894 anterior commissure, the tract is continued backwards on either side of the infundibulum into the red nucleus below and ex- ternal to the aqueduct at the plane of exit of the third nerve. B. Increased Action. II. Acceleration. — Commencing from a point on the convex surface of the cortex within the "sensori-motor " area, the effect may be followed back just below the lenticular nucleus where it borders on the outer and ventral portion of the internal capsule ; the strand runs at first external and then ventral to the motor portion of the internal capsule, and so reaches the tegmentum. The lines from the two sides meet in the interpeduncular grey matter at the level of and just behind the exit of the third nerve. III. Hyperinspiratory Clonus ("snuffing movements"). — This eftect was obtained by excitation at the junction of the olfactory bulb and tract, and then carrying the stimulation backwards along the olfactory tract; the same result was found when the uncinate convolution of the temporo-sphenoidal lobe was irritated. P'oUowed from the uncus this excitable region passed behind the optic tract to the crus, and then lay ventrally to the crusta. The excitable tract on each side thus converged towards the middle line at the upper border of the pons. JV. Hyperinspiratory Tonus. — This experimental result is of such frequency and constancy as to be clearly an important general phenomenon. It can be elicited in various ways : e.g. excitation of the descending motor tract in the corona radiata and internal capsule yielded this result ; so did excitation of the fifth nerve and dura mater, as well as the sciatic nerve, both be- lore and after complete removal of the cerebrum at the tentorium cerebelli. "Experimental Researches into the Functions of the Cerebellum." By Dr. J. S. Risien Russell, Assistant Physician to the Metropolitan Hospital. This paper is based on experiments performed on dogs and m.onkeys, the results of which lead the author to conclude that the cerebellum is an organ whose one lateral half does not in any great measure depend on the cooperation of the other half for the proper performance of its functions. The bulk of the impulses pass from one half of the organ to the cerebrum, or spinal cord, without pa-sing to the other half. Three factors are responsible for the defective movements which result on ablation of different parts of the organ- — incoordination, rigidity, and motor paresis. The last of these is probably directly due to the withdrawal of the cerebellar influence from the muscles, while the exalted excitability of the opposite cortex cerebri, which resulis after unilateral ablation of the cerebellum, is probably a provision for compensation in this and other connections. The alteraiion in the excitability of the cerebral cortex was the most striking result obtained, for both as tested by the induced current directly applied to the cortex, and from the characters of the curves obtained from muscles on Ihe two sides of the body, during general convulsions evoked by absinthe, the opposite cortex showed a greater degree of excitability than did that on the same side, owing, it appears, to an increased state of excitability of the cortical cells of the opposite cerebral hemisphere, and a diminished state of excit- ability of those on the same side. Further, the curves obtained from limb muscles showed that there was a marked alteration in the second stage of the convulsive seizure, on the side of a unilateral ablation of the cerebellum, or on both sides after total ablaiion of the organ, for the tonus characteristic of this stage of similar convulsions evoked in dogs whose central nervous S)siem was intact was eiiherreplaced by clonic spasms, or a large element of clonus was superimposed on the tonus. There is evidence that the one half of the cerebellum con- trols the cells of the cortex of the opposite cerebral hemisphere, and those ol the anterior horns of the spinal cord on the same side chieflv, and on the opposite side to a slight extent. It is further suggested that either the cerebral hemisphere whose ex- citability is increased inliiliits the opposite hemisphere, or that, under norm.il conditions, one half of the cerebellum inhibits the other half, which inhibition being no longer operative, owing to ablation of half ol the organ, allows the remaining half to exett an increased control on the opposite cortex cerebri, or on the spinal centies of the same side, or possibly in both directions ; but which is the mo^t probable explanation of the phenomena idiserved is at present left an open question. The syni, toms which characterise ablation of different parts of the cerebellum are detailed ; and it is urged that instead of Nt>. ' 267, VOL. 49] looking on it as a distinct organ which has a special function, distinct from those subserved by other parts of the central nervous system, it would be more correct to look on it as a part of that system, having many functions in common with other parts of it, the chief difference between one part of this great system and another being the degree in which different func- tions are represented in any given part : e.g. with regard to motor power, the anterior extremity is maximally repre- sented in the cerebrum and minimally in the cerebellum, whereas the trunk muscles are minimally represented in the cerebrum and maximally in the cerebellum. Arguments are adduced in favour of looking on the ocular deviations which result from ablation of parts of the cerebellum as paralytic rather than irritative phenomena, and two forms of nystagmus are recognised as consequent on cerebellar lesions, one which is spontaneous, and the other which is only evoked on voluntary movements of the globes, and the probable difference in their aetiology discussed. Finally, the phenomena characteristic of unilateral ablation of the cerebellum are contrasted with those the result of extirpation of the labyrinth, and it is shown that no single phenomenon is the same in the two. " The Pathology of the Gidema which accompanies Passive Congestion." By Walter S. Lazarus-Barlow. Physical Society, January 26. — Prof. A. W. Riicker, F.R.S., President, in the chair. — Mr. J. W. Kearton read a note on a new mode of making magic mirrors. The author's first idea was that the magic properties were due to differences in reflecting power, but experiments showed this to be im- probable, and indicated that the patterns visible by reflected light were due to slight concavities in the surfaces. Several methods of producing such changes of curvature were tried, such as electro-depositing and electrical etching, the plates being sub- sequently polished to remove sharp edges. The method found most satisfactory was to draw the figures on polished brass covered with wax, and etch them by immersing in nitric acid, subsequently scouring with charcoal, Sheffield lime, and swans- down calico, until all direct traces of the figures disappeared. The scouring rounds off the edges and makes the depressions concave, the two eventually forming one concave sweep, which makes itself visible when light is reflected from it on a screen. To obtain satisfactory results with figures having broad and narrow lines, it was found necessary to paint over with hot wax the fine lines, and the outer edges of the broad ones after the first immersion ; a second immersion etched the middle parts of the broad lines deeper. By repeating the process the broad lines were etched roughly concave in steps, and the scouring made their curvature continuous. Figures in relief, show- ing the paitern in shade on reflection, were obtained by painting the pattern on the plate in sealing-wax dissolved in naphtha, and etching away the uncovered portions by an immer- sion of one or two seconds. A number of mirrors with patterns in intaglio and relief were exhibited to the meeting. Prof S. P. Thompson said the chief interest of Mr. Kearton's work was that he had succeeded in producing mirrors by a process which Prof. Ayrton had found unsuccessful. The spherical polisher used by Mr. Kearton might have something to do with the result obtained. Some of the mirrors had been gilt after polishing, and the reflected pattern improved thereby. Prof. Ayrton said he was greatly interested to see that mirrors could be produced by the chemical method. The polisher used by the Japanese was the flat end of a tight bundle of special straw cut crosswise. When the true explanation of the magic proper- ties was found out, the chemical method was nut pursued further. The Rev. F. J. Smith mentioned that he had pro- duced magic properties on silvered glass by the inductoscript method. Although no markings could be seen directly, the paitern showed itself when light was reflected from the surface to a screen. — Mr. W. B. Crolt read a paper on some obser- vations in diffraction, and exhibited a large number of photo- graphs of diffraction figuies obtained under different conditions. Ihe first series exhibited, related to diffraction Irom parallel light (diffraction of Fraunholerand Schwerd), and were obtained liy placing various combinaiitms of thin circular lines of light on a dark glass plate before the object-glass of a telescope i focussed on a star. Spectral images ol the star are formed by i interference from the eilges of the lines, thus giving diffraction ! patterns whose form depends on the shape of the aperture em- ployed. The next series illustrated diftraction in shadow (Fresnel's diffraction), and were produced by condensing February 8, 1894] 'NA TURE 355 light on a minute pinhole, and placing the object between the hole and a microscope eyepiece. Beyond the eye- piece the camera used for photographing the pheno- mena was placed. Permanent records of remarliably good diffraction figures were obtained in this way, both of the combinations of circles above mentioned and of various other objects and geometrical forms. After showing geometrically that diffraction bands from narrow obstacles and openings were wider than those from broader ones, the author explained the con- ditions necessary for making the bands visible, and pointed out the distinction between internal and external bands. Promi- nent amongst the photographs were several showing " Arago's white spot" at the middle of a shadow, and, in particular, this well-known phenomenon was shown as produced by so large an object as a threepenny-piece. Speaking of diffraction in a microscope, the author said little doubt need exist as to whether an image represented the real object or a diffraction modification thereof, for the latter were usually of a more misty and compli- cated character. Departing somewhat from the subject of diffraction, an excellent photograph of conically refracted pencils was shown, consisting of circular lines of light produced by passing light from pinholes through a crystal of arragonite Dr. Johnstone Stoney thought the obtaining of permanent records of diffraction phenomena of great importance, and was particularly interested in the photograph showing conical refraction. Prof. S. P. Thompson said he had never seen dif- fraction effects exhibited to an audience so well before. He had noticed that in several of the photographs Arago's spot was unintentionally shown to perfection in the shadow of dust par- ticles. The President greatly appreciated the fact that the conical refraction photograph had been exhibited for the first time before the Physical Society. — A note on a new photo- metric method and a photometer for same, was read by Mr. J. B. Spurge. The method consists in using two diffusing screens (illuminated respectively by the lights to be compared) as second- ary sources, and adjusting to equality the luminosity of equi- distant internal surfaces by varying the apertures through which the light passes from the screens to those surfaces. By reducing the sizes of the apertures the author has been enabled to compare lights of different colour, for when of sufficiently feeble intensity coloured lights are indistinguishable from white or grey. The photometer is made up of two tubes mounted at 45° to an axis, about which one of them is capable of rotating. When in the same horizontal plane, the axes of the tubes form the sides of an isosceles right-angled tr angle, at the middle of whose hypothe- nuse the light to be tested is place i ; this illuminates one of the screens, whilst the standard light shines on the other. These screens, used as secondary sources, are situated a short dis- tance away from the outer ends of the tubes, whilst the inner sur- faces of the near ends of the tubes are viewed by means of a mirror. By turning the movable tube about the inclined axis, and rotat- ing the source about a vertical axis, the illuminating effect of the source in any direction can be tested. Capt. Abney saidthe law of inverse squares was not true for weak lights, for the proportions in which the light from sources of equal intensity had to be reduced to appear white or grey depended greatly on the colour ; being much greater for violet than for red. Only for the yellow-green rays was the ordinary law of illumination true when the intensi- ties were feeble. Mr. Blakesley, Prof. S. P. Thompson, and the President also took part in the discussion. Geological Society, January 24. — W. H. Hudleston, F.R.S., President, in the chair. — The ossiferous fissures in the valley of the Shode, near Ightham, Kent, by W. J. Lewis Abbott. The fissures occur in a promontory of Kentish Rag between two tributaries of the Shode. There are four fissures in this promontory, striking at right angles to the valley. Details of the physiography of the area in which the fissures occur are given in the paper. Three of the fissures have obviously been in contact with the surface, and from these the bones appear to have been dissolved out. The fourth does not reach the top of the Rag, and further is sealed by an arragonite-lined chamber with stalactitic floor and ceiling. This fissure is from 2 to 6 feet wide and about So feet deep, and is filled with a heterogeneous col- lection such as constitutes the flotsam and jetsam of streams, along with materials derived from the rock in which the fissures occur. Several thousand bones were found, also twelve species of aquatic and land shells, an entomostracan, Chara and other vegetable remains have been procured. The author gave reasons for concluding that the fissures have never been reopened since I hey were first closed by the materials introduced into them by NO. 1267, VOL. 49] the river, and that all the contained fossils belong to one and the same geological period. He pointed to the discovery of species not before found in Pleistocene beds as only a repetition of what has occurred in other sections he had worked, aud remarked also that the increase of species was corroborative of a suggestion of Mr. C. Reid that the more we discover of the smaller creatures of this and the preceding age, the more they approximate to those of our own times. Even if we iwere to exclude from the lists all the species not previously found fossil elsewhere, we still have an extensive assemblage of the older Pleistocene forms, which must have lived during the filling of the fissures, and this therefore fixes the filling operation as having occurred in Pleistocene times.— The vertebrate fauna collected by Mr. Lewis Abbott from the fissure near Ightham, Kent, by E. T. Newton, F. R.S. The vertebrate remains collected by Mr. Lewis Abbott have been passed in review by Mr. Newton, and as far as possible specifically identified : they represent mammals, birds, reptiles, and amphibians ; but no fishes have been found. In all, 48 different forms have been recognised ; 3 or perhaps 4 are extinct ; 11 are extinct in Britain, but are still living elsewhere ; 21 are living in Britain, but are known to be Pleistocene or forest-bed forms ; and 12 are species now living in Britain which have not hitherto been recognised in Pleistocene or older deposits. Among the more important species found in this fissure, but extinct in Britain, may be noticed, besides Elephas primigenitis. Rhinoceros antiqiiiiatis, and Hyana, the Ursus arcios, Canis lagopiis, Myodes torqiiattcs, Myodes lemtnus, Microtus gregalis, M. ratticeps, Lagomys pusillus, Spennophihis, and Cerviis tarandus. The name of Mttstela robusta was proposed for some limb-bones intermediate between the polecat and marten, and the remains of an extremely small weasel are noticed as a variety of Miistela vulgaris. Although the large number of living species gives a recent aspect to this series of remains, the evidence, it is believed, points rather to their being all of Pleistocene age, and most nearly allied to the fauna of British caves. In the course of some remarks upon the paper, Mr. Topley compared the fissures filled with loam and gravel, and containing mammalian bones and land-shells, of the Maidstone district with the interest- ing example described, and explained that those of the Maid- stone Rag country were connected with overlying deposits of drift, the material now filling the fissures having been let down into the rock by solution of the limestone along joints and cracks. Sir Henry Howorth and Dr. Henry Hicks also spoke, and Mr. E. T. Newton briefly replied. Paris. Academy ot Sciences, January 29. — M. Lcewy in the chair. — An account of the work of A. Scacchi, by M. Des Cloizeaux. — Integration of the equation of sound for an in- definite fluid in one, two, or three dimensions, when there are different resistances to the movement ; physical consequences of this integration, by M. J. Boussinesq. — On the propagation of an electric current in a particular case, by M. A. Potier, — • Anomalies in the force of gravity observed on the North American Continent, by M. Deftorges, The value of g for a number of stations between VVashington and San Fran- cisco is as follows: — -Washington 9So"i67, Montreal 980729, Chicago 98o'345, Denver 979 '684, Salt Lake City 979'8i6, Mt. Hamilton 979'683, and San Francisco 98o'oi6. These values, reduced to sea-level and compared with the theoretical values calculated from Clairaut's law, show regular anomalies which are compared with anomalies exhibited by oceanic islands. — Theory of the elasticity of metals, by M. Felix Lucas. — On the new measurement of the area of France, by General Derrecagaix. A planimeter measurement, calculated on the assumption that the figure of the earth is a true ellipsoid of revolution. Supplementary remarks were made by M. E. Levasseur. — On the rapid summation of certain slightly con- vergent series (alternate harmonic series), by M. A. Janet. — On a common property of three particular classes of rectilinear congruences, by M. Alphonse Demoulin. — Joule's and Mar- riotte's laws in connection with existing gases, by M. Jules Andrade. The author shows that these laws are true for real gases within about the samelimitsof accuracy. — An electric alarm thermometer for laboratory ovens, by M. Barille. Connection of an electric circuit is made when the mercury in the thermo- meter reaches a determined point on the scale by means of a platinum wire which is attached to a small iron tube (sliding along a fixed wire), of which the position can be regulated Q'j a 00< NATURE [February 8, 1894 magnet attached to the supporting frame. — On synthesised borneols, by MM. G. Bouchardat and J. Lafont.— Thermal constants of some polyatomic bases, by MM. Albert Colson and Georges Darzens. For ethylene-diamine the observed values were : — Specific heat 0-84 between 12° and 45° ; heat of solution +7-6 cal. for i mol. in 4 litres of water at 15° ; heat of neutralisation +23-54 cal. (i mol. normal salt in 5 litres of water) ; heat of solution of the normal chloride -7 "55 cal. for I mol. in 4 litres of water. For quinine, observations gave : — rieat of solution for i mol. of Q.S04Ho.6n20 dissolved in 12 litres of water coriaining i mol. HoS04=-6"7 cal.; heat of neutralisation +15 -5 cal. for freshly precipitated quinine. — On the adaptation of the alcoholic ferment to the conditions of living in media containing hydrofluoric acid, by M. E. Sorel. The lac'.ic acid ferment is destroyed by the addition to the mash of a small quantity of hydrofluoric acid, and the yield of alcohol correspondingly increased. ?By cultivation in presence of increasing quantities of hydrofluoric acid the resisting properties of the alcoholic ferment may be considerably increased. — On the relation of the palisade tissue of leaves to transpiration, by M. Pierre Lesage. The palisade tissue appears to function as a means of protecting the leaves from excessive transpiration. — Main lines indicating directions of folds and contortions in the geology of France, by M. Marcel Bertrand. — On the com- position of some calcareous marls, by M. H. le Chatelier. — On the forms of platinum in its bed rock, from the Ural district, by M. A. Inostranzeff. — On the age of the human skeleton dis- covered in the eruptive formation of Gravenoire (Puy-de-D6me), by MM. Paul Girod and Paul Gautier. Berlin. Physical Society, Dec. 15, 1893.- Prof, du Bois Reymond, President, in the chair.— Dr. A. du Bois Reymond spoke on Lilienthal's experiments on flying. As a starting-point he had chosen the study of the flight of birds, which may be divided into three distinct kinds— flapping, steering, and soaring. Of these the one demanding least expenditure of energy is soaring, and investigation showed that under certain conditions flight is possible if the wind possesses a vertical component. Experi- ments showed that surfaces can acquire a horizontal motion by the action of the wind only, when their curvature bears a certain relation to their superficies, and that this relation corresponds exactly to that which is observed in the wings of birds. Dr. Lilienthal's flying machine consists of a correctly curved surface whose area is 14 square metres, made by stretching linen over a light wooden frame, and having a weight of about 20 kilos. In its centre is an aperture for the experimenter's body, and the apparatus is held in position by the person's arms. On running rapidly down a gentle slope of a hill against the wind, the latter soon acquires a vertical component, which then carries the flying apparatus and propels it in a direction against the wind. The speaker had seen Dr. Lilienthal sail over a space of about 120 metres, at an altitude of some 30 metres, in a minute ; with a favourable wind it was possible to cover some 200 to 500 metres, and Dr. du Bois Reymond had himself taken leaps through the air of 20 to 30 metres under similar conditions. He was of opinion that by practice far better results may be obtained as regards soaring, and that then, by combining steering with soar- ing, it will be possible to fly even when the wind is unfavourable. It appears that the three essentials for the solution of the problem of flight are (i) correct utilisation of the wind ; (2) the correct shape of the supporting surfaces, and (3) correct handling of the apparatus. — Herr Haensch explained three different models of Nicol pri-ms, of which Glans' showed itself to be best as regards construction and efficiency. Januarys.— Prof. Kundt, President, in the chair.— Dr. Lum- mer gave a detailed account of the experiments he had made, before his journey to Chicago, on Siemen's and on Violle's unit of light. Both of these must be rejected as standard-units in cases where the platinum is melted in the blowpipe flame. Experiments made to establish the Violle unit by means of an electric current showed that in this case there were variations of from 10 to 12 per cent., which made it unsuitable as an absolute standard of light. Hefner's amylacetate lamp, which the speaker had been examining during the last four years, gives a unit which varies only by some 3 or 4 per cent, as long as the necessary conditions are strictly observed and allowance is made for varying meteorological conditions which aff'ect the lamp. It appears, therefore, that a really reliable unit of light has still to be found. January 19. — Prof. Kundt, President, in the chair. — Prof. Hale, of Chicago, exhibited and explained his lantern-slides of solar photographs. — Prof. Neesen communicated on behalf of Herr van Aubel, of Brussels, the latter's method of silvering aluminium. It consists in cleaning the plate of aluminium with benzol, then dipping it into a solution of sulphate of copper until a thin film of copper is formed on its surface. At this stage a layer of silver is deposited alectrolytically on the plate. Prof. Neesen had found that the layer of silver thus formed does not adhere very firmly to the aluminium. BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books.— A Students' Text-Book of Botany : Dr. S. H. Vines, first half (Sonnenschein). — Johnston's Elements of Agricultural Chemi'^try, revised by C. M. Aikman, 17th edition (Blackwood). —Optical Kxperiments, revised and arranged after the directions of Dr. H. Zwick (Newmann). — The fn- ventioQS. Researches, and Writings of Nikola 'lesla : T. C. Martin (New York, Electrical Engineer Office) — Electricity in the Service of Man : Dr. R. Wormell, revised and enlarged by Dr. R. M. Walmsley (Cassell). — A Textbook of Euclid's Elements : H. S. Hall and F. H. Stevens, Books 2 and 3 (MacmiUan). — Pain. Pleasure, and /Esthetics: H. R. Mar- shall (Macmillan) — Primer of Philrsophy : Dr. P. Cams (Chicago, Open Court Publishing Co.). — The Religion of Science : Dr. P. Carus, extra edition (Chicago, Open Court Publishing Co.). — Investigations on Micro- scopic F rms and on Protoplasm : Prof. O. Biitschli, translated by E. A. Minchin (Black). — C'mgres Internationaux d'Anthropologieet d'Arch^ologie prehistorique et de Zoolugie a Moscou. Mat^riaux, Deux Partie (Moscou). Two Great Scotsmen the Brothers William and John Hunter: Dr. G. R. Mather (Glasgow, J. Maclehose). Pamphlets. — Report of J. P. Lang'ey, Secretary of the Smithsonian In- stitution, for the year ending June 30 1893 (Washington). — Seventh Annual Report of the Liverpool Marine Bi' .logic li Committee and ..their Biological Station at Port Erin : Prof. Herdman (Liverpool, D)bb). — IJber ein Inter- ferenzrefractometer : L. Mach (Wien). — Physical Constants of Thallium : W. H. Steele (Melbourne). — A New Thermoelectric Phenomen n: W. H. Steele (Melbourne) — On the C mductivity of a Solution of Copper Sulphate : W. H. Steele (Melb urne). — Sulle Perturbazioni Magnetiche dell' Agosto 1893, &c. : Dr. L Palazzo (Roma). Serials. — Bulletin de I'Academie Royale des Sciences de Belgique, 63*^ Ann6e, No. 12 (Bruxelles). — Dictionary of Political Economy, sixth part (Macmillan). Naiural Science, February (Macmillan). — Botanical (.iazette. January (Madison, Wis ). Proceedings of the So. iety for Psychical Research. January (K. Paul). — L' Anthropologic, Tome iv. No. 5 (Paris, Masson). — Geological Magazine, February (K. Paul). — Quarterly Journal of the Geological Society, Vol. 1. part i. No. 197 (Longmans) — Bulletin of the New York Mathematical Society. January (New York, Macmillan). — American Naturalist, January 'Philadelphia). CONTENTS. PAGE A Critic Criticised. By Dr. Alfred R. Wallace, F.R.S 333 Dynamos and Transformers. By P. A. M 337 Golf. By W. Rutherford 338 Our Book Shelf — Webb: "Celestial Objects for Common Telescopes " 339 Loney : " Plane Trigonometry " 339 Letters to the Editor :- Music, Rhythm, and Muscle.— Prof. T. Clifford Allbutt, M.D .340 The Cloudy Condensation of Steam.— John Aitken, F.R.S. . . . 340 The Os Pedis in Ungulates.— Prof A. E. Mettam 341 A Brilliant Meteor. — Dr. M. F. O'Reilly . . .341 The Vatican Observatory. {Illustrated.) By R. A. Gregory 341 Notes 345 Our Astronomical Column : — Eclipse Meteorology 349 A Remarkable Cometary Collision 349 Mira Ceti 349 Proper Motions of Stars 349 The System of Algol 349 The Institution of Mechanical Engineers . . . 350 On the Motion of Bubbles in Tubes . . . . 351 Science in the Magazines . 35^ University and Educational Intelligent.- 352 Societies and Academies. {Illustrated.) . . . 353 Books, Pamphlets, and Serials Received 356 NO. 1267, VOL. 49J I NA TURE 357 THURSDAY, FEBRUARY 15, 1 1 RFXENT RESEARCHES IN ELECTRICITY AND MAGNETISM. Notes on Recent Researches in Electricity and Magnetism, intended as a sequel to Prof. Clerk Maxwell's Treatise on Electricity and Magnetism. By J. J. Thomson, M.A., F.R.S., &c., Professor of Experimental Physics in the University of Cambridge. (Oxford : at the Clarendon Press, 1893.) THE supplementary volume to Maxwell's "Electricity" which it was announced the present occupant of Maxwell's chair in the University of Cambridge had in preparation, was looked forward to with keen interest by all electricians. It was sure, of course, to be a work of great scientific importance ; but it was awaited with all the more impatience because certain promises and allusions in the new edition of Maxwell's treatise, lately published under Prof. Thomson's editorship, had led to pleasant an- ticipations that the supplement would be more or less of a commentary on the treatise, and would deal with some of the outstanding difficulties of Maxwell's electromag- netic theory. One promise in particular, made in the notes on the Electricity, we looked forward to seeing fulfilled in the supplementary volume, that of further discussion of the Maxwellian stress in the electro- magnetic field. It is just here that the greatest difficul- ties of Maxwell's theory present themselves to some at least, and that a commentary such as the author could have written would have been particularly valuable. Any little disappointment which may be felt at first as to the contents of the volume vanishes when their solid scientific value becomes apparent, and it is felt that perhaps the author has done the right thing after all by preferring to give a full account of the great work which has been done in recent years, in confirming and verify- ing Maxwell's theory, and in answering the questions it has suggested. The book opens with an account of Prof. J, J. Thom- son's method of regarding electric and magnetic pheno- mena as produced by the motion of Faraday tubes of electric force. This method is fully explained, and ap- plied to the discussion of various physical phenomena, such as electrolysis, the action of a galvanic cell, and so forth. These show, perhaps, to the best advantage the power of the method, which certainly enables a mental image of what goes on in such cases to be more easily and clearly formed. These tubes, according to Faraday's idea, start from positive and end on negative electricity, and the positive and negative electricities at the extremities of a tube, being merely the two aspects or surface manifestations of the state of strain existing in the medium within the tube, are complementary and equal. According to Prof. Thomson's specification, a tube is either closed or terminated by atoms. When it has a length of the same order of magnitude as the distance between two atoms in a molecule, the atoms are in chemical combination ; when the length is of a higher i order of magnitude the atoms are chemically free. NO. 1268, VOL. 49] These tubes move through the field when electrical changes take place, and by their motion produce magnetic force, which is proportional to the velocity of the tube moving at the point considered, and at right angles to the plane defined by the tube and the direction of motion. When a tube as a whole reaches a conductor, it shrinks to molecular dimensions. To account for a steady magnetic field, which occurs without dielectric polarisation, and therefore apparently without the presence of tubes in the field at all, it is sup- posed that there are passing through a given small area just as many positive as there are of negative tubes, (that is, there is a distribution of oppositely directed tubes throughout the field, such that there is nowhere any pre- ponderance of one kind over the other), but that these two sets of tubes are moving with equal velocities in opposite directions, so that the magnetic forces which they produce reinforce one another. A quantity which the author calls the polarisation of the medium is defined, for any given direction at a given point, by the excess of the number per unit of area of positive over negative tubes passing through a small plane surface drawn through the point at right angles to the given direction. When the dielectric is not air, the unit area is supposed taken in a narrow crevasse cut in the medium with its walls at right angles to the given direc- tion. Thus the dielectric polarisation is exactly analogous to the magnetic induction in the magnetic field as ordin- arily defined. The momentum of the tubes per unit volume of the field at any point is a directed quantity which is normal to the plane defined by the magnetic induction and the polarisation, and its components are proportional to the rates of transference of energy, according to Poynting's theory, in the directions of the axes across unit area held at right angles to each of them. When the electric intensity of the field is due solely to the motion of the tubes, they move at right angles to their own directions with the velocity of light. This theory gives a clear idea of why both polarisa- tion and conduction currents and the motion of charged bodies produce magnetic effects. Everything is due to the motion of Faraday tubes, and in all three cases the Faraday tubes are moved through the field. It is questionable whether this theory will ever suc- cessfully compete in electromagnetic discussions with the reciprocal method, that of the motion of tubes of magnetic force. Both were given by Faraday, who speaks most unmistakably in his " Experimental Re- searches," in the language of the modern theory of the induction of currents by the motion of tubes of magnetic induction across conductors situated in the field. It is well to have both, and their use will serve to emphasise what is of very great importance, the reciprocal cha- racter exhibited very strikingly in the modification of Maxwell's electromagnetic equations, given by Heaviside and Hertz, of the relations between the electric and the magnetic forces. After these preliminary discussions comes an account of the phenomena accompanying the passage of electricity through gases. This reviews and coordinates to a con- siderable extent the experimental researches of Crookes, Spottiswoode and Moulton, Hittorf, and others in this R 3.V NA TURE [February 15, 1894 field. This part of the work has a value enhanced by the contributions made to our knowledge of this depart- ment of electrical science by the author himself, both as regards the actual experimental facts and their theoretical explanation. The action of a magnet upon discharges in tubes or bulbs without electrodes is peculiarly interesting. The discharge being oscil- latory in such a case is separated into two distinct portions, consisting of the discharges in the two opposite directions. Thus a ring discharge in a horizontal plane has one part raised, the other lowered by the action of a horizontal magnetic field. Further, as has been observed by the author, the discharge is rendered more difficult when it has to pass across the lines of force of a magnetic field, while it is facilitated when it has to pass along the lines. The explanation suggested by the author is ingenious- The gas breaks down along the line of maximum electro- motive intensity, and a discharge occurs which gives a supply of dissociated molecules, which readily convey subsequent discharges. The magnetic field, when at right angles to the line of discharge, acting on the mole- cules taking part in the discharge, removes them from the line of maximum electromotive intensity, and thus the instability of electric strength which the discharge tends to set up is continually being annulled by the magnetic action. In the other case it is suggested that if branching of the discharge from the main line takes place, the dis- sociated molecules there formed will be brought into the line by the magnetic action, and would thus increase the facility of the discharge, beyond that which would exist, if there were no field. This, as Prof. Fitzgerald has suggested, has an impor- tant bearing on the nature of the aurora, and probably explains the streamers which form so remarkable a feature of auroral displays. These may be simply more than averagely bright discharges along the electrically weaker lines of magnetic force in the rarefied air of the upper parts of the atmosphere. A chapter is next devoted to Conjugate Functions in their applications to the solution of electrical problems. This method is very serviceable for the solution of prob- lems of electrical flow in two dimensions, but it can hardly be applied in a syste.natic manner to the various problems which present themselves. The theory of functions of a complex variable has been o-reatly advanced since Maxwell wrote, and there is certainly much, as has been pointed out, more especially by Klein, that has direct application to the solution of electrical problems. Prof. Thomson has therefore done well to include some of the general transformations of this theory, with their applications to such problems as the effect of the gap between the plate and guard-ring in Lord Kelvin's absolute electrometer or guard-ring con- denser, different arrangements of piles of plates, and the like. This theory of the condenser he has himself made use of in his determination of v. It may be objected that some of the problem s solved by the indirect method employed in this chapter have no very distinct practical application ; but there can be no question of the value of such a discussion. It places within the reach of students who are able to follow it processes NO. 1268, VOL. 49] ready to hand by which problems quite unassailable by ordinary methods are discovered and solved; and who can tell when such problems may not become of great practical importance, in the present rapidly advancing state of the science ? We are taken next to the subject of electrical waves and oscillations, which in some form or other is the theme discussed in the remainder of the book. The problem of periodic disturbances is very fully treated in a large number of practically important cases. Throughout the analysis the method of representing a simply periodic function in the form IMe^"'" "'"^'^^ where i = y/^ I is adopted. This tends greatly to condensa- tion, and the results are always interpretable at will by properly " realising " the solution. First is taken the extremely important case of waves along a cylindrical wire surrounded by a coaxial coating of dielectric, outside which again is an infinitely extend- ing cylindrical conductor ; and this is treated with special fulness. The solutions are expressed in terms of Bessel's functions ; and this part of the book ought to lead to a more general study of the properties of such functions, and their applications to physical problems. They had their origin in a physical problem, and their importance to physicists has gone on increasing with the develop- ment of physical mathematics which has been brought about by the problems disclosed by scientific progress in recent times. The theoretical solution of the problem of waves along wires is mainly due to Lord Kelvin, Mr. Oliver Heaviside, and Prof. J. J. Thomson. The solution given long ago by Lord Kelvin of the more limited problem which was then the practical one, appears as a particular case of the general solutions which these physicists have since obtained. The conclusions they have reached are of the utmost interest in connection with telephony, and seem likely to point the way to a more extended use of telephonic communication than has hitherto seemed possible. Lord Kelvin's early solution, it is not too much to say, gave for the first time light on the vexed question of the conditions of success in sig- nalling through submarine cables and, together with the marvellously delicate and simple instruments which he also invented, rendered signalling through such cables commercially possible. Even now the question of ocean telephony has come to the front, and if it succeeds (and who will venture to say its difficulties will not be over- come ?) it will be in great measure a result of the patient researches of men like Lord Kelvin, O. Heaviside, and the author of the work before us. The complex variable treatment is adhered to, and contributes greatly to brevity of expression. The treat- ment of the subject is very complete, and though it in- volves some rather complicated work seems very accu- rately printed. The author has apparently pressed for- ward from point to point, taking the path which presented itself at the time, and hence, to one coming after, it is possible to suggest some shortening and smoothing of the way. For example, the values of the electromotive and magnetic intensities are perhaps more compactly investigated by first specialising the fundamental equa- tions for the case of symmetry round an axis, noting that the electromotive intensity reduces to two components, February 15, 1894] NA TURE 359 one P along the axis, and the other R at right angles to the axis, in a plane through the axis and the point considered, while the magnetic force H, say, has a single component perpendicular to the plane. Thus two differential equations are got connecting P, R, and H, from which (P having first been found from the differential equation involving P alone) R and H are found at once in the forms MaP/ar, NaP/ar where M and N are multi- pliers, and ;- is the radius drawn from the axis to the point considered. It is to be noted also that the sign between the two groups of terms into which Kj,(.v) is divided in (2), p. 263, should be the same as that before log x in the first group in brackets and that C should be taken with the same sign as log .t-, and log 2 with the opposite sign. This involves a correction likewise in the table of approxi- mate values of the functions given lower down on the same page. Again, the same constant C, which has the value Lt (t^~ -\ogn is called Gauss's constant at p. 263, while the quantity •y = ^"^ is called Euler's constant at p. 430. The estab- lished usage seems to be to call C Euler's Constant from its discoverer, who gave its value (to sixteen places of decimals) in his histitutiones Calculi Differentialis. The " throttling " of the current in wires subjected to rapidly alternating electromotive forces is fully considered for a cable with inner and outer coaxial conductors, and for two flat strips in parallel planes with a stratum of insulating material between them. In this connection the author first introduces Mr. Oliver Heaviside's word impedance. Writing E for the external electromotive force, I for the total current, and R and L for the effective resistance and self-inductance, we have (p. 272) E = L^i + RI. a/ R is called by Prof Thomson the impedance. Accord- ing to Heaviside's proposal it is .^R- + «^L- that should be called the impedance, where n = 27r/T, T being the period of the alternation. The manner in which the damping out of the vibration is taken account of by the complex analysis is well worth remarking. The eating up of the energy and con- sequent tapering off of the amplitude according to an exponential function of the distance from the starting end by the impinging of the oscillations in the dielectric on the conductors bounding it, and the lowering of speed of propagation of phase in the dielectric below the natural speed, that of light, all come out in the most beautiful manner. Mr. Heaviside's careful synthetical explanations of such phenomena are well worth reading in this- con- nection. The author next passes to his own most valuable investigations regarding the effect of subdivision of iron j on the dissipation of energy in the iron of a transformer, I to electrical oscillations on cylinders and on spheres, and 1 other problems of the greatest interest to all students of ' the later developments of Maxwell's great theory carried out by Hertz, now, alas, to be continued entirely by other hands. NO. 1268, VOL. 49] The concluding portion of the book consists of a most valuable account of the work of Hertz, and forms the most appropriate supplement to Maxwell's great work that could have been written. The idea of Faraday tubes is well applied to picture the action of a Hertzian resonator in its different positions relatively to the vibrator in the experiments on direct radiation, and those on waves along wires. Not only is Hertz's own work fully described and explained, but the vast amount of fine work that has been done at Dublin, Liverpool, at Cambridge, and on the continent, is discussed, and much of it submitted to careful mathematical analysis. Space does not permit of even a summary of the topics here treated, and we can only say that the reader who wishes to know these things well, and who shrinks from the labour of digging them out of Proceedings, Annalen, and Berichte, here, there, and everywhere, ought to read Prof. Thomson's work. Such a work is worthy not only of the author, but of the researches of the master and his great disciple who have passed away. A. Gray. GREENHILUS ELLIPTIC FUNCTIONS. The Applications of Elliptic Ftmctions. By Alfred George Greenhill, F.R.S., Professor of Mathematics in the Artillery College, Woolwich. (London : Mac- millan and Co., 1892.) IT would be difficult to exaggerate the part which the study of elliptic functions has played in the pure mathematics of the present century. And this was to be expected ; for whether we regard natural science as the application of common sense to the material needs of life, or as the outcome of the need for expansion in the mental world, and whether we consider mathematics as that exact basis without which progress was not per- manently possible, or esteem it to be those higher Alps — Where we can ever climb, and ever To a finer air — in either case we must see that a development of integral calculus — a development which was competent to fill so large a part of Legendre's life, which suggested such magnificent algebra as we find in Jacobi's Fundamenta, which promised, too, in Abel's hands such generalisations as are not even yet brought to perfection, such a theory, surely, was well worthy of persevering pursuit. And if we attribute the present extent of the theory of curves and of the theory of functions to the day when Rieniann stood best man to the ideas of Cauchy and the sugges- tions of hydrodynamics, we must admit it was because his methods were employed upon the materials left by Abel that such results have come. The importance of the present work lies in its recog- nition that the theory of elliptic functions arose as a deve- lopment of integral calculus, and as such may be expected to supply a formulation of the solution of many problems of physics otherwise regarded as unfinished. Prof. Greenhill is well known to be aman who hasnot allowed his unwearied application to such problems to destroy his sympathy with pure mathematical speculation ; on the contrary, he has sought, by every means in his power, to fill the difficult position of apostle to the Gentiles in this respect, by making as many of the results ;6o NA TURE [February 15, 1894 of analysis as are susceptible of application to physics, easily intelligible to students of that subject. The present book, addressed, we are told, to the trained mathe- matical student, is stated to be primarily a collection of problems (mostly in dynamics and electric flow) whose solutions are expressible by elliptic functions ; and it is intended that the properties of these functions should be suggested by, and developed simultaneously with, the problems in hand. Really, of course, it is much more. In fact, the student who works completely through the book will meet with a good many of the formulae of common occurrence in the ele- mentary part of the subject, and will, moreover, learn to manipulate them for himself ; and whether he be interested most in the motion of tops, or the stability of ships, or the biquadratic form, he will probably be sur- prised at the amount of information condensed here. The book opens with a consideration of the motion of the common pendulum. The fact that in this motion the angular displacement depends uniquely upon the time, suggests the inversion of the elliptic integral ; the existence of a real period of the functions thus obtained, is suggested by the periodic motion of the pendulum. The functions are then immediately used to express the solution of Euler's equations for a body moving about a fixed point under no forces. Then follow seventy pages devoted to the expression of elliptic integrals in terms of the functions, in the course of which, beside a vast variety of examples collected from Legendre and else- where, are found a consideration of Watts' Governor, of the Elastica, of the Sumner lines on a Mercator chart, of the Catenoid, of quadrantal oscillations, and of other things — the notation being sometimes Jacobian and some- times Weierstrassian. It is needless to say that here is a mine of wealth for the examiner. It is only in chapter iv., when we are a third of the way through the book, that the addition theorem of the functions becomes necessary. And while this is proved by a pendulum view of Jacobi's two-circle method, space is found for a thorough examination of Legendre's method and a de- tailed account of the porismof thein- andcircum-scribed polygon for two circles, the diagrams being of the most painstaking character. Then follow sixty pages which will be perhaps the least interesting of the book — at least to the students for whom Prof. Greenhill writes— devoted to an algebraic exposition of the addition theorems for the three kinds of integrals. They contain an examina- tion of the theorems of Fagnano and Graves for the ellipse and hyperbola. They are followed by an account of the tortuous elastica, succeeded by a resumption of the motion of a body about a fixed point under no forces, wherein the author introduces a very full account of the herpolhode. In the hundred pages remaining, the book may be said to be drawing to a conclusion, the double periodicity is considered, Cartesian ovals being intro- duced in connection with the expression of functions of a purely imaginary argument ; a chapter is devoted to the factor expressions of the functions, here suggested by hydrodynamical considerations ; and the last chapter is a summary of the earlier part of the theory of trans- formation, characterised, however, like the rest of the book, by the utmost particularity, numerical and other- wise. NO. 1 268, VOL 49] This summary will show to some extent the scope of the work. It is essentially a student's book, written in a concise conversational style ; but whether the student have more sympathy with physical or pure mathematics, he cannot fail to find much that is new to him, and be surprised at the detail with which it is given ; and the air of practical reality which pervades every page, and the skill and originality with which the results are obtained^ will atone for the tentative nature of many of the de- monstrations. It is, in fact, in this regard that the reader may be most unfair to the author. It is no part of his plan to develop- any demonstration beyond the nearest point at which it suggests the formula required, or to use any more general method of enquiry than is absolutely necessary, or to re- gard the subject in any other way than as a collection of formulae. To forget this is to wish for many things to be ditferently stated — is, indeed, to wish for a quite different book. A few instances will suffice. The author frequently makes the remark that the present state of the theory is due to Abel's brilliant idea in inverting the elliptic integral of the first kind. One fears that the reader may enquire whether the inverse function is a one-valued function of its argument for all the values of the latter, or may forget that the expansion of p. 202 is not valid for all values of the quantities involved. He may even wish to invert the integral of the second kind, notwithstanding that it is here expressed in terms of the integral of the first kind. Or, again, the statement on p. 266, that 0 and \|/- " satisfy the conditions required of the potential and stream func- tions," may lead to misconception, for it is not sufficient that <^ be infinite at A and C ; it must be infinite in the neighbourhood of A like a multiple of the logarithm of the distance from A. And in the same way, on p. 281, in attempting to realise how a " uniform streaming motion parallel to the vector ina " is consistent with the motion in the strips which is represented by the other factors, we are liable to desire a proof that functions whose equality is not identical, but, as here, the result of proceeding to a limit, necessarily represent the same fluid motion. The fact is that the two functions considered here are not equalfor2' = oo , where sine^-has amost essential singularity. Or, again, we may wish that the signs had received more attention ; as, for instance, on p. 24, or throughout chapter ii., and in many other places. And this the more that Jacobi himself is known to have printed a mistaken sign (for en (K + iK') ). And this wish is not allayed by the fact that in the reservation of these difficulties, made on page 45, poles and branch points are mentioned to- gether, as if similar singularities. While, lastly, if we forget the object of the book, we shall most devoutly wish a better recognition of the fact that the Jacobian functions and the Weierstrassian functions are not the fundjfmental fact of the theory. Underlying both is the same algebraic irrationality, now expressed by a binodal quartic, and now by a cubic curve — from either of which i both these functions and many others can be con- ! structed, the distinguishing mark being only the number and position of the poles. One does wish indeed that ' Prof Greenhill had found occasion to state somewhere ; that the algebraic method he adopts throughout, fascinat- ing as it certainly is, is also, in the strict sense employed by him, of only antiquarian interest, in view of the de- ; February 15, 1894] NA TURE ;6i scriptive methods that are available. It is, moreover, essentially incompetent, and therefore unsatisfactory. But if we pass over such considerations as these, funda- mental as they are from some points of view, recognising that in practical life we often count it a saving of time to exhaust the logical consequences of a belief, before pain- fully verifying the grounds of that belief and recognising that in a new subject it is always the most elementary method that furnishes the easiest introduction, we shall find very much for which to value the book before us— beside the excellent diagrams, index, printing, &c. Xote I. — The result of carrying out in detail the work mentioned at the end of § 194 seems worth introducing into a new edition. The result is partly given in Math. Tripos. Part II. 1S92. It seems a pity, too, that the expressions for the Jacobian Z{u) in terms of the Weierstrassian ^{ti) are not given. Note 2.— The example 15, p. 351 (though taken from Math. Tripos, Part II.), is wrong. The result should be — .-. = - (-fi + -Vo + -^3) = — {.x\ + x.^ + X.,) \\\\exp,y = inx-TC is the final position of the line. Note 3. — The example 2 (i.), p. 140, is misprinted. H. F. Baker. THE DISPERSAL OF SHELLS. The Dispersal of Shells : an Inquiry into the Means of Dispersal possessed by Fresh-water and Land Mollusca. By Harry Wallis Kew, F.Z.S. With a Preface by Alfred Russel Wallace, LL.D., F.R.S. With Illustrations. Pp. xi. 291. International Scientific Series, \o\. Ixxv. 8vo. (London : Kegan Paul, Trench, Triibner and Co., 1893.) IT is strange that we have had to wait so long for a manual on dispersal. Many books have been written on the geographical distribution of animals and plants ; and islands and even continents have been raised or lowered to account for the strange anomalies. Yet comparatively little attention has been paid to a study that must be undertaken before we are qualified to ex- press an opinion on geographical distribution. Darwin and Lyell, however, thoroughly recognised the importance of the subject, and the former made many experiments on the vitality of seeds under trying circumstances — such as being immersed in sea-water, or eaten by birds. Direct observation of the species in transit, under natural conditions, has been less attended to, except in the case of flying animals and of certain plants. The cause of this neglect is easy to understand : dispersal, in the groups that are not specially modified to assist the process, is mainly the result of the accumulation of rare accidents, such as would only occasionally be noticed by some naturalist engaged in quite different observations. It is useless to go into the field on purpose to watch the dispersal of snails ; the entomologist, ornithologist, fisherman, or sportsman may once in a season obtain a direct observation, and it is to such observers that we must principally trust. In certain respects the land and fresh-water mollusca are peculiarly valuable for the study of geographical I distribution ; they are essentially sedentary animals ; j some of them can float, but scarcely any except NO. T268, VOL. 49] Dreissena have an active free-swimming larval stage. Few of the species are specialised for dispersal ; though we do not think that there is such a complete absence of specialisation as would at first appear. The study of the dispersal of the mollusca becomes, under these circumstances, of great importance to the naturalist ; for if snails or their eggs can cross rivers and straits, it is probable that other sedentary groups can do so also. The system on which Mr. Kew has worked is to collect all the facts relating to the dispersal of land and fresh- water mollusca, giving the authority for each statement. He has thus gathered into one small volume an enormous amount of information, much of which will be quite new to naturalists. Beginning with the fresh-water shells, he treats first of the anomalies in their local distribution, such as their occurrence in perfectly isolated ponds. Then follow chapters dealing with the means of dis- persal ; and it is surprising how varied these are. Not only are the animals transported down stream on various floating objects, but the author can quote an actual instance in which a number of fresh-water mollusca {Atiodon) were carried by a whirlwind and fell with the rain. Another interesting case of transportation over dry land is that mentioned by Canon Tristram, who found the eggs of some mollusc, probably Sicccinea attached to the foot of a passing mallard shot by him in the Sahara, a hundred miles from water. A few instances are noted in which birds on the wing have been shot with bivalves adhering to their toes ; but there seems to be no recorded case of the occurrence of molluscs or their eggs in the bits of water-weed that so often catch on the feet of aquatic birds. It is probable that this means of transport is common ; but being less striking than the other modes, it has not yet been observed. Insects also lend their aid, and a water-beetle {Dytiscus marginalis) has twice been captured on the wing with Sphceriiim attached to its legs ; another specimen was caught with Ancylus attached to its wing-case. Various other aquatic insects have often been found with mollusca attached to them, though they were not actually caught on the wing. As regards the land-shells, there is a singular dearth of direct evidence. Mr. Kew is able to mention various ways in which they may have been transported ; but the only cases in which the process has actually been ob- served were some live Helix caperata found in a wood- pigeon three days after it had been shot, and an opercu- lated land snail which had caught the foot of a bumble- bee, and was being dragged along. We cannot help thinking, however, that the dispersal of land-shells is a much rarer process than the carrying of fresh-water species. An isolated dew-pond after an existence of ten years will generally yield several species of fresh- water mollusca, and a mediaeval fish-pond has c[uite a large fauna. A church or castle built of limestone, but surrounded by non-calcareous desert, is, for a large group of land snails, the equivalent of an isolated pond ; but it is only on very old buildings that one finds colonies of the special limestone species. We have never come across an isolated colony of this sort on a building less than a hundred years old, and have never noticed more than two or three species on a single ruin under such circumstances. ;62 NATURE [February 15, 1894 The rest of Mr. Kew's book is devoted to the dispersal of shells by human agency, and to a discussion of the claims of certain species to be considered native in Britain. This part is very good, and, like therest of thebook,iscom- mendably free from bias, though we do not always agree with the author's conclusions. Mr. Kew in a future edition should add a counterbalancing chapter on human agency as preventing the dispersal of snails. We cannot help thinking that the making of fences and the extermination of the larger mammals in Britain has largely stopped the transportation of land-shells. Any one who has noticed the masses of earth that adhere to the flanks of an ox that has slept in a damp meadow, must realise that in the days of the shaggy-haired mammoth, bison, Irish elk, and wolf, dispersal both of animals and plants may have been far more rapid than at present. Lyell has pointed out that seeds may often be carried long distances by a hunted animal, and the same reasoning applies to any small moUusca or their eggs that may be entangled in the long hair. Even the coarsely masticated grass in the paunch of a deer or bison torn to pieces by the wolves might contain living snails, for many of the dry-soil species habitually cling in great profusion to grass stems. Migrating animals, especially the bison, may have greatly assisted in the carrying of both land and fresh-water shells for long distances. We must congratulate the author on the publication of this excellent manual. It will undoubtedly lead to the accumulation of numerous observations, and we hope soon to welcome a new edition, in which more ot the suggested modes of dispersal may be confirmed by actually observed cases. We hope also that the publishers will see their way to the inclusion in the International Scientific Series of volumes on the dispersal of other \ groups, for the transportation of species from country to country is certainly a subject that should be fully dealt with in a series claiming to be international. Clement Reid. OUR BOOK SHELF. The Wilder Quarler-Century Book. A Collection of Original Papers, dedicated to Prof. Burt Green Wilder at the close of his twenty-fifth year of service in Cor- nell University (1868-93), by some of his former Students. (Ithaca, N.Y., 1893.) Under the above somewhat fanciful title we have a royal octavo volume of just 500 pages, and twenty-eight plates, which contains some fifteen papers written by former pupils of Dr. B. G. Wilder, Professor of Physiology, Vertebrate Zoology, and Neurology in Cornell University, and dedicated to him as a testimonial of the writers' appreciation of his unselfish devotion to the university, and in grateful remembrance of the in- spiration of his teaching and example. Following the practice of some of the German universities, Cornell has been the first among those of the New World to present the teacher with the results of what he has taught ; and the idea seems so commendable that a notice, rather than a criticism, of this volume seems all that IS demanded at our hands. As a frontispiece to the volume there is a portrait of Dr. Wilder, engraved on wood, by John P. Davis, the secretary of the American Society of Wood Engravers, which is an excellent piece of artistic work. A mere enumeration of the contents of the volume must suffice: Dr. D. S. Jordan, on tempera- NO. 1268, VOL. 49] ture and vertebrae, a study in evolution, being a discussion of the relations of the numbers of vertebrae among fishes to the temperature of the water and to the character of the struggle for existence ; Susanna P. Gage, on the brain of Dieinyctylus viridescens, from larval to adult life, and comparisons with the brains of Amia and of Petromyzon ; Dr. G. S. Hopkins, on the lymphatics and enteric epithelium of Amia calva; S. H. Gage, on the lake and brook lampreys of New York, especially those of Cayuga and Seneca Lakes ; L. O. Howard, on the correlation of structure and host relation among the Encyrtinae ; J. H. Comstock, evolution and taxonomy, an essay on the application of the theory of natural selection in the classification of animals and plants, illustrated by a study of the evolution of the wings of insects, and by a contribution to the classification of the Lepidoptera ; Dr. E. R.Corson, on the vital equation of the coloured race, and its future in the United States ; Dr. T. Smith, the fermentation tube, with special re- ference to anaerobiosis and gas fermentation production among bacteria; Dr. H. M. Biggs, a bacterial study of acute cerebral and cerebro-spinal lepto-meningitis ; Dr. V. A. Moore, the character of the flagella on the Bacillus cJiolerce suis (Salmon and Smith), B. Coli com- i7iunis (Escherich), and the B. typhi abdominalis (Eberth) ; Dr. W. C. Krauss, muscular atrophy con- sidered as a symptom ; P. A. Fish, on brain preservation, with a rc'suiiu' of some old and new methods ; W. R. Dudley, on the genus Phyllospadix ; Dr. J. C. Branner, observations upon the erosion on the hydrographic basin of the Arkansas River above Little Rock. Machine Drawing: By Thomas Jones, M.I.Mech.E., and T. Gilbert Jones, Wh.Sc. (Manchester; John Heywood, 1893.) This book contains properly finished and complete draw- ings of machinery details taken from recent practice, the authors being of the opinion that the best way to encourage the student to make good drawings is to place good ones before him as copies. Exercises are given which require the student to test his power of making original drawings, by deducing from the complete views given, others which are not given. One of the authors, being engineering master at the Central Higher Grade Board School, Manchester, has necessarily had much experience in teaching machine drawing, &c., and the present book was designed by him to take the place of the older specimens of draw- ings, with the intention of placing before the student actual mechanical drawings for copies. This is a step in the right direction, for the nearer mechanical drawing, as taught in the technical school, approaches the real thing in the engineer's office, the better it is for the- students. Taken as a whole these drawings represent modern practice, and are good examples. A locomotive coupling-rod is represented on plate xxiv. fitted with a bush keyed in position and retained on the crank pin by a washer and nut of the same diameter as the external , diameter of the bush. Bushes in time always get loose | in the rod, and in this example there is nothing to pre- | vent the rod coming off the bushes and causing an acci- i dent. The nut and washers are screwed on the pin only ; j these ought to be retained in position by a taper or split pin as well. The authors give much sensible and good advice on 1 the subject of drawing generally, which if carefully fol- ) lowed by the student will make the drawing a creditable j one. The book contains forty plates and many perspec- I tive illustrations ; it is nicely got up, and should prove of j value in our technical schools and colleges. Hydrostatics atid Pneumatics. By R. H. Pinkerton, B.A. ' (London : Blackie & Son, Ltd., 1893.) The application and non-application of the integral calculus seems to be a bar which divides many text-books February 15, 1894] NA TURE 363 into two main divisions. In the present work, although the notation of the integral calculus has not been used, yet the method of integration has been explained, and, in fact, applied to the solutions of some problems, ■such as those of finding moments of inertia, centres of pressure, &c. The treatment of the subject-matter on the whole has, however, been developed by very simple mathematical methods, and although the book is published in the " Advanced Series," it should not for that reason be reckoned as of too high a standard for elementary readers. Indeed the author has inserted several useful introductory chapters to prepare such readers as those who have only an elementary knowledge of the mechanics of solids ; thus we are treated to chapters on units, principles of statics, uniform, circular, and harmonic motions. In these chapters, and also in the others dealing with the mechanics of fluids, the author seems to be especially clear in his explanations, and his remarks are in many cases accompanied with diagrams and illustrations, which are always of great help to the reader studying the subject for the first time. In a work of this kind a student can best obtain a good grasp of the subject by supplementing his study of the text with the working out of numerous typical examples. Those here inserted should be specially useful in this direction, and in many cases they have been divided into two series, the second being of a more difficult type than the first ; many of the examples are taken from such sources as the examination papers set at South Kensing- ton, and those for the Civil Service and the Universities. As a text-book for science schools, and suitable for those wishing to get a thorough insight into the subject, the book will be sure to find favour. Hozv to Ma7iage the Dynamo. By S. R. Bottone. (London : Whittaker andXo.) In this book the author gives, in thirty-five short pages, a few practical directionsfor the installation and manage- ment of a dynamo. The instructions given are intended for the use of engineers who have no knowledge of elec- trical work, but are called upon to undertake the manage- ment of a dynamo. It is hardly possible in such circum- stances to frame directions which can be intelligently carried out. The dynamo attendant, like every other person in charge of machinery, must really learn by an experience which no manual can replace. The instruc- tions in the text are, however, plainly and simply stated, and deal with some of the more important points con- nected with the care of dynamos. An appendix is devoted to the explanation of technical terms used in electricity, and makes up about twelve of the total forty-seven pages of the book. It can hardly be regarded as satisfactory, either in point of accuracy or extent. It is more of a series of detached explanatory statements than a " table of definitions," as the author calls it in the preface. LETTERS TO THE EDITOR. The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part ^/Nature. No notice is taken of anotiytnous communications.'] The Cloudy Condensation of Steam. (i) The fault I have to find with Mr. Bidwell (Nature, December 28, p. 212, C893) ^^^ others who are aiming to revive the chemical hypothesis tentatively broached by the late R. von Helmholiz (Wied. Ann. xxxii. p. i, 1887. r/. p. 7 et seq.), is that these gentlemen are abandoning a tried theory when its capabilities are far from exhausted. To begin at once with the most recent contribution to our knowledge of the subject, Mr. Bidwell's observation, let a series of excessively NO. 1268, VOL. 49] small condensation nuclei be enclosed in a vessel without further interference. They were active before being put there ; but after remaining imprisoned for a sufficient length of time, Mr. Bidwell finds them shorn of their power to produce con- densation in supersaturated steam. Now, I ask, is it at all probable that these particles will remain distinct throughout the whole time of confinement? I think not. Take the familiar case of fine clay suspended in water. What goes on during subsidence is an agglomeration of particles. This process may be enormously accelerated by small additions of acid or almost any other foreign matter to the water. In ether the speed of agglomeration is so marked, that the (dry) mud which may be suspended in water for weeks, or even months, falls out of ether like so many grains of sand. Witness, furthermore, the case of any chemical precipitate. Those little solid corpuscles were originally all but molecular in size ; yet they grew with such enormous rapidity to so enormous a bulk (relatively speaking), that the formed precipitate subsides quickly (in most cases) even in water. Think of those monstrous clots of fresh chloride of I silver ; think, too, that they were being built up of individual [ molecules in an instant and before one's very eyes. Then I why should condensation nuclei be so good as to remain distinct indefinitely? i In brief, it is not probable that the condensation nuclei^ if I once produced can subsist in their original degree of comminu- , tion ; for whatever the nature of the acting forces may be, this I finely divided matter is in a highly potentialised state relatively to coarser matter, and there will be dissipation of energy by mere mechanical agglomeration even when chemical action is excluded. (2) Let us look for further confirmation at the size which these I active nuclei must necessarily have, remembering that the con- densation in question, when properly vievved, always appears coloured.'- Such condensation presupposes droplets nearly all of the same size ; of a size, moreover, which we can reasonably conjecture to lie somewhere between '000,004 centimetre and ■000,040 centimetre, depending on the colour selected. This implies that the nuclei which induce coloured condensation must all be of the same size (certainly an improbable condition), or that they must be small even when compared with the small droplets stated. If it were not so, large drops would condense on large \ nuclei, and small drops on small nuclei (keeping in mind that the whole process of condensation is virtually instantaneous), and there could be no prevailing dimension, and consequently no intense colour. But it will be asked, will these excessively small particles meet the Kelvin conditions of condensation ? Assuredly. One may estimate that pure, dust-free, unconfined steam at 100° would ■ require a pressure of the order of ten or more atmospheres to condense it. Add to this dust particles less than 'ooOtOOl cen- timetre in diameter, and the pressure sinks to 15 centimetres of mercury ; in case of particles "000,010 centimetre in diameter, to i one or two centimetres of mercury ; in other words, to pressure increments •* certainly met with in steam jets. The fact that nuclei of a few hundred molecular diameters are needed is the very feature of these experiments, and explains why smoke and other coarse material is useless, and why the condensation- producing dust must be so highly specialised. (3) Nuclei, it is true, are often equally active if derived from liquids, the mixture obtained by passing air over very strong sulphuric acid being a notable example. Let us remember, how- ever, that these active liquid bodies (acids all of them, while ammonia is not active) may form sulphate of ammonia in contact with atmospheric air. But if this view of the case be unsatis- factory, is there anything in Lord Kelvin's well-known equation connecting vapour tension and curvature which asserts that the nuclei 7nust be solid ? (4) I have equally great difficulties in submitting to the diverse electrical hypotheses put forth, and I cannot understand why so astute and sound-minded an investigator as Mr. Aitken should hazard his birthright for that mess of electrical pottage. It is certain that air passing across an active spark gap will produce condensation ; but it is equally certain that no electric field will 1 It must not be forgotten that the imprisoned nuclei are mixed with the nuclei normally present in air. Whether the mixture is pronounced active o\ not, depends on the sensitiveness of the test applied. Thus there is room for an error of judgment. I recur to this in § 6. 2 I here include the op.ique field mentioned in Mr. Aitken's and in my own articles, since it obeys clean cut colour laws. 3 Pressures between i and So centimetres above the atmosphere were necessary in my work. 3^4 NA TURE [February 15, 1894 be wafted down a metallic tube three or more metres long by a draught of air — a crucial test which I believe to have been the first to make, though Mr. Bidwell does not affirm it. If charged particles, dissociated particles, and the like are sucked down there, I must insist that the said charged or dissociated particle — whatever befall it — is a particle still ! If it is not small enough, it will fail to stimulate condensation in any case or theory. If it is small enough, it mzist produce nuclear condensa- *ion per se, no matter how the particle is otherwise conditioned. Aside from this, the electrical theory becomes more seriously entangled by the faci that the jet itself is no mean generator of electricity. I made a few tests on this point in the line of Faraday's classical researches, and obtained marked charges from the jet, increasing with its intensity. (5) I cannot claim much indulgence for my experiments in air filtration, though I went through them laboriously enough. But the work taught me, at least, the extreme elusiveness of such a thing as "dust-free" air. Naturally I am biassed, therefore, in regard to arguments, in the present case, based on filtration. Suppose an oxyhydrogen flame burning in filtered air is an active dust producer. The question at once arises on what kind of hearth is the flame kindled : if it burns from a glass tube, then sodium is probably volatilised ; if from a metallic tube, then the metal is similarly in danger ; if from no base at all, then where is the flame ? In what does the remarkable activity of flames really consist ? Most reasonably, it seems to me, in this, that particles therein entrapped are (as a rule) at once volatilised, so that for each single particle we have now a whole cloud of active nuclei precisely the kind wanted in § 2 ; i.e. myriads of them, all in that extreme degree of tenuity which best promotes condensation. In my work, glowing smokeless charcoal often did better service than flames. Alkalies are here ready for volatilisation. In general, hot flames are more active than colder flames (Helmholtz), and they should be where dis- gregation is needed. Fmally, a word with regard to red-hot platinum. " Here," says Mr. Bidwell, "there can be no nuclei formed of products of combustion, for there is no combastion, simply ignition and incandescence." Is it possible that Mr. Bidwell is not aware that red-hot platinum is particularly remarkable for scattering small solid particles from its surface? If so, he has narrowly escaped being overwhelmed by the literature of the subject. Aside from this, what may be the nature of platinum dissociated at red heat ? (6) To conclude : I cannot discern that the proof of anything beyond condensation of supersaturated steam, induced by mere "inert" nuclei, has yet been given. Nothing is even said of atmospheric air, which indoors or out, stagnant or fresh, is al ways active ; nor is it even hinted at that the efl'ect of dust is merely an acceiitualion of the eff^ect produced by such air ; that dust- stimulated condensation dift'ers merely in degree, by no means in kind, from jet condensation in air. Air nominally purified needs only a higher degree of supersaturation to evoke conden- sation running through the whole gamut of colours. There are no hard drawn lines. I wish there were. Indeed, I wish the proof in question could or had been adduced, for, together with my colleague Prof. F. H. Bigelow, I am well aware of the important meteorological consequences to which this result would lead. But before I can break away from the time-honoured point of view, so safely trussed by the Kelvin formula, the experimental evidences forthcoming must be as rigorously " dust-foU " as the clear conscience with which I am disposed to admit them. Carl Bakus. The Smithsonian Institution, Washington, D.C., U.S.A. The Origin of Lake Basins. The question of the origin of lake basins has again been raised, and, unfortunately, there is tven now the same diamet- rical opposition between the views of the glacialists and their adversaries. Though the old lines of argumentation, perhaps, have not been followed out with sufficient perseverance, new start- ing-points certainly seem desirable. I should therefore like to challenge the criticism in your columns on a demonstration of the glacial origin of the greatest fjord basins in Norway. On the western coast of Norway we have the well-known series of great fjords, generally of enormous depth, about 400 fathoms in Hardangerfjord, 600 in Sognefjord, and 300 in Nord- fjord, to take only the greatest. The heads of the innermost NO. 1268, VOL. 49I branches are nowhere at a greater distance than some twenty miles from the watershed of the country, and the necks between them nowhere as much as forty miles. When for some reason, change of climate or rise of land, the snow began to gather on the neighbouring plateau, the highest in Scandinavia, glaciers would creep down the steep slopes and valleys, and immediately get to the deep fjords. But here the glacier ends must needs be carried away or dissolved as fast as they came on. By the neces- sarily slow growth of the narrow neves, it is impossible that the glaciers could advance at once with so great dimensions that the fjords were not able to master them successively. Over the narrow necks between them an ice cap certainly might push farther out, but as there is less than twenty miles to draining outlets on either side, this cap could attain no considerable thickness, and bring no great ice flow westwards from the high land behind. On the lower foreland, near the coast-line, there is nowhere sufficient gathering basin for a great neve, and the small fjord branches could easily drain their eventual surplus. My opinion is, then, that no great inland ice could possibly ad- vance farther west in Norway than to the close set row of fjord- heads. It may be said that the whole country in the great Ice Age was so^much elevated that the fjords were only dry valleys. But no amount of elevation could ever drain fjord troughs gen- erally 300 to 600 fathoms deep, and only loo to 150 wide at the brim. And an adequate differential lift of the inner side of the troughs would give the old palaeozoic mountains in Norway the height of the youjigest mountain ranges, and is on the face of it impossible. It may be further said that ice from the high land behind the watershed might have contributed to the supply, and that the glaciers then would be large enough. But even in this case they must needs commence as small ice tongues, which would he cut off successively ; and the boulders show that no transport from any distance behind the watershed took place during the great Ice Age. The ideal have put forward is capable of maintaining itself by its own power, but its position is greatly strengthened by direct facts. It can be demonstrated that a great inland ice has tried to advance from the high land westward beyond the fjord heads, and signally failed. This was the case in the last Ice Age, of which we can trace all the prominent signs. As the ice cap was not able to build itself up to any great dimensions near the western preci- pices to the fjords, its greatest height was piled up farther to the south-east, and the ice shed was drawn in the direction of the eastern margin, down the eastern valleys. From this time we find boulders transported up the eastern slope from a distance up to eighty miles trom the watersheds, and these boulders can be followed in great heights in the western valleys only to the fjord-heads, when they suddenly drop down to the old sea beach. This shows, beyond all doubt, that the glaciers from the second inland ice which far away to the south-east laid up the upper till in Prussia, on the north-western side, only reached the fjord-bottoms, and were not able to fill the fjords. We have in this an empirical proof of my idea. An inland ice is really not able to advance beyond a close set row of deep depressions as the Norwegian fjords. But yet we have unquestionable proof that the exterior part of the west coast was extremely glaciated. Just in the mouth of the great Sognefjord itself we have the Sulen Isles with rock scorings and eastern erratics (but none from behind the water- shed) up to 1800 feet above sea level, 5400 feet above the fjord bottom. How can these boulders have been transported across this abyss when no inland ice could ever have advanced beyond the fjord head, and no local glaciers from the peninsula on either side could ever have crossed the deep channels, or piled itself up to sufficient height here only a few miles from the steep slope to the Atlantic Ocean basin ? I cannot see any way to account for these facts other than by the supposition that the Jjords or depressions of the same kind and depth did not exist when the first great inland ice was forming, but were quite completed when the second (and last) commenced. Ergo, the Norwegian fjords are of early glacial or interglacial origin. At this point of my reasoning comes in the conclusive series of arguments which puts any other origin than glacial erosion quite out of question for this peculiar flat troughs in old solid azoic and palaeozoic country. I wish to lay especial stress upon the fact that Norwegian geologists for many years have laid great weight upon the really marvellous circumstance of lake-distribution only in glaciated districts, as one of the best of the many in- direct proofs of the glacial origin of rock basins. I should think. February 15, 1894J NATURE 365 however, that when the origin in glacial time of the grand Norwegian fjords is sufficiently proved, their origin by glacial forces will be more easily granted. The same may certainly be said of the far smaller lake basins in Norway, for which an analogous demonstration can be given. That the fjords now must really be of pleistocene origin is the point I wish to make in this letter. Only if anyone can, in a simple manner, explain how an inland ice could be able to pass the close set row of fjord heads, is it possible to dismiss my argument. Andr. M. Hansen, University Library, Kristiania, January 29. A FEW words are due from me in reply to the kindly criticisms of my suggestion regarding the erosion of rock basins that have appeared in Nature since its publication on November 9, 1893. In the first place, I must apologise to Sir H. Howorth for having misunderstood his remarks on the plasticity of ice in his letter of July 13, a misunderstanding due, of course, to my not having had an opportunity of reading the chapter devoted to the subject in his book. Unfortunately the libraries of our small outlying stations in India do not as a rule provide us with works of scientific interest, and the conditions of life of most of us wlio take an interest in such subjects out here force us to content ourselves with the possession of very few books of the kind, and only those that are absolutely necessary for our work. Provided that it is admitted that the plasticity of glacier ice is sufficient to allow motion in the upper layers of a glacier, even v/hen it rests on a nearly level surface, it does not matter, so far as my hypothesis is concerned, whether the bottom layers move or not, for a movement of the upper layers alone is required to enable the " moulins " to transfer their action from place to place, and in time to exert their force on every part of the rock surface beneath that portion of the glacier. That the action of the " moulins" is not so restricted as would appear from Prof. Bonney's letter in Nature of November 16, 1893, can, I think, hardly be doubtedbyany one who has traversed a Himalayan glacier of the kind I have described, on a hot summer's day. Hundreds of ihem may be seen in action in every direction, and, given sufficient time, their aggregate effect in wearing down the rock surface must be very large. I have noticed the dry shafts mentioned by Prof. Bonney in front of an active " moulin," but do not see why they should not be accounted for by the opening of a new crevasse, without having to suppose that the new crevasse was in the same position as the old one. The crevasses to which I refer are mostly very narrow, easily stepped across in many cases, and do not appear to ex- tend far down into the glacier, so that they are probably due to some other cause than an unevenness of the rocky floor, which would cause them to form in succession at the same point, and their number would give the " moulins " plenty of opportunity to attack the whole surface in course of time. Besides, the wearing away of any inequality that did exist, would surely cause the crevasse to open at some other point, if it were due to that cause, and the " moulin " would thus be enabled to shift its point of attack. The very rarity, too, of such collections of " giant's kettles " as that at Lucerne would seem to show that it is seldom that the " moulins " keep working at one point for any length of time. I did not mean to suggest, of course, that any lake basin had been due to the action of one " moulin" ; the hollow ultimately produced need not bear any relation in form to the individual "giant's kettles" that gave rise to it ; indeed, there is no necessity that a real " giant's kettle " should be formed at any one point. Just as in the case of a drill moved over the surface of a piece of wood, the pattern ultimately produced need bear no relation to the form of the drill. If we except the doubtful action of the ice[itself, I do not know of any agent that will produce a rock-enclosed hollow in the course ot a river channel, but falling water, aided by boulders and sediment. Such a hollow may be seen at the foot of any water- fall, even of moderate height. In calling attention to the rarity of true rock basins in the Himalayas, an expression that Mr. Oldham takes exception to, I should have said lake basins, that is, lakes lying in true rock basins. As I pointed out, any hollows that may have been formed beneath a pre-existing glacier have been filled with debris, but it is very likely that such hollows do occur beneath the extensive flats found at the foot of the larger glaciers, as in NO. 1268, VOL. 49] the case of the one shown in the view given in my paper. Of course, where such hollows occur in positions where it is im- possible that glaciers ever existed, as in eastern Baluchistan, they must be accounted for in other ways. My suggestions were not intended to account for all rock basins, but merely to apply to those which occur in now or formerly highly glaciated regions, where it seems possible that there is an intimate connection be- tween the excavation of the basins and the existence of glaciers. Sukkur, January 10. T. D. LaTouche. A Plausible Paradox in Chances. It seems worth while to record the following pretty statis- tical paradox as a good example of thepitfalls into which persons are apt to fall, who attempt short cuts in the solution of problems of chance instead of adhering to the true and narrow road. It is true that the paradox would excite immediate suspicion in the mind of any one accustomed to such pro- blems, but I doubt if there are many who, without recourse to paper and pen, could distinctly specify off-hand where the fallacy lies. It will be easy for the reader to make the experiment of his own competence to do so after reading to the end of the second of the two following paragraphs. The question concerns the chance of three coins turning up alike, that is, all heads or else all tails. The straightforward solution is simple enough ; namely, that there are 2 different and equally probable ways in which a single coin may turn up ; there are 4 in which two coins may turn up, and 8 ways in which three coins may do so. Of these 8 ways, one is all-heads and another all-tails, therefore the chance of being all-alike is 2 to 8 or I to 4. Against this conclusion I lately heard it urged, in perfect good faith, that as at least two of the coins must turn up alike, and as it is an even chance whether a third coin is heads or tails \ therefore the chance of being all-alike is as i to 2, and not as I to 4. Where does the fallacy lie? It lies in omitting one link in the chain of the argument as being unimportant, whereas it is vital. This omitted link i5 distinguished by brackets and is numbered (3) below. The reasoning then stands : — (i) At least two of the coins must turn up alike, (2) It is an even chance whether a third coin is heads or tails. [(3) Therefore, it is an even chance whether the third coin is heads or tails. (Here is the error).] The true state of the case is seen by writing out the eight several events^ as in the table below. The eight equally- probable events. h = heads, t — tails. The two letters that are alike in each case. The third letter in each case. A h h h h t h t h h t t t h h t h t t t h t t t h h h h h h t t h h t i t t t t h t t h t k h t No. 2 in the argument is justified by the total number of the /i's in the third column being equal to that of the fs, while No. 3 is obviously not justified. In the particular 8 events with which we are concerned, an h h is associated with a t three times as often as with an //, and a // is associated with an h three times as often as with a /. Hence as the combination hh h is one-third as frequent as that of any 2 h'% and i t, and as tttxi, one-third as frequent as any combination of 2 /'s and I h, and, lastly, as the two classes of combinations are equally frequent, it follows that the frequency of the all-alike cases is to that of the remainder as i to 3, or to that of the total cases as I to 4, which is the result first arrived at. I amused myself with testing the theoretical conclusion by making 120 throws of dice, 3 dice in each throw; the odd ;66 NATURE [February 15, 1894 numbers counted as heads, the even numbers as tails. The 120 throws were divided into 3 groups of forty in each, and gave the results of all-alike 8, 12, 8, total 28 ; as against not all- alike 32, 28, 32, total 92. The most probable expectation having been 30 to 90. Francis Galton. Clerk Maxwell's Papers. I DO not know whether the Clerk Maxwell Memorial Com- •iiiittee have ceased from their labours, but I cannot help thinking th it more might be done towards rendering the work of Max- well more readily accessible to students. The pair of ponderous volumes issued by the Committee are very well in their way, but they are certainly bulky, and the chronological order of papers, though eminently suited to their purpose, is not so suited to the practical needs of students. For instance, the papers on the kinetic theory of gases seem to me far and away better than much that has been written since, and it would be very convenient to be able to procure them separately. My suggestion is, then, that with the aid of a moderate subsidy a publisher be induced to issue Maxwell's papers on special subjects in cheap, handy, separate volumes, which might run somewhat as follows : — On Colour and Optics. On Graphical Statics. On the Kinetic Theory of Gases. On Dynamical Problems. On Electro-dynamics. Lectures and Addresses. Articles and Reviews. Under one or other of these heads almost all the papers could be included ; there would be no need to include anything that did not seem likely to be of frequent use. The series of .'mall books would be a boon to students, and a knowledge of the work of their great author would be more widely spread, Oliver J. Lodge. Abnormal Eggs. The occurrence entitled " A Curiosity in Eggs," related in Kature for February i, is by no means as unusual as your correspondent imagines. It occurs in domestic poultry from over-stimulation of the system by generous feeding. The explana- tion of the production of one egg within another is very simple. The ovum or yolk when mature is received into the upper part of the oviduct, a tube nearly two feet in length in the domestic fowl, and in its descent is clothed successively with the layers of albumen or white, the lining membrane of the shell, and finally, on arriving at the calcifying portion of the oviduct, is enveloped in the shell. In the ordinary course of events the mature egg is then expelled, but in the case of the production of a double-yolked egg, a reverse action of the oviduct occurs. In place of being expelled, the egg is carried back again to the upperportionof the oviduct, where it meets with another mature ovum, and the two descend together, both being surrounded with a second investing series of albumen, membrane, and shell. Some of the occurrences connected with abnormal eggs are very remarkable. I had one forwarded to me during the last month, which was alleged to contain a marble. On examination I found that the supposed marble was a small abortive yolkless egg, which in colour and form, but certainly not in weight, closely resembled a common clay toy marble. It is not unfre- quent for persons to allege the occurrence of various foreign bodies in eggs. The most common substance said to be found in an egg is a horse-bean, which is closely simulated by a mass of hard coagulated blood which has escaped from the ovarium into the oviduct, and is included along with the yolk in the investing structures. I need not further allude to such circum- stances as a horse-hair in an egg, or a small coin not unfre- quently found at the breakfast-table, inasmuch as these are merely the result of practical joking, and require no further explanation. There is, however, one circumstance that may interest some of your physiological readers, and that is the extreme rarity of the hatching of any egg the shell of which is in the slightest degree malformed. In my own experience I have rarely, if ever, found an egg the shell of which was in the slightest degree unsymmetrical, that has been channeled at one end, or having an irregular zone around the middle, to produce a chicken. The occurrence of two ova in the same egg NO. 1268, VOL. 49] is by no means uncommon. It results from excessive feed- ing, and rarely, if ever, occurs in a state of nature. I have known two perfect birds, both chicken and pigeon, produced from such an egg, but the more general result is that the two ova, being developed together, coalesce, possibly from want of room to develop in the confined space, and thus arises the presence of two-headed, or six or eight-limbed monsters, which are much more frequent in fowls than in any other animals whatever. I have from time to time for- warded specimens of these abnormalities to the museum of the College of Surgeons, where they may be seen by those who are interested in the subject. W. B. Tegetmeier. North Finchley. On two occasions fully shelled eggs of about the size of those of the thrush have been found by myself within ordinary hen eggs, one of which is still in my possession. Several times I have hatched twin chickens from double-yoked eggs, and once a monstrosity having four legs. Shirenewton Hall, Chepstow. E. J. Lowe. THE PLEIADES. A MONG the many constellations and star clusters -^~^ which attracted the attention of our early ancestors, few, indeed, were so constantly observed as that small bunch of twinkling brilliants known as the " Pleiades." From a very early date, when our forefathers were not so well acquainted with the divisions of the year as we are to- day, they needed some means by which they could tell when to sow their corn, and make arrangements for other agricultural pursuits which could only be done properly in their right seasons. That they could, at any rate, get a rough approximation of such divisions of the year by means of the positions of the heavenly bodies, they soon found out, and they were thus led to observe sometimes stars, sometimes groups of stars, near the rising or setting of the sun, and even certain stars, or groups of stars, at their times of rising and setting. That they should have chosen that group of sparkling stars, the Pleiades, to serve their purpose, does not seem at all astonishing if one considers how easily they can be recognised in the sky, and also their important position in more remote times. The different relative positions of the sun and the Pleiades had no doubt first attracted special attention to this group of stars, and we know how important a role they played in ancient times for calendar purposes ? Let us just consider the several positions of the Pleiades as a result of the earth's rotation and revolution round the sun. Commencing about the end of May, we find that the Pleiades are altogether invisible, as they rise and set together with the sun. As time goes on, they will appear above the horizon before the sun, the differ- ence in the time of rising of these two objects gradually increasing. In August the Pleiades cross the meridian about the time the sun rises, and by the end of November they are visible throughout the whole night, their upper culmination taking place at the same time as the lower culmination of the sun. As November draws to a con- clusion, they set earlier and earlier, and by the end of February are visible only for a short time, disappearing altogether for a time after the middle of May. Owing, however, to a slight movement of the axis of the earth, which makes a revolution round the pole of the ecliptic once in about 25,800 years, the point of intersection of the ecliptic with the equator is not fixed but movable ; thus we can understand that the positions of all heavenly bodies as regards their right ascensions and declinations suffer a continual but slow alteration. This slow movement explains the reason why the Pleiades have not always been invisible at the end of the month of May, and we have only to form a simple February 15, 1894] NA TURE 367 calculation to become acquainted with the fact that about 2000 years ago this period of invisibility occurred nearly a month earlier. A very interesting point relating to the Pleiades is the great number of different names which have been applied to them, and also the curious myths which have arisen from time to time. A most interesting account of these has recently been published by M. Richard Andrce,i who has brought together a mass of matter relating to both names and myths. First, with regard to the names which were used when referring to the cluster. The general words defined them as a heap, troop, host of dancers, sieve, &c. ; sometimes the simple word "many" was adopted. One finds them spoken of as herds, or hosts of animals, birds, such as hen with chickens, parrots, doves, &c. The simplest expressions really used meant "mass," and an examination of the records confirms this view. In observing the Pleiades anyone would remark how closely they are packed together. This closeness led early peoples, no doubt, to refer to them as a host or herd of animals, and hence the well-known name, " the hen with her chickens." Among many foreign names for this, we have in Ger- man, Der Glucke mit ihren Kiichlein ; in Danish, aften- hone (evening hens) ; in French, la poussiniere ; in Italian, gallinette, &c. Instead of a host of animals, we have a host of people referred to, such as, for instance, in the Solomon Islands, where they are called " togo ni samu," meaning a company of maidens. The North American Indians have also known them under the name of " dancers." It may be thought that a natural name by which they would be known would give some idea of the num- ber of stars in the group ; this was often the case, only with different names, for a'very good pair of eyes could distinguish seven stars, while generally only six were counted. The word for the Pleiades, for instance, in old high German was " thaz sibunstirri " (seven stars), while that of the South Americans, "cajupal," meant six stars. Again, in Cook's Islands the word " Tau-ono" (six) was used, while the Greeks had a special name for each of the seven stars. Seeing that so much importance has been attached to the Pleiades by peoples of all countries, it is natural to find that the number of myths is by no means few ; this is shown to be the case by examining the records of the ancient Greeks, the peoples from East Asia, South Sea Islands, America, &c. To describe a few briefly, let us refer first to that which we owe to the Greeks. The Pleiades in this myth were the daughters of Atlas and Pleione, each one of which bore a separate name. The Hyades, for soitow at the death of their sisters, or, as others say, at the destiny of their father. Atlas, killed themselves and became fixed as a constellation in the heavens. Another myth, by Pindar, describes them as the comrades of Artemis, who were turned into doves, and eventually into stars. A myth of much interest is that of the Dyaks, and the Malays of Borneo. They say the Pleiades were six chickens followed by their mother, who remained always invisible. At one time there were seven chickens in all. One chicken paid a visit to the earth, and there received something to eat, at which the hen got so angry as to threaten to destroy both the chicken and the people on the earth. Fortunately the latter were saved by the con- stellation of Orion, leaving only six chickens in the brood. At that period of the year when the Pleiades are in- visible, the Dyaks say that the hen broods her chickens, while at the time of visibility "the cuckoo calls." The South Sea islanders have a myth which has some originality about it. It is to the effect that the Pleiades 1 See Globus, Cd. Ixiv. No. 22, " Die Plejaden im Mythus und in ihrer Beziehung zuiii Jahresbeginn und Landbau." NO. 1268, VOL. 49] were originally a single star, which shone with such a clear lustre as to incur the envy of the god Tane, who was in league with the stars Aldebaran and Sirius, and followed the Pleiades. Trying to save himself in a stream, the course of which Sirius had so diverted as to bring him close to Tane again, he was broken up into six bright stars by Tane himself, who hurled Aldebaran at him. The blacks of Victoria, Australia, have a myth in which the Pleiades are considered a host of young wives who play with the young men. The myth of the Kamilaroi blacks is as follows : The Pleiades were once pretty maidens on the earth, who were followed by some young men called the Beriberi. To get away from the latter the girls climbed trees, and thence sprang into the heavens, where they were transformed into shining bodies ; one maiden who remained behind was termed "gurri gurri," the shy one, and she is represented by the least bright star in the group. The Beriberi were eventually placed in the heavens, where they appear in the girtle and boomerang in the constellation of Orion. These and many other myths, all of great interest, are mentioned by M. Andree. They inform us to a cer- tain extent of the characters of the different nations. Much might be learnt also about the origin of the various tribes of people, by seeing if the different myths can be traced back to an initial one. Those of the North Ameri- can tribes, for instance, seem to have a common origin. In some instances the Pleiades were undoubtedly looked upon as a god who, besides regulating the year and looking after the fruitfulness, was the ruler of all meteoro- logical and astronomical appearances. Hesiod refers to the rising of the Pleiades as the time for harvest, while the period about which they disappeared for some time he termed ploughing time. Forty days and nights were they invisible, appearing again only as soon as the sickle was sharp. Another very well-known use made of the visibility and invisibility of the Pleiades was the regula- tion of the traffic of ships in Greece, hence probably the Greek word for to sail, TvKenv . The rising of this group of stars was the commencement, so to speak, of the ship- ping season, their disappearance denoting its conclusion. At Rome, also, the same practice was in vogue. Enough has been said to attract the reader's atten- tion to some of the numerous interesting references about this group of stars. The nineteenth century has already seen the end of many a myth which has been solidly upheld ; but as science advances, facts take the place of myths, and although much of the romance may appear to be lost, one always looks back at them with delight. Few stars, perhaps, have been so shrouded in myth as the Pleiades, and the unravelment of these myths has been the source of pleasure to many. NOTES. A MEETING of the International Meteorological Committee' has been arranged to take place at Upsala, commencing August 20. Since the meeting at Munich in 1891, four new members have been added to the committee — Mr. William Davis, Cordoba ; Mr. John Eliot, Calcutta ; Mr. R. L. J. Ellery, F.R.S., Melbourne; and Dr. A. Paulsen, Copenhagen. The last named has replaced Dr. Lang, Munich, who died last year. The arrangements for the sixth session of the International Geological Congress have now been made. The meeting will be held at Zurich, from August 29 to September 2. The pre- sident is Prof. E. Renevier ; Pi'of. A. Heim is vice-president, and Prof. H. ^Golliez, of Lausanne, is secretary. The sub- scription is twenty-five francs, which should be sent to M. Casp. Escher-Hess, Bahnhofstrasse, Zurich. In addition to the 368 NA TURE [February 15, 1894 ordinary work of the congress, special meetings will be held for the discussion of questions relating to (a) general geology, tectonics, &c. ; (/') stratigraphy and palaeontology ; {c) mineralogy and petrography. Numerous excursions have been planned ; six, before the congress, to different parts of the Jura, and six, after the congress, to various districts of the Alps ; three supplementary excursions are also proposed. Mr. W. Topley (28, Termyn-street, London), who acted as general secretary to the London Congress; in 1888, will be glad to receive subscrip- tions or to give information. A MEETING to consider the question of raising a memorial to the late Prof. Arthur Milnes Marshall, F.R.S., was held at the Owens College on Friday last. Mr. Edward Dormer (deputy- treasurer of the College) presided, and there were present, amongst others. Principal Ward, Profs. Boyd Dawkins, Osborne Reynolds, Schuster, Weiss, Leech, Herdman, and Dixon, Dr. Hurst, Messrs. R. D. Darbishire, Forbes Carpenter, R. Assheton, F. W. Gamble, and W. E. Hoyle. The meeting was addressed by Principal Ward, Mr. Darbishire, and others, and it was decided to form a committee to formulate a scheaae, and submit it to a future meeting. Although no definite decision as to the nature of the memorial was arrived at, the general sense of the meeting seemed to be in favour of a fund to maintain Prof. Marshall's library, which has been generously presented to the College by his family. H. R.H. THE Duke of Cambridge has accepted the presidency of a committee which has been formed to present a testimonial to Dr. W. H. Dickinson on his retirement from the office of senior-physician to St. George's Hospital, of which his Royal Highness is a vice-president. Among the members of the committee are the Duke of Westminster, the Earl of Cork and Orrery, Mr. Shaw Stewart, and Colonel Haygarth, vice-presidents of the hospital ; Mr. J. R. Mosse, treasurer ; Sir Henry Acland, Admirals Sir George Willes and Sir W. Houston Stewart, Sir George Humphry, Sir Francis Laking, Surgeon-General Cornish, and a number of Dr. Dickinson's past and present colleagues, and pupils and former students of the St. George's Medical School. The death is announced of Brigadier-General J. Ammen, who for some years held the Chair of Mathematics in Bacon College, Georgetown, Kentucky, and that of Jefferson College, Mississippi. The Right Hon. Sir Harry Verney, whose death, at the age of ninety-two, occurred on Monday last, was the "father" of the Royal Agricultural Society of England — an institution which he assisted to establish in 1838. Lord Playfair has selected "The Modern Needs of Scientific Teaching" as the title of his address to the students of the London Society for the Extension of University Teaching, at the Mansion House, on Saturday, March 10. Mr. Holbrook Gaskell having contributed ^1000 to complete the endowment of the Chair of Botany at Liverpool University College, the college council have decided to confer the professorship upon Mr. R. J. Harvey Gibson, who has held the lectureship in botany during the last five years. The Council of the Royal Meteorological Society have ar- ranged to hold an exhibition of instruments, photographs, and drawings relating to the representation and measurement of clouds, next April. The Exhibition Committee invite co- operation, as they are anxious to obtain as large a collection as possible of such exhibits. The committee will also be glad to show any new meteorological instruments or apparatus invented or first constructed since the exhibition of 1892, as well as photographs and drawings possessing meteorological interest. NO. 1268, VOL. 49] Among the documents in the possession of the Anthropo- logical Institute are a considerable number of MS. vocabularies, in many cases unique in their character. As it has never come within the 'scope of the Institute to devote a large portion of '\\.% Journal to the publication of such material, a fund is being raised by subscription, independently of the Institute, to deal with these documents. The subscription is one guinea, payable in alternate years, and the first vocabulary to be published will be one of the Ipurina Language (Upper Purus River), South America, by the Rev. J. E. R. Polak. We learn from the Keiv Bulletin for February that an ex- cellent portrait of Prof. Oliver, F.R.S., the late keeper of the Herbarium and Library of the Royal Gardens, Kew, has been painted by Mr. J. Wilson Foster (who also painted the portrait of the present keeper, Mr. J. E. Baker, F.R.S., exhibited at the Royal Academy in 1893). Prof. Oliver's portrait was com- missioned by a number of his scientific and other friends, who have presented it to the Herbarium of the Royal Gardens — the scene of his labours from 1858 to 1890. An appeal for assistance has been issued by the committee oftheBethnal Green Free Library, there being a deficit of £200 on the last financial year, while the outlay of the present one is calculated to reach ^^ 1,000. The work that this institu- tion is doing is an excellent one, and the fact that no less than 50,000 persons attended the library and classes, &c. in con- nection with it, and 27,000 the Gilchrist Educational Trust Lectures, tells it is filling a real want. It will be a pity if such a good work should languish for want of funds, subscriptions towards which may be sent to Mr. G. F. Hilcken, the secretary and librarian, Bethnal Green Free Library, London, E. The Academy says that the Hon. Walter Rothschild pro- poses to publish a periodical in connexion with his Museum at Tring, under the title of Novitates Zoologicae. It will con- tain papers on mammals, birds, &c., and also discussions on general questions of zoological or palseontological interest. Descriptions of new species will be confined almost entirely to those of which the types belong to the Tring Museum ; and the other articles will, for the most part, be founded on work carried on at that museum, or on specimens sent by Mr. Rothschild's collectors. Mr. Lloyd Bozvvard, writing to us from Worcester, says that on the 6th instant, shortly after noon, he saw a large meteor of great brightness near the zenith. At the time of the occurrence, the sun was brilliantly shining in a clear blue sky. A remarkable feature was the intensity of the light of the meteor. According to Mr. Bozward, this, if not exceeding the radiance of the sun, was certainly equal to it. The meteor was also seen at Birmingham, several observers comparing its light to that given by the electric arc, while others say that it was of a vivid green colour. The Royal Society of New South Wales offers its medal and ;^25 for the best communication (provided it be of sufficient merit) containing the results of original research or observation upon each of the following subjects, to be sent in not later than May I, 1894 :— On the timbers of New South Wales, with special reference to their fitness for use in construction, manu- factures, and other similar purposes ; on the raised sea-beaches and kitchen middens on the coast of New South Wales ; on the aboriginal rock carvings and paintings in New South Wales. To be sent in not later than May i, 1895 :— On the silver ore deposits of New South Wales ; on the physio- logical action of the poison of any Australian snake, spider, or tick ; on the chemistry of the Australian gums and resins. To be sent in not later than May i, 1896:— On the origin of multiple hydatids in man ; on the occurrence of precious February 15, 1894] NATURE 369 stones in New South Wales, with a description of the deposits in which they are found; on the effect of the Australian climate on the physical development of the Australian-born population. The competition is in no way confined to members of the Society, nor to residenls in Australia, but is open to all without any restriction whatever, excepting that a prize will not be awarded to a member of the Council for the time being ; neither will an award be made for a mere compilation, however meritorious in its way. The com- munication, to be successful, must be either wholly or in part the result of original observation or research on the part of the contributor. The successful papers will be published in the Society's annual volume. Competitors are requested to write upon foolscap paper, on one side only. A motto must be used instead of the writer's name, and each paper must be accom- panied by a sealed envelope bearing the motto outside, and containing the writer's name and address inside. All com- munications to be addressed to the honorary secretaries, Messrs. T. W. E. David and J. H. Maiden, at the Society's House, Sydney. A VERY severe gale reached the coast o( Ireland from the Atlantic on the evening of Sunday the iiih instant, the centre of which passed over Scotland ; much snow fell there during the passage of the storm, and the barometer reading was as low as 28'2 inches. The force of the gusts reached lo to ii of the Beaufort wind-scale (o— 12), and owing to the steepness of the barometric gradients the storm was felt over all parts of Eng- land, and caused much damage both at sea and on land. At Greenwich, which was about 300 miles from the centre of the disturbance, the anemometer registered a pressure of more than 35 lbs. on the square foot, being equal to an hourly velocity of about 85 miles. In connection with these values it may be interesting to state that in the gale of December 12 the wind at Greenwich attained a pressure of 37 lbs. on the square foot ; but in the great storm of November last it did not there exceed 17 lbs. By Monday, the 12th instant, the centre had passed over the Norlh Sea, and the barometer near Christiania had fallen below 28 inches, gales being experienced from the coast of Ireland to the Baltic. In the rear of the disturbance the temperature, which had been unusually high for the time of year, fell considerably, frost occurring in many parts of Great Britain on Monday night. With reference to the above gale. Dr. Buchan writes that at Edinburgh a remarkable fall of the barometer commenced at 5 a.m. on Sunday last, and 2 a.m. on Monday the low reading of 28'3I9 inches at 32° and sea-level was registered. An un- usually rapid rise then set in, and in the one hour from 4 to 5 a.m., pressure rose 0*307 inch, as recorded by Richard's baro- graph, controlled by readings with the mercurial barometer. The traced line of the barograph was clear and distinct, giving little if any indication of "pumping." Consequent on a change of wind from east-south-east to south-west, Richard's thermograph registered a rise of temperature from 37°"5 to 48°*o, or io°"5 in the seven minutes ending i.io p.m. on Sun- day. The fluctuations of Richard's hygrograph early in the morning of Monday were equally striking. An exceptionally heavy storm was experienced in America from Sunday to Tuesday last. At Chicago the velocity of the wind was estimated at seventy five miles an hour, and the streets were blocked with snow ; while at New York the snow- ^ fall is reported as the heaviest this season. The Atlantic coast i was also swept by a fierce wind. j The Meteorological Council have published, as an Appendix i to the Weekly Weather Report for 1893, a summary of rainfall I and mean temperature for twenty-eight years, 1866-1893. The ! values are given for each of twelve districts, together with the NO. 1268, VOL. 49] means for the easterly, or principal wheat-producing districts, for the westerly, or principal grazing, &c., districts, and for the whole of the British Islands generally. These summaries have been published regularly since 1868, and, although chiefly intended for sanitary and agricultural purposes, they furnish a very easy and trustworthy means of comparing the climatological statistics of different periods or districts. A glance at the rain- fall values for the year 1893 shows that they were below the average in every district except the north of Scotland, where the rainfall was as much as 13 inches above the normal amount, being higher than in any year since 1868, and chiefly owing to the areas of low barometric pressure taking a somewhat more northerly course than usual. The greatest deficiency — viz. 9 "5 inches — was in the south-west of England, while the defi- ciency for the whole of the kingdom was 59 inches, which is greater than in any year since 1866, except the Jubilee year, 1887, when the deficiency was 9*2 inches. The temperature was above the mean in all districts ; the excess over the whole kingdom was l"*4, and it was fairly equally distributed over all districts ; the excess has not been equalled since 1868, when it was 2°'o above the normal value available at that date. The first sheet of the " Geologic Atlas of the United States " has recently been issued. It is called the " Hawley Sheet," and comprises the north-west part of Massachusetts, with the Green Mountain Region. The geology is by B. K. Emerson. The scale of the map is i : 62,500, or slightly more than one inch to one mile. The complete map of the United States on this scale will be 240 feet long and 180 feet high. Contours j are drawn at twenty feet intervals, reckoned from mean sea- level. Three copies of the map are given: — (i) Topography, with streams in blue, contours in brown. The hundred-feet j contours are deeply engraved, the intermediate lines being only 1 faintly marked. This gives the appearance of hill-shading over the mountainous ground, but each contour can be traced with the aid of a pocket lens. (2) Areal geology, in which the formations are coloured over the brown, blue, and black of the topographical map. (3) Economic geology, which appears, so far as this sheet is concerned, to differ from the other geological map only in having the tints less pronounced, and in having a sign for mines and quarries. The fourth sheet is entitled " Structure Sections " : here strips of the map are reproduced, but without contours, and sections along the edge of each strip are drawn on the natural scale. Three sheets of text are given, one, introductory, setting out the purpose and plan of the Atlas, the others descriptive of the geology of the " Hawley Sheet." All the rocks consist of crystalline schists of Cambrian and Silurian age, no igneous rocks which can be recognised as such occur. Probably the Silurian "Hawley schist " is largely composed of eruptive material, but the rock is so much altered that its original character cannot be made out. The drift deposits, which in the south-eastern part greatly obscure the geology, are described, but are not shown on the map. The proposals which have lately been made for the renewal of Antarctic research have been very widely echoed, and several geographical journals have given considerable space to the matter. Dr. Neumayer, the greatest continental authority on the subject, devotes the first place in the Annalen der Hydro- graphie to a review of the facts. He translates the abstract of Dr. Murray's paper, given in Natuke for November 30, 1893, and expresses hearty approval of the scheme of an Antarctic expedition there set forth. The Scottish Geographical Magazine for February contains a further account of last year's Dundee Antarctic expedition. Authentic information as to the reported high latitude (84° N.) attained by the American whaler N'ewpori \s at last 370 NA TURE [February 15, 1894 available in the new number of the Bulletin of the American Geographical Society. A quotation from a letter written by Prof. George Davidson, of San Francisco, runs : "The captain has been in to see me, and has given me some graphic descrip- tions of his actual experience in those waters. . . . But he reached only 73°, and is dreadfully annoyed that the newspaper reporter made such an erroneous statement when he had the truth be- fore him." It is unfortunate that the news agency which cabled the invention to this country did not consider it worth while to give notice of the correction, for the record of farthest north has been altered in some books of reference, and there is now no chance for the sober truth being accorded a tithe of the pub- licity given to the sensational report. At the meeting of the Royal Geographical Society, on Mon- day evening, a paper on Johore was read by Mr. Harry Lake, who for three years has been engaged in exploring and survey- ing the interior of this little-known State. Johore occupies the southern extremity of the Malay peninsula, and the interior con- sists of low tropical jungle and swamp, diversified occasionally by undulating or mountainous country. The rainfall is excessive, but the great lake of Bera or Tasek, which was represented in former maps, turned out to be merely a vast swamp. The Blumut Mountains in the interior formed one of the most interesting features of the exploration, and the primi- tive people of the interior, the Jakuns, have been studied with some care. Under its present Sultan, Johore has made great strides in political and economic progress. The chief exports are gambier and pepper, which are cultivated by Chinese labour. The question whether "beats" due to the interference of two nearly equal sounds can originate in the brain instead of in the air outside, is discussed by Karl L. Schaefer in the Zeitschrift Jiir Psychologic iind Pliysiologie der Sinnesorgane. It is well known that two tuning-forks producing beats continue to produce them when one fork is held to the right, and the other to the left ear, in such a manner that the sound cannot reach the other ear through the air. Wundt himself, in his Philosophische Studien, declared the direct cerebral origin of beats to be possible, and connected it with the recently proved possibility of a direct stimulation of the auditory nerve-trunk. Herr Schaefer, on the other hand, does not think that such an origin of beats can be deduced from the experiment quoted. He looks upon conduction by the bones of the skull as the cause of the phenomenon observed. This is confirmed by the fact that even the faintest sounds are capable of propagation from one ear to the other by conduction through the bones. It is generally acknowledged that this is the explanation of beats pro- duced by strong notes. Whether the same applies to faint notes can only be finally decided by determining, with more delicate instruments than any hitherto used, whether beats continue to be heard after conduction through the bones has ceased. At a recent meeting of the Societe Francaise de Physique, M. Hurmuzescu showed several instruments which he has employed in his experiments on static electricity, the insulating medium being a new material to which he has given the name dielectrine. This substance consists of a mixture of paraffin and sulphur, and is preferable to either of these insulators, as it is harder and has a higher melting-point than pure paraffin, and is less hygroscopic and brittle than sulphur. By means of a special method it is possible to obtain dielectrine in homogeneous masses which are very hard, and can be easily worked either in the lathe or with a file. One of the instruments shown was an electrophorus, the handle of the metallic plate and the disc which is electrified being composed of dielectrine. "With this instrument sparks 2 cm. long were obtained even when the air was moist, while NO. 1268, VOL. 49] the charge was retained for a very long time. This new sub- stance, which experiment has shown to be very unalterable, will be of great use as an insulator, particularly in damp situations. Having carried on an elaborate series of experiments on the rotary dispersion of quartz in the infra-red part of the spectrum, M. G. Moreau is now investigating the magnetic rotary dispersion of carbon bisulphide for the same part of the spectrum. He has also measured the refractive index of carbon bisulphide for the infra-red rays, so that he may be able to compare his experi- mental values for the magnetic rotary dispersion with those obtained by the formula deduced by Maxwell's electro-magnetic theory. The magnetic field used in the experiments was pro- duced by the large coil which Verdet used in his classic re- searches in this subject, its intensity being measured by the rotation produced in carbon bisulphide for sodium light. In the infra-red observations a thermopile and delicate galvano- meter were employed. The author has succeeded in measuring the rotation for wave-lengths between 0'8 and i'4 fifx. ; the absorption of the CS2 preventing any measurements being made for greater wave-lengths. The paper in which the above results are given will be found in the Annates de Chimie et de Physique for February. The annual report of Prof. Alexander Agassiz, as director of the Museum of Comparative Zoology at Harvard College, for 1892-93 has just been received ; from it, amid many other interesting details, we learn that Prof. A. Milne-Edwards has in hand a final memoir on the Crustacea of the Blake, that Prof. Ludwig's monograph on the holothurians of the Blake will soon be published, the last plate of the nineteen being in the hands of Werner and Winter. As to Prof. Agassiz's own work we read : " For nearly thirty years since the publication of the catalogue of North American acalephs I have every summer, and irequently during the winter months, also, paid a good deal of attention to the jelly-fishes of our coast. An im- mense amount of drawings and of notes have thus been accumu- lated," and we have the hope expressed that during the coming year he may be enabled to arrange this valuable material for publication. We would join our hopes to his, and sincerely trust that the fascinations of fresh voyages of discovery may be for a time resisted, in order that the scientific world may not lose the record of so much important work, a record which Prof. Agassiz alone can give. Ttie various reports of the various assistants are interesting, and show the large resources of the museum, which, large though the building is which contains it, now urgently calls for more space. The February number of iVa/M?'^ Notes, with which is now incorporated The Field Club, contains a note by Mr. W. M. E. Flower, on a tortoise or " gopher " that he brought over from Florida, last July, in a case of palmettoes and other plants. When the cold weather set in, the gopher made a burrow, in which it has lived until now, but whether it will survive the winter remains to be seen. It will be just as well perhaps if the English climate proves to be unfavourable to the animal, for in Florida gophers do an immense amount of damage to plants and crops, and thousands of pounds have been spent in destroy- ing the pest. Prof. Byron Halsted describes in the Bulletin of the Torrey Botanical Club for December 1893, the Solandi process of sun-printing and its application to botanical technique. The process consists briefly in exposing the subject, necessarily some- what translucent, to the sunlight in a printing-frame in common use by photographers, with a sheet of sensitised paper at the back of the subject, in the same manner as a print is taken from a ^negative of the ordinary sort. The sun-print thus obtained becomes, after it has been toned, the negative from February 15, 1094 J NATURE 371 which the positive picture is printed. The negative is saturated with kerosene for the purpose of clarifying. Mr. G. Nicholson, the curator of the Royal Gardens, Kew, contributes to the February number of the tCe^v Bulletin a report on horticulture and arboriculture in the United States. It contains accounts, among others, of visits to the following gardens : — Holm Lea, near Brooklime, Mass., the residence of Prof. C. S. Sargent ; the Arnold Arboretum, of Harvard University, at Jamaica Plain, Mass. ; th2 Missouri Botanical Garden at St. Louis ; the Horticultural Exhibition at Chicago ; the Mount Hope Nurseries at Rochester, N,"S'. ; and Meehan's Nursery, Germantown, Philadelphia. The paper also contains notes on railway gardening, and on the native flora of the districts passed through. An interesting paper on the possible transmission of the tubercle bacillus by cigars, has appeared in the current number of the Centralblatt jitr Bakteriologie. Dr. Kerez, in the pre- face to his experiments, points out that ample opportunity is given for the infection of cigars with tuberculous material, as so caany of the people employed in tobacco manufactories are known to suffer from consumption. The manner in which the cigars may become infected is apparent when it is remembered that by force of habit and convenience the tobacco-workers prefer to use their saliva for getting the leaves to adhere in cigar making, instead of the materials supplied to them for this purpose. In this way the tubercle bacillus is easily conveyed to the cigar. Dr. Kerez has, therefore, imitated in every detail on a small scale the manufacture of cigars, using saliva con- taining tubercle bacilli for the moistening of the leaves. After being dried and packed away in boxes, cigars preserved for different lengths of tima were carefully unrolled, the leaves washed with water, and the infusion inoculated into guinea-pigs. In all cases where the infected cigars had only been kept for ten days, the animals treated with the tobacco infusion died of tuberculosis, but when the cigars were kept for longer periods the animals suffered no ill-effects, indicating that during this time the tubercle bacilli had either been destroyed or deprived of their virulent character. As long, therefore, remarks Dr. Kerez, as the cigars, presuming them to have been infected in the course of making, are kept for a sufficiently long time in the manufacturer's hands before distribution, this possibility of spreading consumption may be ignored. A CATALOGUE (No, vi.) of works on geology offered for sale by Messrs. Dulaif and Co. has just been issued. A CHEAP edition of "The Religion of Science," by Dr Paul Carus, has been published by the Open Court Publishing. Company, Chicago. Messrs. Horne and TnoRNTHWAixEhave published anew descriptive catalogue of astronomical telescopes and other optical instruments. A second edition has been published of the catalogue of the Camera Club Photographic Library, compiled by Messrs. L. Clark and W. Brooks. Messrs. Blackie and Son have published a guide to the examinations in elementary agriculture of the Department of Science and Art, and answers to the questions set in the subject from 18S4 to 1893. "A Short History of Astronomy," compiled by Mr. George Knight, and published by Messrs. G. Philip and Son, is a little book of twenty-seven pages, in paper covers, con- taining a sketch of the growth of astronomy suitable to begin- ners, and likely to create a desire for fuller knowledge. The first edition of Mr. Bo wen Cooke's work on "British Locomotives " being nearly exhausted, the publishers announce a NO. 1268, VOL. 49] second and revised edition as almost ready for issue. The same publishers (Whittaker and Co.) announce a work on " Survey- ing and Surveying Instruments," by Mr. G. A. T. Middleton. We announced towards the end of last year that the Bntish Nahiralist would be discontinued after the December number. General regret having been expressed at the proposed discon- tinuance of that useful magazine, the opinions of some well- known naturalists were obtained, and with the result that arrangements were eventually made for carrying on the publica- tion. The first number of the new series is before us, and its contents will be appreciated by the student of natural history and collector. Edited by Messrs. J. Smith and L Greening, and with the assistance of the late editor, Mr. J. E. Robson, and others, the magazine should have a wide circulation among naturalists in all parts of the country. Messrs. Macmillan and Co. will publish immediately a volume of "Essays in Historical Chemistry," by Prof. Thorpe, based on lectures and addresses delivered during the last twenty years. The list of subjects includes Boyle, Priestley, Scheele, Cavendish, Lavoisier, Faraday, Thomas Graham, Wohler, Dumas, Kopp, and Mendeleef. Mr. Henry' Louis has prepared, and Messrs. Macmillan and Co. are about to publish, a " Handbook of Gold-Milling," I in which the subject is treated for the first time in a form at I once scientific and practical. It is hoped that the book may be found useful not only for the technical instruction of mill-men, j but also for the guidance of managers and managing directors of : gold-mines. The work begins with an account of the physical 1 and chemical properties of gold, and also of mercury; stamp- . mill construction is considered in detail, the mechanical prin- ciples underlying the design of each part being throughout i elucidated. The theory and practice of concentration, as far as it refers to gold-milling, is next considered, together with the most approved modern method of treating the concentrates and other products of milling. Chapters are appended on the e conomic considerations involved and on the assaying of gold ores and products. The book is fully illustrated. Two new boron compounds, diphenyl boric acid ani the cor- responding chloride, have been obtained in the Rostock Labora- tory by Prof. Michaelis, and an account of them, together with several other more complex aromatic derivatives of boron, is contributed to the latest issue of the BcHchte. In the year 1879 Prof. Michaelis, in conjunction with Dr. Becker, succeeded in preparing phenyl boron chloride, C^HsBCL, the first boron compound containing a benzene radicle. This interesting sub- stance, a liquid which boils at 175°, was obtained by heating together to about 200' in a sealed tube the corresponding quantities of boron chloride, BCI3, and mercury diphenyl, Hg(C^H,5)._,. Upon bringing it in contact with water a beauti- fully crystalline and powerfully antiseptic substance, pheny boric acid CeH5B(OH)._,, was produced, which upon heating evolved water vapour, and yielded the anh>dride CgHjBO. It is now shown that diphenyl boron chloride, (CgHjliBCl, is formed when the mono-phenyl compound is heated along with a further quantity of mercury diphenyl to 300-320° in a sealed tube. The product is a mixture of diphenyl boron chloride with mercury chloro-phenyl Hg(C,;H.,)Cl, from which latter compound the former may be separated by extraction with an organic solvent. Upon distillation of the extract a liquid is eventually isolated which boils at 270°, and which proves to be pure diphenyl boron chloride. It is a thick colourless liquid which fumes slightly in moist air. Upon heating with water it is decomposed with formation of a substance endowed with an exceedingly powerful and penetrating odour. This substance rapidly collects as an oil upon the surface of the water. After 172 NA TURE [February 15, 1894 purification by solution in ether and evaporation of the latter it takes the form of a colourless viscous substance, which soon solidifies to a mass of crystals, colourless at first but subse- quently faintly yellow. The crystals melt at 264°, evolving the characteristic odour in a still more pungent form. Even the merest trace of the compound is at once rendered evident in a room by its unmistakable effect upon the olfactory nerves. A smal! quantity introduced into a non-luminous flame imparts a brilliant green colour to the latter. It appears to act as a truly acid substance, dissolving readily in alkalies ; the salts pro- duced, however, are not endowed with any great stability, for the acid can be extracted from the solutions by means of orga nic solvents. In an appendix to Prof. Victor Meyer's memoir, referred to last week (p. 349), a recent extension of the subject of stereochemistry to purely inorganic elements is alluded to. Dr. Werner, in a treatise upon the nature of the isomerism of the numerous ammoniacal compounds of cobalt, platinum, and other metals, shows that the complex relations of these substances are capable of a surprisingly simple explanation upon the assumption of different arrangements of the various atoms and groups in space. The foundations of a stereochemistry of platinum are laid by assuming the atom of the metal to occupy the centre of a regular octahedron, to the six corners of which the various groups are attached. In this manner the existence of the two isomeric series of complex com - pounds of the composition Pt(N 1^3)0X4 is accounted for, the diff"erence between them being brought about by a difference in the relative positions of the two NH3 groups. It would thus appear that the great concentration of research upon the organic com- pounds, which has been the salient feature of the chemical pro- gress of the last twenty years, has had the fortunate effect of so enlightening us as to the internal structure of chemical molecules as typified in carbon compounds, that the remaining >_complex problems of inorganic chemistry may njw be attacked with much greater likelihood of success. Notes from the Marine Biological Station, Plymouth. — During the past fjrtnight the floating fauna has assumed a considerably richer character, chiefly owing to the marked in- crease in the numbers of Decapod larvae (esp. ZolCx), and to the reappearance of Coelenterates, which have been very scarce for the past two months. Ephynz of Aurelia have appeared , and are already fairly numerous ; a few specimens of the Anthomedusa Rathkea octopuw.tata have been observed, and a Leptomedusa, apparently Phialidiiim varlabilc, has been taken in fair quantity. Some Ctenophore larvae have also been observed. Prosobranch and Opisthobranch veligers are plenti- ful, and a single specimen has been obtained of the pelagic postlarval stage oi Arenicola, discovered at Plymouth last year. Other captures on the shore and with the dredge include ^olis papulosa, Plaiydoris plaiiata, and large numbers of Myzosiomum from Antcdoii rosacea. Littorina littorea is breeding. The additions to the Zoological Society's Gardens during the past week include two Bonnet Monkeys {Macactis sinicus, 9 9) from India, presented respectively by Col. J. North, and Mrs. Hewit ; a Macaque Monkey {Macacus cynoviolgns, 9 ) from India, presented by Mr. F. Reynolds ; a Pinche Monkey {Midas adipus) from New Granada, presented by Miss Farmer ; a Banded Ichneumon (Herpestes fasciattis), two Vulturine Guinea Fowls {Ntunida vultti7-ind), four Red-bellied Waxbills {Estrelda rubriventris), two Madagascar Weaver Birds {Foiidia madagascariensis), two Alario Sparrows {Passer alario) from East Africa, presented by Mr. Besant ; a Red-eared Bulbul {Pycnonotiis jocosus), a yellow-bellied Liothrix {Liothrix luteiis), three Indian Silver-bills {A/unia tnalabarica) from India, a Chestnut-breasted Finch {Donacola castaneothorax) from NO. 1268, VOL. 49] Queensland, two Java Sparrows {Padda oryzivora) from Java, two Russ Weaver Birds {Qiielea russi), a Crimson-crowned Weaver Bird {Euplectes flammiceps) from West Africa, two Saffron Finches {Sycalis plaveohis) from Brazil, presented by Mr. C. S. Simpson ; a ChafBnch {Fringilla coelebs), a Brambling {Fringilla montifringilla), a Greenfinch {Ligurinus chloris), a Linnet {Linota cannabina), three Lesser Redpolls {Linota riiftscens) British, presented by Mr. L. V. Dance ; a Moustache Monkey {Cercopiihecus cephus, 9 )from West Africa^ a Green-winged Trumpeter {Psophia viridis) from the Amazons, deposited. • OUR ASTRONOMICAL COLUMN. A Tempered Steel Meteorite. — Among the many ob- jects collected by the Peary Expedition to Greenland in 1891 was a meteorite weighing about 267 pounds. It was found by Prof A. Heilprin, near Godhaven, Disco Island, and sent to the Academy of Natural Sciences of Philadelphia, in the Pro- ceedings of which (1893, p. 373) it is described by Mr. E. Goldsmith. When received at the Academy, the meteorite ap- peared to be solid and devoid of cracks or any signs of disinte- gration, but this condition soon changed, and the mass slowly cracked and began to fall to pieces. It is thought that this crumbling was due to oxidation resulting from the existence of a higher temperature and a greater quantity of ozone in the latitude of Philadelphia than in that of Greenland. Mr. Gold- smith has examined some of the pieces separated from the mass. The substance could easily be separated into hard, metallic and tough granules, and a powder capable of reduction to any degree ol fineness. A determination of the separated quantities gave 73 8 per cent, as the proportion of the granules, and 26'2 per cent, as that of the powder. The specific gravity of the former proved to be 6'I4, and of the latter 473. One of the pieces from the meteorite was reserved for grinding and etching, but it was found that the process involved con- siderable difficulty owing to the extreme hardness of the specimen. Indeed, the mass was so hard that it would scratch soft iron, making an impression visible to the eye and sensible to the touch. This and other tests seems to warrant Mr. Goldsmith calling the object a tempered steel meteorite. Possibly the meteorite fell into a pool of water or deposit of snow or ice, and was thus quickly cooled down from the heated condition obtained by rushmg through the atmosphere. Analyses show that there is a distinct difference between the granules and the separated dark powder. The former contains a sulphuret, probably troilite ; the latter contains no sulphuret, but, instead, a sulphate. Iron, nickel, sulphur, traces of carbon, chlorine, phosphorus, and chromium were found ; also a silicate in which lime and magnesia were recognised. Copper and cobalt were searched for, but in vain. * According to Prof. A. E. Nordenskiold and J. L. Smith, the Disco Island ter- restrial iron contains copper, cobalt, phosphorus, and compara- tively large quantities of carbon. As Mr. Goldsmith remarks, these differences are too great to be overlooked in comparing analytical work ; they indicate that the mass found by Prof. Heilprin is not of terrestrial, but of celestial, origin. Astronomy in Poetry. — Some litterateurs and ultra- sentimental poets affect to believe with Macaulay that the advance of science means the death of poetry. It was left to Lord Tennyson to show that scientific facts admit of the highest poetical expression. Another instance of the exactness of his references to astronomical matters is given in the February number of the 0/^^£?/'i'a/^;,)'. In "Maud" the beautiful lines occur — " a time of year When the face of night is fair on the dewy downs, And the shining daffodil dies, and the Charioteer And starry Gemini hang like glorious crowns Over Orion's grave low down in the west." A little further reference is made to the planet Mars, "As he glow'd like a ruddy shield on the Lion's breast." The whole passage refers to the Crimean War, which was from 1854 to 1856, and, from the first quotation, it is evident that Tennyson had in mind the months of April and May. It was interesting, therefore, to see whether Mars occupied in the fifties the posi- tion named by the poet. Upon looking up the matter it appears that the planet was in Leo in June 1S52, November 1853^ February 15, 1894] NA TURE 0/ J April and May 1854, October 1855, and not at all in 1856. In 1852 Mars passed rapidly through the constellation, but in 1S54 he was nearly a month in exactly the position— "on the Lion's breast" — described by Tennyson. From internal evidence alone, therefore, the time referred to in the poem can be fixed as the spring of 1854. Nova Aurig.e. — In a brief note to Astronoiiiische Nachrichten, No. 3209, Mr. Martin Brendel says that he has found Nova Aurigoe upon an auroral photograph taken by him at Greifswald, Norway, on January 5, 1S92. It will be remembered that Dr. Anderson announced his discovery at the end of January 1892, and that Prof. Pickering afterwards found the object upon photographs taken in December of the previous year. A GRICUL TURA L EXPERIMENT S TA TIONS. "T^HE general British public regards with suspicion the grant- •^ ing of State aid for scientific experiments. But though the reluctance to give such assistance to pure science may be partly understood, it might reasonably be expected that the shop-keeping instinct would have led to the adequate ''endow- ment of an applied science like agriculture. An article by Mr. James Long, however, in the January number of the Record of Technical and Secondary Education, shows how unfavourably England compares with other countries as regards institutions in which the scientific principles of agriculture are taught. \ye have two or three excellent agricultural colleges carried on by private enterprise, but it is a question whether they supply the requirements of the practical farming class. Compare this with what has been done abroad. " Some thirty years ago," says Mr. Long, "the Government of the United States made grants of land to each State for the purpose of establishing colleges. At the time, the proportion handed over was 30,000 acres for each senator or representative in Congress to which the State was entitled according to the census-of i860. In addition to this grant, large and frequent money grants in connection with the agricultural sides of these colleges and to the experiment stations, which have also been established, have been made. Figures, which have been furnished to me by one of the officials of the U.S. Government, show that in some instances the value of the permanent endowment of each college exceeds ;!^ioo, 000, while the interest brings in amounts reaching, in some instances, to nearly /"io,ooo per annum. To this may be added the value of the buildings which have been erected from funds supplied by the Central and State Governments, which vary from ;ri^20,ooo to ;^200,ooo, and these values are constantly increasing. The first systematic attempt to teach agricultural science in America was conducted at Yale, which, froai time to time, was followed by Michigan, New York State, Kansas, and Massachusetts. There are now some fifty State agricultural colleges, conducted upon a recognised system by men of capacity, and generally equipped in a manner which leaves little or nothing to be desired." The work of these colleges is not restricted to the instruc- tion of students in the science and practice of agriculture, for to each college a State experiment station is generally attached. In England experimental work in agriculture has been left entirely to private enterprise. x\s Mr. Long remarks, were it not (or Rothamsted our scientific work in agriculture would have been sorry indeed as compared with ihat accomplished by the people of other countries. In the United Slates there are more than fifty experiment stations maintained by grants from each State and the Central Government. One of the stations visited by Mr. Long, that of Geneva, in New York State, has an income of ^^4000 a year, from which it pays in salaries ^1650, and in wages ^1200. There are six chemists on the establishment, in addition to the director, an assistant director, a horticulturist, a pomologist, a clerk, and a staff of workmen. No wonder that a large amount of valuable work has been performed at the station during the last eight years. Canada possesses five experimental farms of considerable size. Roughly these farms cost ^15,000 a year, or ^^3000 a year each, omitting salaries. Coming to this side of the Atlantic we find that France has tiiree important agricultural colleges. l"o the chief of these, that in Grignoii, near Paris, a large farm is NO. I26S, VOL. 49] attached upon which experimental work is conducted. Italy possesses the experiment station at Lodi (Reale Stazione Sperimentale di Caseificio), where instruction is given in science and practice, and chemical investigations are conducted, the funds being provided by the Government and the Province and Commune jointly. Germany is full of agriculture experiment stations. The station at Kiel is supported by grants from the Central and Provincial Governments, and combines instruction with experimental work. In Denmark experimental work is carried on in the laboratory at Copen- hagen, in experiment grounds, and at the Lyngby agricultural school and experiment farm, which is a good example of the Danish colleges. In Sweden and Norway Mr. Long visited the agricultural schools and stations at Ultuna and Alnarp. In addition to the usual farm, the former possesses an experiment station conducted somewhat on the Canadian lines. The best class of scientific investigations seems to be carried on at the chief station near Stockholm. Mr. Long also briefly refers to the systems of agricultural instruction adopted in Switzerland, Holland, and Belgium. His report shows clearly that Great Britain is behind other nations, both as regards State provision for instruction in agriculture and the establishment of experi- ment stations. It is quite lime that the necessity for these stations was recognised by the Government. THE SPENCER-WEISMANN CONTROVERSY^ A S most readers of Nature are aware, a very interesting ■^ controversy has arisen between Mr. Herbert Spencer and Prof. ^Veismann. 1 he subject, although many minor issues appeared, is that apple of discord of modern biology, the ex- istence of an inheritance of acquired characters, and in necessary association with that, the extent of the operation of natural selection. The two approach the questions in sharply-contrasted altitudes. Mr. Spencer looks at the problems of biology in their philosophical aspect as part of the large field of abstract thought which he himself has done so much to analyse, synthesise, and codify. Prof. \Veismann, although best known by his theories, has been above all things a minute investigator of structural details. In the present controversy, Spencer maintains that the weight of evidence and argument in favour of the inheritance of acquired characters is so great that " unless there has been inheritance of acquired characters there has been no evolution." Weismann believes that there are insuperable difficulties in the way ; that there is no evidence for such an inheritance : that natural selectio.n is an all-sufficing cause. Mr. Spencer's first argument is drawn from the gradations of tactual discriininativeness in the human skin. These gradations range from the ability of the tip of the tongue to recognise dou'ble contact in the points of a pair of compasses when their points are onelwenty-fourth of an inch apart, to the ability of the middle of the back which requires the i)oints to be two and a half inches apart before double contact can be distin- guished. It is a fair statement that these gradations are so dis- tributed on the skin that those parts which are more used to the opportunity of discriminating are more capable of discrimination than parts with lesser opportunities. Spencer points out the diffi- culty or impossibility of believing that minute increases of tactile discrimination, as, for instance, distinguishing contact as double when the points are one-twenty-fourth inch apart instead of when they are one twentieth inch apart, could not determine the ex- istence of animals, and so could not have been selected. On the other hand, weie the effects of use inherited, the grada- tions are explained. Against this, as against other individual cases, Weismann points out that there are not sufficient data ; we know little or nothing of how variations occur, and what are the least variations that have value in selection. In the parti- cular case of the tongue, one must remember that the tongue is one of the most highly specialised organs of the highest exist- ' ''The Inadequacy of Natural Selection," by Herbert Spencer. I. Contemporary Zevicw,Yit\>r\i&r'j,iZ(il. II. id. March, 1893. "Prof. Wcis.Tia.in's Xhejries," by Herbert Spencer. Contemporary Revieiv, INIay, 1893. '■ A Rejoinder 10 Prof. Weismann," by Herbert Spencer. Contemporary Re7'ieiv, December, 1893. '■ Die All'iiacht der Naturziichtung. Eine Erwiderung an Herbert Spencer." Van August WeUraanii. Jena : Gusav Kischer, September, 1893. (Of this an Eoglish rendering appeared in the Contemporary Rezieiu for September and October, 1393.) 174 NA TURE [February 15 1894 ing type of mammalia, and we know nothing of the myriad changes that have taken place during its evolution. Spencer urges that Weismann has made no reply to the difficulty of the distribution of tactile discriminativeness over the skin. But even were it an established fact that the effects of use are inherited, Mr. Spencer's suggestion would bring us \ no nearer an explanation, as it cannot be supposed that increased 1 use would multiply the number of tactile end organs. If the ! origin of the end organs be left unaccounted for, and it be said that these changes in the brain that are the result of practice in discrimination are accumulated by inheritance, still the argu- j ment is not cogent. For a variation in the brain leading to the | slightest increase of discrimination in interpreting the messages : from the peripheral sense organs certainly have a value in j selection. In the matter of Panmixia, Mr. Herbert Spencer has mis- understood Weismann completely. Panmixia does not_ imply ! selection of smaller varieties, but the cessation of the elimination , of smaller or more imperfect varieties. The discussion of the | variation of cooperative parts leaves the issues open. In the case of the giraffe, Mr. Spencer thinks that the main points of j its extraordinary structure must be due to natural selection. : Nageli some time ago selected the case of the giraffe as a special instance of the inadequacy of selection. But in the giraffe, and 1 in many other cases, as in the horns of a stag, increase of an organ to be of any use must be accompanied by modifications of a multitude of cooperating parts. For such cases of co- adaptation, natural selection without the inherited results of increased use, Mr. Spencer believes inadequate. Weismann's chief reply is drawn from a study of neuter ants. In them there are many structures different from the correspond- ing structures in males and females, and of these some imply the harmonious modification of cooperating parts. Follow- ing those who have investigated ants most fully, Weismann believes that most of these modifications arose subsequently to the loss of reproductive power by workers and soldiers, and that, consequently, we have here an instance of modifica- tions involving coadaplation where there is no possibility of the inheritance of acquired characters. Against this, Spencer has set forth " certain views concerning the origin and economy of social insects, which differ from those that are current." Ac- cording to these views reproductive power was lost by neuters subsequently to the appearance in them of the new characters, and consequently upon his theory the inheritance of acquired characters is not excluded. Thus, on his view the issues are still open. When Mr. Spencer brought forward a set of instances sup- porting the popular belief that offspring to a second sire occa- sionally show traces of the first sire, he was apparently unaware that Weismann had already discussed a number of such cases, grouping them under the name " telegony."' In the famous case of Lord Morton's mare it appears that the only resemblance to the first sire was zebra-like stripes, and it has been known for very long that such stripes not infrequently appear. Settegast and Nathusius, two very great authorities on questions relating to the breeding of animals, deny that there is proof of the existence of telegony, and for the present at least it cannot be said that it forms an argument against Weismann's theories. Moreover, the sug- gestion made by Prof. Romanes, and accepted by Weismann, provides an intelligible explanation of the hypothetical facts. To anyone who has seen under the microscope the intricate method in which nuclear matter prepares for division, Spencer's suggestion that it passes from cell to cell, leaving the embryo and reaching the tissues of the mother, must seem absurd, and his comparison of the wanderings of microbes will not render his supposition more intelligible. The discussions of the "immortality" of the Protozoa, and of the exact meaning of division of labour, are largely academic, and do not admit readily of being summarised. But it is clear that unless generatio ccquivota be admitted, many existing Pro- tozoa have been reproducing by simple division since at least tertiary times, and that is a length of life certainly amounting to the concept of "immortality" as used by Weismann. And if there be a material basis of heredity at all (a view which is by no means peculiar to Weismann), the material basis whether it be called germ-plasm or not, and whether it be modified in each ontogeny or not, stretches from animal to animal since the beginning of things, and has a dower of life immensely greater than the dower of life of somatic protoplasm. P. Chalmers Mitchell, ANCIENT EGYPTIAN PIGMENTS} 'T'HE red pigment used by the Egyptians from the earliest times -*■ is a native oxide of iron, a haematite. Most of the large pieces found by Mr. Petrie are an oolitic basmatite. One spe- cimen, on analysis, gave 7911 per cent, and another 81 '34 per cent, of ferric oxide. The pieces to be used as pigments were no doubt carefully selected, and the samples that I have examined, mostly from Gurob and Kahun, are very good in colour. All the large pieces were of a singular shape, having one side smooth and curved ; and in all cases this side was strongly grooved with striae, giving somewhat the appearance to the mass of its having been melted, and allowed to cool in a circular vessel. No doubt the explanation of this smooth-curved surface is, that these pieces had actually been in part used to furnish pigments, and having been rubbed with a little water in a large circular vessel, had been ground to this shape. By experiment it was found that these pieces of the native haematite yielded, without any further addition by way of medium, a paint which could readily be applied with a brush, as it possesses remarkable ad- hesive properties, and it resembles exactly, in every particular, the red used in the different kinds of Egyptian paintings. In addition to these samples of the pigments, all of which are native minerals and in their natural conditions, there are other reds, finer in colour and smoother in texture, evidently a supe- rior pigment ; these apparently have been made from carefully selected pieces of haematite, which have been ground and washed, and dried by exposure to the air. Some of these pieces are very fine in colour, and it would be difficult to match them with any native oxide of iron that is used as a pigment at the present day. There is every reason to believe that this is the earliest red pigment which was used, and it remains to this day the commonest and most important one ; it is a body un- attacked by acids, unchangeable by heat, and even moisture and sunlight are unable to alter its colour. At the present time many artificial products are used to take the place of this natural pigment. Ycllotv Fig7nents. — These, again, are natural products, and by far the most common yellow used by the Egyptians is a native ochre. These ochres consist of about one-quarter of their weight of oxide of iron, from 7 to 10 per cent, of water, and the rest of their substance is clay. When moist they have a greasy feel, and work smoothly and well with the brush. There is no evidence of these bodies having changed colour, but undoubt- edly they are chemically not nearly so stable as the red form of oxide of iron. Many of the pieces of this pigment, found at Gurob and at Tel-el-Armarna, are very fine in colour. Some of the specimens of the very earliest colours of which the exact history is known, appear to be an artificial mixture of these two colours, the red and yellow, thus producing an orange colour. These samples were found on a tomb at Medum, which, according to Prof. Flinders Petrie, was built by Nefer- mat, a high official and remarkable man at the Court of Senefru. Senefru is known to have lived in the fourth dynasty, about 4000 B.C. and to have preceded Khufu, the Cheops of the Greeks, who was the great Pyramid builder. Now, on Nefer- mat's tomb the characters and figures are incised and filled in with coloured pastes, which I have been able to examine, and it is of interest to know that this use of colour was a special device of Nefermat, for on his tomb is stated that : " He made this to his gods in his unspoilable writing." In this unspoil- able writing the figures are all carefully undercut, so that the coloured pastes, so long as they held together, should not be able to drop out. All the pastes used are dull in colour, consisting entirely of natural minerals. Haematite, ochre, malachite, car- bon, and plaster of Paris appear to be the materials used. Chessylite, as a blue, probably was known even at that date, but the artificial blues seem hardly at this period to have come into use ; certainly they are not found in the specimens of the Nefermat colours which I have examined. Another yellow pigment, far brighter in colour, was also often used. It is a sulphide of arsenic, orpiment ; it is a bright and powerful yellow, again a body found in nature, but a much rarer body than ochre, and consequently, probably was only used for special purposes, when a brilliant yellow was required. As far as it is known at present, this pigment did not come into use until the eighteenth dynasty. Gold might even be placed among the yellow pigments, for it was largely used, and with wonder- 1 A lecture delivered at the Royal Institution of Great Britain, on March 17, 1893, by Dr. William J. Russell, F.R.S NO. 1268, VOL. 49] February 15, 1894] NATURE J/ D fully good effect. Its great tenacity seems to have been fully recognised, for gold is found in very thin sheets, and laid on a yellow ground, exactly as is done at the present day. These pigments are then simply natural minerals, no doubt carefully selected, and sometimes ground and washed previous to being used ; but the blue colour which is so largely used by the Egyptians is an artificial pigment, and consequently has far more interest attached to it than those already mentioned. It is a body requiring considerable care and experience to make, and thus its manufacture enables us to some extent to judge of the knowledge and ability which its producers had of carrying on a chemical manufacture. No doubt the splendid blue of the mineral chessylite was first used, but certainly in the twelfth dynasty — that is, about 2500 B.C. — these artificial blues were used. They are all an imperfect glass, a frit, made by heating together silica, lime, alkali, and copper ore.^ The number of failures which may have occurred, and how much material may have been spoilt, cannot be known, but all the blue frit which I have examined — and it is a considerable amount, some being raw material, lumps as they came from the furnace, and the rest ground pigment — all has been, though differing in grain and quality, well and perfectly made. Now this implies that the materials have been carefully selected, prepared, and mixed, and that definite quantities of each were taken, this necessitating the carefully measuring or weighing of each constituent. An early application of the fundamental law of chemistry, combination in definite proportion. The amount of copper ore added determined the colour ; with 2 to 5 per cent, they obtained a light and delicate blue ; with 25 to 30 per cent, a dark and rather purple blue ; with still more the pro- duct would be black ; if the alkali was too little in amount, a non-coherent .^^and resulted ; if too much, a hard, stony mass is formed, quite unsuitable for a pigment. The difiiculties, however, did not by any means end with the mixture of the materials. For the next process, the heating, is a delicate operation. Unfortunately up to the present time the exact form of furnace in which this operation was carried on is not known. The furnaces were probably, especially after use, very fragile structures, and have passed away. Considerable experience in imitating these frits even when using modern furnaces has taught me that the operation is really a very delicate one ; the heat has to be carefully regulated and continued for a consider- able length of time, a time varying with the nature of the frit being prepared ; and, further, in the rough furnaces used it must have been specially difficult to have prevented unburnt gases from coming in contact with the material ; but if they did, a blackening of the frit must have taken place. However, ! all these difficulties were avoided, and a frit was made which exactly answered all the necessary requirements. It had, for instance, the right degree of cohesion, for many of the large pieces which have been found have, like the haematite, a smooth, curved striated surface, and on rubbing in a curved vessel with water, easily grind to powder. The powder is naturally much less adhesive than the hsematite powder, but on adding a little medium, it could at once be used, without other preparation, as a paint. Some of the pieces vary in ' colour in different parts. This may have arisen from imperfect mixing, or from some parts of the furnace being hotter than ! others. It hardly appears to be intentional, possibly some of the dark, purplish-coloured frits were produced by accident ; large pieces of it have as yet, I believe, not been found. By [ means of coaiparatively small alterations these frits could be obtained of a green colour. One way was by introducing iron. If, for instance, the silica used was a reddish coloured sand, it gave a greenish tinge to the frit ; and frit made with some of the ordinary yellowish desert sand was found to give a frit undistinguishable from the most common of the old Egyptian ; frits. Again, a rather strong green colour is obtained by stop- I ping the heating process at an early stage, this green frit simply on heating lor a longer time becoming blue. Another way in which even the strong-coloured blue frits have been converted into apparently green pigments is by their being coated over with a transparent but yellowish coloured varnish which has to 1 A sample of the pale-blue frit gave, on analysis, the following results : — .SiHca Soda Copper oxide Lime Iron oxide, alumina, &c. NO. 1268, VOL. 49] 8865 o-8i 2'og 7-88 o'57 a remarkable extent retained its transparency, but no doubt become with age more yellow, and although strongly green now, may very likely originally have been nearly colourless, and consequently the frit was then seen in its original blue colour. Even as early as the twelfth dynasty the green frits used were dull in colour, and if by chance a brighter green was required, then they used the mineral malachite. No doubt by far the most brilliant blue used at any time was selected and powdered chessylite, and even down to the twenty-first dynasty they seem to have made use generally of somewhat brilliant coloured frits ; but after that time more subdued colours appear to have been used, and even the scarabs were made of a much duller colour than formerly. All these blue frits form a perfectly unfadeable and unchangeable pigment. Neither the sun nor acids are able to destroy or alter their colour. The only other pigment to which I can refer this evening is the pink colour, which, in different shades, was much used. This is again an artificial pigment, and belongs to an entirely different class from any of the foregoing ones, for it is one of vegetable origin. On simply heating it, fumes are given off and the colour is destroyed, but a large white residue remains ; this is sulphate of lime. It may here be stated that the white pigments used sometimes were carbonate of lime, but more generally sulphate of lime in form of gypsum, alabaster, &c. This substance is often very white in colour, is very slightly soluble in water, and has a singular smoothness of texture, which makes it work well under the brush ; and in addition to I these qualities, it is a neutral and very stable compound, so is well fitted for the purpose to which it was applied. It was easily obtained, being found native in many parts of Egypt. It is also interesting to note that there is an efflorescence consist- ing of this substance which frequently occurs in Egypt, and is of a remarkably pure white colour ; probably this was used as a superior white pigment. It was easy to prove then that the pink colour was gypsum stained with organic colouring matter, and to try and imitate the colour appeared to be the most likely way of identifying it. Naturally, madder, which it is known has from the earliest times been used as a dye, was the vegetable colour- ing substance first tried, and it answered perfectly, giving under very simple treatment the exact shade of colour to the sulphate of lime which the Egyptian pigment had. Essentially the same colouring matter may have been obtained from another source, viz. Munjeet. In the case of madder it is interesting to note that the colour is not manifest in the plant — the Rubia tinctoriim — for it is obtained from the root, and is even not ready formed there. In the root it exists as a glucoside, and this has to be decomposed before the colour becomes manifest. In this root there exist several colouring matters, which are known as madder-red, madder-purple, madder-orange and madder yellow. On breaking up the roots and steeping them in water for some length of time, the colours come out, some sooner than others, so that the tints vary. Again, changes ofcolour are easily obtained by the addition of very small quantities of iron, lime, alumina, &c., so that in these different ways a considerable range of colours could be obtained, but a delicate pink colour was the one probably generally made. This colour is easily obtained by simply stirring up sulphate of lime in a tolerably strong solution of madder, and adding a little lime, taking care to keep the colouring matter in excess ; the colouring matter adheres firmly to the lime salt, and this settles on to the bottom of the vessel; the liquid is then poured off and the solid matter, if necessary, dried, or mixed — probably with a little gum, and used at once without other preparation. That the colouring matter was really madder could also be tested by another method, viz. by means of spectrum analysis. Both the madder-red (alazarin) and the madder-purple (purpurin) give, when the light which they transmit is analysed by the prism, very characteristic absorption bands ; the purpurin bands are the ones most easily seen, consequently it became a point of considerable interest to ascertain whether from a specimen of this pigment, some thousands of years old, these absorption bands could be obtained. A small sample of this pink pigment was taken from a cartonage which was exhibited, and by treating it with a solution of alum, the colour was thus transferred to the liquid, and by throwing the absorption spectrum which it gave on the screen, and comparing it with the spectrum from a madder solution, it was clearly seen to be identical. Many specimens in imitation of different coloured frits, and a large copy of a cartonage coloured with pigments prepared by the lecturer, were exhibited. 376 NA TURE [February 15, 1894 UNIVERSITY AND EDUCATIONAL INTELLIGENCE. Oxford. — At a meeting of the Ashmolean Society, held on Monday last, Mr. V. H. Veley read a most interesting paper, entitled "A Criticism of the Electrolytic Theory of Chemical Change," which excited a warm discussion. At the same meeting Mr. J. E. Marsh read a paper on "Some New Derivatives of Camphene," which embodied some of the re- sults of recent investigations made by him and Mr. J. A. Gar iner. At a meeting of the Junior Scientific Club on Wednesday, 7th inst., Mr. H. Balfour exhibited primitive tobacco pipes and vessels of skin and sinew from India and South Africa. Papers were read on " Hertz's Researches on Electromagnetic i Radiation" by Mr. E. F. Morris, of Balliol, and on "The | Distribution of Extra-marine Mollusca," by Mr. E. W. W. t Bowell. of Wadham. In the list of newly-elected members of the Board of the | Faculty of Natural Science given last week, the name of Mr. | W. Esson was inadvertently given instead of that of Mr, H. T. [ Gerrans. As a result of the memorial presented by the Demonstrators to the Hebdomadal Council last year, the following statute has been passed by Council, and will be promulgated in Convoca- tion on March 20. If all that the Demonstrators demanded has not been conceded, the new statute has at least the merit of recognising their position and given them a definite university status "Whereas it is expedient to make regulations respecting (i) the appointment of Demonstrators and other Assistants in certain laboratories, and (2) their tenure of office, the Univer:ity enacts as follows : — After Statt. Tit. iv. Sect, i, § 3 (page 32, ed. 1893) the follow- ing subsection shall be added : — § 4. Concerning Demonstrators and other Assistants in laboratories. 1. Every Demonstrator or other Assistant appointed by any of the Professors enumerated in the Schedule annexed to this Statute shall receive at the time of his appointment a written statement of the emolument and duration of his office. 2. In all cases in which a Demonstrator or other Assistant is so appointed for a longer period than two terms, Easter and Trinity terms being for this purpose computed as one term, the name of the person appointed and the terms of the appointment shall be submitted for approval to the Vice-Chancellor, who, if he gives his approval, shall notify the appointment in Con- vocation, and cause it to be published in the usual manner. 3. Any Demonstrator or other Assistant who has been dis- missed from office by the Professor shall have the right of appealing against the dismissal to the Vice-Chancellor. Schedule. The Savilian Professor of Astronomy. The Professor of Experimental Philosophy. The Waynflete Professor of Chemistry. The Professor of Geology. The Linacre Professor of Comparative Anatomy. The Waynflele Professor of Physiology. The Sherardian Professor of Botany." Cambridge. — Mr. T. H. Riches has been appointed to the occupation of the University's table at the Naples Zoological Station for the next five months. The General Board of Studies recommend that Dr. Ruhe- mann's Lectureship in Organic Chemistry should be con- tinued for five years from Michaelmas next. Dr. Ruhe- mann's teaching appears to have been very popular ; during last term he had 123 students under instruction. His work, though it is under University auspices, is conducted for the present in the laboratory of Gonville and Caius College. The Agricultural Examinations Syndicate have issued, through their Secretary, Mr. Francis Darwin, Deputy -professor of Botany, a scheme of the Examination in Agriculture to be held next sum- mer. The examination will extend from July 2 to July 8, and will include papers and practical work in Chemistry, Botany, Physiology, Entomology, Geology, Engineering, and Book- keeping (constituting Part I.), and Practical Agriculture and Surveying (constituting Part 11.). The fee for admission will be one guinea for Part I., and two guineas for Part II. The names of candidates are to be sent to the Registrary by NO. 1-268. VOL. 4q] June 13, 1894. Schedules of the subjects over which the exam- ination will extend are published in the University Reporter for February 13. Candidates who pass both parts will receive a diploma testifying to their competent knowledge of the science and practice of agriculture. SCIENTIFIC SERIALS. Wiedemann s Annalen dcr Physik nnd Chemie, No. I. — Radiation of gases, by F. Paschen. The experiments were conducted upon gaseous carbonic acid and steam. By using mirrors instead of lenses, and a prism of fluor spar, purer spectra and more decif^ed maxima were obtained than those found by Angstriim. The absorption spectra of CO2 at ordinary tem- peratures, and of steam at 100°, correspond in general to the emission spectra at higher temperatures, except that at higher temperatures the maxima are displaced towards the less re- frangible end. This displacement was found, however, to be reversed for at least one of the steam maxima. The principal maximum of C0.> was at A 4630. The other, at 2710, nearly coincided with that of steam, at 2660. The other maxima due to steam were found at 8060 and 7160. All these maxima were very decided. A layer of CO., 7 cm. thick showed almost com- plete absorption at the darkest bands. These bands did not, as sometimes supposed, broaden with increasing thicknesses of layers. A layer of air S3 cm. thick showed them clearly. One principal band due to steam was found represented in the absorp- tion spectrum of water, but those of water were as a rule displaced towards the red end. No absorption by oxygen and nitrogen could be discovered under similar conditions. — On the artificial colouring of crystals and amorphous bodies, by O. Lehmann, The recently discovered phenomenon of " liquid crystals," i.e. dissolved crystals retaining their doubly-refracting properties in the state of solution, has confirmed the author's belief that the properties of crystals depend more upon those of their molecules than upon the aggregation of the latter. Hence it is probable that substances which are not isomorphous may, after all, be capable of crystallising together. This has been actually ob- served in the case of sal-ammoniac and copper chloride, and subsequently in a large number of substances, such as meconic, hippuric, and succinic acids when brought into contact with bodies like Hofmann's violet, phenyl blue, or methyl orange. — On galvanic deposits arranged in streaks, by U. Behn. The streaky deposit found in silver voltameetrs and similar apparatus owes its arrangement to currents within the liquid due to varia- tions of density during electrolysis, as was proved by varying the position of the voltameter. In the case of silver nitrate, the streaks are most highly developed when the solution is dense and the current feeble. The amount of E.M.F. is without in- fluence.— The polarisation of solid deposits between electro- lytes, by P. Springmann. The counter E.M.F. generated by a current, flowing through two electrolytes was determined, in cases where the two liquids gave a solid deposit upon the mem- brane (parchment or gypsum) separating them. With a current of 21 '4 milliampt-res, solutions of lead nitrate and copper .sul- phate gave a polarisation of i '964 volts after five, and 2*02 volts after ten minutes. Bulletin de i Acad/ime Royale de Belgique, No. 12. — Essay on the variations of latitude, by F. Folic This is an attempt to explain the observed variations of latitude by a superposition of initial nutation and an annual displacement of the earth's pole of inertia due to inequalities in the distribution of snow in the various north circumpolar regions. Supposing that the snow falling in America between the meridians of 235° and 285° E. of Gr. is counterbalanced by that falling in Europe and Siberia from 55° to 105^ the chief unbalanced tracts would be those between 105° and 135" in Siberia, and 15° and 55° in Europe^^ These masses would have their centres ot gravity at about 120° and 35' respectively, giving a resultant centre ot gravity at 77°. Assuming that the thickness of snow accumulated from autumn till midwinter is equivalent to 0-3 m. of water, and that the solid crust extends down to the extent of one-tenth of the earth's radius, a rough calculation gives o'o6" as the angle by which the pole of inertia would be displaced towards North America during the period considered, afterwards returning by the same amount between midwinter and midsummer. The combination of this annual period with that of initial nutation, of 427 days, would give an apparent period of 396 days, agreeing closely with that of 398 days found by Chandler. — February 15. 1894] NA rURE 377 Remarkable meteors in the night from November 6 to 7, 1893, by the same author. Several striking meteors were observed in various quarters during that night, in the constellations of Pegasus, Ursa Major, and Ursa Minor. The report of the explosion of the last was plainly audible. — On some new pro- cesses for the detection of vegetable and mineral oils, by \V. de la Roycre. An alkaline solution of rosaniline may be used for determining minute quantities of fatty oils mixed with mineral oils. Hall a gramme of fuchsine is dissolved in half a litre of boiled distilled water. A 30 per cent, solution of caustic soda is added drop by drop uniil complete discolouraiion is just obtained. The mixture is then made up to one lure with dis- tilled water, and kept in a well-stoppered bottle. A few drops of this are added to a small quantity of the oil in a porcelain dish, and stirred. The animal and vegetable oils quickly assume a pink colour, and mixtures of these with mineral oils are coloured red with an intensity proportional to the quantity of animal or vegetable oil present. Other coal-tar products, such as picric acid, purpurine, rosolic acid and eosine, show a similar behaviour. Inieniationales Archiv fiir Ethnographic, B 1. vi., Heft vi. — This is the last number of the first series of this valuable journal, which has been so excellently published by Heer Trap. The first article, by Schmeltz, on a Dyak and two Japanese swords, is lavishly illustrated by three coloured plates. Baron van Hoevell describes and figures the flattening of the skull and chest in Buool (north coast of Celebes). The chest flattening- board is always employed on the boys, but not always the head- board ; both are always inflicted on the girls, the object being solely for beauty, and to improve the marriage value of the latter. It is not for the purpose of making them clever and active, foi the people themselves say " Reason is the gift of God." Schmeltz adds an appendix, in which he gives the geographical distribution of the custom of skull deformation. SOCIETIES AND ACADEMIES. London. Royal Society, February l.^-" An Instrument for Grinding Section-plates and Prisms of Crystal- of Ariificial Preparations accurately in the desired directions." By A. E. Tutton. By means of this instrument a truly plane surface may be ground and polished in any desired direction in a crystal ac- curately to within ten minutes of arc, in a fraction of the time required for the hand grinding of an approximately true surface, and without danger of fracturing the crystal. It consists essentially of four parts, (i) A rotating horizontal divided circle, within the vertical axis of which two other axes are capable of vertical motion ; the innermost carries at its lower extremity the crystal and its means of adjustment, and the other is connected with a counterpoising apparatus by which the pressure with which the crystal bears upon the grinding disc can he modified according to its relative softness and friability. (2) A series of graduated circular adjusting movements by which the desired direction (plane) in the cr\ stal can be brought exactly parallel to the grinding .-urface. (3) A horizontal collimaior and telescope for goniometrically ob-rrving the crystal. (4) A rotating table carrying a detachable grinding disc of ground glass, and underneath it a p )lishing disc of much more finely ground glass. A special crystal holder is also provided, which enables a second surface to he ground truly parallel to the first. Prisms may be ground with the same facility as section- plates. " An Instrument of Precision for producing Monochromatic Light of any desired Wave-length, and its Use in the Investi- gation of the Optical Properties of Crystals." By A. E. Tutton. This instrument enables the whole field of an optical instru- ment to be evenly and brightly illuminated with spectrum monochromatic light of any desired wav, length. It has been devised especially for use in coiinecnon with the axial angle polariscopical goniometers, spectrometers, stauroscopes, micro- scopes, and other instruments employed in the investigation of the optical properties of crystals, but is capable of much more extensive application. It was suggesied by the apparatus de- scribed by Abney {/"/z//. Mag. 18S5, vol. XX. p. 172), but differs from that arrangement in most of its deads, and particularly in the employment of a fixed instead of a movable exit slit ; of a rotatory instead of a fixed dispersing a(>paratus, which is capable of accurate graduation for the passage of rays of definite wave- lengths through the exit slit ; and in the manner of utilising the NO. 1268, VOL. 49] issuing line of monochroma'ic light, which, insteai of being directed upon an opaque whiie screen, is diffused so as to be evenly distributed over the field of an observing instrument when thit instrument is placed directly in its path. The instrument resembles a compact spectroscope in appear- ance. The two optical tubes are exactly similar. Each carries a slit, the jikvs of which are made to move equally on each side of the line of contact, and a lens combination of two inches aperture, in order to pass a large am )unt of light. A single prism of heavy flint glass is employeil, of large size and of the highest dispersion compatible with freedom from colour ; it is carried upon a rotating divided circle. Either optical tube may be used as collimator. The other may be converted inio a telescope for the purpose of graduating the instrument by attach- ing an eyepiece in front of the slit ; the knife edges of the latter, which are clearly focussed by the eyepiece, serve as parallel cross wires between which solar or metallic lines may be adjusted by rotation of tlie prism. The readings of the circle for such positions are recorded in a ta ile supplemented by a curve. Upon removal of the eyepiece and illumination of the receiving slit by any sufficiently powerful source of light, monochromatic lijht of any desired wave-'e igth may at once be produced by setting the circle to the reading recorded for that wave-length. The issuing line of coloured light is widened just sufficiently to fill the whole field of the observing instrument by attaching a screen of very finely ground glass, carried in a short tube sliding along a bar, about one inch in front of the exit slit. Upon bringing the optic axial angle goniome er, carrying an adjusted section plate, close up so that the end of the polarising tube almost touches the ground glass, the interference figure is ob- served sharply defined upon a homogeneously coloured and illuminated background. The arrangement is particularly valuable for the study of cases of crossed axial plane dispersion. It is equally adapted for use in the determination of indices of refraction by the methods of refraction or total-reflection, and also in the determination of extinction angles by means of ihe stauro-cope. Chemical Society, January 18. — Dr. Armstrong, President, in the chair. — The following papers were read : — The molecular formula; of some liquids as determined by their molecular sur- face energy, by Miss E. Aston and W. Ramsay. The molecular weights of phenol and bromine in the liquid state are somewhat greater than in the gaseous state ; liquid nitric acid has ap- proximately the molecular formula HoN^Og. The molecule of liquid sulphuric acid below 132' has the composition 32H.SO4 ; liquid phosphorus has the normal molecular composition P4. Chloropicrin has the composition CO^i^^-iii- — Contributions to our knowledge of the aconite alkaloids. VIII. On picra- conitine, by VV. R. Dunstan and E. F. Harrison. The " picraconitine," obtained by Groves from the roots of Aconi- tum Napellits is merely impure isaconitine. — Contributions to our knoaledi^e of the aconite alkaloids. IX. The action of heat on aconitine, by W. R. Dunstan and F. H. Carr. On heating aconitine it bieaks up into ace:ic acid and pyraconitine, C3iH4iN'0,„ ; the latter ba-e on hydrolysis yields benzoic acid and pyraconi ine CajHsyNOg. — Contributions to our knowledge of the aconite alkaloids. X. Further observations on the con- version of aconitine into isaconitine, by W. R. Dunstan and F. H. Carr. — Interaction of benzylamine and ethylic chlor- acetate, by A. T. Mason and G. R. Winder. The first product of the action of benzylamine on ethylic chloracetate is benzy- lauiidoaceiic acid ; the latter readily condenses, yielding dibcnzyl-a-7 diacipiperazine. — Condensation products from be zylamine and several benzenoid aldehydes, by A. T. Mason and G. R. Winder. — Constitution of rubiadin, by E. Schunck and L. Marchlewski. The authors assign the following con- stitution formula to rubiadin : — O OH OH O Me — The monalkyl ethers of alizarin, by E. Schunck and L. Marchlewski. — Ruberythric acid, by E. Schunck and L. March- lewski. —The colouring matter of the Indian dye-stuff "Tesu," by J. J. Hummel and W. Cavallo. The dye-stuff" " Tesu ' consists of the dried flowers of Biitea frondosa ; the latter con- tain a glucoside which on hydrolysis yields a compound of the formula CigHj405. NA TURE [February 15, 1894 Linnean Society, February i. — Prof. Stewart, President, in the chair.— The President exhibited a remarkable specimen of a Soulh African butterfly, Teracolus halyattes, from Natal, in which the wings on one side were those of a male, and on the oiher tho?e of a female, and made some remarks on hermaph- roditism in the Lepidoptera. — On behalf of Mr. William Borrer, of Cowfold, Sussex, there was exhibited a skull of the pine maiten, Martes svlvatica, Nilsson, from a specimen killed near Crawley {Zool, 1891, p. 458), an examination of which conf-rmed the view of the late E. R. Alston (P.Z.S. 1879, p. 469), that so far as could be ascertained this is the only species of marten found in the British Islands. — On behalf of Mr. W. B. Tegetmeier, there was exhibited a drawing of a snow leopard taken for the first time from life, namely, from the animal now living ;n the Zoological Society's Gardens, Regent's Park. The long, thick, and soft fur, suggestive of a cold habitat, and the unusual size of the wide spreading feet, well suited for travel- ling overan expanse of yielding snow, were noteworthy features. — Mr. Malcolm Laurie read a paper on the morphology of the Pedipalpi. He considered the first two ventral sclerites of the abdomen to be appendages, and not sternites. The first of these — the genital operculum — covers the ventral surface of two segments, the genital aperture and the first pair of lung books lying beneath it. The first pair of lung books, he thought, probably represent the remains of the appendage of the second segment. The arrangement of this region resembles that in EurypteridiT and in the spiders {e.g. Liphislius), while differing markedly from that in scorpions. The posterior end of the intes- tine is diluted into a large stercoral pouch which is part of the mid-gut, the malpighian tubes arising from its posterior end. The cephalothoracic portion of the mid-gut differs in structure from the abdominal portion, and in addition to lateral diverticula has two median ventral diverticula. The conal gland opens at the base of the third pair of appendages, and a sensory organ of unknown function occurs on each side of the last segment. A discussion followed, in which Mr. R. I. Pocock, Mr. H. M. Bernard, and the President took part, and Mr. Laurie replied. — A paper was then communicated, by Mr. W. West, on the fresh water algas of the West Indies, in which several new species were described and illustrated. Mr. G. Murray, in commenting on this paper, testified to the extreme care and accuracy with which the species had been worked out. Zoological Society, February 6. — Sir W. H. Flower, K.C.B., F.R.S., President, in the chair. — The secretary read a report on the additions that had been made to the Society's menagerie during the month of January, 1894. — Mr. Sclater exhibited a fine mounted specimen of the Riverhog of Mada- gascar from the Tring Museum, lent for exhibition by the Hon. W. Rothschild, and pointed out that three distinct species of this well-marked genus of Snider were now known to occur in the Ethiopian region. A communication from Mr. Last gave an account of the habits of this animal, as observed in Madagascar. — Mr. Sclater also exhibited a stuffed specimen of the Whitebilled Great Northern Diver {Colynibns adamsi) from Norway, which had been lent to him by Prof. R. CoUett, and made remarks on the distribution of the species, and on its interest as occasionally occurring on the British coast. — Prof. Howes read a paper on synostosis and curvature of the spine in fishes, with especial reference to the Common Sole. — Mr. F. E. Beddard, F. R. S., gave an account of the development of the Tadpole of an African Frog {Xenopus IcEvis), as observed in specimens of this Batrachian hatched and reared in the Society's Gardens. — Mr. Chas. W. Andrews gave an account of some remains of the extinct gigantic bird {/^pyornis) which had been recently received at the British Museum from several localities in Madagascar. These were referred to three species — /E. muelleri, AL. meditts, and AL. titan, the last being of larger size than even A^,. 7naximus. Another set of remains showed differences which might eventually prove to be of generic im- portance, and were perhaps referable to the newly established genus Muellerot7iis. — Mr. M. Barkley read some notes on the Antelopes of the Pungue Valley, East Africa, as observed by him during a recent hunting expedition in that district. — The Marquis of Hamilton made some observations on the Antelopes met with by him during a recent excursion from the Pungue along the coast northwards towards the Zambesi.-^ Mr. O. Thomas read the description of a new species of Bat of the genus Stenoderma from Montserrat, West Indies, proposed to be called S. montserralense. This Bat was stated to be very injurious to the cacao plantations in that island. NO. 1268, VOL. 49I Entomological Society, February 7. — Mr. Henry John Elwes, President, in the chair. — The Pre>ident announ ced that he had nominated the Right Hon. Lord Walsingham, F. R.S., Prof. Edward B. Poulton, F.R.S., and Colonel Charles Swinhoe, vice-presidents of the society for the session 1894-95. — Mr. Jenner Weir exhibited, on behalf of IMr. J. M. Adye, a specimen of Phisia tnoneta, Fabr., which had been captured at Christchurch, Hants, and remarked that this species, which had been found in this country for the first time so recently as June, 1890, was apparently becoming a permanent resident here, as it had been since taken in several of the southern counties. He also remarked that Aconitum napellus, on which the larva fed, though rare in England as a wild plant, was very common in gardens. Mr. Jenner Weir also exhibited a nearly black speci- men of Venilia maadaria, L. , the yellow markings being re- duced to a few small dots. — Mr. Hamilton Druce exhibited a female specimen of Hypochrysops scintillans, lately received by him from Mioko, New Ireland. He said that only the male of this species had been as yet described. — Mr. F. Enock exhibited, and made remarks on, a nest of the British Trap-door Spider, Atypus picetis, recently found near Hastings by Mrs. Enock. — Mr. W. F. H. Blandford stated that he had recently obtained an additional species of Scolyto-platyptis from Japan, which, though closely allied to the species he had formerly described, showed a very distinct modification of the male prosternum. — Mr. M. Jacoby exhibited and remarked on a specimen of Leptispa pygmaa, Baly, which was doing much injury to sugar- cane in the Bombay Presidency. Mr. G. C. Champion stated that he had found an allied species on bamboo. — Dr. F. A. Dixey read a paper (which was illustrated by the oxyhydrogen lantern) entitled " On the Phylogeny of the Pierince as illus- trated by their wing-markings and geographical distribution." A long discussion ensued, in which the President, Mr. Osbert Salvin, F. R.S., Mr. Jacoby, Colonel Swinhoe, Mr. Jenner Weir, Mr. Hampson, and Mr. Kenrick took part.— Dr. T. A. Chapman read a paper entitled " Some notes on those species of Micro-Lepidoptera whose larvje are external feeders, and chiefly on the early stages of Eriocephaia calthella." Mr. Hampson and the President made some remarks on the subject of the paper. — Mr. Hamilton H. Druce read a paper entitled "Description of the km2i\Q oi Hypochrysops scintillans, Butl." — ■ The Rev. Dr. Walker communicated a paper by Mr. R. H. F. Rippon, entitled "Description of a variety of Ornithoptera (^Priamoptera) urvilliana. " Cambridge. Philosophical Society, January 29 — Prof. T. McKenny Hughes, President, in the chair. The following communica- tions were made : — Electricity of drops, by Prof. J. J. Thomson. The experiments and observations of Lenard were first referred to. No electrification is detected in a free falling drop, but if drops after falling be arrested by coming in collision with a plate or wire, the droplets generated in the splash are found to be electrified. Prof. Thomson, has studied the condi- tions more closely. The electrification on a free falling drop is masked by the opposite electrification of the air surrounding it, till by some sudden blow the drop is broken up. Special observations show that the blow does not generate the electricity, but merely separates already existing opposite electrifications. The effects produced by various liquids have been studied, and it appears that there is an obvious connection between the nature (reducing or oxidizing) of the liquid used and the kind or amount of electrification detected. A very small amount of impurity in water is enough to produce a marked change in the electrification observed. The most remarkable case is that of phenol ; this substance is only moderately soluble in water, but if only 'ace. of water saturated with phenol is added to 100 cc. of pure water, the increase in electrification is obvious ; and when 2 '5 cc. of solution are added to lOO cc. of water, the effect on the electrometer is nearly seven times that due to pure water. The sign and magnitude of the electrification depend | on the nature of the gas through which the drop-; fall before 1 breaking up, hydrogen producing effects opposite to those produced by air. No electrification can be detected when drops of water fall through pure waier-vapour, but the smallest \ addition of air brings about eUctrification. — Mr. Griffiths | described an easy method of making absolutely air-tight joints I between glass and metal tubes, by means of an alloy which has a low melting-point The use of this alloy was suggested by Mr. F. Thomas. An illustration was given of the ease and February 15, 1894] NA TORE ;79 certainty of the method. — A compensating open-scale barometer was then exhibited and described by Mr. Griffiths. The principle of this instrument is the same as that of Prof. Callendar's long distance air thermometer. An air bulb is placed within a second bulb, and the annular space between them is filled with sulphuric acid. The air and the H0SO4 have a common surface in a tube connecting the two bulbs, the HoSOj also communicates with the air by means of a vertical tube partially lilled with acid. The masses of air and sulphuric acid are so adjusted that when the tempera- ture of the instrument is raised, the increase in pressure due to the increased length of the sulphuric acid column in the vertical tube exactly counterbalances the increase in pressure of the con- tained air, and thus the position of the common surface is un- changed by alterations in temperature, although at once affected by alterations in the external pressure. The resulting scale is about six times as open as the scale of a mercury barometer, and the readings give the pressure expressed in terms of the length of a column of mercury at 0° C. in latitude 45°, without any pre- liminary calculations. — On the condition of the interior of the earth, by Rev. O. Fisher. The author has lately calculated the tidal deformation of a liquid earth owing to the attraction of the moon, assuming Laplace's law of density ; the moon's potential is substituted for that of the centrifugal force in the usual calcu- lation of the earth's figure by means of Laplace's functions ; and the result obtained is a deformation of 3"45 feet, or 690 feet from highest to lowest. This value is nearly four times as great as a value used in an earlier paper " On the hypothesis of a liquid condition of the earth's interior, &c." read in May, 1892. The calculation of the new value leads the author to consider that the first three pages of the earlier paper lose their force, though the remaining portions stand unaffected. The author points out that the existence of ocean tides is not a con- clusive argument in favour of rigidity, inasmuch as on the hypo- thesis of liquidity mountains must have "roots," sinking deep into the heavier liquid, the result being a deflection of the tidal wave in the substratum, whence would arise irregularities analogous with " establishment of ports." — On a combination of prisms for a stellar spectroscope, by Mr. H. F. Newall. An isosceles and nearly equiangular prism is polished on three faces, and light from a collimator after falling on the base and emerg- ing from one side falls normally on the hypotenusal face of a right-angled prism, and after two reflections within the prism is made to fall upon the third face of the first prism and to emerge from its base. The spectroscope has therefore a dispersion equal to that of two prisms, and is arranged so that the light reflected from the base at primary incidence passes into the same telescope as is used to view the spectrum, and gives rise to a simple image of the slit, which can be used as a luminous pointer. For as- tronomical purposes it is convenient ; for, when the slit is widened, an image of the star can be seen, and the star may be identified among-t its neighbours. The brightness of the pointer is proportioned to the spectrum to be observed. No double ad- justment is necessary in directing the telescope. Dublin. Royal Dublin Society, December 20, 1893. — Prof. D. J. Cunningham, F.R.S., in the chair. — Dr. G. Johnstone Stoney read a paper upon vision, with special reference to vision with compound eyes. The most interesting points brought out by this investigation are the two following: — (i) The amount of detail that is visible by human beings is limited by the spacing of the cones in the macula lutea of the human eye, by the limited size of the pupil, and by spherical and chromatic defects in the eye regarded as an optical instrument. In persons w?th the best vision, these three limiting causes concur in fixing about one minute of arc as the smallest angular in terval to be subtended by two objects at the eye, in order that they may be visible as two. With an insect's compound eye a corresponding limit is placed by the spacing of the lenses over its cornea, and by the small aperture of each lens. Judg- ing from these, we learn that predatory insects, such as dragon- flies, which have the largest number of lenses, see so much less perfectly than we do that the angular interval at which two objects must stand to be seen as two, is nearly a degree ; while in moths, butterflies, bees, ordinary flies, &c. which have not this great number of facets, the angular interval that is requi- site rises to be two degrees or more : so that such insects do not see details upon their own antennas, close to them as they are, so distinctly as we can see them from the great distance from which we are obliged to view them. Moreover, when NO 1268, VOL. 49] the number of facets ha? to be increased, as it is in predatory insects, in order to improve their vision, it is necessary at the same time that the aperture of each lens should not be unduly diminished. This accounts for why the compound eyes of such insects are of excessive size when compared with their other features. (2) Again, our eyes see distinctly only a small central patch of the field of vision, but can be directed towards various objects in succession by rotating the eye in its orbit, and can be accommodated to the distance of each. There is no such motion of rotation possible to insects, but in com- pensation they seem to be able to see distinctly throughout the whole of the field of vision, and to have the remarkable power of being able simultaneously to adjust the different parts of their compound eye to see distinctly at different distances, so that, for instance, a wasp hovering over a break''a5t-table can accommodate his eyes to see with as much distinctness as the insect can see, the several objects on the table, though they may be at very different distances from him. — Dr. J. Joly, F.R.S., read a paper on the effect of temperature upon the sensitivness of the photographic dry plate, of which the follow- ing is a brief abstract : The visible spectrum photographed upon plates one-half of which were maintained at a lov/ tem- perature (about - 30° C. ) and the other half kept warm, showed that the loss of sensitiveness is in the case of isochromatic plates confined almost entirely to the yellow-green and green-blue. In fact the sensitiveness ordinarily conferred by the action of the dye is annulled save for some survival of the very strong band in the green, which is continued, much weakened, from the warm half across the cold half, and without shift. It appears from this that the use of orthochromatic plates in cold climate-; out of doors offers little or no advantage over ordinary gelatino- bromide plates. The spectrum taken upon a cold region on the ordinary gelatino-bromtde plate shows a very slight weaken- ing throughout, but most markedly in the rays of lowest refrangibility. The feeble action of the dye at low tempera- tures seems to confirm Abney's view that the action of the dye is mainly of a chemical nature. — At the meeting held January 17, Prof. J. Mallet Purser in the chair, the following communications were presented : — Dr. J. Joly, F. R. S., demon- strated some simple methods in teaching elementary physics. By the use of a floating piston (a contrivance enabling a wide column of mercury to be supported without friction or risk of falling out in a tube), the author uses as a "Boyle's tube'' a uniform straight tube about i metre long, closed at one end. The tube is placed vertical with the closed end downwards, a certain volume of air v^ (defined by linear measurement upon the tube) is enclosed by a short column of mercury ; the length of this added to the height of the barometer affords P^. The air is now further loaded with mercury ; and y, and P., measured as before. The operations are evident at a glance, and very accurate results may be obtained. To show the lae of thermal expansion of air and to convey the meaning of absolute zero, by gas therometer, the end of the lube — all as above — is placed in melting ice, and mercury added till the air occupies 273 mm. of the tube. It is then dipped into a flask of boiling water having a long neck. The column of air now increases to 373 mm. when the usual inferences may be drawn. — Prof. D. J. Cunningham then gave a magic-lantern demonstration of the development of the convolutions and fissures of the human brain Paris. Academy ot Sciences, February 5. — M. Lcewy in the chair. — On the propagation of sound against various resistances in a fluid, by M. J. Boussinesq. An analytical determination of the problem discussed in several recent coamiunications. — On the propagation of electromagnetic waves, by M. Mascart. The mean speed of propagation is given as 302,850 km. rejecting the more doubtful results. No regular variation with the length of the waves is apparent. — On the theory of the satellites of Jupi- ter, by M. J. J Landerer. — On the temperature of the higher regions of the atmosphere, by M Alfred Angot. A reply to a recent criticism by M. G. Hermite. — On the thermal value of the replacement of phenolic hydrogen in orcin, by M. de For- crand. The heat of solution for i mol. of anhydrous orcin in 2 litres of water at 10° C. is - 2 64 Cal. The mean value for re- placement of one atom of hydrogen by one atom of sodium is + 39'68 Cal., a number very near those given by other plenols. — On campholene, by M. Guerbet. The author obtains a 73 percent, yield by distilling CiqHj-C10 in presence of a trace of phosphoric anhydride. Campholene yields a a hydrocarbon 38o NA TURE [February 15, 1894 C^Hi^ by reiuction wiih H[ at 280°. It boils at I32°-I34° and has the sp. gr. 0783 at o^ It is saturated and very in ert ; it yields trinitropseudocumene with difficulty when treated with fuming nitrosulphuric acid. It is identical with the hexahydro- pseudocumene obtained from Baku petroleum. — Attenuation of viper poison by he.-it and vaccination of the guinea-pig against this poison, by MM. C. Fhisalix and G. Bertrand. The authors conclude that the toxic substances present in the poison cf the viper include (i) a diastasic substance — echidnose ; (2) a nr.rve poison — echidnotoxine. These are considerably modi- fied if not destroyed by a temperature of 75°, and the product acquires vaccinating properties. — On the utilisation of ligneous products for the feeding of cattle, by M. Emile Mer. — Physio- logical observations on ihe kidney of the snail {Helix pomaiia, L.), b'' M. Paul Girod. Tbe snail possesses, in its urinary vesicule, a special alkaline gland which transforms the uric acid excreted by the kidney into sodium urate. — On the salivary glands oi Hymenoptera, by M. Bordas. — On an aquatic stridu- lating Hemipteron, Sigara viimitissima, L., byM. Ch. Bruyant. — On the relation between marine ercroachments and the move- ments of the earth-crust, by M. A. de Grossouvre. The move- ments occurring in Europe during the secondary era are traced. — On the chances of obtaining artesian waters along the Wady Ighargar and the Wady Mya, by M. Georges Rolland. — On a possible relation between the frequency of storms and the posi- tion of the moon. A letter from M. A. Barrey pointing out the relation between the age of the moon and the frequency of storms in France, in which the possibility of a connection be- tween the perturbations of the earth's path due to the moon and the frequency of stormsis shown. Berlin, Physiological Society, January 12. — Prof, du Bois Reymond, President, in the chair.— Dr. D. Hausemann, on the various forms of mitotic nuclear divisions, which he divided into two groups, pathological and physiological. The first kind he further divided into three classes, according to the behaviour of the chromosomata, viz. hyperchromatic, normochromatic, and hypochromatic, of which examples are found in carci- nomata and sarcomata. He had also observed differences of the chromosomata in physiological cell division, according to the tissue from which they were taken. — Piof. Munk spoke on I the tactile areas of the cerebral cortex, which he had found in the well-known motor areas, whereas other observers had located them either in the hippocampal convolution (Ferrier) or the gyrus fornicatus (Horsley and Schiifer), or in the parietal regions (many clinicians). The hippocampal convolution had been soon given up as the seat of the tactile areas for the skin. The speaker had shown that it is impossible to operate on the gyrus fornicatus, owing to its position, without injury to the motor regions, and since the localisation of the tactde areas for the skin in the motor regions of the brain can only be deter- mined by extirpation ot the latter, he regarded the experiments of Horsley and Schafer as inconclusive. With regard to the parietal lobes, experiments on monkeys and dogs showed that its removal did not upset their tactde sensibility. It is important in these observations to discnminaie sharply between touch, perception of contact, pressure, &c. ar.d the general sense of pain. The perception of the cuiicular sense is connected with the motor regions, and is permanently lost when these are destroyed, whereas, on the other hand, general sensibility can be done away with by many different injuries to the brain, but reappears after a short time. The tempi.rature sense of the skin belongs to the sense oigan, and is permanently destroyed by removal of the motor areas. Amsterda.m. Royal Academy of Sciences, January 27. — Prof, van de Sande Bakhuyzen in the chair. — Messrs. Hoogewerff and van Dorp gave the results of their investigations on some derivatives of camphoric acid. They succeeded in isolating two camphor- amic acids, which are formed according to ihe equations : /CO\ /CONII2 C«Hi4< >0-t-2NH3=.C8H / ^rc\/ \COONII4 plained by the authors in the following way. Camphoric acid being dissymmetrical, the atom of oxygen, linking together the two groups of carbonyl in the camphoric anhydride, and also the group NH, linking together the two groups of carbonyl in the imide, will not be attracted with equal force by the two carbonyls. The carbonyl exerting the smallest attraction towards the O in the anhydride, will also exert the smallest attraction towards the NH in the imide. In the reactions, represented by the above equations, the rings in the anhydride and imide will therefore be opened in corresponding places, whereby two camphoramic acids must be formed. — Mr. Fran- chimont communicated a paper in his name and that of Mr. H. van Erp. The authors have compared the zinc and copper salts of the dinitromelhylic acid of Frankland with the corre- sponding salts of the methylnitramine, because it seems that many chemists think the two bodies were identical. Treated with dilu'ed sulphuric acid and ether, the methylnitramine salts yield the methylnitramine with the known properties ; thesalts of the diniircmethyhc acid yield in the same manner an acid body, which melts ± 20" higher than the methylnitramine, and differs in form and solubility. The authors intend to investi- gate the chtmical structure of the dinitromelhylic acid. BOOKS AND PAMPHLETS RECEIVED. Books. — The Mean Density of the Earth : Prof. J. H. Poynting (Griffin). — Economic Geology of the United Slates : R. S. Tarr (Macmillan). — Materials for the Study of Variation : W. Bateson (Macmillan) — Ihe Theory of Heat : T. Preston (Macmillan).— Annuaire de' L.'Observatoire Royale de Belgique, 1894: F. Folie (Bruxelles). — Faraday as a Discoverer: J. 1 yndall, 5th edition (Longmans). — Statistique de la Production des Gites Metalliferes : L. de Launay (Paris, Gauthier-Villar>). — Construction du Navire : A Croneau (Paris, Gauthier-Villars). — Tree Pruning : A. des Cars, translated by Prof. C S. Sartient (Rider). — Practical Forestry : \. D. Web- ster (Rider). — Tobias Mayer's Sternverzeichniss (Leipzig, Engelmann). — Wood Working Positions, sheets i to 12 (large and small sizes): (Chapman and Hall). — Annuaire pour I'an 1894 publi6 par le Bureau des Longitudes (Paris, Gauthier-Villars). — Ostwald's Klassiker derExakten Wissenschaften, Nrs. 43 and 45 (Leipzig, Engelmann). —Gestaltung und Vererbung ." Dr. W. Haacke (Leipzig, Weigel). — Beni-Hasan : P. E. Newberry, part 2 (K. Paul). — Norwegian North Atlantic Expedition, 1876-8, xxii., Zoology, Ophiuroidea : J. A. Grieg (Low). Pamphlets. — Scarlatina and Scarlatinal Sore Throat : Dr. A. K. Chal- mers (Glasgow). — Researches on Matr.ces and Quaternions : Dr. Th. B. van Wettum (lleyden. Brill). — A Short History of Astronomy : G. Knight (Philip). ^CO^ .CO \ XOOK CgHii^ >NH-t-KH0 = C8lIi/ ^CO^ \CONH2 These substances are both derivatives of the same camphoric The formation of these camphoramic acids v\as ex- acid. CONTENTS. PAGE Recent Researches in Electricity and Magnetism. By Prof. A. Gray 357 Greenhill's Elliptic Functions. By H. F. Baker . 359 The Dispersal of Shells. By Clement Reid . . .361 Our Book Shelf:— " The Wilder (Quarter-Century Book " 362 Jones: " Machine Drawing " 362 Pinkerton : " Hydrostatics and Pneumatics " . . . . 362 Bottone : " How to Manage the Dynamo " .... 363 Letters to the Editor : — The Cloudy Condensation of Steam.— Dr. Carl Barus 363 The Origin of Lake Basins.— Dr. A. M. Hansen ; T. D. LaTouche . . 364 A Plausible Paradox in Chances.— Francis Galton, F.R.S 365 Clerk Maxwell's Papers.— Prof. Oliver J. Lodge, F.R.S 366 Abnormal Eggs.— W. B. Tegetmeier ; E. J. Lowe, F.R.S 366 The Pleiades 366 Notes 367 Our Astronomical Column : — A Tempered Steel Meteorite 37^ Astronomy in Poetry 372 Nova Auriga; 373 Agricultural Experiment Stations 373 The Spencer- Weismann Controversy. By P. Chalmers Mitchell 373 Ancient Egyptian Pigments. By Dr. W. J. Russell, F.R.S 374 University and Educational Intelligence 37^ Scieniific Serials 37^ a >cieties and Academies 377 Books and Pamphlets Received 3^° NO. 1268. VOL. 49] NA rURE 381 THURSDAY, FEBRUARY 22, 1894. BOLTZMANN ON MAXWELL. Lectures on Maxwell's Theory of Electricity and Light. Part ii. By Dr. Ludwig Boltzmann. 8vo. pp. 166. (Leipzig: Barth, 1893.) THIS second part of Dr. Boltzmann's account of Maxwell's electromagnetic theory is written from a somewhat different point of view from the first part. The first part presents the theory from the mathematical point of view of a dynamical system whose generalised coordinates are known. This one presents the theory from the physical point of view of a continuous medium whose intimate structure is indeed not fully understood, but whose changes of structure can be fully represented by certain vectors. Although Maxwell has presented the subject from both points of view, the one which really determines the form of his work, and that appears to have led him in his investigations, is the physical view of this second part. A purely analytical view is hardly ever as suggestive as a physical and geometrical one. This latter one suggests extensions, suggests advances in a way that purely analytical investigations seldom do. Compare, for instance. Ampere's investigation of the action of elements of currents on one another with Faraday's treatment of the same subject. The latter has suggested the whole of the recent advances, the working of the ether, the identity of light and electromagnetic waves. The former was magnificent, brilliant no doubt, but it was cold and dead. In the preface to this second part, Dr. Boltzmann ex- plains the absence of diagrams, marginal notes, &c. virhich appeared in the former part. He says a friend conveyed to him the valuable criticism that "Your book is dear." He has consequently left out the embellish- ments that Englishmen love, as being too expensive for the poor German student, and has only left the motto, which costs nothing, to wit : — " War es ein Gott, der diese Zeichen schrieb Die mit geheimniisvoll verborg'nem Trieb Die Kriilte der Natur uiu mich enthiillfn Und mir das Herz mit stiller Freude fiillen." And even this he has not taken from that classic lore that Englishmen delight in. but from a German poet. Although he regrets the dark and inconsequent character of much of Maxwell's work, he congratulates scientific men that this has left them the more to do. For himself, he only claims to be an exponent of Maxwell's views, and hopes that he may succeed in helping students to under- stand them. Electromagnetic equations lend themselves to a great variety of interpretations by analogy with displacements of a medium. They are a system of vectors related to one another by a very simple method of derivation each from the last, by the process of what Dr. Boltzmann says the English call " curling." Starting with the vector potential, the magnetic force is its curl, and the curl of the magnetic vector is the time rate of variation of the electric vector. Any one of this system of vectors may be likened to the displacement or velocity of an incom- pressible medium, and hence we have one system in NO. 1269, VOL. 49] which the vector potential is so likened, one in which the electric displacement is so likened, and one in which the magnetic displacement is so likened. These latter two analogies have been the favourite ones. Maxwell fre- quently speaks in terms of the system in which the electric vector is likened to a displacement of an incom- pressible medium, and the likening of the magnetic vector to a flow is quite common. In these systems electric energy is generally considered as potential, and magnetic energy as kinetic. Dr. Boltzmann, however, likens the vector potential, which he calls the tonus, and which Mr. Oliver Heaviside relegates to the realms of merely convenient suppositions, to a displacement of the medium ; and in ac- cordance with this analogy the magnetic energy becomes potential, and the electric vector, which is proportional to the rate of variation of the vector potential, being thus a velocity, requires the assumption that electric energy is kinetic. An obvious difficulty arises here from the necessity of making an electric current an accelera- tion which cannot of course be constant for ever. In this connection it may be worth while observing that the possible existence of one closed surface inside another with static lines of the electric vector between them makes it necessary to assume either (i) that the vector potential represents a twist round its line, and not a displacement along it ; or (2) that it is a displacement up some lines and down others ; or (3) that there are sources and sinks of the ether where there is electrification, be- cause without sources and sinks we cannot have a con- tinuous flow going on out from a closed inner surface to a closed outer one. If the tonic vector be a twist, the magnetic vector will be of the nature of a A% and it would be this structure which should be elastically re- sisted, and not a twist, as Dr. Boltzmann's and Mr. Larmor's assumptions give. This would return some- what to Mr. Glazebrook's proposal of years ago. Of course, a complex change of structure, such as a com- bination of I and 2, or any other change, such as crystal- lisation in a hemihedral crystal, would be a possible solu- tion. In a hemihedral crystalline form, because its two ends must differ in sign. Gravity is probably due to a change of structure produced by the presence of matter^ which is analogous to a non-hemihedral crystallisation because it is always attractive ; there seems no reason to suppose that any bodies exist possessing negative gravita- tion, the supposed levity of the old philosophers. To the vector potential, Boltzmann gives Faraday's name of electrotonic state at the point, or, shortly, the tonus of the element of volume. The rate of change ot this tonus is the electric vector E, and the kinetic energy due to it is the electric energy per unit vol. T = K/8 -K . E- This tonic strain is accompanied in general by a tonic stress depending on the curl of the tonic vector which is the magnetic vector, H = curl E, and a corresponding potential energy V= "- H-. 2 All this is most interesting in connection with Mr. Larmor's recent papers. He uses Maxwell's analysis in which the magnetic energy is kinetic, and consequently assumes the magnetic vector to be a flow, which he has R 382 NA TURE [FeBRUARV 22, 1894 pointed out can exist as an irrotational one without reaction in MacCullagh's medium. This same observa- tion of course applies to Dr. Boltzmann's analysis, the difference being that vortex rings would be rings of magnetic current instead of electric current, and atoms would act like electric diads instead of elementary magnets. The existence of unclosed lines of electric ; vector, however, seems to make this simple interpretation of Dr. Boltzmann's analysis impossible, and as we cannot t in general substitute whirl for flow in fluid motion, the vortex ring analysis could not be applied if Dr. Boltz- 1 mann's electric vector were interpreted as a whirl ; and hence Mr. Larmors investigation seems confined to the . interpretation he has given. Having assumed that the medium is such as to react j elastically against curl of the tonus (t), and his funda- mental equations thus being — (I), E = f ; (3), T=K/8 7r.E2 (2), H = curlT ; (4), V=i//2 . H- he proceeds to deduce the equation corresponding to (2), namely, (5)KE = curl H by applying Hamilton's principle to T- V in a way which isvAell known. He now remarks that in accordance with his dynamical principles KE is rate of change of momentum, and he adds to curl H any external impressed forces, which he divides into two classes : (i) those due to reversible causes, such as electro- motive of contact, chemical action, &:c. (F) ; and (2) those due to irreversible causes, such as ohmic resistance, &c., which are proportional to the electric vector, and thus obtains this equation in the form KE = curl H-47rC (E + F) It would thus seem as if the electric conduction current were a differert thing from a changing electric displace- ment, though both depending on curl H. This arises from the difficulty noticed above, and seems to require careful consideration. By judicious theories as to the function of the matter in stopping the continual acceleration with- out uncurling the H,the difficulty can be surmounted. In order to get over all the difficulties of discontinuities at the surfaces of bodies. Dr. Boltzmann assumes that the properties of the ether vary rapidly but continuously in passing across a surface, so that he can assume that these equations apply everywhere. Depending on his dynamical basis, Dr. Boltzmann has obtained the following dimensions for electromagnetic quantities, which, of course, differ entirely from both the electric and magnetic systems of units — [E] - [LT-i], [K] = [ML-3] [HI = [ML-iT-2]* [m] = [M-iLT--] After a short discussion as to the possibility of found- ing the science upon a purely analytical basis, by assuming equations and showing that they lead to true results, which is the basis of Hertz's method, and a short criticism of this method as applied by Hertz, Dr. Boltzmann pro- ceeds to show how the old equations of action at a dis- tance and von Helmholtz's work are connected with Maxwell's view of the subject. His treatment of super- ficial effects by means of a rapid variation of structure of the ether at the surface of solids, seems essentially the * This is misprinted in the text, but right in the table of formulse at the end of the book. same as Mr. O. Heaviside has advocated in opposition to von Helmholtz's double electric layers. All this analytical method is, of course, necessary and interesting in what may be called a transition work, one that con- cerns those who have been brought up under one school of thought and are entering another ; a sort of epistle to the Hebrews, a college between youth and manhood. It concerns the past rather than the future, towards which we should press, forgetting those things that are behind. Although Dr. Boltzmann has left out all embellish- ments, he has had pity on his readers. There are necessarily included in a transition work of this kind innumerable formulae, of which 168 are frequently referred to, and these he has collected into two folding sheets, each of five folds, at the end of his work. This is most considerate. Books dealing with many formulas might well follow suit, although it certainly is a little terrifying to have 168 formulae presented as the outcome of the book in a way that necessarily attracts the atten- tion of anyone who thinks of reading it. Those who are frightened by this should, however, recollect that the whole subject of electromagnetism depends on only four very simple equations. Dr. Boltzmann would have much simplified his work if he had adopted any vector symbolism. It is to be hoped that this part of Dr. Boltzmann's work, as well as the former part, will soon be translated, and so made easily accessible to English students. The work of a great master, the product of a great mind, helps all men who can understand it. THE STORY OF THE SUN. The Story of the Sun. By Sir Robert Ball, LL.D. (London : Cassell and Co., 1893.) THERE is no more interesting chapter in science than that which deals with our great central luminary. Its story has been gradually gaining in interest since the first application of the telescope to its study by Galileo, and since the advent of the spectroscope our knowledge of solar phenomena has advanced by leaps and bounds. At the present time the scrutiny of the sun is more minute and continuous than ever, and the constant acquisition of fresh information sufficiently explains the need for additional works on the subject, or for new editions of old ones. The author of the book before us does not approacfi the subject as a practical investigator in this branch of astronomy, and his efforts are therefore chiefly intended for the delectation of that class of readers for which he chiefly caters. The first thing that strikes one on glancing through the pages of the book is the great variety of the matter which it contains, and one begins to wonder if he has mistaken the title of the volume. It is not too much to say that nearly every department of astronomical inquiry is touched upon more or less ; from the deter- mination of the polar flattening of the earth to the photo- graphy of minor planets and the appearances of nebute. Though the author never seems at a loss to give reasons for the introduction of matter apparently not at first sight connected with the subject in hand, his reasons frequently appear to be nothing more than excuses for fiUmg so many pages. For example, we fail to see the necessity NO. T269, VOL. 49] February 22, 1894 NA TURE ;83 of devoting a whole chapter to the members of the solar system, or a large part of a chapter and a full-page plate to eclipses of the moon ; again, the discussion of the Glacial Period surely belongs more to the story of our own planet than to that of the sun, and might very well have been omitted. This method of treatment is the more objectionable as it has evidently involved the omission of reference to many observations of great interest, and must inevit- ably tend to give the impression that our knowledge is very much less than it is in reality. At the same time it does an injustice alike to the reader, and to the army of workers who devote their energies to the pursuit of this branch of knowledge. Again, the story of thesun would certainly lose none of its charm by historical treatment, but we look in vain for even the barest mention of the names of Angstrom, Thaltfn, Faye, Cornu, Perry, Balfour Stewart, and a host of other workers who have taken so great a part in solar inquiries. So far as it goes, however, the story of the sun is told in that fascinating way which has deservedly brought the author fame, and our greatest cause of complaint is that it does not go far enough. The first five chapters, occu- pying nearly one-third of the book, deal with the solar system, the sun's distance, and the sun's mass. In these well-worn subjects there is nothing new to tell and little scope for novelty, but occasionally we come across some of the bright illustrations at which the author is so expert ; as, for instance, the endeavour to impress the reader with the magnitude of the velocity of light. In chapter vi. a fair account is given of the total amount and spectroscopic analysis of the "light of the sun." A coloured plate of the solar spectrum is of unusual excel- lence, but many of the finer details of Mr. Higgs's photo- graphic spectrum are lost in the reproductions, and scarcely do justice to the originals. After a chapter on the causes of eclipses, we come to one on sun-spots, and here we first find evidence of the incompleteness to which reference has been made. The appearances presented by spots are fully described and illustrated by a most liberal allowance of diagrams, but no mention is made of "veiled spots." The rate of solar rotation is discussed in considerable detail, but if the spectroscopic results are to be mentioned at all, Duner's observations might have found a place alongside those of Mr. Crew. The author seems to favour the idea that the varying rotation of the photosphere in different latitudes is produced by the friction of concentric shells of the matter of which it is formed ; other views, not less probable, are utterly ignored ; as, for instance, one which follows from the theory that spots are formed by down- rushes of cool vapours — an explanation which Sir Robert Ball has adopted as the most probable. The reader is also left in blissful ignorance of the fact that astro- nomers have taken the trouble to make a minute study of the spectra of sun^pots, although this work has been going on continuously for the last fifteen years, chiefly at Kensington and Ston> hurst. Uf the existence of the Committee on Solar Phvsics, and of the continuous photographic record of the spots which it has organised, the author seems to have no knowledge. Even the importance of the eleven-yearly period does not appear MO. 1269, VOL. 49] to be clearly grasped, and only the very briefest references are made to this fundamental solar unit. The chapter on solar prominences contains most of the ordinary information on the subject, and has the merit of including some of the most recent observations by Trouvelot and Fenyi. In addition, Prof. Hale's remarkable work in photographing these objects is con- sidered in some detail. Very little attempt is made, however, to distinguish between quiet and eruptive prominences. The solar corona is dismissed in very few words, and the illustrations have not been well chosen. In giving a somewhat detailed account of the American expedition to French Guiana to observe the eclipse of December 1889? it would have been gracious to record the fact that it was during an expedition to this place at the same time that the late Father Perry met with his fate. The authors estimate of our spectroscopic knowledge of the corona is very low, and it is disposed of in twenty lines ; but this meagre description is due to the fact that the most recent observations referred to are those made by Janssen in 1871 ! It has been well remarked that ''hypothesis is the soul of investigation,'' but our author makes no at- tempt to give a full or complete account of any theory ; apparently on the ground that we are still so " very ignorant concerning the actual physical nature of the great luminary." The principal pomt of theory touched upon is that which concerns the materials of which the photosphere is composed, the ordinary view that it consists of glowing clouds being accepted. Working on the lines of a suggestion made by Dr. Johnstone Sloney in 1867, the author argues in favour of the view that to carbon " belongs the distinction of being the main source whence sunlight is dispensed." (p. 289.) This certainly seems as probable as the generally accepted idea that the photosphere consists of liquid metals, but it does not give us any further insight into the causes of the various phenomena which are observed. The study of the circulation of the sun's atmosphere will no doubt eventually furnish the key to most of the problems of solar physics ; but here our author leaves us, with nothing more than an unexplained diagram illustrating a theory of the solar currents. Of the chapter dealing with solar and magnetic phenomena, we have only to note that the author lepeats the mistake with reference to the Carrington- H.idgson outburst — a subject which has already been discussed in these columns. He makes a suggestion, however, which may be well worth consideration, namely, that the solar and magnetic disturbances may not stand in the relation of cause and effect at all, but are each of them "manifestations of some other influence of electro- magnetic waves on a vast scale sweeping through our system, and mfluencing the magnetic phenomena in the various bodies of which our system is composed." (p. 234). We see the author at his beat in the neesiciilosiis (a rotifer), and Ceratium hirunditiella. The enlarged size of this report gives evidence of the increa-ing interest in fresh-water biology, also shown by the fact that a new station is in process of erection on the border of the Miiggel See, near Berlin. Two plates, illustrating the new species obtained, and a map of the neighbourhood of Plon, are given with this part. F. W. G. Biology as it is applied agaitist Dogma and Freewill, and for Wetsinannism. By H. Croft Hiller. Second edition. (London: Williams and Norgate, 1893.) On a first glance through this unusual book, there rises in one's mind the delightful remark that the mother of David Hume is reputed to have made to him — " Man, Davie, you'ed believe anything if it's no in the Bible." For Mr. Croft Hiller accepts in the most trusting spirit the newest conclusions and theories of modern biology, and thrusts them with a fierceness that makes the index as combative as the text, against freewill and dogma — by dogma apparently meaning ecclesiastical Christianity. But it is only fair to say that although his acceptance of scientific authorities is from the point of view of science absolutely uncritical, he states the views he has selected with an acumen that his discursive and flamboyant style cannot disguise completely. A considerable part of the book is given to accounts of controversies in which the author has been engaged, and hell-fire, plenary inspir- ation, and the immorality of the clergy reappear like King Charles' head. He endeavours to show that recent investigations have established the dependence of man's physical qualities on physical structure, and he accepts Weismann's view that acquired characters are not inherited. From these premises he draws socio- logical conclusions that made a writer in the National Reformer (to the pages of which Mr. Hiller was an esteemed contribu'or) accuse him of Toryism. Bu* his conclusions do not alwavs justify such a use of that ap- pellation. They are such as the following : — That how- ever society may attempt to equalise men, nature will L NO. I 269, VOT . 40] insist on producing great inequalities. That education, as its effects are not transmitted, will not directly ameliorate society by raising the general standard. That criminals are no more worthy of punishment than geniuses of reward. That while for the benefit of individuals training of individual qualities is necessary, for thebenefit of the race selection of the naturally better endowed is necessary. That the mainspring of all action is selfishness, but in practice the selfishness of the individual is restrained by the selfishness of the com- munity. ' P. C. M. Heat : an Elementary Text- Book, Theoretical and Practical, for Colleges attd Sc/iools. By R. T. Glaze- brook, M.A., F.R.S. (Cainbridge : University Press, 1894.) A FEW months ago it was announced that the Cambridge University Press intended to publish a series of science manuals, and since that time we have looked forward with pleasurable anticipation to the appearance of the works in the series. But expectations are rarely realised. The book before us is the first of the volumes devoted to physical science, and we are not strikingly impressed with it. Some books favourably force themselves upon one's notice by their originality of treatment or lucidity of expression, but Mr. Glazebrook's volume possesses neither of these characteristics to a noticeable degree This is said at the risk of being considered hypercritical ; but there are so very many ordinary books in exis- tence, that we almost expect a new work to be different from its predecessors in order to Justify its publication at all. However, though the book before us is not the best elementary class-book on heat, it is very good. The author has not confined himself to the experimental or to the theoretical side of his subject, but has happily com- bined the two, so that the book suits both the lecture- room and the physical laboratory. Another commendable feature is the statements of" sources of error" after the descriptions of some of the experiments. The illustra- tions are line-drawings, and though somewhat coarse, they possess the merit of being clear, and that is^ perhaps, the chief desideratum of a book designed for use in our schools and colleges. These institutions will certainly benefit by adopting the book for their students. Electrical Experiments. By G. E. Bonney. (London : Whittaker and Co.) "This book," the author states, " is written in response to suggestions received from correspondents," and is in- tended to stiow how " induction coils and other electrical apparatus" may be used for instructive amusement. In the two hundred and fifty pages to which the book extends, the writer describes in some detail a number of well known electrical experiments. The experiments de- scribed appear to be well chosen, and the instructions given for performing them are fairly accurate, but the theoretical explanations are, in most cases, entirely wrong. The claims of the book to scientific accuracy may be judged of from the following typical extracts, which convey the full meaning of the context. On p. 68 it is stated that "an electric current passing through a wire conductor develops therein a magnetic condition which exeits an influence on the air surrounding the wire, converting it into a magnetic shell," and on p. 203 we find the statement that " the quantity of electricity pass- ing through a resistance of one ohm in one second will liberate 0001 58 grain of hydrogen." Inaccuracies of this kind are far too serious to pass unnoticed, even in a book intended to provide instructive amusement, and we cannot recommend the seeker after electrical knowledge to trust to the guidance of a work in which they occur. From the publisher's point of view, however, the book is well got up, and will no doubt answer the purpose for which it was written and published. FkBKUAKV 2 2, 1894] MA TURE 38; LETTERS TO THE EDITOR. [The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond -with the writers of, rejected manuscripts intended for this or any other part ] is a velocity. The matter is not of the first importance, but a notation which requires the state- ment that the ratio of two like things "is a velocity," makes the subject unnecessarily difficult. Any doubt to which such expressions might have given rise has, however, been completely set at rest since 1882. A discussion, initiated by Prof. Clausius, then took place in the Philosophical JlJagazine ($\h series, vols. xiii. and xiv.), in which Profs. Everett, J. J. Thomson, Lodge, and Larmor took part. It is only necessary for my present purpose to cite the fact that Prof. Lodge explicitly stated that "the number of fundamental relations must be limited by the number of fundamental experiments, viz. three — Coulomb, Coulomb, and Oersted ; and the shortest way of writing the independent rela- tions is this : — [fie"-] = [Km"-] = [ML] and [f^Kv-]=i. The electrostatic convention makes [K] = i ; the electro- magnetic convention makes [/x] — i." This paper was published in September 1882. In January 1883 a paper by MM. Mercadier and Vaschy appeared in the Comptes Rendus. No reference was made by them to the discussion between English and German physicists, NO. I 269, VOL. 49] but up to a certain point they adopted precisely the same line of argument as that with which we were familiar in England. Taking the formulae and f=^kn r Jii'dsds' f OC k ;; they had no difficulty in showing that m = m It was well known in 1883 that Maxwell's theory requires only two constants, K and n, to define the constitution of the medium, and that L^] = [R].f"'= [m] (Maxwell, vol. ii. p. 289, equation 24). Hence from this point of view the equation is the same as m - m [fiKv^] = I. Up to this point, therefore, there was nothing in the paper of MM. Mercadier and Vaschy which could not be directly deduced by Maxwell's theory from the explicit statements ol Lodge. Alter this they proceeded to develop the sufiject further in an argument which may be summarised as follows : — The constant k is inversely proportional to the specific in- ductive capacity. Specific inductive capacity is proportional to the square of the index of refraction. The index of refraction is inversely proportional to the velocity of light in the medium. Hence k = aV", "o etait une constant numerique" (the italics are in the original). Hence, since [1] = [V-] and [k] = [V-], k' is a number "et I'emploi du systeme electromagnetique d'unite- electriques se trouveraii justifie thhriquement." The fallacy in this is obvious even if the experimental justifi- cation of the siep k' ca (lefractive index)- be admiiti-d. Because k (x V- it wever, is elaborated by experiment and further argument in another pai'er {C. R. t. xcvi. 1883, p. 250). The conclusion that k' is a constant is supported by the fact that an induced current is arteris paribus the same, whether the currents are or are not surrounded by non-magnetic materials such as alcohol and i>eiizene. Again the statement is made — ten years after the publication of Maxwell's book — " D'apres les idees universellement ad- mises, les coefficients des formules de magreiisme et d'electro- magnetisme seront analogues a. k' par consequent ils devraient eire comme lui independants des milieux " (p. 252). The fact is that, according to Maxwell's theory, one of these coefficients is independent of the medium, while the other two vary, the one inversely as the other, when the medium is changed. Quite apart then from the question as to whether these factors rep'C enied pure numbers or concrete quantities, ii was at that date almost universally believed that the values of two of them 388 NA TURE [February 22, 1894 depended on the medium. Of course the same view is even more universally held to-day. All this might, however, have been passed over as an " indis- cretion de jeunesse " if M. Mercadier had not in June last made the extraordinary claim to have proved on such a basis of argu- ment and experiment that the electromagnetic system of units has a theoretical justification which the electrostatic system lacks. In this recent paper the notation is changed, and k' is used for l/ju. Here again the invariability of this quantity in non- mr.gnetic materials is used as an argument to prove that it does not depend on the nature of the medium. For the rest M. Mercadier develops certain mixed systems of dimensions, which I need not discuss. In answer to his complaint that I omitted to notice his memoir in a paper which I wrote on the same subject in 1889, I wish to point out that I did not then enter upon the biblio- graphy of the subject. I regarded myself as dealing with a theory well understood by experts, and as advocating a change in notation chiefly for the benefit of less advanced teachers and students. The considerations advanced were direct deductions from Maxwell's theory. That theory was more generally under- stood in 1889 than when the discussion in the Philosophical Magazine took place in 1882, and since the latter date the practice ofretainingK and /i in dimensional formulae is spreading. As far, however, as M. Mercadier's papers of 1883 were cor- rect, the ideas ihey embodied had been explicitly stated in the Philosophical Magazine some months before. As far as they went beyond that point, by the attempt to discriminate between the theoretical validity of the electrostatic and electromagnetic systems, the arguments adduced were quite unsound. Arthur W. Rt cker. Royal College of Science, South Kensington, February 5. The Cloudy Condensation of Steam. Mr. Aitken's letter (p. 340) shows that he has curiously mis- understood me. I never entertained the smallest "objection to" his "not countenancing the nucleus theory to explain " the action of electricity upon the steam jet. On the contrary I was rejoiced to find that so able and distinguished a physicist appeared to hold the same opinion on this point as myself. In labouring to abbreviate I must have become very obscure. Per- haps my meaning may be made clearer by an amplified and annotated paraphrase of the words in question (see ante p. 213). After trying to show that dense condensation takes place only when there is an actual discharge of electricity, which, however, need not necessarily electrify the jet, I go on : " The inference clearly is that in some way or other the action is brought about by the air in which electrical discharge has taken place, and not directly by the electricity itself. Since so much has been said in the earlier part of the lecture about the influence of dust in promoting condensation the [erroneous] idea has, no doubt, occurred to many of you that in the present case also the air owes its condensing power to the fact that it has become charged with dust. [The great majority of the many scien- tifically educated people to whom I have at different times shown the experiment at once made this suggestion.] Minute particles are indeed torn off the electrodes by the discharge and [you may think] form nuclei upon which the steam condenses. This [mistaken] hypothesis seems at first sight to be favoured by the experi- ments of Liveing and Dewar, and by the well-known fact that burning touchpaper induces condensation ; it also has the support of Prof. Barus, who appears inclined to think that such condensation is in all cases due to the action of small particles of matter. On the other hand, it is noteworthy that Mr. Aiiken, who knows more about the condensing property of dust than any man living, gives no countenance to the nucleus theory as explaining the action of electrical discharge upon the steam jet. The possibility of such an explanation must necessarily have presented itself to the mind of one so familiar with the subject, and since he does not make the slightest allusion to it, I imagine that his experiments have led him to the conclusion that it is untenable. This affords me great satis- faction, inasmuch as my own experiments have led me to the same conclusion — not only as regards the action upon the NO. 1269, VOL. 49] steam jet of electrical discharge, but also of burning matter."' [I did not intend to imply, though the words of the abstract apart from the context unfortunately seem to bear that meaning, ihat Mr. Aiiken thought the action of burning waiter was not due to nuclei, but that I myself thought it was not.] Then follows an account of experiments tending to show that the air does not derive its power of condensing the steam jet from dust but from dissociated atoms. The above will, I hope, convince Mr. Aitken that^ except perhaps as regards one slipshod sentence, which I regret having overlooked when correcting the proof, he has no cause to feel agijrieved. I am confident that my hearers never for a moment understood me to say that he had abandoned one iotaj of his conclusions regarding the action of dust, but merely that he did not consider the dust-nucleus theory applicable to the case of the electrified steam jet. I believe that I am well acquainted with all Mr. Aitken's papers on the subject of condensation, but I do not remember the experiment with the polished ball referred to in his letter. Perhaps it is an unpublished one. The experiments which he mentions in his final paragraph, relating to the condensation caused by certain acids, were made upon water-laden air con- tained in closed vessels, and not upon the steam jet. The con- ditions in the two cases are very different, so much so that, for i example, liydrochloric acid, which in the steam jet is the most active source of dense condensation that I have met with, was- I found by Mr. Aitken (he will pardon me for reminding him) to j form no foggy condensation at all in a receiver of moist filtered I air ; while ordinary dusty air, which exerts such a powerful : action in the closed vessel, fails to produce any sensible effect j when introduced into the open steam jet. I Shelford Bidwell. Southfields, Wandsworth, February 11. On the Cardinal Points of the Tusayan Villagers. In the second volume of the yournal of American Ethnology and Archicology I have pointed out, for the first time, that the four cardinal points among the Tusayan villagers are not the same as those of the astronomers, or that their north is approxi- mately north-west. I also gave, in the same article, tables with the amount of the angular variations, showing that the sacred rooms, or kivas, where the mysteries of their ceremonial worship are performed, are oriented, riiughly speaking, in accordance- with their conception of the positions of north, west, south and east. It was shown that the amount of angular variation was constant, and later, in a description of the ruins of A-na-to-bi, the same orientation was made known. In an article published in the December number of the yournal of American Folk Lore, it was stated by me that the- cardinal points among these aborigines are determined by the solstitial risings and settings of the sun. The publication of Piof. J. Norman Lockyer's work on "The Dawn of Astronomy," in which the orientation of certain of the sun-temples in the Nile valley and elsewhere in the old world is referred to solstitial points in the horizon, gives a new interest to these observations among the aboriginal house- builders and their descendants in America. Since the publication (1892) of my observations on the orientation of Tusayan (Moki) kivas and its relationship to solstitial points of sunrise and sunset, I have examined the scanty data which we have regarding the orientation of temples in Central American ruins, and have unearthed significant facts bearing on this question, as well as that of the kinship of the Pueblo people and those who once inhabited the "cities" of Mexico, including Yucatan. Evidences of relationship between the aboriginal housebuilders of Arizona and New Mexico, and those of Nahuatl and Maya stocks have elsewhere been pre- sented. It seems to me that the above observations made in 1891, quite independently of the discoveries of Lockyer on the orientation of temples in the old world, in the light of his dis- cussion, open a field of research in the archaeology of the house- builders of Central America which is sure to lead to interesting discoveries. J. Walter Fewkes. Boston, Mass., U.S.A. The Scandinavian Ice-sheet. Many geologists affirm that the Scandinavian ice-sheet became confluent with that of Scotland, and reached the East February 22, 1894] NATURE ;89 Anglian coasts. Perliaps some of your readers could inform me whether the following difficulty, wliich has occurred to me, has been alread> raised, or has received a satislactory answer. A submarine channel, some 400 lathoms deep, sweeps round the southern coast of Norvvay irom the Catiegat to about the 62nd parallel of latitude, whence it gradually opens out into the deeper water furiher north. If the 100 fathom line of sound- ings were to become the coast margin of north-western Europe, this channel would form a fjord, considerably broader than the straits ot Dover, and for the most part 1800 feet deep. A further general upheaval, amounting in all to some 2500 feet, would convert this fjord into a wide valley, sloping gently towards the north, which was bounded on one side by the Scandmavian mountains (then commonly rising to a height of about 5000 to 9000 feet) ; on the other by a nearly level plateau (with a yet slighter slope, but in the main northward), elevated generally some 2000 feet above the bed of the valley. In such cases, if any trust can be placed on the evidence afforded by Greenland at the present day, the drainage of Scandinavia would obey the law of gravitation, even when in the form of ice, and would be diverted down the fjord or va'ley towards the northern Atlantic. T. G. BONNEY. The Nomanclature of Radiant Energy. Referring to Prof. Simon Newcomb's letter in your issue of November 30 last (p. 100), suggestmg a nomenclature for radiant energy — if no one else has already pointed it out, I would suggest that the word irradiate might be used in place of illuminate. It would be just as expressive, and would have the advantage of consistency ; and its use would leave the word "illuminate" to its proper sphere. A. N. Pearson. Melbourne, January 9. THE FOUNDATIONS OF DYNAMICS. T T is rather curious that at the present time, when ■^ applied dynamics embraces so wide a range, so much attention should be directed to its foundations. One would have thought that the basis of a department of science which is used and used successfully in the inves- tigation of the motion of vorte.K rings in a fluid, and the propagation of waves of electromagnetic disturbance, had been fully understood, and that no doubt of the firmness of the logical structure on which so huge a weight is laid, was entertained by those who are most active in turning it to practical account. If, as some appear to believe, our dynamical methods are founded on a vicious circle, how is it that the same men have been so successful in apply- ing them to the elucidation of physical phenomena .'' Surely the repeated attempt to do this ought only to have led, if not to confusion of contradictory results, to con- tinual failure to obtain any explanation at all. On the other hand the extended use of dynamics has led scientific men themselves to a more general famili- arity with dynamical processes. The study of dynamics is now a recognised part of scientific education, and the exigencies of teaching the subject have rendered neces- sary a much more complete examination of its funda- mental assumptions than was usual before, when a few gifted mathematicians, by the force of their own genius, were led, almost " by a way they knew not," to the glorious results of physical astronomy. Again the recog- nition, more or less clear, that the old action-at-a-distance theories are really mathematical shortcuts, each gathering up into a single formula the result of the physical actions on molar matter of a medium in which it is immersed, has directed attention to the ether, and raised many ques- tions of extreme interest as to the localisation of energy, and the conditions of its transference from place to place. Though a whole race of subtleties has with the new views sprung into being to mock our attempts to find firm foot- ing, we are forced to the conviction that in this action of a medium lies the best means of scientific progress at the present time. As a consequence we are led to the re- NO. 1269, VOL. 49] consideration of the theory of energy, and therefore alsa of the conceptions of force, &c., and discussions as to the foundations of dynamics have been revived and carried on with a keener interest. No one has worked with more zeal at the task of re- stating the doctrine of energy on anti-action-at-a-distance principles than Dr. Oliver Lodge, and it happens that re- cently his views have again been brought to the front by an address on the Fundamental Hypotheses of Dynamics delivered in 1892 by Prof. J. G. MacGregor before the Royal Society of Canada, and an article by the same author in the Philosophical Magazine for February 1893. An instructive paper has been presented by Dr. Lodge to the Physical Society, in which he has re-stated and defended his position. The discussion which took place on that paper, and the divergence of opinion then mani- fested, showed how wide is the interest in this subject,, and how far it is still from being completely settled.* The chief points in Dr. Lodge's papers are his insist- ence upon contact action as the cause of all action between bodies, and his re-statement of the principle of the con- servation of energy. Only incidentally and as a pre- liminary, in his last paper at least, are the laws of motion touched upon. On the other hand, the chief burden of Dr. MacGregor's address is the laws of motion, and an attempt so to formulate them so as to give a logical basis for the science of dynamics in its application to- physics. In his Phil. Mag. paper, however, he deals with Dr. Lodge's views with respect to energy. I do not propose to restate the positions of the parties to the present controversy, but to endeavour to say how the question appears to an outsider who has felt keenly the difficulty of teaching the elementary principles of dynamics without introducing confusion by unnecessarily obtruding the fundamental cruces of the subject ; or, on the other hand, slurring over matters of really vital im- portance. In the first place, it seems to me that there is in general no sufficiently clear recognition of the fact that abstract dynamics is really abstract, and depends upon certain ideal conceptions just as much as does geometry, and that its application to practical problems must be made on certain assumptions, axiomatic in the proper sense or not, which must be justified by the results of experience. Abstract dynamics is a purely ideal science, geometric in a somewhat extended sense, caused by the introduction of certain notions not ordinarily employed in purely geometrical processes. So long as we confine ourselves to the ideal as we do in geometry, there are about it only difficulties of the same kind as we have in geometrical conceptions, and these I do not here propose to discuss. It is only when we apply the science to the interpretation of nature that we meet with the dif^culties that every one must admit do exist, and which there is no blinking if we want to be straightforward, as to absolute direction, uniform motion, &c. In this application we take some standard for the measurement of time. In this we are guided by the idea derived from the first law of motion, that any body in relative motion, which there is reason to conclude is not changed by the action of other bodies, may be taken as timekeeper. In practice we have recourse to a joint result of this idea and the equality of action and reaction, and take as our standard the rotation of the earth on its axis. [Of course this standard may not agree with some other and preferable standard means of time reckoning, but this will not affect the argument.] In abstract dynamics we can and do imagine a system of axes of reference of some kind or other, but quite ideal so far, and agree upon or assume the existence of some mode of measuring intervals of time. We then consider the velocities and accelerations of different particles rela- 1 A rejoinder to tfiis paper appeared in tfie September number of the Philosophical Magazine. 390 NA TURE [February 22. 1^94 lively to those axes. We suppose different particles to have any accelerations relative to those axes which may be assigned, or which are deducible from data given, and so from the configuration at any given epoch that at any other, that is, to speak shortly, the motion, can be found. If the particles do not change their configuration relatively to one another a limitation is imposed on the motion, the particles constitute a rigid body. Thus we may con- sider any conceivable cases, and the science which deals with them is one of pure kinematics. Now we may st'ppose our reference system, which we may call A, to have a motion relatively to some other reference system B, and the motion of the particles con- sidered if referred to that other system will be com- poundccl, for any instant, of the motion which the particles would have with respect to B, if they were rigidly con- nected with A, in the positions they have at that instant, and of the motions which the particles then have with respect to A. There is no difficulty, if the motion of A with respect to B is specified, in determining the former part of the motion of each particle. It will vary, of course, with the changing positions of the particles in consequence of their motions with respect to A. Similarly we can push the reference still further back, and so from reference system to reference system when- ever we find it desirable to do so. Of course we should never by any such process as this reach axes absolutely fixed ; but it is the process by which we introduce correc- tions suggested by experience, as explained below. It is, then, a result of observation that we can stop at some reference system, it may be the first A, which is suggested to us by the circumstances of the case. To a certain extent we can consider the effect of referring our chosen reference system to other reference systems naturally suggested, and be sure that the additional motions necessary for the parts of our system are negligible. In practice we generally make the supposition that we may refer to a naturally suggested system of reference and find in what manner the results deduced require correction. For example, we refer the motion of a projectile to axes fixed in the earth, say one vertically upwards, and two others, one north the other west, and consider the motion. We find that the results only approximately coincide with experience, and we have to correct them on account of the earth's rotation. It may be that there are other corrections which on account of their smallness relatively to unavoidable errors of observation we can take no account of. So far we have made no mention of mass or inertia. This idea is derived from experience of physical phenomena. If we wish to apply our ideal science to the investiga- tion of physical relations from experimental or observa- tional data, we can only do so on certain assumptions tacitly or explicitly made, and these are to be regarded as postulates to be justified by the consistency and accuracy of our results when tested in their turn by observation. The term axiom, it may be remarked, seems inapplicable to many of these unproved assump- tions, inasmuch as though they are simple concise state- ments, neither their truth nor their falsehood commends itself at once to the mind. Now, with reference to our naturally chosen system of axes, we find that different bodies have, iti the same circumstances, different accelerations, and hence we get the idea of the masses of bodies. In estimating similarity of circumstances we assume the constancy of the physical properties of materials, such as constancy of the quantity of matter in a body, the elastic properties of a spring, and the like. Thus, if we take a given spiral spring and apply it repeatedly to the same body with the same stretch, we find the same acceleration given to the body each time. Of course this result might be pro- NO. T269, '^OL. 49] duced by a. pari passu variation of the mass of the body, and the properties of the spring, but since we find the results consistent with those obtained with different masses and springs, the possibility of such variations need not be discussed. To this ideal method of compar- ing masses, the ordinary method by weighing is shown to be equivalent by Galileo's experiment with the falling bodies, Newton's pendulum experiment, &c. Thus applying similar circumstances (which we may typify by a spring with a given stretch) to different bodies, we find their accelerations different, and we are led to a comparison of their masses, and, thence to a prediction of the accelerations which in different cir- cumstances will be produced in the same mass or in different masses, that is to the comparison of rates of change of momentum or of force. For example, suppose a spring with a given stretch in it to be applied for a second to each of a number of masses, and let the accelerations produced be oj, a^, a.j, &c. Then if we take quantities inversely proportional to aj, a.,, a.^, &c., say /Li Oj, /i a.), M, O;;, &.C., aud multiply each of these by the accelerations produced, we obtain, of course, the same product fi in each case, and we take this as a measure of the stress in the spring regarded as the producer of motion in bodies. In the ordinary system of measuring forces we take yL as ma, where m is the mass of the body reckoned in terms of a chosen unit of mass. This gives the dynamical method of comparing the masses of bodies. The masses of the bodies here considered are /aaj, iJ.la.j, &C. On the Other hand, when we have to compare the motion-producing powers of springs having different stretches, that is, the forces they exert, we may use the same system of bodies if we please (or any system of which the masses have been compared as just described), and suppose that accelerations a\, a'.,, a'^, &c. are pro- duced by different springs applied to the bodies. Thus applying the method of reckoning explained above, we are led to measure the forces exerted by the springs by the products ixa\ja^, fiu'^a.,, &c. Thus from the point of view here adopted, Newton's second law sets up this mode of comparing masses and forces, and thereby furnishes a perfectly simple and con- sistent method of writing in a form ready for solution the equations of motion of a body relatively to any system of axes which we know from experience we may regard as at rest. Here I wish to remark that when we write such equa- tions as mx = X, tny = V, ms = Z, the quantities on the right, commonly called the applied forces on the particle of mass m, are, it seems to me, merely put provisionally for values of the quantities on the left, which from the given circumstances of the motion, that is from the relations and data given, we may be able to calculate, or to supply from the results of ex- periment or observation. There is not any necessity for considering them as the causes or the measures of the causes of the accelerations x,y, z, of the particle. The idea of force as cause of acceleration is useful as enabling us to speak and write with brevity about dyna- mical problems, and so to arrive quickly at the necessary equations. For example, take the problem of the motion of a particle of mass m hung by a massless spiral spring which the weight of the particle stretches by a length s. Then we know (i) that the stretch of the spring if not counteracted by the weight w^g'of the particle would cause the particle to receive an upward acceleration g, and since experiment shows that different weights stretch the spring by amounts proportional to them, we infer (2) that when the spring is stretched by an amount s-\- X, the elastic reactiom would produce an acceleration g{s-\-x)ls. Hence an upward acceleration of amount February 22, 1894.J NA TURE 39i gxis will be produced, and if x represent downward ac- celeration, we get the equation of motion : — vix = - ing~. s which is ready for solution, and gives the well-known result. We greatly abbreviate the above statements by saying that the upward " force " exerted by the spring in the first case is vig, and in the second, from the experimental result, vig{s-\- x)js. This gives at once -mg.vis as the downward force on the particle, which being substituted for X in the formal equation of motion, nix = X, puts the latter into a form adapted for solution. Thus, though we may use, and do use constantly, the language of cause and effect in this connection, it ought to be remembered that when matters have been reduced to the solution of a dynamical problem, we have a purely mathematical process to carry out, by which we render explicit only that which is already implicitly involved in our equations. This does not exclude or do away with the considera- tion of stresses as physical realities, it only states what I believe is substantially involved in the application of dynamics to physical problems. The objectivity, in the metaphysical sense, of force does not concern us, and discussions regarding it are, so far at least as physical results are concerned, not likely to be profitable. 1 have heard it said by more than one very competent judge, that there is a certain vicious circle at the founda- tion of dynamics which there is no avoiding. We define force by mass, and mass by force. Thus it is sometimes said in effect, "Equal forces are those which produce equal accelerations in equal masses — equal masses those in which equal accelerations are produced by equal forces." But, as shown above, if we can assume con- stancy of mass of a body, and of the physical proper- ties— say of a spiral spring — there is no difficulty in getting out of this circle of definition. These are assumptions we are entitled to make as the result of experience. It is to be observed that since the measure of force in Newton's second law, namely, inx, is relative, the forces considered must be also relative. This is noticed by Prof. MacGregor in his address (p. 4), but he states that as our idea of force is derived from sensation, force in this sense is not relative. "Accordmg to this concep- tion a body either is, or is not, acted upon by force." It is possible that I have failed to follow Dr. MacGregor here, but it seems to me that he has confounded r^rt/ with absolute. Our muscular sense certainly tells us that a force, that is a stress as distinguished from a mass- acceleration, exists, but in no case can it inform us as to what in any absolute sense are the forces acting on the body considered. The force we feel " does not depend upon our point of view," but the force we regard as acting on the body certainly does. An acceleration which we observe is also a perfectly real thing in itself, but the acceleration of the particle is altogether dependent for its value on the point of view from which we regard it. The ordinary misunderstanding that continually crops up with respect to the equality of action and reaction is feelingly alluded to by Dr. Lodge in his paper, and per- haps as a sympathiser I may be pardoned for devoting a paragraph or two to its consideration. A recent dis- cussion of precisely the same thing in another journal has made it clear that the difficulty felt by the beginner in this matter is not clearly appreciated by many who endeavour to remove it. Because action and reaction are equal and opposite in the case (to take Newton's illustration) of a horse pulling a stone, the student (and the would-be critic of dynamical processes !) imagines NO. 1269, VOL. 49] that neither the horse nor the stone can get into motion. Now the confusion arises from regarding the action which is a forward force on the stone as being cancelled by the (if for a moment we neglect the mass of the rope or chain between the two bodies) equal and opposite force which acts, and this is what is overlooked, 7iot upon the stone, but upon tlic horse, and therefore cannot affect the motion of the stone. There may be other forces acting on the stone, and others again acting on the horse, and the motion of each body is changed by the forces acting on that body, and those forces alone. Thus there are two groups of forces, one group acting on the stone, and the other on the horse, and all that is asserted in the law of equality of action and reaction, as applied in this illustration, is that that particular force of the first group, which is the force exerted on the stone by the horse, is equal to that force of the second group which is the force exerted on the horse by the stone. Action and reaction, however, are, I believe, most properly regarded as applied at the same place, though not to the same thing. Across any cross-section of the rope in Newton's illustration a stress acts, one aspect of which is a forward force on the part of the cord imme- diately behind the cross-section, the other a backward force on the part of the cord just in front of the cross- section. An excellent example is the action and reaction between two links of a chain, which are exerted across the surface of contact between the links, the action being a force on one link, the reaction a force on the other Imk. Here, as in all other cases, the action and reaction do not cancel one another, simply because they are applied lo what are here regarded as entirely different things. [Of course, if we are considering the motion which a system consisting of different parts may have as a whole, the actions and reactions between these parts do cancel one another.] I agree with Dr. Lodge in believing that in a certain sense we have nothing but contact action, that is, that all radiation phenomena are propagated by contact between portions of matter (not necessarily ultimately discrete portions) fiUmg space. Thus at every place where such propagation is going on, and consequently changes of the motions of bodies are taking place, stresses are set up, and just where we have one aspect of a stress we have its other aspect. This view, if it is adopted, certainly seems to lead to the conclusion that a process of transformation accompanies transference of energy ; but it is not, so far as I can see,, inconsistent with, and does not render in any way un- tenable, the doctrine of conservation of energy as ordinarily stated. The doctrine that all energy is kinetic in reality, and that transformation consists in a passage of the energy from being kinetic energy of the bodies whose velocities can be observed and measured to being kinetic energy of those parts of the system regarding which we cannot have such knowledge, or T'ice versa, when it is more familiar, and more clearly understood in the light of further scientific progress, may possibly help to clear away some of the many difficulties which crowd round this subject. This article is long enough, and we must defer to some other opportunity any further consideration of Dr. Lodge's theory of the transference of energy. But both he and Dr. MacGregor have done good service in discussing from their several points of view this very difficult but apparently for many minds exceedingly fascinating subject. Nothing but good can come of "a revision of the standards" in dynamics, provided it has no destruc- tive object in view, but only the improvement and,, if necessary, correction of the methods of presenting and. teaching: the science. A. Gray, 392 NA TURE [February 22, 1894 AX INCIDENT IN THE CHOLERA EPIDEMIC AT ALTONA. THE third contribution by Dr. Koch last year to the subject of cholera appears in the Zeitsclirift fiir Hygiene, vol. xv. part i. It covers no less than seventy-six pages, and is entitled " Die Cholera in Deutschland wahrend des Winters 1892 bis 1893." As :he title implies, it is an elaborate essay giving a most lucid and remarkably interesting exposition of the rise and course pursued by the several epidemics of cholera which visited Hamburg, Altona, and Nietleben near Halle, respectively. Several figures serve to illustrate the descriptions of sites, buildings, &c., referred to in the text. From a bacteriological point of view, perhaps the most interesting part of the paper is that which relates to the disease in Altona, and in which an account is given of ! the successful elucidation of a remarkable outburst of cholera which occurred in a restricted area of that town, and which in many respects recalls the incidents of the now classical cholera explosion which took place in 1854 in connection with the Broad-street pump in London. In a district of Altona, rejoicing in the suggestive name of " der lange Jammer," and inhabited by about 270 persons, cholera made its appearance onj January 21, 1893, and in a week nine cases had occurred, of which seven ended fatally. Strange to say, in the neigh- bourhood and, indeed, for some distance around this centre, no other cases of cholera were recorded at all, thus pointing very clearly to some local cause as respon- sible for the outbreak. A searching investigation was at once instituted, resulting in the discovery that the in- fected houses were not connected with the Altona water- supply, but dependent for their water upon a well in their midst. The ordinary town water-supply was in fact regarded as an article of luxury and an extravagance which the humble inhabitants of "der lange Jammer" were too poor to indulge in. In May, 1892, a systematic inves- tigation had, it appears, been made of all the wells in Altona, and ninety-two out of 366 had been condemned as unfit for use. This particular well was, however, amongst those which had been passed, as its construction appeared to be satisfactory, and its surroundings suf- ficiently protected to remove all fear of contammation. During the severe frost, however, there can be no doubt that surface water, unable to get away by the usual channels, gained access to the well, for when the courts of the surrounding houses were washed down with strong carbolic it was noticed that the well-water acquired a smell of this material. Thus the possibility of its con- tamination with choleraic matters was established, and on January 26 the well was closed. After this date only four more cases of cholera occurred, the last one recorded being on February i, and all of these might have been contracted prior to the closing of the well, and are therefore still attributable to the use of this water. The bacteriological examination of the water was taken in hand on January 31, and on this day large numbers of cholera bacilli were revealed by the usual special methods employed. A sample of the water collected on January 31 was preserved for further in- vestigation, and was kept in a room having a tempera- ture of 3— 5" C. ; in this sample cholera bacilli were found on the 2nd, 3rd, and 17th February respectively, showing that under the particular circumstances the bacilli were able to maintain their vitality for eighteen days in the water ; on the other hand, in samples of water collected later directly froffz the well itself no cholera bacteria could be detected. It is to be presumed, therefore, that as no further cases of cholera occurred in the adjacent houses after February i, no fresh bacilli found their way into the well, and those cholera bacilli which were proved to be present on January 31, must NO. 1269. VOL. 49] have either become altogether extinct or have been so much reduced in number as to defy detection. The incident is instructive, if only in demonstrating the folly of presuming that a well with flagrantly unsanitary environment may be regarded as safe for drinking purposes, just because its past history happens to be untarnished by any observed connection with an outbreak of zymotic disease. But another point which I consider is very clearly brought out by the case in question, is the uncertainty which attaches to the actual discovery of the cholera or, indeed, of other pathogenic bacteria in water, even under such peculiarly favourable conditions as were present in the case of the Altona well. Had the examination of this water been delayed only for a few days, the search for cholera bacilli would have been absolutely fruitless, and the direct bacterio- logical evidence entirely wanting. Chance, in this particular instance, decided otherwise, and a very satisfactory confirmation of a most probable hypothesis was obtained. Nevertheless, it is very apparent that however im- portant bacteriological evidence may be in determining the hygienic value of water purification processes, and as I have so often pointed out, it is in this matter the only competent referee ; on the other hand, in the matter of the actual detection of disease organisms in any given water, its usefulness is of a much more restricted character. There is undoubtedly a tendency at the present time to regard the detection of pathogenic bacteria as the most important object of bacteriological water examina- tion. It is, however, surely a matter of far greater moment to anticipate and be forearmed against evil by ascertaining whether the principal conditions, such as purity of source, efficiency of subsidence, filtration, &c. attaching to a given water-supply are such as to reduce to a minimum the danger of its disseminating zymotic disease, than to wait for the actual discovery of patho- genic bacteria, and only then to be led to see the necessity of, as it were, locking the stable-door after the horse has been stolen ! The failure to discover the typhoid bacillus in the Worthing water-supply is another instance in point, and in the majority of cases the task of tracing the connec- tion between an outbreak of disease and an infected water-supply must obviously still be performed without the direct support of the bacteriological detection of the zymotic poison. Percy Frankland. NOTES. The foundation of the Bakerian Lecture, to be delivered to-day at the Royal Society by Prof. Thorpe, F.R.S., and Mr. J. W. Rodger, although not so ancient as that of the Croonian, is yet of respectable antiquity. Established during the presidency of Sir John Pringle, the predecessor of Sir Joseph Banks, it has its origin in the bequest, in 1774, by Henry Baker, antiquary, naturalist, and Fellow of the Society, of the sum of one hundred pounds, the interest of which is directed to be applied for an oration, or discourse, to be spoken or read yearly by a Fellow on some subject in natural history or experimental philosophy. The forfeiture of the bequest is contingent on the lecture failing to be delivered in any one year. The founder of this lecture was himself a man of considerable parts, and, besides being the author of numerous memoirs in the Philosophical Transactions published two treatises on the microscope, and some poetical works. He was elected into the Royal Society in 1740, and in 1744 was awarded the Copley medal. He married the youngest daughter of Daniel De Foe. The first lecture under the bequest was given in 1775 by Mr. Peter Woulfe, the subject being " Experiments made in order to ascertain the nature of some February 22, 1894] NA TURE 393 mineral substances, and in particular to see how far the acids of sea-salt and of vitriol contribute to mineralise metallic and other substances." It is now arranged that the Croonian Lecture of the Royal Society will be delivered by Prof. Ramon y Cajal, on Thursday, March 8 ; not March i, as announced in our issue of December 21. We understand that the U.S. Bureau of Weights and Measures has recently decided to use the metre and kilogram as fundamental standards, and, from the fifth day of next April, to consider the yard and pound as derivatives from the metrical standards. This decision practically means the adoption of the metrical system by the United States. It has been decided to hold the autumn meeting of the Iron and Steel Institute at Brussels, from September 2 to 7. M. L. GuiGNARD has been elected president of the Botanical Society of France for the present year. M. AiM^ GiRARD has been elected a member of the Rural Economy section of the Paris Academy of Sciences, in succession to the late M. Chambrelent. M. Alboff, who has been collecting for the past six months in the Caucasian Alps, for the Boissier Herbarium, has returned with large collections. A BOTANICAL garden has been established in the mountains near Grenoble, at an altitude of 1875 m., under the direction of Prof. P. Lachmann. Dr. E. Baroni, of Florence, is preparing a monograph of the genus Atrip/ex, and would be obliged by specimens or memoirs from any botanists who have worked at the genus. The yournal of St. Petersburg states that the Russian Tech- nical Society has decided on the organisation at St. Petersburg of an exhibition of gold ores and of precious metals and stones. The Council of the Sanitary Institute have accepted an invi- tation, received from the Lord Mayor and citizens of Liverpool, to hold their next congress and exhibition in that city in the autumn of this year. Mr. William Garton, of Woolston, Southampton, has presented a sum of five hundred pounds to the Council of the Hartley Institution towards the cost of the new engineering laboratory, which is about to be added to that institution. The fine engineering laboratory belonging to the Purdue University, Lafayette, Indiana, and which has cost some ;^35,ooo to build and equip, has been completely destroyed by fire. The building was only completed on January 19 last, and was burnt four days afterwards. We learn from the North British Agriculturist that the Lancashire County Council have decided to take over a farm at Penwortham, at an annual rental of /"400, on a lease terminable at five, ten, or fifteen years, for the purposes of agricultural experiment and instruction. Sir H. Trueman Wood has been elected president of the Photographic Society of Great Britain. The 1894 Camera Club Photographic Conference will be held in the theatre of the Society of Arts, on Monday and Tuesday, April 23 and 24, under the presidency of Capt. W. de W. Abney. The members' annual exhibition of photo- graphs will be commenced at the club on the first day of the conference. NO. 1269, VOL. 49] According to the British Medical Journal, the Hungarian Government has established a bacteriological institute at Buda- Pesth for the purpose of giving facilities for the study of infec- tious diseases from the scientific point of view ; for the employ- ment of bacteriological methods for the combating of such diseases ; for general bacteriological researches ; and for sup- plying information on bacteriological questions to public authorities and private inquirers. An interesting experiment, that of the cultivation of tea, is shortly to be tried in Russia (says the Board of Trade yournal). The Czar, under the guidance of experts, has given his consent to a proposal for the cultivation of this plant in the western limits of the Caucasus, where the temperature is much the same as that under which the plant grows in China. The death is announced of Prof. E. Weyr, at the age of forty- six. He was known especially for his contributions to modern geometry. The AthencBum announces the death of Prof. J. von Diimichen, the Egyptologist, at Sirasburg, on February 7. He was born in 1833 at Weissholz, in Silesia, and pursued his Egyptological studies under Lepsius and Brugsch. In 1862 he made his first journey into Egypt, Nubia, and the Soudan, returning in 1865. At the foundation of the German University in Alsace, Diimichen was nominated to the chair of Egvptology. In 1875-76 he spent a great time in Egypt in order to complete the researches begun during his earlier journeys. He was the author of numerous works on the geography, inscriptions, architecture, and history of ancient Egypt. The anniversary meeting of the Geological Society was held at Burlington House, < n Friday, February 16, when the medals and funds were awarded as follows : — The Wollaston Medal to Geheimrath Professor K. A. von Zittel ; the Murchison Medal to Mr. W. T. Aveline ; the Lyell Medal to Prof. J. Milne, F.R.S. ; the balance of the proceeds of the Wollaston Fund to Mr. A. Strahan ; that of the Murchison Fund to Mr. G. Barrow ; that of the Lyell Fund to Mr. W. Hill ; and a portion of the pro- ceeds of the Barlow-Jameson Fund to Mr. C. Davison. The following is a list of the officers and council elected at the meet- ing for the ensuing year: — President: H. Woodward, F.R.S. Vice- Presidents : Prof. A. H. Green, F.R.S., Dr. G. J. Hinde, Prof. J. W. Judd, F.R.S., R. Lydekker. Secretaries: J. E. Marr, F.R.S., J. J. H. Teall, F.R.S. Foreign Secretary: J. W. Hulke, F.R.S. Treasurer: Prof. T. Wiltshire. Council: H. Bauerman, Dr. W. T. Blanford, F.R.S., Sir John Evans, F.R.S., Prof. A. H. Green, F.R.S., Dr. J. W. Gregory, Alfred Harker, Dr. G. J. Hinde, T. V. Holmes, W. H. Hudle- ston, F.R.S., J. W. Hulke, F.R.S., Prof. J. W. Judd, F.R.S., Prof. C. Lapworth, F.R.S., R. Lydekker, Lieut. -General C. A. McMahon, J. E. Marr, F.R.S., H. W. Monckton, Clement Reid, F. Rutley, J.J. H. Teall, F.R.S., Prof. T. Wiltshire, Rev. H. H. Win wood. Dr. H. Woodward, F.R.S., H. B. Woodward. On Saturday, February 24, at four o'clock, a meeting will be held in Queen Elizabeth's Lodge, Chingford, Epping Forest, in support of a proposed Epping Forest free local museum. For many years the idea of a museum to illustrate the natural history, history, archaeology, &c. of the forest has been in the minds of residents of the district, and the Queen Elizabeth's Lodge seems to be admirably suited to contain a collection of the kind indicated. The Council of the Essex Field Club have expressed their willingness to undertake the gathering together of specimens, and the curatorship and scien- tific superintendence of the collections, as a branch of their central museum at Chelmsford. The specimens and exhibits which it is proposed to place in the museum would include 394 NA TURE [February 22, 1694 such as the following : — {a) Specimens of the natural history and geology of the forest district — the quadrupeds, birds, fishes, reptiles, insects, trees, wild flowers, fungi, fossils, &c. (/') Instructive preparations to illustrate the variety of form colour, structure, habits, transformations, and development, &c.. of the above, with examples of galls and other plant disease and injuries, (f) The antiquities of the forest districts; illus- trations of the camps, and other earthworks ; prehistoric im- plements and other remains, &c. {d) Plans, maps, photo- graphs, pictures, models, &c. relating to the district ; illustra- tions of the history of the forest, and its scenic beauties ; the archil:es:iural and archseological features of the di>trict, &c. (f ) A small collection of books — guides, histories, manuals of natural history, &c. — useful to those wishing to learn something about the district before taking rambles therein. A local museum of the kind proposed would be a source of interest and utility to all lovers of nature, and might be made of con- siderable educational value. In the early part of this week a very severe frost set in over the midland, eastern, and southern parts of England, accom- panied by piercing easterly winds ; the night minima in the shade fell to i6° at Loughborough, and to about 25° at Shields ; while in London the temperature on the grass was as low as 14°, and fog occurred over the inland parts of England. These conditions were due to an area of high atmospheric pressure which lay over Denmark, the Netherlands, and south of Scandinavia, where the barometer readings were as high as 30*6 inches, with lower readings further south. But our extreme north and west coasts were under the influence of low pressure areas, and a south-westerly gale was blowing at Stornoway on Monday evening ; conse- quently the temperature in these parts was higher. In Dr. Wild's Annalen des Phyiikalischen Central Ohserva- torinms for 1892, just received, it is recorded that at Wer- chojansk, Lat. 67° 34' N., Long. 133° 51' E., the temperature fell in February to — 69°'8 C. or - 94°'6 F. This is absolutely the lowest temperature of the air hitherto observed anywhere on the surface of the earth. In Ciel et Terre of the 1st inst. M. A. Lancaster contri- butes an interesting paper " On the commencement and end of winter," as determined by the first and last occurrence of snow and frost at Brussels. He gives tables showing these dates for sixty-one years, from 1832-3 to 1S93-4 (the data for the first and last of these years being incomplete). On an average, the first frost occurs about November 10, and the first snow about five days later, while the first frost of much intensity (below 20° F. ) occurs about six weeks afterwards. At times these phenomena occur much earlier or later ; the first frost occurred in 1864-5 ^"^ in 1881-2 on October 5, while in 1877-8 no frost occurred until December 10. The last frost occurs, on an average, about April 4 ; in 1885-6 there was a frost as late as May i, while in 1835 6 the thermometer did not fall below 32'^ after February 24. The fall of snow is much more irregular ; it fell seventeen times in May, and once in June (in the year 1866). A paper of a imilar nature was published for Sweden in 1880, by M. Hilde- brandsson. The practice of spraying fruits with certain mineral com- pounds, such as salts of copper and arsenic, to destroy insects and fungi, has called out discussion in regard to the ripened (ruit after such spraying, and its fitness for food. The first condition for intelligent discussion of any subject is to know the facts in the case, so experiments have been made on the matter at the State Agriculture College, Michigan, and Bulletin No. lOl contains the results. In these experiments, extending over two years, the minerals used in spraying the fruits were lound in appreciable quantities in every instance, though the amount was small in all NO. T269, VOL. 49] cases except when the spraying had been purp'isely excessive. The question naturally arises whether the sprayed salis merely adhere to the surface or penetrate the substance of the Irui'. Ex- periments made to test this showed that while most of the copper salts, in the case of a solution containing copper sulphate, ad- hered to the surface of pears sprayed with the solution, a portion found its way into the body ol the fruit. Dr R. C. Kedzie, who has made the analyses, remarks that the use of poisons in horticulture is largely in excess of the amount required for a fungicide. One-half or even one-third of the amoun usually employed would probably give as good results. To be on the safe side, no fruits should be sprayed with solutions of mineral salts during the period of ripening, for though the amount found in a single pound of fruit may be very small, repeated doses of the poison might produce slow poisoning. The new theory of light-sensation devised by Christine L, Franklin, and intended to avoid the difficulties involved in the acceptance of the two chief theories in the field at present, known as Helmhohz's and Hering's theory respectively, is ex- pounded in ihe last two numbers of Mind. While the Young- Helmholtz theory supposes that the judgment picks out of a mixture of colours all the even red-green-blue sensations, and deceives itself into thinking them to be a new sensation called white, the new theory assumes an independent retinal process as ground for the latter sensation, therein agreeing with Hering's theory. Bat while Meringsupposesthat some parts of the spectrum produce construction, and others destruction of the tissue of the retina, Miss Franklin considers that the sensations of the black- grey- white series must be regarded as the fundamental ones, and attributed to the dissociation of certain molecules, which she provisionally calls the grey molecules. The atoms thus dis- sociated have different periods of vibration, and in the more highly developed visual organs — those capable of colour- sensations — these colour-atoms differ in behaviour according to the wave-length of the light beating upon them. Thus some atoms would only be torn off" by red light, and would give rise to the sensation of red. The prevalence of such colour molecules- would coincide with the predominance of the structures known as cones in the fovea of the retina, while the " rods " are en- dowed chiefly with grey molecules. This is simply translating into the language of the theory the well-known fact that the colour sense is chiefly confined to the centre of vision, as any- body may prove by looking at a coloured object through the corner of the eye. This distribution, says Miss Franklin, offers a perfect analogy with that of the organs of hearing. In the ear we have a very simple apparatus for hearing noise only, and also a highly differentiated structure for the discrimination of notes of various pitches. In 1881 M. Blondlot gave the results of some experiments he had made on the velocity of propagation of Hertzian waves. The velocity was determined by calculating the period of the electrical vibiations from the dimensions of the resonator,, and measuring experimentally the wave-length. The results obtained, while they indicated that the velocity is always approximately that of the propagation of light, showed that as the wave-length increased the velocity diminished. In a note, communicated at a recent meeting of the Academie des Sciences (Paris) {Comptes Rendus, No. 6, 1894), M. Mascart has shown that a more accurate calculation of the frequency gives a remarkable agreement between the different experiments. In this note the author gives the formula for the self-induction of a rectangle of wire, and applies it to the reduction of M. Blondl-.t's observations. He finds that the values obtained for the velocity of propagation show no systematic variation with the wave-length within the limits of observation, that is,, between wave-lengths of 9 and 35 metres. The mean of all i the experiments gives the value 303,200, kilometres per second February 22, 1894] NATURE 395 as the velocity, while, if the results obtained with one of the resonators which M. Blondlot thinks are less trustworthy are omitted, the mean becomes 302,850 kilometres per second, the maximum variation obtained from this mean amounting to 2'5 per cent. The author also points out that it is interesting to note that the mean value of the velocity of propagation of electro-magnetic waves obtained is about one per cent, higher than the velocity of light. The difference he considers to be due to the fact that the calculated value of the self-induction is too small, for the radius of the wire is an important factor, which may be estimated too large, either owing to errors in measurement or to the fact that the current in the wire is not exclusively confined to the external surface of the wire (as the formula employed supposes), but penetrates some distance into the wire. The employment of wires of larger section, he thinks, might perhaps lead to a better result. With reference to some recent experiments on the railway between Beuzeville and Havre, \.\\^ Electrician says : — " When, about three years ago, a scheme was announced for building a locomotive on which a high-speed engine was to drive a three- phase alternator, which was in turn to drive motors, it met with a little ridicule, and the two sets of tests which have been re- ■cently made on the Chemin de Fer I'Ouest at Havre have raised a smile, but only where the reasons of this roundabout system have not been understood. The two chief difficulties in obtain- ing higher speeds than from 70 to 80 miles an hour with ordinary express locomotives are want of balance and want of space. The impossibility of avoiding the superfluous vertical action of bal- ance weights on an ordinary single-wheel locomotive is alone sufficient to reduce adhesion, and to allow slip at speeds a liitle over 80 miles an hour. All these difficulties are reduced, if not avoided, in the Heilmann locomotive, thout;h not without the introduction of others, and it remains to be seen how the balance of advantage works out." Mr. H. Work Dodd has investigated the question as to a relationship between epdepsy and errors of refraction in the eye, and the current number of Brain (pirt Ixiv.) comainshis results. He has examined the eyes of one hundred case^ of true epilepsy, and compaied the refractions with those of apparently normal eyes. It appears that of simple hypermetropia there were twenty-eight cases per cent, less in the epileptic than in the apparently normal class. Of astigmation of all kinds, there were twenty-six cases per cent, more in the epileptic division than in the normal one. These and other differences lead Mr. Dodd to conclude that, given a certain condition of instability of the nervous system: (i) errors of refraction may excite epilepsy ; (2) the correction of the errors of refraction will, in combination with other treatment, in many cases cure or relieve the epileptic condition ; and (3) that in some cases, when the refraction error has been corrected, the epilepsy will continue, generally in a modified form, in consequence of other irritation, €ven though the error of refraction may have been the exciting cause of the fits in the first instance. Mr. Dodd is strongly of opinion that in every case of epilepsy — in addition to general treatment and llie investigation of other organs — the eyes should be carefully examined under a mydriatic with a view of correct- ing any error of refraction that may exist by the use of proper spectacles. The bacterial contents of ice from various sources has been very exhaustively investigated, but only a few experiments have been made on the vitality of particular micro-organisms in artificially frozen ice produced by means of freezing mixtures Prudden exposed various bacteria to 24° of cold, and amongst these the typhoid bacillus was found still present in large numbers after 103 days of continaous exposure to this low temperature ; if, however, the freezing was interrupted during iNO. 1269, VOL. 49] the twenty-four hours by three separate thawings, they were entirely destroyed at the end of three days. Prudden also showed very clearly that the resistance of an organism depends upon its initial vitality, for whereas the staphylococcus pyogenes aureus taken from a fresh agar cultivation was present in very large numbers at the end of sixty-six days, if an old and half dried-up agar culture was used for the original infection, none were found after seven days. Renk (Fortschritte der Med. No 10, 1893) has quite recently examined the behaviour of the cholera organism in ice artificially prepared from sterilised river Saale water, and finds that five days unin- terrupted exposure to a temperature of from — 0*5 to — 7° C. is sufficient to entirely destroy these bacilli ; but contrary to Prudden's experience, he found that if the freezing was interrupted, which took place when the vessels containing the organisms were removed for examination, a longer time (6-7 clays) was necessary for their annihilation. When unsterilised Saale water was used, the cholera organisms disappeared at the end of three days, and the ordinary water bacteria present were reduced in 24 hours from 1,483,000510 62,445 per c.c. whilst after three days only 4480 were found. Prudden's experiments with the typhoid bacillus, together with those on the cholera organism, indicate how important it is that ice for consumption should only be prepared from sterilised water, or from water the source of which is altogether beyond suspicion of contamination. The Societe d'Encouragement pour I'lndustrie Nationale has issued its Annuaire for 1894. With the present year the bi-monthly cryptogamic journal, Heiwi^ia, published at Dresden, and edited by Prof. G. Hieronymus, commences the publication of a periodical synopsis of cryptogamic literature. We have received a copy of "Bourne's Handy Assurance Directory" for 1894, The work appears for the first time under the imprimatur of Mr. William Schooling, who will doubtless sustain the reputation for accuracy earned for it by the late editor, Mr. William Bourne. Dr. M. Baratta has prepared a series of maps showing the topographical distribution of earthquakes in Italy for each year from 1887 to 1891. The maps, which originally appeared in the Annali deW Ufficio Centrale di Meteorologia e Geodinamica, should be of great interest to seismologists. The second volume of Sir David Salomons' " Electric Light Installations," dealing with apparatus, engines, motors, governors, switches, meters, &c. will be shortly issued in Messrs. VVhittakers' "Specialists' Series." The third and concluding volume is now in the press, and will deal with the application of electricity. Mr. W. Thynne Lynn's "Celestial Motions" (Edward Stanford) has reached the eighth edition. The first edition of this useful little book was published ten years agn. Another little treatise by the same author, " Remarkable Comets," has just passed into a second edition. Both books have been revised and brought up to date. An important report on the Ainu of Yezo, Japan, prepared for the U.S. National Museum, by Mr. Romyn Hitchcock, has been received. It is profusely illustrated from photographs taken by the author, and contains a mass of detail concerning the remnant of a once numerous people in Yezo and on the islands Kumashiri and Zeterof. Messrs. Bliss, Sands, and Foster announce that they have made arrangements with the editor of " A Son of the Marshes," and with Prof. Boulger, for the joint production of 396 NA TURE [February 22, 1894 twelve monthly volumes to be entitled "The Country, Month by Month." Mr. Lock wood Kipling has supplied a design for the cover. The first number will appear on March i, and will be descriptive of that month. A NEW work is announced by Mr. Leland, bearing upon his favourite subject — practical education. The manual deals with elementary metal work, including bent iron, repousse, cut melal, and easy silver work. It is written primarily for manual training classes in elementary and preparatory schools, but will probably be found interesting to any one who has a mechanical bent. Mr. Karl Krall has revised the work while passing through the press. The publishers are Messrs. Whittaker and Co. The first part of the new journal, Novitates ZoologiccB has been issued. It is a large Svo, with 266 pages and four coloured plates, while six others are deferred, to appear in part ii. An excellent memoir, by Dr. Forsyth Major, on the small lemurs of Madagascar {Microcebus., &c. ), commences the work ; then follow articles by Mr. Rothschild (on a new pigeon, and on some new sphinx-moths), and by his two assistants, Dr. E. Hartert and Dr. K. Jordan, on various birds and insects. The organ of the Tring Museum has made a good start, and promises to be of great interest to zoologists. Lovers of nature will be glad to know that the supposed dissolution of our old contemporary, Science Gossip, after nearly thirty years' prosperity, proves to be only a case of suspended animation, and that its familiar face will again be seen in public after the 25th inst. In future Science Gossip will be under the editorship of Mr. John T. Carrington and Mr. Edward Step. The character of the paper as a medium between amateur natur- alists, and for the recording of observations, will be fully main- tained ; at the same time, it is intended to give it a higher educational value by enlisting the aid of the leading men in every department of natural science. Messrs. Simpkin, Mar- shall, and Co. will in future be the publishers. In our issue of November 9, 1893, we gave a description of some Hindoo dwarfs photographed by Colonel A. T. Eraser. Dr. A. E. Grant afterwards suggested that the dwarfs were afflicted with the disease known as pseudo-hypertrophic para- lysis. Colonel A. T. Eraser writes to us, however, as follows : • — "On observing Dr. A. E. Grant's letter in Nature for January 4, I lost no time in sending him a copy of the dwarfs' photograph, to which his reply states — ' It is evident they are true dwarfs, and not subjects of the disease I alluded to. Their heads and trunks appear to be of normal size, whilst their limhs are stunted and deformed.' " Under the title, "Climates of the United States," Dr. Charles Denison has prepared a revised edition, in a condensed form, of his annual and seasonal climitic charts of the United States. The book is published by the VV. T. Keener Co., Chicago. It consists of twelve charts and eleven tables re- presenting the climatic statistics of different sections of the United States. The annual rainfall and temperature are shown on one chart, the former by means of broken lines, and the latter by the usual isothermals. A chart is devoted to the illustration of annual cloudiness, and one to regimal elevations. Upon the four charts exhibiting the isothermal lines for the four seasons of the year, a number of arrows of three different kinds are drawn, showing not only the directions of the pre- vailing winds, but also the directions of winds likely to be followed by rain or snow, and the directions of those that usually herald fine weather. Tue average atmosphere humidi- ties during different seasons of the year are clearly shown in ei^ht degrees of colour. Altogether the book presents in a handy form a mass of climatological information. NO. 1269 VOL, 4q] The late Prof. Hertz could have no more permanent monu- ment than that afforded by his work on the propagation of electric energy through space, reviewed in these columns on October 5, 1893. ^'^ English edition of the collected papers contained in that volume has recently been published by Messrs. Macmillan and Co., under the tiile "Electric Waves." Prof, D. E. Jones is the translator, and he had the advantage of Dr. Hertz's supervision and advice while the book was passing through the pres-. In a preface, Lord Kelvin briefly describes the development of the idea as to action at s. distance, and concludes by pomting out that "absolutely nothing has hitherto been done for gravity either by experiment or obser- vation towards deciding between Newton and Bernoulli, as to the question of its propagation through a medium, and up to the present time we have no light, even so much as to point a way for investigation in that direction." Lord Kelvin also calls attention to the experimental work on electromagnetic waves done previous to the publication of Hertz's researches, but which do not detract in the least from their merit. The English reading public will doubtless fully appreciate Prof. Jones' translation of one of the most important works of this century. Th E polymeric modifications of acetic aldehyde form the subject of an interesting and important communication by Messrs. Orn- dorff and White to the January issue of the American Chemical yournal. These remarkable substances, paraldehyde and metaldehyde, have furnished the theme of many investigations, but their nature and their relation to common aldehyde has not hitherto been definitely established. In the older treatises upon organic chemistry, no less than five difTerent polymeric forms of aldehyde are mentioned, but the researches of Kekule and Zincke resulted in the existence of only two being established, the liquid paraldehyde and the solid metaldehyde. It was shown that care- fully purified aldehyde suffers no change on heating or cooling, or on being kept for a length of time, and that polymerisation is always connected with the presence of certain substances, such as hydrochloric and sulphuric acids or carbonyl chloride. In most cases both forms are simultaneously produced, a low temperature, particularly below o\ favouring the formation of metaldehyde, and a higher temperature being more favourable to the production of paraldehyde. The vapour density of paral- dehyde was further shown to correspond to the triple formula (C2H40)3, and it was assumed that three molecules of ordinary aldehyde unite to form the closed chain compound, paralde- hyde. The constitution thus arrived at for the liquid polymer of aldehyde has since received remarkable confirmation from the spectrometric work of Briihl, who found that the molecular refraction of paraldehyde corresponded to that calculated upon the assumption of the triple formula. Metaldehyde only differs from paraldehyde in its physical properties ; chemically, the two compounds behave precisely alike. The vapour density of metaldehyde cannot be directly determined owing to its partial dissociation into ordinary aldehyde when heated, hence its formula has not hitherto been definitely known. Hanriot and CEconomedes succeeded, however, in determining its density by introducing a correction for the amount of ordinary aldehyde produced, and their results indicated that the formula of this solid polymer was the same as that of the liquid paraldehyde. Orndorff and White have here taken up the subject, and show that determinations of molecular weight by Raoult's method, using phenol and thymol as solvents, point irresistibly to the same conclusion, the molecular weight found being always in the neighbourhood of 132, corresponding to three times 44) the molecular weight of aldehyde. They have also rept-ated and ex- tended the vapour density determinations of the former observers, and have definitely settled the fact that paraldehyde and metal- dehyde are isomers, both possessing the molecular composition February 22, 1894] NA TURE 397 (C2H40)3. They further show that metaldehyde is by no means | so scable as has been supposed ; it decomposes completely in a j few days' time, the products of decomposition being paralde- hyde and a new polymer, tetraldehyde (CoH40)4. The latter substance, whose composition has been definitely established by vapour density and cryoscopic determinations, is a solid of I similar appearance and properties to metaldehyde. It is finally shown that paraldehyde and metaldehyde are in all probability stereo-isomers, like maleic and fumaric acids, the more stable paraldehyde corresponding to the fumaroid or so-called " cis- trans" form, and the less stable metaldehyde to the maleinoid or "cis" form. The additions to the Zoological Society's Gardens during the past week include a Macaque Monkey {Macaciis cynomol- g»s, $ ) from India, presented by Mr. James Carter ; two Vulpine Phalangers {Phalangista vnlpixa, $ 9 ) from Australia, presented respectively by Mrs. Percy Morton and Mr. \V. Hughes ; two Garden Dormice (Myoxiis quercimis) Euro- pean, presented by Dr. R. B. Sbarpe ; a Goshawk {Astur palumbaritis) European, presented by Mr. Duncan Parker ; a Jackdaw {Corvtts fiiout-dula) British, presented by Mrs. Dixon Brown ; two Striped Hyaenas {Hyirna striata) from North Africa, a Mitred Guinea Fowl [Numida mitrata) from Mada- gascar, deposited. OUR ASTRONOMICAL COLUMN. Sun-spots and Magnetic Disturbances. — The Memoirs of the Societa degli Spettroscopisti Italian! (vol. xxii. p. 189) contains a paper by Dr. L. Palazzo on the magnetic disturbances of August 1893, considered in relation to the extent of solar spots. When the very large spot, or rather group of spots, was passing the central meridian on August 6 and 7 of last year, the bifilar magnetometer of the Roman College Onsetvatory was considerably disturbed. On August 18, that is, when the spots were again near the plane of the central meridian, but on the other side of the sun, all three magnetic elements suffered a dis- turbance. Another magnetic storm was recorded at the Marine Observatory of Pola on August 12 and 13. Dr. Palazzo has collected all the facts connected with these three disturbances, and discusses them with the idei of determining the relation, if any, between them and sun-spots. From the paper it appears that the magnetic perturbation of August 6 commenced at 4*7 hours, when the double spot was about I5°'4 from the central meridian. The middle point of the pair passed the central meridian at 8 '5 hours on the following day. It would be interesting to know whether the sun was under observation at any place east of Rome at a time corresponding to that given for the commencement of the brusque magnetic disturbance described by Dr. Palazzo, and if so, whether any strange phenomenon was observed. The disturbances of August 12 preceded by about twelve hours the transit of the largest spot visible upon the sun at the time. On August iS, however, no spot could be seen near the central meridian when the magnetic needles were recording a perturbation, while neither when the double-spot again appeared on the sun's limb, n.ir when it passed the central mer'dian on September 2, did the magnetic needles flutter. We have, therefore, spots without disturbances, and disturbances without spots, thus indicating that there is no connection between the phenomena. Prof. Ricco's discussion of the relation between solar spots and disturbances of terrestrial magnetism {Mem. degli Spettrosc. vol. xxi. p. 153, 1892) led him to believe that magnetic disturbances occur, on the average, about 45'4 hours after the transit of spots over the central meridian of the sun. M. Marchand {Comptes Rendtts, 1887, p. 133) showed that such disturbances occurred when groups of spots or faculse were near the centre of the sun's disc, and Dr. Veederhas given evidence to prove that the appearance of spots on the sun's eastern edge is the signal for magnetic fluctuations. Dr. Palazzo, however, believes that the position with respect to the earth of the solar region disturbed is really unimportant. Stonyhurst College Observatory. — Father Sidgreaves' report on the meteorological, magnetic, and solar observations NO. 1269, VOL. 49] made at Stonyhurst College Observatory during 1893 lias been issued. We extract from it the chief points of astronomical interest. The ordinary work of the solar chromosphere was practically suspended during the year on account of the anticipated dis- mounting of the telescope for the erection of the Father Perry Memorial. But the sun-spot drawings have been continued, and wt-re carried on with the six inch objective which was mounted on the equatorial during the absence of parts of the eight-inch telescope. The new objective, with its mountings, was erected on November 6. It has a clear aperture of 14I inches, and was worked by Sir Howard Grubb, of Dublin. It is valued at ;^650, and constitutes the substantial tribute to the memory of the late Father Perry, raised by the generosity of his many friends. The large grating spectrograph has been employed upon the solar spots and faculK with the result that 175 photographs were obtained of spot-spectra in the green-yellow region, and ninety- two plates of facuise-reversals of the H and K lines. The night-work with the equatorial has been confined to stellar photographic fpectra. In May, it was decided to make use of every opportunity upon the variable star & Lyrse ; and as the exposures upon this were necessarily long, and there were many failures, other stars were let alone. Out of the whole number of exposures forty-five plates of )3 Lyrae proved to be available for careful measurements, and the results are pub- lished in the December number of the Monthly Notices of the Royal Astronomical Society. The " Annuaire " OF the Bureau des Longitudes. — A copy of the Annuaire of the Bureau des Longitudes, for the present year, has been received. Every year sees an increase in the quantity of matter compressed into that veritable vade mectiin. To the present volume has been added notes by Prof. Cornu on the physical aspect of the sun. solar spectroscopy, and the spectra of comets and nebulze. The descriptive note on stellar spectra, began in the 1893 issue, is completed, and an account is given of recent observations of )3 Lyrae, and the spectrum of Nova Aurigae. The articles include one by Prof. Poincare, on light and electricity, according to Maxwell and Hertz ; another, on the origin and u^e of the compass, by Contre- Amiral Fleuriais ; and a third, in which Dr. Janssen describes four days of observation on the summit of Mont Blanc. Alto- gether, the 1894 Annuaire adds to the reputation gained by its predecessors ; it is a volume which no astronomer can afford to be without, and which every student of physical science will find useful. The Spectrum of Nova Norm.e. — A telegram received at Kiel on February 15 announces that Nova Normae was observed by Prof. Campbell at the Lick Observatory on February 13, and found to have fallen to magnitude 95 {Astr. Nachr. 321 1). The spectrum was seen to consist of four bright lines of the same relative intensity and position as those shown by Nova Aurigse in August, 1892 (see Nature, vol. xlviii. p. 524). Like this new star, therefore, Nova Normae has descended to the condition of a planetary nebula. THE SMITHSONIAN INSTITUTION REPORT. 'T'HE report of Prof. S. P. Langley, Secretary of the Smith- ■^ sonian Institution, for the year ending June 30, 1893, has just been published. Its contents refer, not only to the Smith- sonian Institution, but also to the work of the U.S. National Museum, the Bureau of Ethnology, the Bureau of International Exchange, the Zoological Park, and the Astro-Physical Ob- servatory. To do justice to the many and various operations of all these sections is impossible within the limits of space at our disposal, but some idea of the woik may be obtained from the following abstract : — • Research. It appears to be an essential portion of the original scheme of the government of the Smithsonian Institution ihat the secre- tary should be expected to advance knowledge, in letters, or in science, by personal research. Prof. Langley has continued the traditions of the Institution and the usage of former secretaries by contributing to the objects stated, as far as his increasing administrative duties would permit. During 1893 he continue d the researches, of which a portion was published in 189 1, in a 398 NA TURE [FeBRUAR\ 2 2. 1894 treatise emiiled " Experiments in Aerodynamics." Interesting results have since been reached, which appear to be of wide utiliiarian importance, but though Prof. Langley hopes soon to be able to make some communication of them to the public, they are not yet complete. In this same connection, in pursuit of an investigation begun some years ago, he has made experi- ments upon the variations cominually going on in the atmo- sphere, in what is regarded for ordinary meteorological purposes as a steady wind. Specially light anemometers have been con- structed and mounted upon the north tower of the Smithsonian building, and connected with a suitable recording apparatus. The complete resuils, which promise conclusions of practical importance, are being collated and will be published at a later date. (See Nature, January 18.) The extensive invesiiga ions carried on in astro-physics are referred to in the adjoining column. As in previous yt-ars, aid to a limited extent has been given to original investigators who are not immediately connected with the Institution. Prof. E. W. Morley has coniinued his determinations of the density of oxygen and hydrogen, for which special apparatus has been provided by the Institution. A paper by Prof. A. A. Michelson, upon the " Application of interference methods to spectroscopic measurements," with a view to increased precision in measuring specific wave- lengths of light, has been published in connection wiih his work upon a universal standard of length. Mr. F. L. O. Wadsworth was detached from the observatory staff, and sent (at the expense of the Smithsonian lund) to the Bureau Internationale des Poids et Vlesu res, near Paris, to assist Prof. Michelson during a stay of six weeks in preparati >n of this standard. The Hodgkins Fund. Numerous applications, which are referred to the advisory cominiitee for considera'ion, have already been made for grants from the Hodgkins Fund to aid original investigations upon the nature of atiuo-^pheric air and its properties. Two have been approved, a jjrant of 500 dollars havrng been made to Dr. O. Lummer and Dr. E. Pringsheim, members of the Physical Institute of the Berlin Universi'y, for researches on the deter- mination of an exact measure of the cooling of gases while expamlinsj;, with a view to revising the value of that mo^t im- portant constant which is technically termed the "gamma" function. I irs. Luminer and Pringsheim were recommended for this work by Dr. H. von Helmholiz, of Berlin. A second grant of 1000 dollars has been made to Dr. J. S. Billings, U.S A., Army Medical Museum, Washington, and to Dr. Weir Mitchill, of Philadelphia, for an investigation into the nature of the peculiar sut)stances of organic origin comained in the air expired by human beings, with a specific reference to the practical applicaiion of the results obtained to the problem of ventilation for inhabited rooms. The Naples Table. In the spring of last year, a petition, signed by nearly two hundred bi. ilogists, who represented some eighty universities and scientific institutions, was presented to Prof. Lanjiley, ask- ing that a table he maintained by the Smithsonian Institution at the Naples Zoological Station, for the benefit of American invesiigaiors. This step was favourably decided upon, and in April last an advisory committee was appointed, at Prof. Langle\'s request, in onler to obtain opinions as to the best administration of the table. The four members of this com- mittee are :— Major John S. Billings, U.S A., nominated by Prof. O. C. Marsh, President of the National Academy of Sciences; Dr. E. B. Wilson, Professor ol Zoology, Columbia University, nominated by Prof. Chittenden, President of the Society of American Na uralists ; Dr. C. W. Stiles, Zoologist, Bureau ot Animal Industry, U.S. Department of Agriculture, nominated by Prof. C. O. Whitman, President of the American Morphological Society; Dr. John A. Ryder, Professor of Em- bryology, University of Pennsylvania, nominated by Prof. Allen, President of the Association of American Anaiomists. Dr. J. S. Billings, U.S.A., has been designated chairman, and Dr. C W. Stiles secretary of the committee. Satisfactory conditions as to the occupancy of the table have been arranged with Dr Dohm, the director of the station at Naples, and a contract has been signed and completed. Numerous applications for the occupancy of the table have been received, but at the close of the fiscal year sufficient con- sideration had not been given them to render it possible to jnake any definite assignment. NO. T269, ^^'^- 49] The Astro- Physical Observatory. Prof. Langley has continued his important investigations with the bolometer. The instrument, as now constructed, is a minute strip of metal barely 7,^^ of an inch wide, and less than ifo^Tnrof an inch thick. Through this frail thread of metal a cur- rent of electricity is continually kept flowing. When the spectrum, visible or invisible, is thrown upon it, the thread is warmed and the current decreased by an amount corresponding to the in- tensity of the effect received, while novel instruments specially mounted and constructed are in electric connection with the thread, and now automatically record every minute change in this current. With late improvements these instruments are so delicate that a change of temperature of one-millionth of a degree is readily detected and even measured, and it is easy to see that as a consequence of this delicacy the greatest care must be taken in their use. Thus the laboratory must be almost completely darkened, and closed tightly, so as to exclude all draughts and to keep it at as nearly a uniform temperature as possible, while for other reasons it must be kept under constant hygrometric conditions. In spite of numerous difficulties, most of which are due to the very temporary and inefficient nature of the small wooden building in which the work is carried on, and its proximity to the traffic-laden streets, the expectations of last year have been largely realised, and a detailed publication of the work, accom- panied by charts showing several hundred new and before un- known lines, will shortly be issued. The result of the year's work has been the discovery and approximate determination of position of about 150 or 200 new lines in the hitherto unexplored region of the solar spectrum. Important as these results are, they are but the beginning of of what Prof. Langley hopes will be accomplished. In addition to the bolometric work proper, experiments on three special methods of investigation of the infra-red spectrum have formed a considerable portion of the year's work : — -(i) Preliminary experiments on the measurement of wave-lengths in the invisible spectrum by interference methods. (2) Experi- ments on photographing the invisible spectrum by the aid of phosphorescent films. (3) Preliminai'y experiments on bolo- metric investigation of the infra-red normal spectrum. What might almost be said to have been the chief work of the observatory for the year, has been the improvement of the apparatus and instrumental conditions of working. Lttnar Photography. Prof. Langley has been interested for a considerable time in the possibility of preparing a chart of the moon by photo- graphy, which would enable geologists and selenographers to study its surface in their cabinets with all the details before them which astronomers have at command in the use of the most powerful telescopes. Such a plan would have seemed chimerical a few years ago, and it is still surrounded with difficulties, but it is probable that within a comparatively few years it may be successfully carried out. No definite scale has been adopted, but it is desirable that the disc thus presented should approximate in size one two-millionth of the lunar diameter ; but while photographs have been made on this scale, none of them show detail which may not be given on a smaller one. The work has been favoured with the co-operation and interest of the directors of the Harvard College Observatory, of the Lick Observatory, and others, who in response to a letter ade to so great I an extent, bearing chiefly upon discovery and invention, which, with others, now occupy nearly 300,000 titles. Over 100 tons of books passed through the exchange office during the fiscal year 1892-93, and while the service is used almost exclusively for the transmission of printed matter of a scientific nature, natural history specimens having no commercial value are occasionally transmitted under special permission, when they cannot be conveniently forwarded by the ordinary means of I conveyance. I The National Zoological Park appears to be in a satisfactory ;condition, and fulfils the chief purpose for which it was made, iviz. to keep from extinction species of American animals, jseveral of which are now upon the point of vanishing from the ilace of the earth, and would vanish for ever if something were jnot done to preserve them. j In conclusion we must say that the report covers so many ;branches of science, and so much has been done to advance feach of them, that in the above abstract it has only been possible i vo. I £69. VOL. 49 i to mention a few of the investigations. Sufficient has been said, however, to show that considerable contributions to know- ledge have been made. THE GREENLAND EXPEDITION OF THE BERLIN GEOGRAPHICAL SOCIETY. "PARTICULAR inteiest is f<.lt by ihe Geographical Society of Berlin in ihe re-ults of an txpediiion t'l the norih of Greenland, which h y fitted out some two y<-ars ago. At the sitting of the Socieiy hrld on November 4, 1893, Dr. Erich von Diygalski and Dr. E. Vanhotfen communicated papers on the work ol the expedition, Di. Diygalski giving a geneial account of their life in Gre< niand. On June 27, 1892, they reached Umanak, a Dani-h colony on the shores of Nonh Greenland, and selected as iheir base of operations a position some distance inland at ihe hear! ol the Umanak Kjoid. They placed iheir house in ihe hollow of a great ice-cirque. East and vtesi were ihe icr-^iream- ol ihe Great and Lesser Karajak, behind ihem stretched he l>are expanse of the ice-sheet of ihe in'erior. in Iront lay the open waitr of the narrow fiord. Dr. Stade had charge of ihe meieon h gical station; Dr. Drjgslski and Dr. VanliofTen made journeys mto the interior and along coasial re^i^n^ 01 glacier and moinit e. Ai first, wht-n ihey ascended ihe Kaiajak, none ol the Green- landers were willing 10 acconqiany iheni, as the) are full of superstitions about the ict-wastes of the interior. Thiec ulti- mately consented, and overcame their fears »■■ far as 10 enter will spirit into the difficulties of the tour. Bamboo canes were fixed as marks in the ice, and the " inteiference area " --ludied where the upper ice of the Karajak streams meets the inlai d ice. In the winter mon:hs, Dr. Drygalski, with two tiusiy Gieen- landeis, explored the Gieat KarHJak glacier. He look m- asure ments on the relative rate of movement 111 the smoo her and more cleft parts of ihe glacier. He tells how, as the big blocks of icetumbled down, fine ice-dust w as raised, which hui g like a transparent veil around the ice-pillars and hummoiks, ^ome- limes catching the sun-rays and glancing with colour effects. Ice-grottoes were found, the remnants of old wau r-channel in those the temperature was vi'onderfully high, and the ice-wa quite moist. From February until June, Dr. Drygalski and Dr. Vanhoffen were engaged in a long sleigh journty to the most northerly part of the Upernivik colony, in Lat. N. 73°. Ai this latitude the outer margin of the great ice mantle of the interior ex- tended to the sea level. Another toui which they ai'^mp ted in June had to be given up on account of the warm Fo m wind. Before their final departure fn m Karajak, they ascended the ice once more lo take observations on the bamboo maiks pre- viously set. Dr. Drygalski attributes the movement of the ice- streams to their content of water, and says there would be no motion whatever unless the melting temperature were rea. hed. Farther, the increase of temfieraiure in summer, due to the downward passage of heated surface-water, is much gieaierihan the decrease of temperature in v\ inter. The warming effect of the water is at its maximum in the deepest layers of ice. where also the movement is most marked. Microscopic examination of the ice also proved that it was iho oi'ghly penetrated with water. It will be some time bef )re ihe expediii>n can publish their results in detail. Dr. Vanhoffen's work was mainly- biological. THE SUN-SPOT PERIOD AND THE WEST INDIAN RA IN t ALL. THE irregularities of the rainfall from year to year are so large that apparently there is no connection whatever between the sun-spot period and the Jamaica or any oiher rainfall ; but if we smooth down these irregularities by taking the mean for three years as the rainfall for 'he middle of tho-e yea^s — that is to say. if we take the mean of the rainfall during 1S66, 1867, and 1868 as applying to the middle of 1 867, the mean of the rainfall during 1867, 1868, and 1869 as applying to the middle of 1S68, and so on — we shall then set a -eries which rises to a maximum about the time of a solar minimum, and which falls to a minimum about the time of a solar maximum. It is now a'lout a year ayo since ihis connection was found between the sun-spot period and the Jamaica rainfall, and my- article on the subject appeared in the journal of the Jamaica Institute, No. 5. 400 NA TURE [February 22, 1894 The Barbados, Antigua, and Trinidid rainfalls have been sub- jected to the same treatment with the same results ; but it will be noticed in the following table that the smoothed Jamaica rainfall rises and falls with much greater regularity than the smoothed rainfall in Barbados, Antigua, and Trinidad ; the irregularity in the last island is due to the circumstance that we are dealing with the rainfall at one station only, namely the Botanic Gardens, instead of the rainfall deduced from many stations, as ia the other islands. ON PREPARING THE WAY FOR TECHNICAL INSTRUCTION. CIR PHILIP MAGNUS discoursed on methods of tech- nical instruction on February 14, at the College of Preceptors. In the course of his address he pointed out that our intermediate schools were generally described as in a state of chaos, and it could scarcely be expected that so nebulous a system would be largely influenced by the definite movement in Jamaica. { Barbados. | Antigua. | Tri nidad. Year Sun- spot (middle 1 oO- period. Rainfall, Average Rainfall, Average Rainfall, Average Rainfall, Average 90 stations. for 3 years. 90 stations. for 3 years. 47 stations. for 3 years. 1 station. for 3 years. in. in. in. in. in. in. in. in. 1843 Min. 45-31 — 44 74-45 54-56 45 43-91 61-39 46 65-82 5261 Min. 47 I 48 10 1 5923 48 , Max. 63-77 ■ 54-88 49 52-77 , 61-47 50 ' 67-88 i 60 02 51 , 59-40 62-02 52 58-77 I 62-34 53 68-84 59-50 54 50-88 65-68 Max. 55 77-31 58-89 56 1 Min. 48-49 62 23 57 60 90 51-54 58 45-22 5345 Min. 59 54-22 5245 60 Max. 57 9> 61-98 61 7382 63-97 62 5927 1 58-49 63-15 — 63 42-38 53-61 66 So 64-28 64 59-19 5674 62-90 71-66 65 08-64 62-50 85-28 72 01 Max. 66 5365 — 59-68 66-08 Max. 67 86 73-23 67 Min. 64-47 61-95 69-93 5807 6656 63-54 68 6774 62-53 44-60 54-35 56 21 58-74 69 55-37 70-85 Max. 48-52 51-10 5346 5967 70 Max. «9-43 64 96 60-17 50-05 6935 66 13 71 50-09 61 57 41-46 50-06 75-58 64 96 72 45-I8 52-78 Min. 48-55 47 23 Min. 49 95 56'52 ,.. 73 63 06 59-06 51-69 53-15 44-02 56-75 Mm. 74 68-94 61-47 59-22 57-54 31-16 — 76-28 60 40 75 52-42 64-24 61-71 57-89 28-78 33-97 60-90 7304 . 76 71-35 64-06 5273 62-85 41-98 39-94 Si -95 71 65 77 68*40 72-06 74-10 66-64 49-05 46-05 72-10 71-43 78 76-42 77 89 Max. 73-10 73-83 47-11 52-55 61-24 \ 66-26 79 Min. 88 84 73-57 74-30 72-79 Max. 61-50 5277 65-43 69-67 80 55-44 70-96 7098 71-91 49-69 54-98 Max. 82-34 71-16? 81 68 -60 60-64 70-45 63-83 53 75 45 49 65-72 6702 82 57-87 61-91 50-06 61-21 33-04 47 43 5299 ! 6307 83 59-26 i 58-01 63-12 57-04 55-51 44-13 Min. 70-so 60-12 84 Max. 56-90 I 58-67 Min. 57-95 55-05 Min, 43-98 47-63 56-88 1 56-87 Min. 85 59-86 69-12 44-08 61 61 4r39 45-05 43-22 62-31 86 90-61 73-71 82-81 65 '3° 477S 44-95 8682 6471 87 70 -66 77-79 Max. 69-01 73-64 43-68 45-23 64-09 72-12 88 72-11 72-31 69 09 7 1 -67 Max. 44-23 53-83 Max. 65-44 1 67-77 89 Min. 74-15 70-23 76-92 66-iS 73-59 50-27 73'79 74-04 ? 90 64-42 74-42 52-53 65-25 33-00 52-20 82-90 70-14 91 i 84-70 7403 66-30 — 5001 40-51 53 74 75-93? 1892 72-98 ~ 38-53 91-14 i " The Barbados rainfall was discussed by Sir Rawson -W. Rawson in 1873,^ ^"^ indeed it neither was, nor yet is easy to make out the connection between the years 1843 ^^'^ 1863 ; but since 1863 it is all plain sailing, especially when aided by Jamaica on one side and Antigua on the other. I have written to Mr. Hart, the superintendent of the Botanic Gardens, Trinidad, asking him to assist me in getting the Trinidad rainfall into better form. Maxwell Hall. ' Nature, vol. viii. i>\>. 245, 547 : vol. x. p. 263 ; and vol. xi. p. 327. NO. 1269, VOL. 49] favour of technical education. As a fact, they had been much, less affected than the institutions above and below them, and^ probably in consequence of the recognised absence of organisa- tion. It might be that the Royal Commission about to be ap- pointed would introduce order into this chaos, and that when, each school knew exactly its position in the school hierarchy- its relation to the schools above and below it, and the special and particular purpose it was required to serve — our interme-. diate schools, both first and second grade, would become more efficient than they now were in preparing the way for that February 22, 1894J NATURE 401 technical education which, in every branch of professional and commercial life, was being recognised as indispensable. In the New Education, the most important subject of instruction was .'■cience. It was the development of science, and its application to the varied work of life, that had changed to a great extent, and would change still more in the near future, the entire character of our school teaching. In an ad- dress given in 1876, Sir Philip remarked upon the inadequate attention given to the teaching of science in our endowed schools. Out of one hundred and twenty-eight schools which furnished replies to the Commissioners at that time, there were only sixty- three schools in which any kind of science was taught, and of these only thirty devoted any regular time to scientific study. Since then a great change had taken place ; but the change was more markeii in the elementary than in the secondary schools. And the right of science to be included in the school curriculum had only recently been generally recognised. The advance was very satisfactory ; but the important ques- tion was whether, with the increase in the number of schools in which science was taught, there had been any corresponding improvement in the method ol science teaching? The progress in this direction had not been as marked as one might have wished. The correct methods of science teach- ing were only very gradually being understood. It was largely owing to the usefulness of the information which the study of science involved, that the value of the study as a means of edu- cation had been lost sight of. It should be remembered that " acquirement of every kind has two values — value as knowledge and value as discipline " ; and, in early education, the latter was by far the more important. With the first feeling of in- toxication which the breathing of the atmosphere of science excited, there was a sir mg reaction against the teaching of sub- jects apparently useless, as mere instruments for mental gym- nastics. There was a loud cry for useful information ; and the scientific lecture, with its platform experiments, served both to awaken the interest of the pupil and to afford such informa- tion. But, gradually, better views prevailed, and it was recog- nised, although very slowly, that information was not the first object of science teaching, and that, valuable as was the in- formation which science conveyed, such information was of little use unless the process of informing served to train and discipline and educate the faculties. Accuracy in thought and expression, the power of arranging and co-ordinating facis, and of acquiiing, retaining, and reproducing in logical order, new ideas, and the habit of deliberation in arriving at conclusions, were educational ends of far more real value than any amount of mere knowledge which the student of science might gain. The recognition of this educational truth had rudely shaken methods of teaching, and even of examining in scientific subjects. Herbert Spencer, in his well-known essays on Education, had said: — "It would be utterly contrary to the beautiful economy of nature if one kind of culture were needed for the gaining of information, and another kind were needed for mental gymnastics. Everywhere throughout creation we find facul- ties developed through the performance of those functions which it is their office to perform ; not through the performance of artificial exercises devised to fit them for those functions. . . . The education of most value for guidance must at the same time be the education of most value for discipline." The method of teaching science must therefore be carefully considered, so that the training of the faculties might be steadily kept in view as the aim and object of the instruction, rather than the mere acquisition of Knowledge. This change of method involved the substitution, from the very commencement, of practical work on the part of the pupil for the ordinary lecture or lesson. At the outset, the practical exercises should be of the very simplest kind. The pupil must take nothing for granted. It was clear, thf-refore, that he must commence with simple exer- cises in measui ement. In physics they were always dealing with quantities, and could not understand what is meant by a quan- tity except by measuring it. The first measurements to be made were those of length. In making such measurement, certain standards had to be considered, and different systems (the Eng- lish and the metric systems) should be compared. These com- parisons involved easy exercises in arithmetic, which might be practised in connection with such concrete examples. Various objects should be actually measured, and the length calculated by rnultiplication or division of other measurements. But the pupil should be made thoroughly famdiar with his standard of measurement before passing away from this exercise. This should be followed by measurement of areas, the consideration NO. 1269, VOL. 49] of which was fruitful in useful exercises. In country schools the actual measurement of the areas of fields, by simple methods of surveying, might be usefully attempted ; in town schools there was generally a playground which would afford opportunities for similar exercises. Then the methods and results of all such measurements should be carefully and neatly transferred to paper, and the pupil should be thus incidentally exercised in elementary drawing. The measurement of volume would follow, with more varied and more difficult problems. Immediately connected with the measurement of volume was that of mass. There, of course, a difficulty arose, owing to the close connection between mass and7veig/il, and the difficulty of distinguishing between them. But the explanation of this diffi- culty might be postponed, and the pupil could be allowed to use ordinary weights as measures of mass. At this stage he was in- troduced to a balance, and, with a view of inducing habits of accuracy, he should at once use a fairly good balance. The ex- ercises were very numerous which the pupil could practise with a good pair of scales. From this point the order of any elemen- tary series of lessons could be varied at the discretion of the teacher. The balance suggested experiments, to be done by the pupil, on the use of the lever, whence the principle of the lever could be obtained. From the common balance to the Roman balance, and to other modes of weighing, the steps were very gradual. The relative volumes of bodies of the same material could then be ascertained by the balance, and former exercises in measurement be verified and repeated. The pupil should not only do the actual work himself, but should write out clearly a description of what he had done, thus learning to connect action, thought, and words. From these exercises the pupil might pass to the consideration of the difference in homogeneous bodies of the same volume and of different weight, and so on, by very easy stages, to methods of ascertaining relative weights of different substances. Exercises in finding specific gravities of solids, powders, and liquids, gave opportunity for very valu- able instruction, and prepared the way for the use of instruments of precision, and for knowldege of interesting properties of dif- ferent kinds of bodies. The value of these lessons consisted in the accuracy of measurement, and in the clearness and correct ness of the written record, as regards the statement of facts, the sequence of reasoning, the numerical calculations, and the use of words and phrases. It was, of course, essential that these written exercises should be carefully corrected, as are exercises in Latin or Greek com- position. The aim of the instructor, in compiling such an in- troductory course as that suggested, should be to include those subjects, an acquaintance with which was required to enter upon the systematic study of any one branch of science, and which were practically common to all branches. The character of an introductory course might be intluenced by the consideration of the special science which, in any particular school or district, would be likely to be studied, or indeed by the special taste of the instructor. A knowledge of the use of simple measuring instruments, including the thermometer, the barometer, the hygrometer, having been acquired, the pupil might pass by carefully suggested experiments to the determination of simple physical laws, and to the discovery of the composition of common substances, such as air, water, salt, lime, &c. ; and it was needless to say that such exercises would open up wide views of the elementary facts and laws of different branches of science, and would prepare the way for the specialised teaching which more properly belongs to technical education. UNIVERSITY AND EDUCATIONAL INTELLIGENCE. Oxford. — Prof. August Weismann will deliver the Romanes Lecture in the Sheldonian Theatre, on Wednesday, May 2. Prof. H. H. Turner has selected "The International Photo- graphic Chart of the Heavens " for the subject of his inaugural lecture as Savilian professor of astronomy, to be delivered to-morrow. Cambridge. — The Vice-Chancellor has appointed Mr. J. W. Clark, Registrary and formerly Superintendent of the Museum of Zoology, to the office of Reader on Sir Robert Rede's foundation lor the present year, in succession to Prof. Foster. The Special Board for Medicine report that in consequence of the great increase in the number of candidates for the M.B. degree (in 1893 there were 224 to be examined), it is necessary to increase the staff of Examiners to four in Medicine and four in Surgery. 402 NA TURE [February 22, 1894 The Somerset County Education Comminee announce that three Senior County Scholarships will be offered for competi- 'tion in June 1894. They will be tenable for two years in the scientific or technical depariment of a university college, the Royal C' "liege of Science, South Kensington, or some other college or institution approved by the County Education Com- mittee. The annual value of each scholarship will be from ^50 tO;i^6o, according to the place of instruction chosen, and, subject t.. the maximum limit, will be fixed at a sum sufficient to cover the cost of instruction, together with ^30 per annum toward's the scholar's maintenance. The compeliiion will be open to any boy whose parents or guardians are bona fide resi- dents in the administrative county of Somerset, and who has regulaily attended any secondary school (public or private) within the county for two school years preceding August I, 1894, provided that every candidate is over 15 and under 17 years of agr- on July I, 1894, and that his pirents are in receipt of an income ot nut more than ;^400 a year from all sources. Six intermediate County Scholarships will also be offered for competition in June 1894. They are of the annual value of ^30, and will be tenal>le lor two } ears at some pui>lic secondary school approved for the purpose by the County Committee. SCIENTIFIC SERIALS. American yoiirnal of Scunce, February. — On the chemical compo'^iiion c)i staur>'lite, and the regular arrangement of its car- bonaceous inclusions, by S. L. Penfield and J. H. Pra't, A careful analysis of several si ecimens gave the formula H ALgFeSio'^is, which may he written as a basic orihosilicate. Thr aiuminuun is partly replaced by feiric iron, an'l the ferrous iron by niat;ne- sium and manj^aiiese. Basal sections of the rhombic prism show the carbonaceous inclusions to t'e disposed in the form of a rhombus parallel to the outline, with the coiiers joined together. This figure develops into a simple cross towards the centre, whereas ioward> the ends the rhombus uidtns out until it coin- cides wiih the outline. This provc-s that the inclusions are arranged in ihe surface of a douMe p)ramid with iis aprx in the centre, and also in planes joining the e>lges of this py.amid with those <)• ihe prism. — Aiidiiional species of i>leislocene fos.sils from Winihrop, Mass., by R. K. Dodge. Three more spec es of preglacial -hells have deen found in the drumlin in Boston Harbour, known as Winthop Great Head. They a'e LunatUi Grtznlandica, Siimpson, S' apharca transversa, Ad.ims, and Buccinum iindatum, Linne. These lo^^il- give additional evidence of the higher temperature of MassachuS' tts Bay in pre-giacial as compared with the present time. — On the basalts III Kiila, by H. S. Wa-hin^ton. These basalts occur near Kula, about 125 km. east by n 'rth of Smyrna, where ihey from cones and stieams of a fresh a' d unaltered appearance. The lavas are to be classed as hornblende- lagioclase basalts, distinjiuished by the constant presence and gnat relative •quanti y ol the hoinhlende, its peculiar njafjm.itic alteration, the small quantity of both phigioclase and olivine, and the large amount of glass basis. The name Kulaite is proposed for thi m. — The fishi g liank^ betwem Cape Cod and Ncwioundlaiid, i>y Warren Upham. If a portion of the continental bolder irom Cape Cod to the Grand Bank south east of Newloundland could be uplifted, we shoul 1 behold nearlv as much diver-ity ol valleys, ri'lges, hiJls, plateaus, and all the forms of subae ial land erosion, as is exhii>iied by any portions of the adjacent New England states and eas'ern provinces of Canada. The submerged channels of ou let from the Gulfs of Maine and St. Lawrence, and the less profound valleys that divide the fishing banks from each other, prove that this region during a compara- tively late ge logic time was a land aiea, us maximum elevation being a' least 2000 ect higlier than now. Bulletin of the Nfw York M Uhemalical Society, vol. iii. No. 4, January. — "Modern Maihemiii>.al Ttiough ," ihe presidt-nnal addiess, delivered by Frof. Newcomi), before the New York Mathematical Society (pp. 95-107), has been printed in our columns (see Naiurh, vol. xlix. pp. 325- 329). " Recent Reseaiches in Eleciricity ana Magnetism " (pp. I07-III) IS a review, by G. U. Squ er, of Prol. J. J. Thomson's "Notes." The leviewer leels a-sured thai this "supplementary" volume will lake its proper place be^iite Maxwell s great trea ise in the library of eveiy irue student of electrical .-cience. "JNutes" and "new publications" occupy pp. 112-118. SOCIETIES AND ACADEMIES. London. Physical Society, Fe' ruary 9. — Annual general meeting. Prof. A. W. Riicker, F. R.S., President, in the chair. — The annual report of the Council was read by the President. Dr. Atkinson read the Treasurer's Report, and also an o'atuary notice of the late Prof. Tyndall. The adoption of the Reports was moved by the President, and carried 11cm. con. Dr. Chichester Bell and Mr. Griffiths were appointed scrutators, and sub>equently declared the following irentlemen duly elected to form the new Council : — President, Prof. A. W. Riicker, F.R.S. Vice-Presidents: Walter Baily, Major-General E. R. Festing, F.R.S., Prof. J. Perry, F.R.S. , Prof. S. P. Thomp- son, F.R.S. Secretaries: H. M. Elder, 50 City Road, E.C., and T. 11. Blakesley, 3 Eliot Hill, Lewisham, S. E. Treasurer: Dr. E. Atkinson, Portesbery Hill, Camberley, Surrey. De- monstrator: C. Vernon Boys, F. K.S., Physical Laboratory, South Kensington. Other members of Council : Shelfoid Bidwell, F.R.b., W. E. Sumpi.er, Prof. G. Fuller, J. Swin- burne, G. Johnstone Stoney, F.R.S., R. E. Baynes, Prof. G. M. Minchtn, L. Fletcher, F.R.S., Prof. O. Henrici, F.R.S., Prof. S. Young, F.R.S. Prof. Reinold proposed a hearty vote of thanks to the Lords of Committee of Council on Educa- tion, for the use of the rooms and apparatus in the Royal College of Science. This was seconded by Piof. J. V. Jones, and carried unanimously. Votes of thanks were similarly accordeu to the auditors, Mr. A. P. Trotter and Mr. R. Inwards, on the motion of Mr. Watson, seconded by Prof. Fuller ; and to the officers of the Society, on the motion of Dr. Barton, seconded by Mr. Trotter. At an ordinary science meeting then held, Mr. Owen Glynn Jones read a paper on the vi^coSlty of liquids, and exhibited the apparatus used in his ex- peiiments. The method employed consists in measuring the -peed at which a small sphere travels through the liquid under the ac ion of gravity. As Prof. Stokes had stiown, the velocity of a sphere falling in an infinite liquid becomes con- stant, this velocity being given by the equation ,;■ 2 o(r - p 9 M where a is the radius of the sphere, a its density, p the density ol the liquid, and fx its viscosiy. If sliding friction exists between the sphere and liquid, the equation becomes NO. 1 269, VOL. 49] 9^ M P ^« +_Ji" . j8a + 2fi ' where ;8 is the coefficient of friction. In making the experi- ments, small spheres (usually of mercury) were allowed to fall through a burette containing the liquid, and the time taken to travel the dis ance between two marks about 50 cms. apart noted. The radii of the spheres being small, it was considered better to deduce this from the mass. Direct deiermination of such small masses being difficult, a larger mass (M) was taken, weighed, and divided in o, say, ten or twelve pirts, and the speed of tailing of each part observed in a liquid of constant viscosity. The velocity V, with which a sphere containing the whole mass would have fallen, was deduced from the equation V' = Sz'-. Similarly, the mass of any part which falls with a velocity v is given by ^(?y M. In this way the author had been able to determine the mass of a sphere weighing only about 0*003 grammes to four significant figures. Referring to experiments made with a view to ascertaining whether sliding Iriciion existed, j ihe author said the divergence from the simpler formulaj did not exceed experimental errors. In determining viscosity,! changes ot temperature were found to be of great importance, especially in the case of glycerine, whose viscosity varies a^! much as 10 per cent, for l° C. Small differences of temperature between different pans of the liquid are, however, not very serious, provided the mean temperature be known, for the mear speed observed is shown to be that corresponding to the iiiear^ temperature. To determine viscosity accurately at a given tem- perature, very delicate thermometers must be employed. Mos, February 22. 1894J NA TURE 40: of the liquids e^peritnented on were bad conductors of heat, and hence required considerable time for the temperature to become uniform. Differences in temperature could readily be detected by observing if the speed of descent of a small sphere varied at different parts of its path. The author suggested that this fact might be used to determine the thermal ccinductivity of liquids heated at the lop by Forbes' method. The falling sphere would form a thermometer of almost infinitesimd thermal capacity. For most oils, spheres of water coloured with eosin could be employed to determine the viscosity. A water-drop of l mm. radius was found to fall one inch per hour in castor oil at 8° C. To determine the variation of viscosity with temperature a special apparatus was used, with which observations could be made in rapid succession by simply invert- ing the tube containing the liquid and the falling sphere. In Mr. Trouton's viscosity experiments, which were somewhat analogous to those described, surface tension complicated the results considerably ; the author's aim had been to eliminate such disturbing influences. Prof. Everett, in a written com- munication, suggested that the motion of the liquid spheres be checked by using beads of quartz or glass. Lord Rayleigh pointed out, in a letter, that the formula employed related to a solid sphere, and thought it not legitimate to use it for liquid spheres, for the tangential forces at the surface would set the interior liquid in relative motion, and modify the resistance experienced. He also thought the existence of a finite coefficient of sliding friction between two fluids an impossi- bility. Mr. Watson said temperatures might be kept constant for days together by Ramsay and Young's vapour jacket. Dr. Sumpner thought the surface tension of such small spheres of mercury was so very large that they would act practically like solids. The want of solidity might be of importance when the two liquids were very nearly alike in density and other pro- perties. Mr. Blakesley said that at high velocities the falling sphere might get a palpitating motion, in addition to the gradual descent, and this might introduce errors. Prof. Perry considered that the experiments on the velocity of a small sphere, and those of the two parts in which it was divided, which showed that V- = v{- -}- v.^ proved the simple formula used to be correct. Mr. Boys inquired if any tests had been made on the constancy of dimensions of the spheres used. . He would expect that in the case of water and oil, for example, that mutual contamination would take place. Speaking of the indirect method of determining the masses of suiall spheres, he thought direct weighings might be made, for, as the President and Prof. Poynting had shown, the balance might be immensely improved. Prof. S P. Thompson suggested that small globules of aluminium or slag might be used. Dr. C. V. Burton thought Lord Rayleigh's criticism important, and that large corrections might be necessary. He failed to see how the large surface tension mentioned by Ur. Sumpner could prevent internal circulation. Mr. Trotter said Lord Rayleigh's point might be tested by using a sphere of oiled wax. Mr. Boys mentioned that Lord Rayleigh had shown in the case of soap rings that variation of surface tension due to stretching or compression produced stability. The same phenomena would probably retard internal circula- tion. The President said there was little doubt that internal circulation, as mentioned by Lord Rayleigh, would modify the velocity. In his reply, Mr. Jones said he could not imagine how in pure liquids internal motion in the falling spheres could be set up. In answer to Mr. Boys, he had found slight changes in the masses of the water spheres after being used many times, but this was a question of days. During an ordinary series of observation the dissipation was too small to be observed. After the meeting had been adjourned, Mr. Boys and Dr. Burton considered the question of internal circulation, and the latter pointed out that with perfectly liquid spheres there would be infinite slip, and the coefficient of sliding friction /3 would be zero. The velocity of descent would therefore be \ times that given by the first equation. Geological Society, February 7.— W. H. Hudleston, F.R.S., President, in the chair. — Mr. C. J. Alford, in expla- nation of specimens of auriferous rocks from Mashonaland exhibited by him, stated that several of them were vein-quartz occurring as segregations in the slates, generally forming veins between the cleavage-planes. Another specimen was a mass of chromate of lead, with pyromorphite and other lead minerals, occurring in masses in decomposed and dislocated talcose slate NO. 1269. VOL 49I in the Penhalonga Mine near Umtali, and probably resultin.; from the altera ion of masses of galena by weathering, as a broken vein of galena was found in close proximity. This cro- coisite was supposed to be a somewhat rare mineral, but he had found it and also the native red oxide, minium, in several places in South Africa. The most interesting specimen, was, how- ever, a mas^ of diorite showing visible gold througl'out the rock, an assay of which gave upwards of 130 ounces of gold per ton. From information obtained from the prospector who made the discovery, he gathered ihat the deposit was a dyke of diorite running for a consideiable distance, about 8 feet in width, flanked on one side by granite and on the other by slates. There were extensive ancient workings extending to a depth of about 60 feet, and the prospecting shafts had not gone much below that depth, so not much information was obtainable at present. The diorite showed a development of epidote, but little or no quartz ; and the gold appeared to enter in an extra- ordinary manner int;o all of the composing minerals. Mr. Alford hoped, after his next visit to Mashonaland, to be in a position to lay before the Society more definite information regarding these interesting rocks. — The following communications were read : — On some cases of the conversion of compact greenstones into schists, by Prof. T. G. Bonney, F. R.S. By the path lead- ing from the Bernina Hospice to the Grtim Alp (Engadine)' some masses of compact green schist are seen, intercalated in a rather crushed gneiss. They prove to be intrusive dykes modi- fied by pressure. Microscopic examination of specimens from these revealed no trace of any definite structure indicating an igneous rock ; a slice, cut from one of the masses within an inch or so of a junction, showed it to be a foliated mas of minute chlorite or hydrous biotite, with granules of epidote (or possibly some sphene) and of a water-clear mineral, perhaps a secondary felspar. An actual junction showed a less distinct foiiition and some approach to a streaky structure. A slide from the middle of another dyke (about 18 inches thick ) exhibited a more coarsely foliated structure and minerals generally similar to the last, except that it may contain a little actinolite and granules of haematite {?), and the clear mineral, in some cases, seemed to be quartz. The structure and most of the minerals appeared to be secondary. Chemical analysis showed the rock to have been an andesite. A specimen from a third dyke was generally similar, but was rather less distinctly foliated. A somewhat similar, but rather larger intrusive mass by the side of the Lago Bianco showed more actinolite and signs of primary felspar, with other minerals. Here the rock retained some likeness to a diabase. The resemblance of certain of these rocks to somewhat altered sediments is remarkable. The author considered the bearing of this evidence upon other and larger masses of "green schist" which occur in the Alps, and expressed the opinion that their present mineral structure may be the result of great pressure acting on more or less basic igneous rocks. — The Waldensian gneisses and their place in the Cottian sequence, by Dr. J. Walter Gregory. The lower part of the sequence of the Cottian Alps has been universally divided into three series, of which the lowest has been regarded as a fundamental (basal) Laurentian gneiss. It was the o ject of the present paper to show that this rock is really intrusive in cha- racter and Upper Tertiary in age. The writer endeavoured to prove this by the following line of argument :—(i) The gneiss consists of only isolated outcrops instead of a continuous band, and these occur at different positions and not always at the base of the schist series; (2) the gneiss is intrusive, because (a) it includes fragments of the overlying series instead of vice versa, (b) it sends off dykes of aplite into the surrounding schists, (c) it metamorphoses the rocks with which it is in contact, and ((/) the schists are contorted near the junction ; (3) the gneisses were further shown to be later than the igneous rocks intrusive into the " pietre verdi " series, as these never traverse the gneiss. No positive opinion as to the age of the overlying schists was expressed, though it was pointed out that the recent discovery of radiolarian muds in the series may necessitate their inclusion in the Upper Palceozoic. The freshness of the gneisses, the fact that these have not been affected by the early Tertiary earth-movements, and the absence of authentic specimens of the gneiss in the Cretaceous, Eocene, and Miocene conglomerates, renders their late Tertiary age highly probable. The nature of the contact-metamorphism and the origin of the gneissic structure were discussed, and a classification offered of the earth-move- ments in the Cottian Alps. A discussion followed, in wtiich the President, Prof. Judd, Mr. Barrow, Prof. Bonney, Mr. A. M. 404 NATURE [February 22, 1894 Davies, Mr. Vaughan Jennings, and Dr. G. J. Hinde took part. The author briefly replied. Paris. Academy of Sciences. February 12. — M. Lcewy in the chair. — On a theorem connecting the theory of synchronisation with the theory of resonances, by M. A. Cornu. A demon- stration is given leading to the theorem : "A verysmall periodic I'orre, varying wiih the time according to any law capable of development by Fourier's series, is equivalent in its action on a vibralii'g system, damping slowly and of almost the same period, to the simple pendular force represented by the terms of the first order of the series." The general character of synchronisation is pointed out, and the necessity of considering it where resonance i'^ an important property is insisted on. — New experiments on the production of artificial diamonds, by M. Henri Moissan. — On interior pressure in gases, by M . E. H, Amagat. The author defines interior pressure asir= (T-^-/! and traces its value for carbon dioxide, ethylene, oxygen, nitrogen, air, and hydrogen. With the more perfect gases, ir as the volume decreases first increases to a maximum, and then decreases ; the maximum for hydrogen is reached at a couipara- tively low pressure, and tt for this gas continues decreasing through zero to a negative value. With ethylene and carbon dioxide the maximum has not been reached. — On the time of departure for the Iceland fishery, by M. Jean Sicard. — Note on the solar observations made at the Lyons Ol)servatory (B runner equatorial) during the second quarter of 1893, by M. J. Guillaume. — On rectilinear congruences and on Ribancour's problem, by M. E. Cosserat. — On a characteristic propeity of the linear element of spiral surfaces, by M. Alphonse Demoulin. — On some points in the theory of functions, by M. Emile Borel.^ — On a theorem concerning harmonic functions of several real variables, by M. G. D. d'Anme. — Researches on the mode of combustion of balli-iic explosives, by M. Paul Vieille. The author has studied the character of explosions under pressure, and will publish the results in a coming [>aper.- — On the conductibiliiy of discontinuous conducting substances, by M. Edouard Branly. Two hypotheses appear to explain the experimental results : — (i) The insulator interposed between the conducting particles becomes a conductor by the passage of a current of high potential, ai d the observed phenomena characierise the Ciky. — On the aniituxic property of the t)l<>od of animals vaccina ed against viper pmson, f)y MM. C. Phi^alix and G. Bcrtrand. If viper poison be mixed with certain proportions of the detibrina ed blood (if an inocu- lated animal it fails to pnison on injection. — Researches on the anaiomv and development of the fe.uale genital armaiature in lepidop'erous insects, by M. A. Peyt-ureau. — Observations on h)permetamorphosis or hypnodia among the cantharuiise. The stage called pseudo-chr\>alis, ciin>idered a> a ptienomenon of encystment, by M. J. Kiiickel d'Herculais. — Salivary glands of hymenoptera of the faaiily of the Crabronidae, by \1. Bur 'as. — On some parasites of the Lepidudendra ol Culm, by M. B. Rrnauli.- — Observations on the character of the relation-hip between platinum and its mother- rock, 17 M Stanislas Mcunier. The autbor points Mut the agreemt- nt between the views ol M. Inosiraiizeff (C R. January 29) and his o*n previously published ob-ervations. The metallic platinum must have been deposited in the inter>tices of leridotic masses by the interaciiun 01 hydrogrn and platinic chloride vapours at a red heat, much below ihe temperature of fusion of tlie r^ck. — On a be.i of apophylliie in the environ-i of Collu (Algeria), by M. L. Gcntil. — Eru|itu>n of the volcano C-tlbuco, by M. A. F. Nogues — Rtmaikson the earthquakes in the island of Zante during 1893, by M. A. Issel. NO. 1269, VOL. 49] BOOKS, PAMPHLETS, and SERIALS RECEIVED, Books. — The Student's Introductory Handtiook of Systematic Botany: J. W. Oliver (Blackie). —A School Course m Heat ;th eduim : VV. Larden (S. Low). — Rematkable Comets. .;nd edition: W. I". Lynn (Stanford). — Celestial Motio is. 8ih edition: W. T. Lynn (Stanford). — The Voices of the Siars: J. E. Walker (Stock). The Universal f.lectrical Directory. 1894 (Alabaster). — B 'urne"s Handy Assurance Directory, 1894 ; W. Schooling (London). — Social Kvolution : B. Kidd (MacmiUan). — Manures and the Principles of Manuring: C. ^^ Aikman (Biackw od). — SociiSt^ d'Encou- ragemeni pour I'lndustrie National Annuaire pour I'.Ann^e 1894 (Pans). — A Memorial \V .rk, chitfly on Botany and Zoology, in Conimemoratiun of the Ninetieth anniversary of Kei>.uke Ito, 2 vols. T. Ito(Nngoya, Japan. Pamphi F.TS — Imitaiion : a Chapter in the Natural History of Conscious- ness : Prof. J. M. Baldwin. — Stonyhurst College ' ib'-ervatory. Results of MeieoroloKical and M ignetical Observations, 1893 (Clitheroe) — Erinnerung an Eilhard Mitscherlich. 1794-1863 (Berlin). — Guide to the Examinations in Elementary Agriculture and Answers to Questions, Elemcniary Mage, 1884-93 (Blackie) — The Internal Work of ihe Wind : S. P Langiey (Wash- ington— Revision ofthe Japanese Species of Pedicularis, L. : T. lto(Vagoya, Japan). — Note on the Burmanniacee of Japan: T. Ito (Nagoya, Japan). — The Development of the Skeleton of the Limbs of the Horse: Prof. J. C Ewart. Serials. — Journal of the Chemical Society, F«bruary (Gurney and lack son). —M'-moirs anlin, Band x.\. No. 10 (Berlin) American Journal of Mathematics, Vol. xvi. No i (Baltimore). — Proceedings of the Royal Society of Edinburgh Session 1892-3. Vol. xx. pp. 97-160 (Edinburgh). — Transactions of the Royal Society of Edinburgh. Vol. xxxvii. p.irts i and 2 (Edinhurgh). — Himmel und Erde, February (Berlin). B Uettino della Societa Geografica Italiana, Serie 3, V'^l. 6, fasc. 10 and 11 (Koma). — Indian Museum Nfntes, Vol. vii. No. 7 (Calcutta). — J. urnal ot ihe Asiatic Society of Bengal, Vol Ixii. part 2. No. 3 (Calcutta). — Journal of the Anthropolo ical Insiitute, February (K. Paul). — Harvard University Bulle- tin, January. — American Meteotol gical Journal, February (Ginn). CONTENTS. PAGE Boltzmann on Maxwell 381 The Story of the Sun. By A. Fowler 382 The Lepidopiera of the Atlantic Islands, By W. F. Kirby . 384 The Active Principles of Plants 385 Our Book Shelf - Zacharias : " Forschungsberichte aus der Biolo- gi-chen Station zu Pion." — F. W. G 385 Hiller : " Biology as it is applied against Dogma and Freewill, and for Weismannism." — P. C. M. 386 Gla^cbrook : " Heat : an Elementary Text- Book, Theoretical and Practical, for Colleges and Schools ' . . 386 Bonney : " Electrical Experiments " 386 Letters to 'he Koiioi : On M. Mercadier's Test of the Relative Validity of the Electrostatic and Elect lOmaj^jnetic Systems of Dimensions. — Prof. Arthur W. Riicker, F.R.S. 387 The Cloudy Condensation ol Steam. — Shelford Bid- well, F.R.S 388 On the Cardinal Points of the Tusayan Villagers. — ^J. Walter Fcwkes 388 The -icamiinavian Ice-sheet. — Prof. T. G. Bonney, F.R.S 388 The Niimenclature of Radiant Energy. — Prof. A. N. Pearson . 389 The Fecundations of Dynamics. By Prof. A, Gray . 389 An Incident in the Cholera Epidemic at Altona. By Prof. Percy Frankland, F.R.S 392 Notes 392 Our Astronomical Column : — Sun-spots and Magnetic Disturbances 397, S'onyhurst College Observatory 397' The " Annuaire " of the Buieau des Longitudes . . 397 I he S[ieetium of Nova Nutmse 397 The Smithsonian Institutio.i Report . . . 397 The Giccniand Expedition of the Berlin Geo- graphical Society 399! The sun-spot Period and the West Indian Rain- fall. By iVlaxwell Hall ... -399 On Prepan.f; iiie Way for Trchnical Instruction. B> Sir Pnilip Magnua . 40° University dno Eauc-itional Intelligence 40' Scientific SeriaiS . ... 40^1 Societies 4nii Acaderait-s .... . • 4^^ i Books, Pamphlets, and Serials Received 4°"' 1 NA TURE 405 THURSDAY, MARCH i, 1894. THE REPORT OF THE GRESHAM UNIVERSITY COMMISSION. THE "Report of the Commissioners appointed to consider the Draft Charter for the proposed Gresham University in London, together with Dis- sentient and other Notes," is a document of sixty-three pages full of important matter from beginning to end. It bears evidence of very careful thought, and is worth attentive study. The Commissioners accept at once two principles, both of which were included in, and one of which was peculiar to, the scheme of the Association for promoting a Professorial University in London.^ They lay it down that there should be one University only in the metropolis, and that the changes which they recommend should be eflfected not by Charter, but by legislative authority, and by the appointment of a Statutory Commission. They thus adopt the only satisfactory theoretical solution of the problem, and the only possible way of putting theory into practice. Every one is tired of the game in which the shuttlecock is tossed backwards and forwards from the University to the Colleges, from the Senate to Convocation. London and learning cannot wait in- definitely. The time has come when Parliament must arbitrate between conflicting views and interests. The Commissioners also decide that the same University is capable of carrying on simultaneously systems of internal and external examinations, though Prof. Sidgwick has thought it right to express his dis- approval of this conclusion. They further propose that the scope of the University shall be enlarged in respect both of the subject-matter and the method of its teaching, so as to include six Faculties, viz. .Arts, Science, Medicine, Law, Theology, and Music. The first two of these are, of course, fundamental, and we hope that even if difficulties should arise with regard to the others, the foundation of a Teaching University in London, with the Faculties of Arts and Science only, will not thereby be pre- vented. If the existing University and the institu- tions of University rank which are chiefly interested in Arts and Science can be united, a most important result will have been achieved. The law of gravitation will in time do the rest. We shall, therefore, confine ourselves chiefly to the proposals of the Commissioners with respect to Arts and Science, but a mere recapitulation of their recommenda- tions would be of little interest unless the points of agreement with or divergence from previous schemes were indicated. We propose, then, in the first instance to institute a comparison between the scheme of the Commissioners and three of the more important proposals which have been made in the course of the long discussion as to the best constitution for a Teaching University in the metropolis. The abortive Gresham Scheme may at once be put on one side. Its authors aimed at founding a 1 This will be hereafter referred to as the Association Scheme. NO. 1270, VOL. 49] second University in London. Everyone now agrees that there should be one only. The schemes which we select for our purpose are (i) the so-called Revised Scheme, which was approved by the Senate but rejected by the Convocation of the University of London ; (2) the scheme approved in 1893 by Convocation ; and (3) the Association Scheme. The "Revised Scheme" and that of Convocation differ from the others in that their authors contemplate the possibility of the University having direct relations with educational institutions outside the metropolitan area. As it is probable that the teaching operations of the new University will be confined to London, we shall pass over this point without further reference. The Association and Convocation agree in fashioning the University out of materials which closely correspond to the " Chancellor, Masters, and Scholars " of our older seats of learning. On the other hand, the Revised Scheme and that of the Commissioners make a beginning with such bodies as the Senate, Convocation, &c. The matter is not of fundamental importance, but it is necessary to refer to it as the phrase " the University shall consist of" is applied in different ways. Putting this difference aside, the government of the University is distributed among various bodies named as follows : — Revised Scheme Convocation Association Commissioners Senate Convocation Constituent Colleges Faculties Board of Studies Senate Convocation Professoriate Faculties Board of Studies Court Convocation Professoriate Senate Convocation Academic Council Faculties Board of Studies In what follows we shall use the word Senate to desig- nate the Supreme Governing Body of the University. Its constitution under the different schemes is as follows : — Nominated or Elected by Revised Scheme C onvoca- tion Associa- tion Com- missioners Crown 10 8 15 3 Ministers . — — 5 Convocation 10 12 3 9 Institutions represent- ing : (o) Medicine . 4 2 — 5 (3) Law 2 2 — 6 (7) Applied Science — — — 4 (5) Pure Science . — — — 2 (e) Education 10 2 — 5 Corporation, County Council, &c. . — 4 4 4 Teachers in University or Colleges . 16 10 25 22 Nominated by Senate itself — — 4 — Total 52 40 " 65 It will be observed that while but slightly reducing the absolute number of members claimed by Convocation S 4o6 NA TURE [March i, 1694 and the Association for the interests with which they are specially connected, the relative importance of the re- presentation of the graduates and the Professors has been reduced by the Commissioners. The reduction has been about in the proportion of one-third to one-seventh in the case of Convocation, and one-half to one-third in the case of the Teachers. We are inclined to think that Convocation is still over- represented, and should have been glad to see the principle admitted that half the entire Senate should consist of Teachers in the University. As far as these numbers are concerned, however, we accept the decision of the Commissioners as that of a body of men who have weighed most carefully the evidence submitted to them, and have evidently tried to do impartial justice. A mere numerical comparison, such as the foregoing, does not, however, show all the points of difference between the schemes. The most fundamental divergence is in the proposed relations between the University and the chief Educational Institutions which already exist in London. The Revised Scheme contemplated the establishment of Constituent Colleges, that is, institutions which the University recognised as giving teaching of University rank in some or all branches of learning. The Teachers in the Constituent Colleges who were thus recognised by the University were grouped into Faculties, to which bodies certain powers and privileges were given. Over and above this the Senate was to have the power of entering into arrangements with any Constituent College by which it approved certain courses of study given in the College, accepted certificates of attendance at such courses, recognised special examinations con- ducted in the College by a College Professor and an adjoint Examiner appointed by the Senate, and gave Degrees to candidates who attended the specified courses and passed the special examinations. A Standing Com- mittee of the Senate was to co-operate with the Con- stituent Colleges in the organisation and improvement of University Teaching in and for London, "including the establishment of Professorships." Inasmuch, how- ever, as the Faculties were to consist of Teachers of the Constituent Colleges only, and no provision was made for the admission to them of University Professors who were not connected with a Constituent College, it would appear that the University itself was not to be a Teaching Body. As far as the Colleges are concerned, this was in effect the plan which has worked successfully in the Victoria University. The Colleges were to be independent, to appoint their own Professors^ to find their own funds. If they succeeded they were to be recognised, and to share in the government of the University. Success would de- pend in part on the number of their students. Hence they were to be rivals, but the University would neither help nor hinder them. Equal privileges could be won by all. They would be impartially withdrawn from those v;ho failed. The idea of recognising special examinations to suit special needs was an advance, and a very important advance, on the scheme of the Victoria University. A fundamental difference between the two Universities would, however, have been that, whereas the Victoria University can only give Degrees to candidates who have NO. 1270, VOL. 49] passed through a College of the University, the Uni- versity of London would have been able to give Degrees to all-comers, as well as to make special arrangements for students in Constituent Colleges. The scheme of Convocation went a step further. It contemplated the possession by the University of inde- pendent laboratories, and therefore of a teaching staff of its own. It also proposed that Professorial Chairs in other Institutions should be endowed by the University on condition " that the appointment to such Chairs whenever a vacancy occurs should pass to the Univer- sity." It was not stated whether the Professor so appointed should be subject to the University only, or whether he should be under the partial or exclusive con- trol of the Governing Body of the College in which he worked. The Professorial Scheme was very similar. Every Professor of the University was to be appointed and paid by the University, and a Statutory Commission was to make arrangements with existing Institutions for complete or partial incorporation. The Commissioners propose that certain Institutions, or departments in Institutions, shall be recognised as Schools of the University. The teachers in these Schools must be individually approved to secure a University status. The principle laid down by the Professorial Association, that Teaching Insti- tutions as such are not to be represented on the Senate, is accepted, and thus the Constitution of the University is not in theory federal. On the other hand, places on the Senate are allotted to University College, King's College, the Royal College of Science, and the City and Guilds of London Institute, "regarded as important and wealthy public Corporations, or Societies, having and exercising wide educational aims and powers in connection with University education in London." The distinction is rather a fine one, but we gather that in the Commissioners' opinion King's College ought to have two representatives on the Governing Body, even if some theological difficulty led to its refusing to accept the position of a School of the University. The Commis- sioners decline to accept the idea either of immediate or of ultimate absorption of Educational Institutions as the basis of the University. But even if this is so, we think that they have gone too far in allotting a definite number of representatives to certain Teaching Institutions which happen at the moment to be the most important in London. The very exist- ence of the Royal College of Science depends on the will of a Minister. We suppose that the City and Guilds Institute would collapse if the subventions it receives from the City Companies were withdrawn. The Com- missioners themselves would surely be unwilling to throw any obstacles in the way of the complete absorption of University College by the University if in twenty years time it should itself desire it. Yet as matters stand any such change would involve a change in the Charter. It would surely be better to allot six representatives to the Governing Bodies of important Educational Institutions to be distributed in the first instance as the Commissioners propose, with the condition that the Senate may from time to time revise the list, subject to an appeal to the Privy Council. This at all events would secure greater flexibility. It is also possible that the Senate might March i, 1894] NATURE 407 delegate the government of institutions founded by the University to committees like the Kew Committee of the Royal Society, and, subject always to the approval of the Privy Council, there seems no reason why, if the number of independent Teaching Colleges were diminished, the places of their representatives should not be occupied by experts chosen from among the members of such Committees. • Among the Institutions which the Commissioners think should be at once admitted in whole or in part as Schools of the University, those which would be chiefly concerned with the Faculties of Arts and Science are the following : University College. King's College. The Royal College of Science. The City and Guilds of London Institute. Bedford College. And six Theological Colleges. The University is to be able to appoint Professors and to found Teaching Institutions of its own, and it is also to have the power "to allocate funds for the enlargement and assistance of the teaching staff of recognised institu- tions, the extension of their buildings, the improvement of their equipment for teaching and research, and the endowment of University Professors, Readers, Lecturers, Demonstrators, or assistants, or for other purposes in connection with such institutions." It is to be "under- stood that in these cases the University will impose such terms and conditions as will secure to it a reasonable and proper amount of control over the educational resources thus provided, and will have the power of determining the duties of the University Chairs which it establishes or subsidises in any institution, and of regulating the fees payable for attendance on the lectures." " But," the Commissioners continue, "we do not think it necessary to lay down any rules which would fetter the discretion of the University in this matter. We take it for granted that it will be the endeavour of the University and of the institutions to organise a homogeneous system of Uni- versity education, to utilise, to combine, and to economise ■existing resources to their fullest extent, and to supple- ment them in such a mode as will best serve the progress of knowledge." In spite of this optimistic view of the future, it may be feared that the financial relations between the Colleges and the University will be difficult to adjust. Indeed, there are several points on which the Government will have to decide before putting the scheme into operation. The University will have to be endowed by State or Municipal funds, if it is to be able either to subsidise or to add to the number of Colleges. If no such funds are provided, the state of things contemplated in the Revised Scheme will, in effect, be realised. The Colleges will be pecuniarily independent of the University, and since the University is to have no power of control except in re- turn for subsidies, it will only be able to influence the " Schools '' indirectly by visitation and by prescribing courses of study for the Degrees. The Commissioners, however, evidently contemplate the large endowment of the University by the State. In this case it may have a more important part to play ; but unless the control it claims in return for subsidies is NO. 1270, VOL. 49] sufficiently great to act as a deterrent, there will certainly be an undignified scramble for funds among the Colleges. It will be a miserable ending to the long controversy if the University is to be merely the guardian of a Government Grant fund, doling out one paltry sum here to build a second-rate laboratory, and forth^vith bound to match it by another grant there, just to show that, like Justice, it is blind. If the University establishes on a German scale a laboratory of its own, chiefly intended for post-graduate study, there will be an outcry against divorcing teaching from research. If it selects one existing Institution as that with which the laboratory is to be connected, it will be held to be neutralising the public- spirited efforts of the promoters of the others. If it tries to level up all round, it will achieve nothing really great. We do not say that such results must necessarily follow from the realisation of the scheme of the Commissioners, but the Commissioners themselves appear to have thought that the only way out of the difficulty was to appeal to the good feeling and good sense of all concerned. It is evident that the future of the University largely depends upon whether their appeal is successful, and upon the action of the Statutory Commissioners when appointed. It might be possible to establish " spheres of influence " in the territory of Knowledge as well as in the Dark Continent. But whatever device be adopted, it cannot be made too clear that the Commissioners leave to the Statutory Commission and to the University itself the solution of the most difficult problems connected with its establishment. The character of the University will largely depend upon its relations with the Colleges, and. their relations have yet to be defined. We do not point to this " lacuna" in a spirit of adverse criticism. As nothing is known about the funds and resources the University will possess, it would probably have been useless for the Commissioners to have made detailed suggestions. But it is all-important that those who have most knowledge and experience in educational matters should agree upon some scheme more subtle than the suggestion that Colleges, like savages, should adhere to the good old rule — " That he should take who has the power, And he should keep who can." The relations of the Colleges and of the Teachers toahe University are so intertwined that it is difficult to separate them. In what has been said, however, stress has chiefly been laid upon the former. We now turn to the position of the Teachers in the University. The Association Scheme insisted that every Professor of the University should be " appointed and paid by the University." The Commissioners state that this " re- stricts within a narrower area than any other scheme which has been proposed to us the class of teachers who are permitted to share in the Government of the University." It is doubtful whether this was the intention of those who framed the Association Scheme. They un- doubtedly desired that the University should be a Teaching University, and not merely a body with funds to be exploited by Teaching Colleges. Their proposal, therefore, was that all Professors teaching in the name and on behalf of the University should be directly responsible to it, and should therefore be paid by the 4o8 NATURE [March i, 1894 University, whether the ultimate sources of their emolu- ments were provided by it or by a College. The regu- lation was probably intended to indicate a status, and not to restrict the number of those who attained it, and we hope it will be incorporated in the final scheme. But if this is so, it must be admitted that the Association's proposal is open to the second criticism which the Coin- missioners pass upon it. It created, they say, a single and undivided assembly of Teachers, on which, though in subordination to the Court, it conferred not only deliberative and consultative, but executive powers in matters which must necessarily involve much detailed and constant supervision. In opposition to this the Commissioners group the Teachers into Faculties, and allow them to elect a very important body to be called the Academic Council, It is to consist, in addition to the Vice-Chancellor, of fifteen members, chosen as follows : Arts 4, Science 4, Medicine 3, Law 2, Theology i. Music i. The term of service is to be four years. Six to be a quorum. To this body will be entrusted the duty of regulating, subject to the Ordi- nances of the University, the teaching, examinations, and discipline of the University, and of determining what Teachers in any school of the University shall be recognised as University Teachers, and to what Faculties they shall be assigned. In addition to these executive functions, it will be its duty to advise the Senate upon the affairs of the Uni- versity, and particularly upon the assignment of funds for the erection or extension of buildings and the provision of teaching or equipment in connection with admitted Institutions or otherwise, and upon a number of similar points. It is evident that by the establishment of this Council the Commissioners are prepared to give power to the Teachers of the University with no ungrudging hand. They assume that seats on the Academic Council will be held only by men of unquestioned reputation and experi- ence, whose views will command the respect of the Senate. The Council is given very wide executive powers and the right to advise on matters of the utmost delicacy and importance. The only difficulty that we see is the possible intervention of College jealousy. It will be all-important that the men who are chosen shall be not only eminent in their own lines of work, but fair-minded and possessed of administrative powers. If once the easy expedient of taking turns is adopted, or if Professors working in University institu- tions are boycotted in favour of those connected with Col- leges, or wV^ T/^rjw, the Academic Council will be a failure. These considerations will probably suffice to prevent such evils arising ; and if so, we think it possible that the Academic Council of the future University of London may develop into a body of the utmost importance, and that its views may acquire an authority which would never be attained by the decisions of a large assembly, many of the members of which would necessarily be comparatively unknown men. It will thus be seen that the Teachers of the University are to share in its govern- ment in two different ways. First, they are in their Facul- ties to elect one-third of the members of the Supreme Body or Senate ; secondly, they are to elect fifteen of their number to form an Academic Council with wide execu- NO. 1270, VOL. 49] tive and advisory powers. It only remains to add that machinery is also provided by which this Council is to be kept in touch with the main body of the Teachers,. For this purpose Boards of Studies are to be appointed, the number and composition of which are to be determined by the Academic Council, with the proviso that not less than three -fourths of any Board are to be elected by the Faculty to which it belongs, and the remainder (if any) appointed by the Academic Council. These Boards are to have advisory powers, and it is laid down that no rule should be made with regard to or change effected in the curricula unless it has either been recommended by the Board or Boards of Studies of the Faculty concerned, or has been submitted to them by the Academic Council for consideration. It is also provided that in dealing with the courses of study to be pursued at any Institution it is reasonable that the Academic Council should first consult the authorities of the Institution. In neither case, however, is the Academic Council bound to con- form itself to the view expressed by the bodies which it consults. Such then, in general outline, is the scheme for the government of the new University proposed by the Commissioners. It is in many respects bold and drastic. The existing Senate of the University of London is swept away. Thus, and in our opinion very rightly, it is made clear that the carrying into effect of the scheme of the Commissioners would be an absolutely new departure. It would be preceded by the complete dissolution of the Governing Body of the present University, no single member of which might find a place in the new order of things. The Association, or some members of it, no doubt desired that a similar act of renunciation should precede the admission of a College to the University. Had this desire been fulfilled the whole problem would have been simplified, and the chances of success enor- mously increased. It is still possible for the Govern- ment to set the example in the case of the Royal College of Science. University and King's Colleges are, however, the results of private effort. It would have been sheer confiscation to compel their Governing Bodies to resign their functions, though we believe that if they had sufficient confidence in the scheme proposed by the Commissioners to do so, their last ser- vice to learning and to education would surpass all the good work they have done in the past. Assuming, how- ever, that they continue to exist as independent organi- sations, the most that can reasonably be urged is that the scheme shall throw no impediment in the way of absorption if all concerned should ultimately desire it. The Commissioners have evidently been anxious to leave the University as free as possible to develop in this as in any other direction. In one point only — and in that probably from inadvertence — have they imposed an un- necessary restriction. Representation on the Senate should not be allotted to particular Colleges, but to a class of Institutions, the list of which is capable of being revised with the approval of the Privy Council without a change in the Charter. On the other hand, it must be admitted that the Com- missioners, like the advocates of the Association Scheme^ March i, 1894] NATURE 409 leave so much to be settled by the Statutory Commission that the ultimate character of the University is still very doubtful. Though non-federal in theory, it may be practically federal in fact, and it behoves those who are interested in the matter to do all in their power to protect it from the grave dangers which will beset the earliest stages of its career. The position assigned to Teachers, though not exactly that claimed by the Asso- ciation, is so strong and so dignified that on this point we hope there will be no further controversy. To sum up. Putting aside the relations of the Univer- sity to Theology, Medicine, Law, and Music, the scheme of the Commissioners is the Revised Scheme, improved and modified so as to be much more closely in accord with the ideas of the Association. The question as to whether the University is, as far as Arts and Science are concerned, practically a federation of Colleges, is left to a Statutory Commission to decide. The main danger with which the University is threatened is jealousy be- tween semi-independent Colleges. The only safeguard against this which the Commissioners suggest is that they taice it for granted that everybody concerned will do his best "for the progress of knowledge." To which we heartily say " Amen." S TEREOCHEMIS TR V. Handbuch der Stereocheinie. Unter Mitwirkung von Dr. Paul Walden herausgegeben von Dr. C. A. Bischoff. I. Band. (Frankfurt: H. Bechhold, 1893.) STEREOCHEMISTRY growsapace. Thebirth of this ^^ youngest scion of the chemical family, which occurred about twenty years ago, when Van't Hoff and Le Bel published almost simultaneously their now famous memoirs, was not greeted with universal acclamation. The event excited at the time but little interest among English chemists, and when the young science was introduced, through F. Hermann's Lagerung der- Atome ijn Rauine, to the acquaintance of our German col- leagues, it was regarded not without suspicion in some quarters. There was one chemist of high rank who denounced the Chimie dans VEspace as " fanciful non- sense," as the outcome of " a miserable speculative phi- losophy, whose treatment of scientific subjects is not many degrees removed from a belief in witches and spirit-rapping." Stereochem.istry, however, soon found a congenial home in the German laboratories, and flourished marvellously. About four years ago the young stripling was duly christened by Victor Meyer on the occasion of an address to the German Chemical Society, and thus received formal recognition as a legitimate member of the chemical family. Since then three general treatises have been called for in order to chronicle the progress of this latest development of chemical science— the " Chemistry in Space " of Van't Hoff, trans- lated into English and re-edited by J. E. Marsh ; Meyer- hoffer's " Stereochemie,"a later translation into German of the same work with much additional matter, and the admirable " Grundriss der Stereochemie,"by A. Hantzsch. Following quickly in the wake of these, we have, in the "Handbuch der Stereochemie," a much more elaborate -and complete treatise, chiefly from the pen of Dr. C. A. NO. 1270, VOL. 49] Bischoff, whose well-known indefatigable labours in the new field of research eminently qualify him for the serious task he has undertaken. As explained in the publishers' announcement, stereo- chemistry has extended with such rapidity in recent years, and the numerous theoretical and experimental researches in this department are dispersed throughout so many different periodicals and pamphlets, that it is not easy for anyone who^has not closely followed the subject from the outset, to obtain a general view of the develop- ment and present stand-point of the science. The object of the work before us is to remove this difficulty, and to attract more adherents to the new study. The book is further intended to exhibit the present position of all the problems which have been touched by stereochemistry, and to furnish a brief record of all the compounds which have any relation to optical and geometrical isomerism, so that it may serve as a convenient and reliable work of reference to the investigator. The first volume of the treatise, extending to about 450 closely printed pages, comprises a general part, entitled "Die historische Entwickelung der Principien der Stereochemie," and the first subdivision of a special part, dealing with the relations of stereochemical theory to the phenomena of optical activity in organic com- pounds. The second volume, which is to appear shortly, will contain the remaining two subdivisions of the special part, which are to treat respectively of geometrical isomerism, and of the influence of intra-molecular space relations on chemical reactions. The book has two distinct aims, which it is not easy to combine. As a work of reference the " Handbuch," we believe, fulfils all its claims, and will supply a much-felt want. The matter throughout is well up to date, the references to literature are copious, and the systematic account of all the known optically active organic com- pounds, which occupies more than half the volume, is the only complete collection of the kind we have at the present time. The organic chemist will understand the force of the commendation when we describe the book, from this point of view, as a stereochemical Beilstein, which will be indispensable in every laboratory where stereochemical research is being conducted. With re- spect, however, to the other purpose of the book, that of presenting a general picture of the development and present position of the science, the result is less satis- factory. The general part, which, judging from its title, was written with this end more particularly in view, is somewhat disappointing. The history of stereochemistry is an extremely fascinating subject ; it contains all the elements of a good sensational scientific story, mys- terious facts, wild speculations, ingenious hypotheses, beautifully verified predictions ; but the subject as here presented is, to our mind, rather dry. The title of the chapter indicates that the development of the principles of stereochemistry is to be brought prominently into view ; but we shall be surprised if the student, unless he is already pretty familiar with the literature of the sub- ject, does not rise from its perusal, so bewildered in a maze of subtle speculation and conflicting hypothesis, as to conclude that stereochemistry has really no principles to develop. The introduction into a work of this kind of the speculation and hypothesis, to which stereochemical 4IO NA TURE [March i, 1894 discovery has given such a wonderful impulse, is of course not only justifiable, but highly necessary at the present stage. It is not to this, nor to the matter of the book gene- rally, which indeed is admirably selected, that we venture to take objection, but rather to the method of treatment. The method adopted in the general part is not calculated in our opinion to present a history of the development of the subject in a striking and lucid manner. The chapter really consists of a series of abstracts of memoirs, -anting over the whole field of stereochemistry, placed in chrcrnological order of publication, to which the author seldom adds expository or critical remarks. The paucity of experimental facts in illustration of the theories described, adds still further to the unattractiveness of the pic:ure. The author, it is true, expressly states in the preface that details have been intentionally omitted, but the unavoidable result is that the abstracts are in many cases so bald as to be shorn of much of their interest, and the often repeated reference to the special part for application of the theories described becomes tantalising. Stereochemistry has already in the short period of its existence pushed its way in so many different directions, that to present an effective picture of its growth, it would be necessary to trace its development along a number of more or less independent lines. The opening chapter of the special part, we ought to state, supplies this want to a great extent with respect to optical isomerism, and similar sketches will, no doubt, be given in the other subdivisions. The idea that the relative position of atoms in space within the molecule, must be an important factor in de- termining the properties of compounds, was, no doubt, present to the minds of many of the founders of the atomic theory, and it is interesting to learn from a correspondent in these columns (vol. xlix. p. 173) that Wollaston had a very clear conception of this fact. The history of stereochemistry, however, begins with Pasteur, and we are glad to see that the importance of his ex- perimental discoveries and far-seeing predictions receive ample recognition. A portrait of the veteran chemist is placed opposite the title-page, with that of his younger colleagues, Van't Hoff and Le Bel. As is generally known, these two distinguished chemists arrived at their fruitful theory of the asymmetric carbon atom by two entirely different paths, and their positions with respect to it are by no means identical ; indeed, Le Bel has entered a protest on several occasions against his views being confounded with those of Van't Hoff. The disadvantage of the chronological method, to which we have alluded, is very apparent here, for to form any adequate idea of Le Bel's present stand-point, the reader has to hunt up the summaries of various papers which are scattered throughout the general and special parts. The views held by Le Bel are particularly interesting-, as they lead him to sundry fundamental conclusions, which must seem very heretical to those who have adopted the doctrine of Van't HofF without qualification into their chemical creed. Thus he has recently concluded that even a molecule of the type CR4 does not necessarily possess a configuration which can he symbolised by a regular tetrahedron, and that the usually accepted argu- ment for the symmetrical distribution of the four hydrogen atoms in the molecule of marsh gas, based on the exist- NO. 1270, VOL. 49] ence of only one monoderivative, is unsound. The experimental ground of his conclusion is the more interest ing, as it furnishes one of the few instances in which the obvious property of the crystalline form of a compound has been used for the purpose of determining its mole- cular configuration. He finds in fact, contrary to Wislicenus' prediction with respect to compounds of the type indicated, that carbon tetrabromide does not crystallise in the regular system. Again, Le Bel's views do not exclude the possibility of optical isomerism in unsaturated bodies, and he finds indeed that solutions of citraconic acid become strongly active when mould is grown in them ; should this discovery prove to be due to the production of an active isomeride of this acid, the discovery would revolutionise an important branch of stereochemical theory. Such considerations remind us that the prevailing stereochemical theories, fruitful as they have been, are nevertheless only a first approxi- mation to the truth, and will have to undergo important modifications with the progress of discovery. The reader of Dr. Bischoff's book will find abundant food for reflection in the numerous monographs, of which very good abstracts are given. Many of them, dealing with such fundamental subjects as the nature of chemical affinity, valency, the significance of double and treble linkage, the influence of the form and motion of atoms on chemical action, are highly interesting and suggestive ; some of these papers will be already familiar to the readers of the Berichte and Annalen, but others which have been published in separate form are not readily accessible to the English chemist. The perusal of the opening chapter will convince the reader that stereochemical conceptions are already initiating a searching revision of the very foundations of the chemical edifice, and that they are destined in the near future to play an important, perhaps a predominant, part in the progress of chemical theory. ■.. We may add that the book is abundantly illustrated with geometrical figures, and that a detailed index is promised with the second volume. We have observed the following misprints: "sym- metrischen " instead of " unsymmetrischen" in the last paragraph, p. 24 ; " + " instead of "x," p. 97 ; " Nach- wirkung" instead of " Nahewirkung," p. 121. T. P. MARINE BOILERS. By Marine Boiler Management and Cotistruction. C. E. Stromeyer. (London: Longmans, 1893.) THE difficulties attending the economic management of marine boilers have engaged the serious atten- tion of engineers for many years, and Mr. Stromeyer's book will be welcomed as by far the most valuable addition which has been recently made to the subject. The author treats in detail the generally accepted plans for the construction and methods of management of marine steam generators, and discusses, more or less fully, the causes of corrosion and other sources of wear and tear in boilers. Fuels and the conditions of heat transmission through plates are treated at length, whilst in the latter portion of the book, strength of materials March i, 1894] NA TURE 411 and details of boiler construction and design are discussed. It is a matter for regret that from so good a book a certain number of errors could not have been eliminated. Thus, in speaking of the pitting of boiler plates below the surface of the water, the author states that in con- tact with the heated portion of the plate, the water gives up its dissolved air in contact with the surface of the metal, and that the bubbles there remain until large enough to rise, and he considers that during this period of rest the "nascent" oxygen which they contain will attack the iron. The idea that oxygen driven out of solution by the action of heat possesses the powers attributed to the nascent condition, will come as a sur- prise to his chemical readers. And again, on p. 6i it is stated that in the lungs the process of slow combustion is continually proceeding. In an age of specialism it is unlikely, and perhaps undesirable, that an author should speak witli equal authority as engineer and physiologist. Reference to any modern text-book of physiology would have made clear the fact that diverse as may be the opinions as to the actual field of oxidation, the author appears solitary in selecting the lungs as the sphere of action. The collection of formulas put forward by various authorities for calculation of the calorific value of fuel from its chemical composition is very complete, but the author might have insisted more strongly than he has upon the errors inseparable from any such calculated heat values, which are due to our present ignorance of the molecular groupings in coal, and the thermal changes attending its formation. An amazing confusion of idea is exhibited in the state- ment made on p. 69, " that gun-cotton ignites so readily that it could not be used for ammunition until it was dis- covered that the admixture of camphor or nitroglycerine raised this temperature." In the table of temperatures of ignition, on the same page, the ignition point of coal is given at 600° F. ; this, on the evidence of recent experi- ments, is too low. In the valuable chapter on heat transmission, no men- tion is made of one of the chief sources of loss in the passage of heat from the furnace to the water, namely, that the burning furnace gases are extinguished by con- tact with the comparatively cold surface of the plates, with the result that the flame never comes in contact with the metal, a layer of unburnt gas of very low conductivity existing between flame and plate ; and this not only im- pedes the passage of heat to the water, but the gas creeping along the surface of the metal often escapes combustion, both in the furnace, combustion chambers, and tubes. Coming to the engineering portion of the book, there is much which will excite comment from practical men. In the basic Bessemer steel process using phosphoric pig-iron, the purity of the blown metal is usually judged by the bath sample " fracture," which is quite as easy to gauge as a sample from the open-hearth working, and the procedure given in paragraph 6, p. loi, is at vari- ance with every-day practice. Again, in describing the acid Siemens-Martin process, on p. 103, the author speaks of adding 25 per cent, scrap-iron, the ordinary practice being to charge steel scrap with the pig-iron before melt- NO. 1270, VOL. 49] ing. In fact, scrap-iron could not be used in any quan- tity in this process, on account of the phosphorus and sulphur often contained in it ; and it is the custom in most works to pick out all the iron found amongst the steel scrap for use in the Siemens-Martin furnace. On p. 107 there is an excellent paragraph on cold bending, which contains valuable suggestions ; but the remark that the bending of samples after annealing is valueless, may be objected to. The obvious reason of doing so is to bring the sample to the same condition as the finished article, and it is a common practice to specify that flange plates, or plates which have to be worked in any way, shall be annealed as a final process to bring them to a uniform condition ; they may have been rolled at various temperatures, in which case the tensile and elongation tests would vary considerably. Nor will Mr. Stromeyer's remarks upon drift tests meet with the general approbation of railway engineers. Surely, also, the first paragraph on p. 122, when considered in con- junction with the remarks on annealing made on p. 107, are of a contradictory nature .'' The opinions expressed in the first paragraph of p. 156 are not justified by results of recent experiments, and the percentage of failures on the weld is not nearly so high as one would be led to expect from the experimental figures given on p. 157. The tools described as being in use in boiler shops, on p. 182, are of an old-fashioned type, for special machines with three or more spindles capable of drilling up to 120 tube holes per day of nine hours, without any pre- paration of the plates, such as punching or drilling small holes, have been in use in most shops for a considerable period. The statement made on p. 237, that fitting a sufficient number of stay tubes will overcome the trouble consequent upon forced draught, is open to criticism, as it is not borne out by facts, and has indeed been the cause of considerable trouble in boilers. It would have been better on the whole, considering the large number of books which now exist on design, to have curtailed the space devoted to this branch of the subject, which, although no doubt useful to the young draughtsman, might with advantage have been omitted from Mr. Stromeyer's book. These are minor and technical criticisms of an excel- lent work, exhibiting signs of much industry in com- pilation. The author is to be especially commended for his habit of reference on all occasions to the source of information. OUR BOOK SHELF. Chapters on Electricity. By Samuel Sheldon, Ph.D. (New York : Charles Collins, and the Baker and Taylor Co.) In the preface the author states that "these chapters on electricity, prepared for and included in the fourth revised edition of Olmsted's ' College Philosophy,' are here offered in a separate volume." The chapters deal in much the usual way with the stock work commonly found in elementary text-books on magnetism and electricity. The writing, however, appears to have been carefully done ; the general style is clear and concise, but a little more explanation would, inmany cases, have added to the clear- ness and, in a few cases, to the accuracy of the work. 412 NATURE [March i, 1894 In connection with Coulomb's law, the statement that F = Q/r- (Art. 581) is "strictly true only when the two bodies are in a vacuum," requires a little more elucidation than the author gives. Similarly the explanation of polarisation, the definition of specific resistance (in terms of the metre and square millimetre), the statement of Ohm's law, and the laws of thermo-electric phenomena require more detailed and accurate treatment. The paragraphs on recent work, such as Hertz's ex- periments, theories of magnetism and electrolysis, and modern theories of the ether, are far too meagre to be of any service ; they give no information even to the student who is able to read between the lines. Apart from thesa points, the book appears to present a fairly reliable exposition of the elements of the subject, which may justify its issue as a separate volume. Meteo-Tdogy. By H. N. Dickson, F.R.S.E. (London: Methuen and Co., 1893.) In this little book the author has attempted to lay down "a certain amount of 'permanent way' specially adapted to practical purposes, but at the same time leading to- wards the more theoretical grounds of modern research." The fundamental facts and principles stated in the earlier chapters furnish the inquirer with much of the necessary stock-in-trade of information culled from other branches of science; as, for example, the behaviour of gases under varying conditions of temperature and pressure. Cyclones and anticyclones receive some- what detailed consideration, but the account is very intelligible, and the mathematical expressions are of the simplest character. The present position of meteorology in regard to weather-forecasting is very clearly and im- partially stated. In the chapter on mstruments the author leaves a little to be desired in the shape of illus- trations and descriptions, especially as he aims at pro- ducing a practical treatise. An excellent account of cloud classification is given. The relation of meteorology to agriculture is a subject of great practical importance, and this is carefully discussed in the final chapter. The author has availed himself of all the most recent sources of information, both British and foreign, and the references to original papers form a valuable feature of the book. To all who desire to carry theirmeteorological observations beyond the mere hobby stage, we heartily commend this little book. posing an edifice has been built, and the only "variant " of it deserving of consideration is to the effect that the price of the big egg was five instead of two francs. I may add that this- simple story was published by the late owner of the egg, the Baron Louis d'Hamonville, in the Bulletin of the French Zoo- logical Society for 1891 (tome xvi. p. 34), Alfred Newton. Magdalene College, Cambridge, February 24. LETTERS TO THE EDITOR. [ The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected 7nanuscripts intended for this or any other part of Nature. No notice is taken of anonymous communications. \ Great Auk's Egg. Imagination has long had a large share in the accounts given of the Gare-fovvl or Great Auk, notwithstanding the efforts of those who have tried to set forth nothing but the truth on the subject, yet I do not call to mind meetmg with so " many inventions " regarding it as have appeared in the newspapers within the last week, on the occasion of the recent sale of a specimen of the egg of that bird. I should occupy too much space were I to dwell upon them ; but 1 would ask for the admission of a few lines in which to state what is known exactly of the origin of that specimen, which I well remember in the collection of the late Mr. Yarrell. He told me, as he told others of his friends, that he bought it in Paris ; and, to the best of my belief, not many years after the peace of 1815. In a little curiosity-shop of mean appearance, he saw a number of eggs hanging on a string ; he recognised one of them as an egg of Alca impeiinis, and asking their price was told that they were one franc apiece, except the large one, which from its size was worth two francs. He paid the money and walked away with the egg in his hat. That is the whole story on which so im- Frost-Cracks and " Fossils." Several letters appeared in Nature last winter describing some of the more interesting plant-like forms due to frost acting on various surfaces, and both Prof. Meldola and myself drew attention to the possible deceptions which might arise from a preservation of such patterns as fossils. I yesterday met with a striking case illustrating this. It was at Cullercoats, on the Northumberland coast. There had been a slight frost the night before, and the surface of a talus of semi-liquid mud at the foot of a low cliff of boulder clay (actually on the line of the great Fault known as the "Ninety-Fathom Dyke ") was found 10 be indented with cracks about \ to i an inch deep and \ of an inch in breadth. These cracks were disposed in beautifully branched patterns bearing a surprising resemblance, in out- line, to some of the more subdivided sea-weed fronds. A sandy beach lay close by, and a high wind was blowing the sand on to the mud. It was obvious that the sand would soon fill in the frost-cracks under these conditions. The cracks would thus be preserved, and if at any future time the mud surface be again ex- posed it will be found covered with sand (or, after induration of the mud and pressure of overlying material, sandstone) casts of what it would be very difficult to believe were not vegetable organisms in an unusually perfect state of preservation. Newcastle-on-Tyne, February 25. G. A. Lebour. The Origin of Lake Basins. I WISH to draw the attention of your correspondents, Messrs. Aitken and Tarr, to p. 94 of the Geological Magazitte, vol. iv. 1876, in regard to the manner in which, in all probability, the greater number of the lakes in British North America were formed. There are, however, doubtless many other causes by which lake basins have been formed. The object of my notice, was simply to point out that the ice need not be supposed to have exerted any extraordinary or abnormal influence in scooping out rock basins which have subsequently become lakes. Ottawa, February 16. Alfred R. C. Selwyn. Note on the Habits of a Jamaican Spider. Observing in your issue of January 11, p. 253, an interesting: note on the Nephila madagascarieiisis, I am prompted to send you some unpublished observations on the Jamaican species,. N. clavipes. They are from the MSB. of the late Mr. William Jones (concerning whom s^cjourn. Inst, /atnaica, 1893, p. 301), and date from over fifty years ago. The record begins : "Aranea clavipes, or the great yellowish wood-spider. I fancy Sir Hans Sloane must have been misinformed when he states that this spider's web will not only stop small birds but even pigeons. I will venture to assert that its strength would not even endure the struggling of the smallest humming-bird." But below is an- other entry : " Dec. 25, 1839. I wronged the accuracy of Sir H. Sloane's statement ; a little boy returning from an errand brought me a little black and yellow bird that he found entangled in a web of ^. clavipes." After this he adds a more general statement concerning the spider : "St. Thos. ye East, on bushes and outhouses, — I found in the old cooper's shop at Slamans Valley Est. in Portland, many hundreds of these, some of a monstrous size. These spiders weave an almost large [sic) spiral web, yellow and strong, Hke silk, glutinous or viscid, and well adapted for arresting the flight of large insects. I have frequently seen some of their lines two or three yards long. Butterflies appear their favourite food. They form an oblong oval cocoon of a white substance like soft chamois leather, out- side composed of little round-shaped compartments ; the cocoon is covered over with a mesh of strong yellow thread or silk. Finally he gives a technical description of the spider, which need not be quoted. The spider's size is said to be I to i^ inches la length, with the fore-legs 2A inches long, the second pan- 2 inches,, the third pair i inch, and the fourth pair 2 inches. NO. 1270, VOL. 49] March i, 1894] NATURE 41. Thus it appears that N. clavipes is not altogether unworthy of comparison with the great Madagascar species in regard to its web. It is one of the very commonest spiders of Jamaica, as 1 have myself observed, and has a wide distribution in the neo- tropical region. T. D. A. COCKERELL. Las Cruces, New Mexico, U.S.A., February 8. The Cloudy Condensation of Steam. With reference to Prof. Barus's letter (p. 363), I have never suggested that condensation nuclei in smoke, &c. would • ' remain distinct indefinitely, " but that, if there were no chemical action, they would hardly disappear in the course of a few seconds. . . • . » There is no mention in my lecture of " dissociated particles, or of the dissociation of platinum at red heat. What I said was that electrical discharges and incandescent substances probably caused dissociation of oxygen and nitrogen in the surrounding air {ante, p. 214). Shelford Bidwell. February 22. Astronomy in Poetry. With reference to the note in the Astronomical Column of Nature, No. 1226 (p. 372), it is worth remark that the nebular theory of the universe is briefly and accurately set forth by Tennyson thus — " This world was once a fluid haze of light, Till toward the centre set the starry tides And eddied into suns, that whirling cast The Planets." \The Princess.l A little knowledge of astronomy would have led Coleridge's Ancient Mariner to know that he could never have seen " The horned moon, with one bright star within the nether tip." Tennyson is always accurate in his descriptions of natural phenomena. Edward Geoghegan. Bardsea, February 19. A Plausible Paradox in Chances. With reference to the paradox in chances mentioned by Mr. Francis Gallon in Nature of February 15 last, I think the following remarks will show very simply where the fallacy lies. If I assert that at least two out of three coins must turn up alike, I am saying what is evidently true ; but if I go on to say that it is an even chance whether a third coin is head or tail, I am assuming that only two coins have been tossed, and that the fate of the third is still uncertain ; but this is directly counter to my first assertion, which requires the tossing of three coins. If this method of reasoning is to be used at all, I must say first that the chance of two coins turning up alike on being tossed is h, and then that the chance of a third coin being the same as the other two is also i, and that therefore the required chance of all three being alike is i x 2 o"" i- Lewis R. Shorter. THE PLANET VENUS. Tj^ROM time immemorial the planet Venus has -*- attracted the attention of mankind. Before the days when the " optic tube " began to be turned towards her disc, Venus, we might say, was still in myth, and she was hailed as Hesperus and Phosphorus, according as she was an evening or a morning star, the fact that the same object was in question being then unknown. Shining as she does at times with a brilliancy surpass- ing any other body except the moon, it is only natural that she should have been so often sung about by poets in all lands, liking her unto " the fair star That gems the glittering coronet of morn." And she is highly honoured by Homer, in that she is the only planet to which he refers : "EffTrepos OS kUWkttos iv ohpavcf "ararai daTr]r]p. Hesperus quae pulcherrima in coelo posita est Stella. NO. I 270, VOL. 49] To Galileo belongs the honour of first having viewed the planet through a telescope, but it is curious to re- mark the lapse of time that he allowed to pass before he made his first observation. The discovery that Venus exhibited phases did not take place until the end of September 1610, though Galileo first observed the satel- lites of Jupiter on January 7 of that year. That Galileo should veil this important discovery of the phases of Venus under a Latin anagram,^ does seem at first rather strange, but when one considers the vast importance of the discovery in that it supplied a simple proof of the planet's revolution round the sun, one can understand that he would first desire to be quite certain of his facts before giving the key to the anagram. An historical fact of interest with reference to Father Castelli maybe mentioned here. In Venturi's collection there is a letter from Father Castelli to the celebrated Florentian astronomer, dated November 5, 1610, in which he asks Galileo whether Venus and Mars show phases. Galileo evidently did not wish to give a direct answer, so evaded the question by saying that, although he was en- gaged in various investigations, he was better in bed than out in the open air in consequence of great in- firmity. It was not until December 30, 1610, that he informed Castelli of his recognition of the cusps. Fig. I. — February 20, 1070 (Trouvelot). With an ever-increasing number of telescopes at the dis- posal of astronomers, it is not astonishing that facts con- cerning surface markings, form, period of rotation, &c. should be rapidly forthcoming, and the sum total of what we now know about the planet has been gained at the expense of much labour and patience at the eye-piece end of the telescope. During the past three months Venus has been a striking object in the south-western and western region of the sky, being in a position more than usually favour- able for observation. Towards the end of November last her great southern declination began to decrease, while the planet became brighter and brighter, passing her greatest elongation east on December 6. On January 11 she attained her maximum brilliancy, the crescent form gradually increasing until on February 15, that is, at inferior conjunction, it was totally invisible. Gradually the crescent will become visible again, but in the inverse order, and we shall have another maximum on March 22, superior conjunction occurring on November 30. Thus we know that Venus is now lost in the sun's rays, and is, in consequence, invisible to us as an evening star for some time to come. The accompanying iliustra- tion (Fig. i) gives a drawing of the planet as recorded by 1 " Hsec immatura a me jam frustra leguntur,"or with the letters properly arianged — "Cynthiae figuras aemulatu Mater Amorum." 414 NA TURE [March i, 1894 Trouvelot in 1878, at a time when only a very fine crescent was visible. (The bulging at the south-south-east portion of the crescent was olaserved, and is not a defect in the drawing.) Of all the planets, Venus approaches us the nearest, her minimum distance amounting sometimes to approxi- mately five million miles, that is, about five times nearer than when she is furthest from us. Unfortunately, at these times her illuminated disc is turned away from us, and all we can do is to direct our attention to the small crescent that remains before inferior conjunction is reached. This accounts for the uncertain knowledge that we pobsess with regard both to surface markings and the period of rotation. The latter question is still a moot point among astronomers, and it is interesting to note the historical sequence in which these investigations have been made. The first spots on the planet's disc were noted by Dominique Cassini in October and June of the years 1666 and 1667 respectively, and from them he deduced a period of 23h. 21m. Bianchini, about 60 years afterwards (1726-27), came to quite a different result, substituting 24 days 8 hours for that obtained above. Jacques Cassini, discussing his father's observa- tions and those made by Bianchini, concluded that a period of 23h. 20m. satisfied both the old and new observations, but that Bianchini's value would not agree Fig. 2. — Details of snow-caj)s January 19, 1S78 (Trouvelol), with that of his father. This value seems for some time to have been accepted, and Schroeter's (1798-1799) and De Vico's (1840-42) observations practically confirmed it. Fig. 2 gives a view of the planet as seen on January 19, 1878, and shows the details in the polar spots some- times available for "period of rotation" determinations. Thus matters stood till that keen-eyed observer Schiaparelli took the field. After a most careful study, extending over many years, in which some single obser- vations were made extending over eight consecutive hours, he was led to make the statement that the rotation of the planet is exceedingly slow, and probably takes place in a period of 224 days 7 hours, the duration of the revo- lution of Venus about the sun. At Nice, M. Perottin has come to a similar view, expressing his opinion in the following words : " Ne differe pas de la durce de la revo- lution siderale soit 225 jours environ, de plus de 30 jours." These two observers, especially the former, thus upset our whole belief in a short duration of the period, but we are still again brought to consider the question from observations emanating from another source. We refer to those made by Prof. Trouvelot (see Nature, vol. xlvi. p. 470), whose opinion is of great weight. The im- portance of his work lies in the fact that it was carried on at the same time as that of Schiaparelli " souvent dans la mCme journce, sous un ciel egalement propice et NO. I 270. VOL. 49] precisement sur la meme point de la planete." The value ultimately deduced was 23h. 49m. 28s., which again brings us back to a short period. In referring to Schiaparelli's observations he says ; " La cause probable de I'erreur de M. Schiaparelli semble resulter de ce fait que les taches Ji et /■, qui ont servi de base a ses conclusions, faisaient partie de la tache polaire meridionale qui, etant situt^e centralement sur I'axe de rotation de la planete, semble rester stationnaire, comme cela se voit sur la February 5, 2h. Fig. 3. "February 5. 50. 43m. tache polaire de Mars, quand elle se trouve reduite a de faibles dimensions." He also refers to the general features visible on the planet's surface as indications of a rapid rotation, especially that of the rapid deformations of the terminator and hours. Thus we are left with the choice of two periods, one long and consisting of 224 days, the other short, of 24 hours nearly. We leave our readers to adopt that which they think best, the balance of favour falling, in our opinion, slightly towards the 24-hour side of the scale. But just as Schiaparelli's observation of the doubling of the canals of Mars was finally observed and universally accepted, so perhaps time may prove his case as regards this period of rotation. Some of the most recent work on the planet Venus relates to the measurement of her diameter. Among a few of the reduced measures the following may be given : — Hartwig, with the Breslau heliometer, from forty-three observations obtained a diameter of \'j"'6'j. The same observer, from a reduction of the Oxford observations, and also from Kaiser's observations with Airy's double- image micrometer, obtained 17'' "5 82 and I7"'409 from Fig. 4. — Showing irregularity of terminator November 23, 1877 (Trouvelot^ thirty-three and thirty-four observations respectively. Auwers from the transit of Venus measures deduced the value i6"'8oi, while Ambronn ^, from thirty-four observa- tions, measured the diameter as i7""jii. Among other interesting points to which we might refer, are the planet's visibility in full daylight, the snow- caps, the secondary light, the planet's form, &c. Each of ■^ See As/r. A'ac/ir. No. 3204, p. igo. March i, 1894] NA TURE 415 these have raised ,'i host of questions at various times, which even yet are not fully answered. The question as to the form of the planet itself is also one full of interest, and observers, from Beer and Miidler down to Trouvelot, have made numerous drawings of the different appearances. Observations have shown that the surface, or whatever it is that we look at, is by no means level, but extremely uneven or irregular. Such irregularities can be best detected naturally at the terminator and limb. Fig. i indicates a bulging at the lirnb, while Fig. 3 shows a similar phenomenon at the terminator at two different times— February 5, 2h. and 5h. 43m. (Perhaps this is one of the best proofs of a "short duration" period for rotation). Fig. 4, which we also owe to Prof. Trouvelot, shows a more decided case of irregularity, and on perhaps a much larger scale. Much remains, however, to be done before we are on anything like a footing with this planet as we are with Mars. With this latter we can observe directly the land and water markings, time to a second the period of rota- tion, observe local storms, and many other details ; but with the former the case is different. Here the planet is for the most part lost in the rays of the sun, or at other times not very easy for observation. That Venus has an atmosphere is a fact which has long been known, and that this is denser than the earth's enve- lope is also very probable. The part this atmosphere plays in the determination of the period of rotation seems to be of great importance, and it is rather a question of whether we have been observing real rigid markings on the planet itself, or only what has been described as " a shell of clouds, the appearances interpreted to signify the exist- ence of lofty mountains, snow-caps, vast chasms, and crater-like depressions, are really nothing but the varying features of cloud scenery." Whichever the case may be, future observation has still to show ; but it seems that with the rapid advance now taking place in large instrument-making, such a question as this could be settled, given a few fine evenings or mornings near a favourable time of observation, a clear and still air, and a large aperture. Such occasions, perhaps, may be rare, but the point at issue is important, and should be settled as soon as possible. W. J. L. NOTES. All the arrangements have now been made for the eleventh International Medical Congress, shortly to be held in Rome. The inauguration of the congress will take place on March 29, in the presence of the King of Italy. On the following day will commence the work of the scientific sections, which will be continued till April 5, A CONGRESS of chemistry and pharmacy will be held in Naples at the beginning of next September. The congress will be divided into two sections — the one scientific, the other professional, M. EuGKNE Catalan, a member of the Sciences Mathema- tiques section of the Paris Academy of Sciences, died at Liege on February 14. On March 18, Prof. J. Bertrand, the popular perpetual Secre- tary of the Paris Academy of Sciences, will have spent fifty years in expounding science. In order to celebrate this jubilee in a fitting manner, a committee has been formed, consisting chiefly of his old students at the Ecole Polytechnique, the Sor- bonne, the College de France, and the University, and a circular has been issued asking for subscriptions towards a commemora- tive medal which it is proposed to have struck for the occasion. NO. 1270, VOL. 49] The committee appeal not only to the eminent professor's old pupils, but also to his colleagues and friends who desire to do him honour. Among the members of the committee are Profs. Cornu, Marcel Deprez, Jordan, Maurice Levy, Mascart, Mer- cadier, Picard, Poincare, and M. Tisserand, the Director of the Paris Observatory. Subscriptions may be sent to any of these names, or to M. le Trtjorier, de I'Ecole Polytechnique, 2i Rue Descartes, Paris. An offer made by Miss Marian Brockhurst, to build a museum in the public park of Macclesfield, and endow it with ^^loo a year, has been accepted by the park committee. Among the bequests of the late Mr. Thomas Avery, of Bir- mingham, is the sum of ^^2000 to the Midland Institute, and ;^iooo to Mansfield College, Oxford. The Malte-Brungold medal of the Paris Geographical Society is to be awarded to M. A. Delebecque, for his researches on the French lakes, of most of which he has constructed detailed bathymetrical maps. We learn from the Chemist and Druggist that the centenary of the birth of Friedlieb Ferdinand Runge, whose name is con- nected with the discovery of aniline, carbolic acid, and the paraffines of coal-tar, was celebrated at Oranienburg, near Berlin, on February 6, by the unveiling of a memorial tablet in the wall of the present Royal Seminary, which occupies the place where Range's laboratory formerly stood. The Council of the Society of Arts attended at Marlborough House on Friday, when the Prince of Wales, President of the Society, presented to Sir John Bennet Lawes the Albert medal, and a like medal to Sir J. Henry Gilbert, awarded to them in 1893 "for their joint services to scientific agriculture, and notably for the researches which, throughout a period of fifty years, have been carried on by them at the Experimental Farm, Rothamsted. " WElearnthatthe collection of fossil plants, got together by Mr. James M'Murtrie, of Radstock, has passed away from the county where it was chiefly collected to the Natural History Museum at South Kensington, where it has found a permanent home. The Somerset coal measures generally, and especially the Rad- stock seams, have long been known for the richness and variety of their fossil flora, which is found in a state of preservation probably not equallei in any other coal-field in the country, and a residence of more than thirty years amidst such surroundings, with the aid of many willing assistants, had enabled Mr. M'Murtrie to accumulate one of the finest private collections in the country. The collection, consisting of more than 300 speci- mens, includes every variety of plant life of the Carboniferous age, from the smallest variety of fern to the largest tree ferns. A FINE egg of the gare-fowl or Great Auk was put up for auction by Mr. Stevens, on Thursday, and, after a keen compe- tition, was purchased by SirVauncey H. Crewe for 300 guineas. The egg originally belonged to the late Mr. William Varrell, and the facts relating to its purchase are stated by Prof. Newton in another column. In 1856 the late Mr. Frederick Bond purchased the specimen for twenty guineas. It remained in this gentleman's possession until 1875, whenit was soldto Baron Louis d'Hamonville. Of the sixty-eight true specimens of the Great Auk's eggs known to be in existence, Great Britain is said to possess forty-eight ; Prance, ten ; Germany, three ; Holland, two ; Denmark, Portugal, and Switzerland, one each ; and the United States, two. The origin of gold nuggets is a question about which much controversy has arisen. Dr. A. R. Selwyn long ago suggested that the nuggets grow in alluvial deposits by the deposition of 4i6 NA TURE [March i, 1894 gold upon their surface. His theory has been supported by other geologists and chemists. Prof. A. Liversidge has recently made a large number of experiments bearing upon this ques- tion, and his conclusion is that although large nuggets may be artificially produced, those found in alluvial deposits have been derived from gold-bearing rocks and reefs, and have obtained their rounded and mammillated surface by attrition ; also, any small addition of gold which they may have received from meteoric water has been quite immaterial. (Roy. Soc. N.S. Wales, September 6, 1893.) Ws have received the annual report of the Geological Survey of Canada for 1890-91 (vol. v. new series). The volume consists of 1566 pages, bound in two parts, and con- taining thirteen separate reports, with maps and illustrations descriptive of the geology, mineralogy, and natural history of the various sections of the Dominion to which they relate. The region surveyed is so large, and the matters described are so numerous, that a bare mention of the results would take up many columns of this paper. One of the points of interest that attracted our attention while glancing through the pages of the report, relates to the discovery of a considerable deposit of in- fusorial earth on the right bank of the Bras, just at its junction with the Montmorency River. The deposit is about fifteen feet thick, and occurs in sand containing boulders, about forty feet above the river, and is overlaid by fifty feet of the same mate- rial. In colour the earth is partly yellowish and partly lead- grey, these tints being sometimes arranged in different layers, and sometimes irregularly intermixed in spots and patches. Another deposit of the same kind has been found on the east side of the north branch of the Ste. Anne River. This deposit is said to extend over an area of half an acre in the river valley, and in places is more than four feet in thickness. Dr. A. R. C. Selwyn, the Director of the Survey, has the thanks of all students of geology for the mass of material he has brought together in the report, and for the manner in which it is arranged and indexed. Another Arctic expedition is announced by Reuter's agency as being prepared in the United States by a journalist named Wollman. The proposed route is by Spitzbergen, whence "^a dash is to be made for the pole," and America regained by November of the current year. In this connection it is in- teresting to note that an expedition under the Norwegian Ekroll was stated in the newspapers to have started in June, 1893, from the north of Spitzbergen, but from private information we understand that this expedition never set out. The experi- ment of an Arctic journey from this side would be well worth making, if the expedition were properly equipped and adequately organised. The recent planimetric measurement of France by the Geo- graphical Department of the Army, gives as the total area 536,891 square kilometres, or 206,381 square miles, which is 2000 square miles more than was formerly accepted as the area of the country. The problem of the exact area of a country is one of the most difficult in geography, involving as it does a survey of high accuracy and very laborious computation from large scale maps. The datum is of extreme importance, as it enters into all questions of quantitative distribution ; in the case in point, it reduces the average density of population in France at the census of 1891 from i8y8 to i85'8 per square mile. At the last meeting of the Royal Geographical Society, a paper by Mr. Warington Smyth, oh the Upper Mekong, was read in his absence. The journey which was described was carried out for the Siamese Government, with the primary object of investigating a reported deposit of rubies and sapphires NO. 1270, VOL. 49] opposite Chiang-kong. Mr. Smyth left Bangkok in December, 1892, ascended the Menam for some distance, and crossed the mountainous country inhabited by the kindly and hospitable Laos eastward to the Mekong, which was reached near Chiang- kong. Across the river a series of low hills of crystalline rock gave origin to the gem-bearing gravels carried down by the streams which flowed from them to the main river. These gravels were being actively worked by the Burmese, who tried to keep the place of occurrence of the gems secret. The survey finished, Mr. Smyth's party came down the Mekong, five days' journey amidst beautiful scenery, to Luang Prabang, a large un- walled town of teak houses and numerous picturesque, often ruinous, monasteries. A French store established there seemed to do little business, the people preferring their home-woven cottons to the product of European looms. We have received an excerpt paper from the Beobachtnugen der Rleteorologischen Stationen im Kbnigreich Bay em for 1893, containing an account of two balloon ascents, made at night- time, under the auspices of the Munich Balloon Society. The ascents were made for the purpose of investigating the conditions of the atmosphere at a time when the disturbances arising from heated ground were not effective, and the observations have been discussed by Profs. L. Sohncke and Finslerwalder, who also took part in one of the ascents. The instruments recorded automatic- ally, electric light being employed both for attending to them and for obtaining photographic traces from some of the apparatus. The first ascent was made at i a.m. on July 2, 1893, from Munich, there being a barometric maximum at the time, and the second ascent was made on the 8th of the same month, under similar conditions. We can only refer here to one or two of the results of the first ascent. The most important feature in this case was the observation of a maximum temper- ature at a height of about 1000 feet above the ground. At a height of 400 feet the temperature was 63" '5, or 5°"4 higher than at the place of starting. In a stratum of another 450 feet there was only an unimportant rise o^ temperature, after which a rapid fall occurred, so that at a height of a little over 1000 feet the maximum temperature of 65° '8 was recorded, being 7°'7 higher than at the place of starting. From this point the temperature steadily decreased, and at 2900 feet it had fallen to 56° -3. The relative humidity first decreased regularly with height from 85 to 49 per cent., and then from 1400 feet to the highest point attained (2900 feet), it steadily rose to 72 percent. A VALUABLE contribution to the study of thunderstorms, by R. De C. Ward, appears in vol. xxxi. part ii. of the Annals of the Harvard College Observatory, which has just been published. Full details are given of all the storms observed in New Eng- land during the years i886 and 1887. June, July, and August were the months in which thunder was most frequently heard, and July had the greatest number of distinct thunderstorms. The hours of greatest frequency were 5 to 7 p.m. On about 40 per cent, of the days when thunder was reported there were storms with progressive movement, the average rate in both years being about 35 miles per hour, while the maximum and mini- mum velocities were 50 and 14 miles per hour respectively. The results of 1886 tend to show that the dependence of thun- derstorms on the larger atmospheric disturbances or cyclonic storms is not so striking as many observations have shown it to be for Europe. While in 1886 over 60 per cent, of the thunder- storms occurred in the southern or south-western quadrant of cyclones central north of New England, in 1887 the majority of the storms occurred in the south-eastern quadrant under anti- cyclonic conditions. A meteorological summary for New England in 1891, by J. Warren Smith, of the U.S. Weather Bureau, appears in the same volume. The last number of the Memoirs and Proceeding of the Manchester Literary and Philosophical Society (vol. viii. No. i) March i, 1894] NATURE 41 contains a paper by Dr. G. H. Bailey, on some aspects of town air as contrasted with that of the country. He proves that as a means of discriminating between polluted and unpolluted air, and as a means of forming some estimate of the extent of pollution, the determination of the sulphurous compounds and of organic matter are much to be preferred to that usually adopted, viz. an estimation of the carbonic acid. It is also urged that however minute the quantities of polluting matter may be, they are sufficient to bring about serious disorganisation in plant life and in human beings. Dr. Bailey has prepared a number of tables showing considerable variations in the quantity of sulphur compounds present in different localities in Man- chester and London on clear days and on slightly or densely foggy days. A remarkable result derived from one of the tables is that during the dense fogs of December, 1892, in Manchester and London, there was a much larger proportion of sulphur compounds present in the London than in the Manchester air, notwithstanding the fact that the coal consumed in Manchester is generally understood to be much more sulphurous than that burnt in London. An ingenious method of photographing the spectrum of lightning is proposed in the current number of Wiedemann' s Annalen by G. Meyer. The difficulty of directing the slit of the spectroscope upon the flash is got over by substituting a diffraction grating for the prism. A grating ruled on glass is { placed in front of the object-glass of the apparatus, the object- 1 glass being focussed for infinite distances. Under these circum- stances several images of the flash are obtained, a central image produced by the undiffracted rays, and images of the first and higher orders belonging to the diffraction spectra. The number of images of each order corresponds to the number of lines in the spectrum of the lightning. The arrangement was tested during a night thunderstorm. Two plates were exposed in a camera with a landscape lens of 10 cm. focal length, provided with a grating with 40 lines to the mm. One of the plates showed two flashes with their diffraction images of the first order, but representing one line only. The other showed a number of flashes, and one very strong one, passing apparently between two chimney-pots, with its diffraction images well marked. A calculation of the wave-length of the light produc- ing these images gave 382 ju/x. The measurement was not sufficiently accurate to warrant an identification of this line with a known wave-length, but it is certain that a radiation of about this wave-length must be added to the lines determined by Schuster and Vogel. It is probable that with better apparatus the method may be made to considerably increase our know- ledge of the ultra-violet spectrum of lightning. The current number of the Electrician contains an abstract of a paper, by J. Sahulka, on the measurement of the capacity of condensers under alternating currents. The author has found that condensers with a solid dielectric have a smaller capacity when used with alternating currents than is given by measure- ment by direct current methods. He considers that the reason for this phenomenon lies in the condition of the dielectric; for €ven if it has a very high electrical resistance it absorbs energy in the process of charging, which energy is partly returned to the circuit in the discharge, and partly converted into heat. Thus, if a measurement of charge or discharge is made, the galvanometer deflection is too high, for it is a measure not only of the quantity of electricity passing on to or out of the coatings, but also of that taken up or returned by the dielectric. Now it is well known that the dielectric takes an appreciable time to take up this quantity of electricity, and since in alternate-current working charge and discharge occur successively -with great rapidity, it follows that the dielectric has not time at every charge to take up as much electrical [energy as it would if it NO. 1270, VOL. 49] were charged by an electromotive force applied for a much longer time. It is thus necessary to define what is meant by the capacity of a condenser where alternating currents are con- cerned, and the author proposes the following definition : — ' ' The capacity of a condenser on an alternating current circuit is equal to the reciprocal of the product of 2 ttw and its inductive resistance, the latter being equal to the quotient of the potential difference at the condenser terminals caused by the charge, divided by the strength of the current flowing into it." The author mentions an experiment on a condenser with paraffined paper as dielectric, having a capacity of about one microfarad when measured on direct currents, which was found on an average of several experi- ments with alternating currents to have a capacity about 14 per cent, lower. Steinmetz's law, according to which condensers having solid dielectrics should absorb, under alternating Currents, an amount of energy proportional to the square of the potential difference, was found by the author to be very approximately true. We have received a copy of the seventh annual report of the Liverpool Marine Biology Committee and their Biological Station at Port Erin (Isle of Man), by Prof. W. A. Herdman, P'.R.S. The report shows that progress has been made in the scientific exploration of the Irish Sea during 1893, ^"d a number of important investigations have been carried out by the sixty natui^alists who worked at the station. The protective coloura- tion of Vibrius varians was under observation during last summer. The manner in which individuals of this small prawn resemble the green, red, or brown seaweeds with which they are associated, on even sandy and gravel bottoms, was discussed in the report for 1S92, and the question was raised as to whether, or to what extent, the adult animal could change its colour. Prof. Herdman says that a number of specimens, of various colours, were kept under observation in the laboratory during the year, in jars with various colours of seaweed and of back- ground, and in very different amounts of light. The results of these experiments show clearly that the adult animal can change its colouring very thoroughly, although not in a very short space of time. The change in colour is due to changes in size and arrangement of the pigment granules of the chromatophores. It is remarked that an interesting point to determine is whether in this case, as in some others of similar colour changes, the modification of the chromatophores is due to nerve action and is dependent upon sight, or is the result of the direct action of light upon the integument. A FURTHER contribution to our knowledge concerning the action of sunshine on microbes is to be found in a recent number of the Comptes Rendiis (vol. cxviii. p. 151). MM. d'Arsonval and Charrin find that if the b. pyocyanetis (an organism frequently found in the pus from wounds) is exposed to sunshine in culture liquid (presumably broth) for from three to six hours, it is deprived of its pigment-producing power ; if, j however, it is only subjected to the influence of the red va.ys in the spectrum, it exhibits subsequently the typical fluorescent green colour on cultivation in agar-agar at 37° C. Moreover, if the amount of sunshine it receives is extended, no growths at all subsequently make their appearance, showing that it has been destroyed ; whilst it can tolerate a similar exposure to the red ' rays without exhibiting any signs of discomfort. This loss of ' pigment-producing power may also, these investigators state, be brought about by subjection to very low temperatures ; thus at between - 40° and - 60° C. this bacillus loses its characteristic rod-like shape, frequently becoming ovoid ; it multiplies very 1 slowly, and exhibits only creamy white growths on agar-agar. i We have received a volume containing statistics of the colony I of Tasmania for the year 1892, compiled in the office of the [ Government Statistician from official records. 4i8 NATURE [March i, 1894 The February Joitr^ial of the Royal Microscopical Society contains the address on " The Progress and Present State of our Knowledge of the Acari," delivered by the president, Mr. A. D. Mitchell, on January 17 of this year. The number just issued of the Journal of the Institution of Electrical Engineers contains Prof. G. Forbes's paper upon " The Electrical Transmission of Power from Niagara Falls," and the valuable discussion which it raised. Messrs. Witherby and Co. will issue next month a volume of esoays on zoological and geological subjects by Mr. Richard Lydekker. The volume is to be entitled "Life and Rock," and will be fully illustrated. A FIFTH edition of Mr. W. Larden's "School Course in Heat " has been published by Messrs. Sampson Low, Marston, and Co. The book has been enlarged, and in places rewritten, and has gained in value by the refining process to which it has been subjected. A FIFTH edition of the late Prof. Tyndall's biographical sketch of Faraday has been published by Messrs. Longmans, Green, and Co. The preface of this new edition possesses a melancholy interest, for, in a brief note appended to it, Mrs. Tyndall says it was only written a few days before her husband's death. Judging from the twenty-fourth annual report just received, the Wellington College Natural Science Society is in a very satisfactory condition. The report contains abstracts of the papers read before the Society during the year, the results of meteorological readings, observations of plants and insects, and a statement of entomological occurrences and peculiarities. The Society is certainly a creditable part of the College to which it belongs. The iSg^ a nmtaire of the Municipal Observatory of Mont, souris contains, in addition to the usual meteorological, physical, and chemical tables, an article by M. Albert Levy on the chemical analysis of air and water, and a memoir by Dr. P. Miquel on the organic matter in air and water. The latter paper deals with the microscopic analysis of the air of Montsouris and that of the centre of Pnris, the microscopic analysis of water, and statistics as to ammoniacal ferments in the air and water of different places. The Universal Electrical Directory (J. A. Berly's) for 1894 has been published by Messrs. H. Alabaster, Gatehouse, and Co. It contains the names of the members of the electrical and kindred fraternities throughout the world. For simplicity and facility of reference the work is divided into four groups, deal- ing respectively with British, Continental, American, and Colonial names, and these parts are again subdivided into alphabetical and classified sections. Several thousands of new names have been incorporated in the present issue, and 104 pages have been added, making a total of 888 pages. ! In March of last year we noticed the first report of the proceedings of the International Congress of Prehistoric Archaeology and Anthropology held at Moscow in 1892. The second volume has now reached us. The memoirs included in it are arranged into three classes, referring respectively to pre- historic archaeology, anthropology, and prehistoric ethnology. In addition to tbese memoirs, many of which are of great importance, the present volume contains the Proces-verbaux of the meetings. Another volume that has also been recently published contains descriptions of the places and institutions visited during the Congress, and reports on some of the ques- tions discussed. NO. 1270, VOL. 49] It is announced that a new monthly review of current scientific investigation — Science Prog7-ess — will make its debut to-day. The new journal will be published by the Scientific Press, and will be edited by Prof. J. Bretland Farmer, with the assistance of an editorial committee, consisting of Prof. H. E. Armstrong, F.R.S. ; Prof. C. S. Sherrington, F.R.S. ; Prof. J. W. Judd, F.R.S. ; Prof. R. T. Weldon, F.R.S. ; Prof. G. B. Howes, and Prof. H. Marshall Ward, F.R.S. The editors propose to include in Science Progress notices and reviews of all the effective work that is being accomplished in the various branches of science, and the articles will aim at providing a critical exposition of current work in the departments to which they refer. In this way it is hoped that the journal will be of use, not only in recording what has actually been done, but also as indicating the direction and general tendency of research. The first number of the new series of Science Gossip contains, among other articles, one by the editor, on science at the free libraries. A recent tour through the metropolitan libraries, and those in some of the larger midland counties' towns, has shown Mr. Carrington that in many cases the income of the library goes in the purchase of fiction or general expenses, and the librarian depends upon donations for the science section of his catalogue, and must accept whatever comes to hand. To remedy this, it is suggested that some authoritative body, such as the Education Department of the Imperial Government, or failing that, the Library Association, should invite the councils of various learned societies, like the Royal, Linnean, Zoological, Geological, Geographical, Astronomical, Botanical, Chemical, Anthropolo- gical and Meteorological, to draw up a list of works dealing with their especial subjects, so as to get a list of good text- books and authorities. This list might be revised from time to time, as changes became necessary through the progress of research. The atomic weight of palladium has been subjected to re- vision by Prof. Keiser and Miss Breed. A previous investiga- tion of the value to be ascribed to this metal was carried out by Prof. Keiser in 18S9, the salt palladium diammonium chloride, Pd(NH3Cl)2, which was considered for many reasons to be particularly suitable, being employed. The number derived from nineteen determinations was 106*27. Since that time three other determinations of the atomic weight of palladium have been carried out, by Bayley and Lamb, and by Keller and Smith in 1892, and by Joly and Leidie in 1893, the results of which are most discordant, differing by as much as a unit and a half. Dr. Keiser has therefore returned to the work, and has succeeded in discovering a compound of palladium which can be vapourised, and therefore subjected to fractional distillation, a method which Stas considered as the only one by which substances may be obtained in the highest state of purity. The compound in question is the dichloride PdCL, which can be distilled at a low red heat in a current of chlorine. The pure chloride thus obtained was converted into palladammonium chloride, and the latter compound analysed by reduction to metallic palladium in a current of pure hydrogen. The results of all the analyses afford as the final mean value for the atomic weight the number io6"25, which agrees remarkably closely with that previously obtained by Dr. Keiser. The most diver- gent of all the individual values are only 007 apart, so that it would appear that the atomic weight of palladium is now definitely determined. A further communication upon the subject of the artificial preparation of the diamond is contributed to the Comptes Rendus by M. Moissan. It was shown in an earlier memoir that when carbon is dissolved in various fused metals at the temperature of the electric furnace and at the ordinary pressure. March i, 1894] NA TURE 419 it invariably crystallises out upon cooling in the form o graphite of density about 2 ; but that when the operation is performed under increased pressure the density and hardness of the carbon which eventually separates are augmented, and black diamonds are produced in considerable quantity. A modification of the original form of these pressure experiments is now described, which results in the production of small but perfectly trans- parent and colourless diamonds similar to those found naturally. The former experiments were made with iron and silver as sol- vents for the carbon, the mixture of metal and excess of charcoal being heated in the arc of the electric furnace under pressure until most of the charcoal was dissolved in the white-hot metal, after which the hot crucible was th rown into a tank of water to effect sudden cooling. Bismuth has since been tried as a solvent' but is not found suitable, as a violent explosion is caused when the fused mass is projected into water, probably owing to the sudden decomposition of a carbide of bismuth. Iron is there- fore used, and the cooling is effected by pouring the contents of the crucible into a bath of just melted lead. The solution of carbon in molten iron, being lighter than liquid lead, rises to the surface in spherical globules ; the smaller spheres solidify before reaching the surface of the lead, but the larger ones are still liquid and are still so hot that they cause the lead at the surface to burn in contact with the air, incandescent particles of metal and oxide being projected out, and torrents of fumes of litharge produced. Upon removing the globules floating at the surface of the lead, dissolving their leaden coating in nitric acid, and subsequently removing the iron by suitable solvents, as previously described by M. Moissan, the transparent diamonds are readily jsolated. They frequently exhibit well-defined crystal faces, which are usually curved and striated and etched with cubical markings exactly like those of natural diamonds. They possess the same wonderful limpi dity, high refractive power, hardness, and density (3 '5) as native diamonds, and exhibit many of the properties, such as anomalous polarisation and occasional spon- taneous disruption, owing to their state' of strain resulting from their formation under high pressure, which are characteristic of some Cape diamonds. The hemihedral forms of the cubic system appear to predominate in the crystals examined. They scratch rubies, and resist the action of a mixture of potassium chlorate and fuming nitric acid, but burn in oxygen at a tem- perature of about 900° with formation of pure carbon dioxide. Notes from the Marine Biological Station, Plymouth. — During the past fortnight the alga Halosphcera viridis has fre- quently been present in the tow-nettings. The proportion of Mollusc, Polychcete, and Cirrhipede larvae to the res-t of the floating fauna has become still greater. The medusa Phiali- dhim variabile is obtainable in about the same numbers as previously, and a few Obelia medusas have made their first appearance for the year : but, strange to say, Rathkea octo- punctata has not been observed, and even the ephyrse of Aurelia, although numerous in the open Channel, have been scarce within the Sound. No Echinoderm larva; have been yet observed. The Hydroids Tubidaria indivisa, Endendrium ramosiim, and Sertnlaria argentea, and the Molluscs Nassa reticulata, Lamellaria perspiciia and Lamellidoris pttsilla are now breeding. The additions to the Zoological Society's Gardens during the past week include two Mozambique yioVLV&^%{Cercopithectis pygerythrusy i S ) from East Africa, presented by Lt.-Gen. Owen L. C. Williams ; a Hooded Crow {Corvus comix) from Norway, presented by Mrs. Wroughton ; a PuSf Adder {Vipera arietans), a Hoary Snake {Coronella cana) from South Africa, presented by Mr. B. Matcham ; a Hairy Porcupine ^Sphingitrus villosus) from Brazil, deposited. NO. 1270, VOL. 49] OUR ASTRONOMICAL COLUMN. A Large Sun spot. — During the foggy days of last week, when the brightness of the sun was not too great to permit direct observation, a sun-spot, which was very plainly visible to the naked eye, attracted general attention. It was first seen in the south-east quadrant on February 19, and will probably pass off the visible disc about March 2. It has been somewhat remarkable for its relatively large penumbra and the scattered character of the umbra ; a very distinct nucleus was also observed. In the course of an interview, Mr. Maunder stated that the spot was at a maximum on February 20, when it was about 48,000 by 46,000 miles, and the area 1870 millions of square miles. It was therefore much smaller than the {jreat spot of February 1892. Though the magnetic disturbances have not been so great as in the case of the 1892 spot, a marked effect on the Greenwich recording magnets was noticed at 3. 15 p.m. on February 20, the disturbance lasting about twenty- seven hours. After an interval of about twenty-four hours, another and more intense storm commenced, and reached a maximum at 3 p.m. on February 23. In the case of the spot of February 1892, the violent magnetic storms occurred after the spot had passed the central meridian ; but in the present instance, the disturbances seem to have preceded the central transit of the spot. Anderson's Variable in Andromeda. — Prof. E. C. Pickering announces in Astronomische Nachrichten (No. 3213) that an examination by Mrs. M. Heming of photographs taken at the Harvard College Observatory confirms the variability of the star in the constellation Andromeda (K.A. oh. 14m. 48s. Decl. -f26'' 10-3) observed by Dr. Anderson (Nature, Nov. 30, 1893). The observations, and those quoted by Dr. Anderson, as having been made at Bonn and Cambridge, indicate that the period of the variable is 281 days, and that the next maximum will occur on March 30. A determination of the form of the light curve led to the interesting result that during the three months following a maximum, the diminution in light is at the uniform rate of one magnitude in twenty-five days ; for the three months preceding the maximum the increase is also uni- form, and at the rate of one magnitude in twenty-six days. Prof. Pickering points out that this great uniformity in the variation in light of the star appears less extraordinary if a similar uniformity in the diminution of the light of Nova Aurigse is considered. From March 7 to March 31, 1892, the light of this star diminished from magnitude 6'3 to I3'3 with almost perfect regularity at the rate of three-tenths of a magni- tude per day. Following Prof. Pickering's note is one in which Dr. E. Hartwig gives observations to show that the next maximum of the variable under consideration will occur on March 10, and that the period of variability is 74-4 days. A Bright Meteor. — Mr. Andrew Greig writes to us as follows: — "A very bright meteor was seen at Dundee at yh. \%\\n. p.m. on Wednesday, February 21. It was a little to the east of south, and midway between Sirius and Orion's belt. It was falling in a westerly direction, or parallel to a line joining the stars Betelgeux and Rigel. It was visible for about three seconds. There was a slight haze above both southern and northern horizons at the time, but Vega could easily be seen low down in the north. The portion of the sky around Jupiter and the Pleiades was quite clear. ' Streamers' were observed in the north for about three minutes afterwards." This meteor was also seen in North Lincolnshire. To an observer in that district it appeared in the north-west by northern part of the sky, and fell in a westerly direction. Among other place? in which the object was observed are Colwyn Bay, Whitby, How den, and Sandal ; but no details as to the path it traversed, or the times of observation, have reached us from these places. An explosion was heard at Colwyn Bay, but no sound is mentioned by other observers. THE BAKERIAN LECTURE. AN investigation on the internal friction of liquids, carried out by Prof. T. E. Thorpe, F.R.S., and Mr. J. W. Rodger, formed the subject of the Bakerian Lecture delivered at the Royal Society on February 22. The following is an abstract of the communication : — The purpose of this paper is to throw light upon the rela- tions between the viscosity of homogeneous liquids and their chemical nature. 420 NA TURE [March i, 1894 The first of the three parts into which the paper is divided contains a summary of the attempts which have been made, more particularly t>y Poiseuille, Graham, Rellstab, Guerout, Pribram and Handl, and Gartenmeister, to elucidate this question. Although it is evident from the investigations of these physicists that relationships of the kind under considera- tion do exist, it must be admitted that they are as yet not very precisely defined mainly for the reason that the conditions by which truly comparable results can alone be obtained have received but scant consideration. For example, it seems futile to expect that any definite "toichiouietric relations would become evident by comparing obbtrvations taken at one and the same temperature. Practic- ally, nothing is known of a quantitative character concerning the influence of temperature on viscosity. From the time which a liquid takes to flow through a capillary tube under certain conditions, which are set out at length in the paper, a measure of the viscosity of the liquid can be obtained. An apparatus was, therefore, designed on this principle which admitted of the determination in absolute measure of the vis- cosity, and for a temperature range extending from o° up to the ordinary boiling point of the liquid examined. Full details ot the conditions determining the dimensions of the apparatus and of the modes of estimating these dimensions, together with the methods of conducting the observations, are given in the paper, and the corrections to be applied to the direct results are discussed. The question of the mathematical expression of the relation of viscosity of liquids to temperature is considered, and reasons are given for preferring the formula of Slotte — »/ = <:/( I + bt)"' T] is here the coefficient of viscosity in dynes per square centi- metre, and c, b, and n are constants varying with the liquid. With a view of testing the conclusions set out at length in the historical section of the paper, and, in particular, of tracing the influence of homology, substitution, isomerism, and, generally speaking, of changes in the composition and constitution of chemical compounds upon viscosity, a scheme of work was arranged which involved the determination, in absolute measure, of the viscosity of some seventy liquids, at all temperatures between o° (except where the liquid solidified at that tempera- ture) and their respective boiling points. Part ii. of the memoir is concerned with the origin and modes of establishing the purity of the several liquids ; it contains the details of the measurements of the viscosity coefficients, together with the data required to express the relation of viscosity co- efficients to temperature by means of Slotte's formula, and tables are given showing the agreement between the observed and calculated values. In Part iii. the results are discussed. In the outset the factors upon which the magnitude of the viscosity probably depends are dealt with. The influence of possible molecular aggregations, as indicated by observations of vapour densities, boiling points, and critical densities, and, more especially, by measurements of surface energy, made by Eotvos in 1886, and more recently by Ramsay and Shields, are taken note of. The deductions which may be made by considering the graphical representation of the results, showing the variations of viscosity coefficients with temperature, are then set forth. For liquids which probably contain simple molecules, or for which there is little evidence of association of molecules at any temperature, the following conclusions may be drawn : — (i) In homologous series the coefficient of viscosity is greater, the greater the molecular weight. (2) An iso-compound has always a smaller viscosity co- efficient than the corresponding normal compound. (3) An allyl compound has, in general, a coefficient which is greater than that of the corresponding isopropyl compound, but less than that of the normal propyl compound. (4) Substitution of halogen for hydrogen raises the viscosity coeflicient by an amount which is greater, the greater the atomic weight of the halogen ; successive substitutions of hydrogen by chlorine in the same molecule bring about different increments in the viscosity coefficients. (5) In some cases, as in those of the dichlorethanes, substitu- tion exerts a marked influence on the viscosity, and in the case of the dibromides and benzene, it may be so large that the com- pound of higher molecular weight has the smaller viscosity. (6) Certain liquids, which probably contain molecular com- NO. 1270, VOL. 49] plexes, do not obey these rules. Formic and acetic acids are exceptions to Rule i. The alcohols at some temperatures, but not at all, are exceptions to Rule 2 ; at no temperatures do they conform to Rule 3. (7) Liquids containing molecular complexes have, in general, large values of dr\ldt. (8) In both classes of liquids the behaviour of the initial members of homologous series, such as formic acid and benzene, is in some cases exceptional when compared with that of higher homologues. As regards the influence of temperature on viscosity, it is found that the best results given by Slotte's formula are incases where the slope of the curve varies but little with the tempera- ture. From the mode in which the values of the constants n and b are derived, it cannot be expected that their magnitudes will be related in any simple manner to chemical nature. With the exception of certain liquids, such as water and the alcohols, which are characterised by large temperature coefficients, and in which there is reason to expect the existence of molecular aggregates, the formula 7j = i SociETy, at S. — Algological Note? from Cumbrae —On the Origin of the Filamentous ThalUis of Dumontia filiformis: George Brebner. — Entomostraca and the Surface Film of Water : D. J. Scourfield. 428 NATURE [March i, 1894 Royal Institution, at 3.— The Vendanta Philosophy: Prof. Max Miiller. Chemical Society, at 8.— Aerial Oxidation of Terpenes and Essential Oils : C. T. Kingzett. Camera Club, at 8.— Light Waves in a Shadow ; W. B. Crofts. Society of Antiquaries, at 8.30. FRIDA Y, March 2. RovAL Institution, at 9.— The Theory of the Cochlea and Inner Ear: Prof. J. G. McKendrick. Sanitary Institute, at 8.— Scavenging Disposal of House Refuse : C. Mason. Institution of Civil Engineers, at 7 30 (Students' Meeting). — Efficiency and Economy of Elevators: Herbert W. Umney. Geolosists' Association (University College), at 8— The Hythe Beds of the Lower Greensand, in the Liphooh and Hind Head District: Bin- stead Fowler.— Tertiary Man : J. B. M. Findlay. SATURDAY, March 3. Royal In--T!TUTion, at 3. — Light, with special reference to the Optical Discoveries of Newton : The Right Hon. Lord Rayleigh,-F.R.S. SUNDAY,Vi.\-Rcm,. { Sunday Lecture Society, at 4. — Glimpses of the Life, Lore, and Legend of Old Japan (with Oxy-hydrogen Lantern Illustrations] : R. W. Atkin- son. MONDAY, March 5. Society of Chemical Industry (Chemical Society's Rooms, Burlington House), at 8.— The Zyniean Metallurgy : Admiral J. H. Selwyn.— The Commercial Production of Chlorine by the Ammonia Soda Process : F. Bale. — Notes on Lithographic Varnish: F. H.Leeds. Victoria Institute (8 Adelphi Terrace, Strand), at 8. — The Origin of the Australian Race : Dr. John Eraser, F.R.S. TUESDA Y, March 6. Royal Institution, at 3. — Locomotion and Fixation in Plants and Animals : Prof. C. Stewart. Society of Arts, at 8. — Travels in the Basin of the Zambesi : M. Foa. Zoological Society, at 8.30. — On the Factors that appear to have influ- enced Zoological Distribution in East Africa (to be illustrated with Lan- tern Slides): Dr. J. W. Gregory. — On the Habits of the Flying Squirrels (Anomalurus) of the Gold Coast: W. H. Adams. — On Two Cases of Colour-variation in Flat-fishes illustrating Principles of Symmetry : W. Bateson. Sanitary Institute, at 8.— Diseases of Animals in Relation to Food Supply : Prof. A. W. Blyth. Institution OF Civil Engineers, at 8. — Papers to be further discussed : The Liverpool Overhead Railway : J. H. Greathead and Francis Fox. — Electrical Equipment of the Liverpool Overhead Railway : Thomas Parker. Royal Victoria Hall, at 8. — Lakes : W. W. Watts. WEDNESDAY, March 7. Society OF Arts, at 8. — Refrigerating Apparatus: Prof. Carl Linde. Geological Society, at 8. —The Systematic Position of th'> Trilobites: H. M. Bernard. — Landscape Marble: Beeby Thompson. — On the Dis- covery of Molluscs in the Upper Keuper at Shrewley in Warwickshire : Rev. P. B. Brodie. THURSDAY, March 8. Royal Society, at 4.30. — Croonian Lecture : The Minute Structure of the Nervous System : Prof. S. Ramdn y Cajal, of Madrid Royal Institution, at 3. — The Vendanta Philosophy ; Prof. Max Miiller. Institution of Electrical Engineers (25 Great George Street, West- minster. S.W.), at 8.— A Note on Parallel Working through Long Lines: W. M. Mordey. Ca.mera Club, at 8. — Composite Heliochromy by Three-colour Printing • F. E. Ives. Mathematical Society, at 8. — Groups of Points on Curves: F. S. Macanlay. On the Buckling and Wrinkling of Plating supported on a Framework under the influence of Oblique Stre^ses, and on a Simple Contrivance for Compounding Elliptic Motions : G. H. Bryan. — On the Motion of Two Pairs of Cylindrical Vortices which have a Common Plane of Symmetry : A. E. H. Love. Society of Antiquaries, at 8.30. FRIDA Y, March 9. Royal Institution, at 9.— The Making of a Modern Fleet : Dr. W H. White. Physical Society, at 5.— Calculating Machines, and especially a Nf w Harmonic Analyser : Prof. O. Henrici, F.R.s. Sanitary In-;thutk., at 8.— Infectious Diseases and Methods of Disin- fection: Dr. W. H Uainer. RovAL Astronomical Society, at 8. Malacological Society, at 8. SATURDAY, March 10. Royal Institution, at 3. -Light, with special reference to the Optical Discoveries of Newton: The Right Hon. Lord Rayleigh, F.R.S. NO. 1270, VOL. 49J BOOKS, PAMPHLETS, and SERIALS RECEIVED. Books. — Modern Plane Geometry: G. Richardson and A. S. Ramsey (Macmillan). — Essays in Historical Chemistry: Prof. T. E. Thorpe (Mac- millan). — Comite International des Poids et Mesures, Seizieme Rapport (Paris, Gauthier-Villars). — Travaux et Memoires du Bureau International des Poids et Mesures, Tome viii. i(Paris, Gauthier-Villars). — Annuaire de Observatoire Municipal de Montsouris pour I'Anrn^e 1894 (Paris, Gauthier- Villars). — Light, an Elementary Text-Book, Theoretical and Practical: R. T. Glazebrook (Cambridge University Pie-is). — The Flowering Plants of Western India: Rev. A. K. Nairne (W. H. Allen). — Object Lessons in Botany from Forest, Kield,and Garden: E. Snelgrove (Jarrold). — The Al- chemical Essence and the Chemical Element : M. M. P. Muir (Longmans). — Statistics of the Colony of Tasmania (Tasmania). — Hume, with Helps to the Study of Berkeley: T. H. Huxley (Macmillan). Pamphlets- — Report of Observations of Injurious Insects and Common Farm Pesfs during the Year 1893, &c. : E. A. Ormerod (Simpkin). — Die Lehre von der Wellenberuhigung : Dr. M. M. Richter (Berlin, Oppenheim). Twenty-fourth Annual Report of the Wellington College Natural History Society. 1893 (Wellington College). — On the Definitions of the Trigono- metric Functions : Prof A. Macfarlane (Boston). Serials — American Journal of Science, February (New Haven). — Journal of the Frankl n Institute, February (Philadelphia). — Zoologische Abhand- lungen — Berichte der Naturforschenden Clesellschaft zu Freiburg i. B. viii. (Williams and ^forgate). — Astronomy and Astro-Physics, February (Wesley). — Royal Natural History, Vol. i. Part 4 (Warne). — Proceedings of the Royal Society of Victoria, Vol. vi. new series (Williams at^d Norgate). — Journal of the Royal Horticultural Society. January (117 Victoria Street). — Journal of the Polynesian Society, Vol. ii. No. 4 (Pctherick). — Journalof the Institution of Electrical Engineers, No. 108, vol. xxii. (Spon). — Kryptogamen- Flora von Schlesien, 3 Band, 2 Halfte, 2 Lief (Williams and Norgate). — Journal of the Institute of Jamaica, December (Kingston). — Meteorological Record, vol. xiii. No. 50 (Stanford). — Quarterly Journal of the Royal Meteorological Socie:y, January (Si^nford). — L'Anthiopologie, tome iv. No. 6 (Paris, Masson). — Zeitschrift fiir Physikalische Chemie. xiii. Band, 2 Heft (Leipzig, Engelmann). — The Humanitarian, March (Sonnenschein). — Journal of the Royal Microscopical Society. February (Williams and Norgate). — Bulletin de 1 Academie Royale des Sciences de Belgique, tome 27, No. i (Bruxelles). — Journal de Physique, February (Paris). — Bulletin of the American Museum of Na'ural History, vol. v. 1893 (New York). — National Academy of Sciences, Vol. vi. : Eighth Memoir: Further Studies on the Brain of LijHiihis polyphentiis,\v\xh Notes on its Embryology: A. S. Packard. — Records of the Geological Survey of India, vol. .xxvi. Part 4 (K. Paul). CONTENTS. PAGE The Report of the Gresham University Commission 405 Stereochemistry. By T. P 409 Marine Boilers 410 Our Book Shelf:— Sheldon: " Chapters on Electricity " 411 Dickson : " Meteorology " 412 Letters to the Editor :— Great Auk's Egg. — Prof Alfred Newton, F.R.S. 412 Frost-Cracks and "Fossils." — Prof. G. A. Lebour 412 The Origin of Lake Basins. — Alfred R.;C. Selwyn, F.R.S 412 Note on the Habits of a Jamaican Spider. — Prof. T. D. A. Cockerell 412 The Cloudy Condensation of Steam. — Shelford Bid- well, F.R.S 413 Astronomy in Poetry. — Rev. Edward Geoghegan . 413 A Plausible Paradox in Chances. — Lewis R. Shorter 413 The Planet Venus. [Illustrated.) By W. J. L. . . 413 Notes 415 Our Astronomical Column : — A Large Sun-spot 419 Anderson's Variable in Andromeda 419 A Bright Meteor 419 The Bakerian Lecture. By Prof. T, E. Thorpe, F. R.S.an.lJ. W. Rodger 419 The Dynam cs of the Atmosphere 422 University and Educdtional Intelligence 422 Scientific Serials 423 S icietics and Academies 424 Diary of Societies 427 Books, Pamphlets, and Serials Received 428 NA rURE 429 THURSDAY, MARCH 8, li ELECTROMAGNETISM AND DYNAMO CONSTRUCTION. A Text-Book on Elcctromagnetism and the Construction of Dynamos. By Dugald C. Jackson, B.S., C.E., Pro- fessor of Electrical Engineering in the University of Wisconsin, &c. Vol. I. (New York and London : Macmillan and Co., 1893.) IN this work an excellent attempt is made to present the elements of a very important subject in small compass and in a clear and readable form, without any sacrifice of accuracy. The present volume is only the first instalment of the complete treatise promised by the author, but it contains in nine chapters, covering some \ 280 pages, a fairly comprehensive survey of the elements j of electromagnetism, the magnetic properties of iron, magnetic circuits and characteristic curves of dynamos, a discussion of efficiencies, and the action of multipolar dynamos. The primary definitions and statements regarding units, which are always a good test of the competency of at least the theoretical treatment in a book like the present, are generally clear and accurate. The author begins by discussing lines of force, and on p. 2 gives the needful caution that such lines "have no material existence, but are merely hypothetical." It might have been added here, perhaps, that this notion of lines of force is a concept corresponding to a state of the field produced by the presence of the magnetic distribution, that is to say that there is some kind of "displacement or motion of the medium" perfectly real though not material, the direction and amount of which is typified by the grouping of the lines of force. On the same page it is stated that "when the lines of force in a magnetic field are parallel and of equal number per square centimetre a magnet pole will experience the same force at all points of the field, and the field is said to be uniform." This is, of course, quite correct ; but it ought to be noticed that if the lines of force are parallel throughout any finite portion of the field, they must be of equal number per square centimetre, and vice versa. The usual definitions of B and H are given on p. 5, and we do not criticise in any adverse sense the author's procedure in so doing. But we cannot help thinking that it is much more conducive to clearness to give to each medium, whatever it is, a magnetic inductivity, and to consider this as a physical quantity depending on the medium. Thus, denoting the inductivity by \i., we should have the relation B = /iH. Then if the inductivity of a standard medium be fi^ we should have, for the same H, Bo = /ioH. The ratio B/Bq or /n//zo is then properly the permeability Qi the former medium, and might be denoted by ■^. This, it seems to us, would be much more in accordance with Lord Kelvin's original presentation of the matter. The permeability •»• would be in all circum- stances a mere ratio, and therefore of zero dimensions ; while the confusion caused by at one time regarding /x as NO. 1271, VOL. 49] a mere number, and at another as a quantity having certain dimensions (for example, the dimensions of the reciprocal of the square of a velocity), would be entirely avoided. This procedure was recommended some time ago by Heaviside, and there can be no question of the desirability of its adoption. Instead of the equation we should have |U = I + 4 TT K M = Mo ( I + 4 'T «) where k is the magnetic susceptibility, also a pure number. If, as Heaviside strongly advocates, " rational " units be adopted, the 477 must be omitted in these formulas. The ordinary mode of dealing with the subject begins by making B a quantity of the same dimensions as H, and later when the energy of the electromagnetic field is discussed the definition of B is virtually altered, so that BH/Stt becomes the energy per unit volume of the medium, and B has not the same dimensions as H. This change may be explained, but it constitutes a sore difficulty to the student. In the present case, however, the matter is not so im- portant, as for the dynamo application it is sufficient to regard the relation as that which holds when ^q is put equal to i. There is, however, essentially the same kind of difference between \k and ■»• that there is between density and specific ^gravity. The former depends on the units adopted, the latter does not. A very good account is given in chapter iii. of the magnetic properties of iron. The more important recent researches on this subject are summarised, and the results illustrated by curves. The author seems, however, to have missed, or at any rate has not brought out, the point of Dr. Hopkinson's divided bar method, which was to test the total magnetic induction in the bar after certain specified series of changes of magnetic force had been applied. This object would not be attained by having the bar undivided and the coil fixed, and simply reversing the magnetising current, as Mr. Jackson suggests. The description in this connection of a ballistic galvanometer as " a galvanometer with a rather heavy needle, and therefore a considerable time of vibration," has the merit of brevity, but is curiously inaccurate. It is no doubt an off-hand careless statement which has escaped correction in proof, but it may mislead a reader into supposing that weight of -needle was in itself an advantage in such an instrument. Hysteresis is adequately discussed in this chapter, and Steinmetz's formula for the energy dissipated in a cycle as depending on the quality of the iron and the number of cycles per minute is exemplified by numerical values found by experiment for different kinds of iron. Here we notice the phrases " watts of energy," " energy in watts," improperly used for "joules of energy," " energy in joules." With regard to the discussion of energy-losses by hysteresis, it is worth remarking that no assertion can be made as to the disposal of the energy given to the medium (or taken from it) in an unclosed cycle. The ordinary diagram and mode of discussing it easily shows that at certain parts of the cycle more energy is given to T 430 NA TURE [March 8, 1894 the medium, at others less, than is accounted for by the increase in electrokinetic energy, and that similarly when energy is being returned from the medium more or less is received than disappears from the electrokinetic energy of the field. It seems not impossible that these energy differences may be related to the cyclic changes of dimensions of a specimen of iron, which it has been shown recently by Mr. Nagaoka {Phil. Mag. Jan. 1894) ac- company the cycles of magnetisation. In chapter iv. we have a business-like discussion of what the author calls the establishment of electric pressures, in which the building up of a nearly uniform current by the commutation of successive sinusoidal currents in the different sections of the armature is descrioed in the usual manner, but clearly and without un- due elaboration. The winding of Gramme and Siemens armatures is dealt with in the same chapter, which ends with some numerical calculations of armature constants, and the heating caused by the Joulean dissipation of energy in the coils. Hopkinson's method of studying dynamo construction by means of the idea of the magnetic circuit, in con- junction with his brilliant invention of dynamo character- istic curves, and the valuable practical results which he and others have obtained by this mode of investigation, have gone far to clear up the whole subject of the design- ing of steady-current machines. Prof. Jackson has done well to devote a considerable amount of space to this part of the subject ; in fact, taking in the topics of regulation and connecting dynamos, it occupies no less than half the present volume. Opinions will no doubt differ as to the practical value of a good deal in this chapter, but the selection made seems satisfactorily dealt with. Short chapters on efficiencies and multipolar dynamos conclude the volume. A second is promised on alter- nating current and arc lighting machinery. As it is the object of the author only to present funda- mental principles, and he very rightly holds that the electrical student should study typical dynamos mainly in the workshop or generating station, he has not burdened his pages with cuts of actual machines of different kinds. There the student who has had a sound course of instruc- tion such as this book represents, based upon previous knowledge of certain cognate subjects, and satisfactory divergences into others, will be able to read to advan- tage what is essential of the more elaborate works of reference on dynamo machinery. A small incidental advantage is the absence of those embarrassing folding plates, which cannot be avoided in works of the latter kind, and which, instead of being printed on cloth-backed sheets, arranged to fold always at the same place, are made of the most exasperatingly brittle and frail material. The book is excellently printed in good, bold type, and reflects credit on the Norwood Press, Boston. There is less than we have seen in some other cases of that dis- agreeable glare of regularly reflected light from the hot- pressed paper, which renders many American books, notwithstanding their often excellent typography, so difficult to read with comfort. A. Gray. NO. I 27 I, VOL. 49] INTERNAL COMBUSTION MOTORS. A Text-Book on Gas, Oil, and Air Engi?tes. By Bryan Donkin, Jun., M.Inst.C.E. (London: Charles Griffin and Co., Ltd., 1894.) AS the results of recent researches on internal com- bustion motors are usually only to be found in the proceedings of our technical societies and institutions, we greet the present volume with pleasure. The gas engine in its present form has attained a lasting success, and this is due principally to the labours of Messrs. Crossley Bros., of Manchester, a history of that firm being really a record of the advance of the gas engine from its early stages to its present high state of development. The manifold advantages of a gas engine over a steam engine are evident, particularly when the power is required intermittently ; moreover, for elec- tric lighting, this type of motor is invaluable for small powers, being started at a few minutes' notice. For larger powers where town gas would be expensive, the addition of a Dawson gas plant renders it far more econom- ical in fuel consumption than any steam engine, and with proper supervision the cost of repairs can be maintained at a low figure. Once started, a gas engine can be allowed to run for several hours unattended, thus reduc- ing the cost of skilled attention to a minimum. Experiments are now in progress with the object of reducing the consumption of gas in the Crossley Otto engine, and the following results show the progress made in this direction. A 14-h.p. nominal engine has recently been tested, and gave a brake horse-power of 3991, and used i6"487 cubic of gas per b.h.p. per hour. These results are far in advance of the older engines, and show there are still means of improving what is already a wonderfully economical motor. Mr. Donkin's work is divided into three parts, treating respectively of gas, air, and oil engines. Part i., on gas engines, is divided into two sections, the first dealing with the early history of these motors, and the second with I modern gas engines. The subject of gas engines occu- pies more than half the book, and has been treated in a careful and very complete manner ; most known engines are described and illustrated, and indicator diagrams are shown in many cases, thus rendering the descriptions very complete. Although the Atkinson engine has not come in for very general use, it is an excellent example of a type giving an impulse every revolution, using one cylinder, whereas the Crossley engine gives an impulse every two revolutions. Another engine of a similar type is that designed by Prof. Rowden, and although it is not described in this work, or elsewhere, yet the consumption of gas is very low per brake horse-power, and owing to the complete expansion of the heated gases the water jacket round the cylinder is not so necessary. Part ii. of the volume under review deals with petroleum engines, a class of motor now rapidly coming to the front, and used in places where gas is not available. If Messrs. Crossley Bros, can claim the honour of having made the gas engine a practical working success, Messrs. Priestman can claim the same honourable position as regards the oil engine. Like all new machines it is more or less complicated, and recent engines made by other firms March 8, 1894] NATURE 431 are decidedly more simple. Here again we find Messrs. Crossley Bros, to the fore with an engine designed on the lines of their Otto gas engine, and certainly working economically and without trouble. Part iii. deals with air engines, a subject which has occupied the minds of engineers for many years, and one which appears to baffle their best designs and schemes. These motors deal with low working pressures, and are necessarily bulky for their power. In the Ericsson engine, for instance, the pressure was only 3 lbs. per square inch. The author says in the preface that, "in both oil and gas engines, about 40 per cent, of all the heat received now goes off in the exhaust gases, and about 35 per cent, in the jacket water." This is nothing new, and the remedy lies in the better expansion of the heated gases. This with the Crossley engine is difficult, but with Prof. Rowden's engine very complete expansion is obtained, and consequently a low pressure at exhaust and a far cooler cylinder. Of course this end is obtained by sacrificing simplicity of design and working parts ; at the same time it is questionable whether it would not be worth while experimenting in this direction, considering the great saving to be obtained by more complete ex- pansion. The question of compounding gas engines has not been overlooked, more than one having been con- structed ; but difficulties have arisen in connection with the valves, and these have only partly been overcome. The difficulty of making a valve to continually pass hot gases is enormous. Yet this is evidently the direction in which economy is to be found, and its solution is merely a question of time. Another point of importance in the economy of the gas engine is the question of accuracy of manufacture ; a badly made gas engine is sure to be a constant trouble, and as many now on the market are bad copies of the Crossley engine without its accuracy and finish, one is not surprised to occasionally hear of failures of this class of motor. This volume contains a very complete and accurate record of all that has hitherto been done in the design of internal combustion motors. The information has been well brought together, and the illustrations are excep- tionally good. The author is to be congratulated on the completion of an excellent book on a subject very little understood by general engineers. N. J. Lockyer. PHYSIOLOGY FOR SCIENCE SCHOOLS. Human Physiology. By John Thornton, M.A. (Lon- don : Longmans, Green and Co., 1894.) ' I "HE book before us belongs to a class which requires J- some apology for its existence. This particular work has been prepared for lay students intending to present themselves for the second or advanced stage of the Science and Art Department. It aims at being something more than a mere cram book, and in justifi- cation of this aim it professes '• to furnish precise and accurate information on such parts of histology and anatomy as are required, as well as to give a reasoned account of the physiological processes of the human body." For all this, however, the book belongs to a class NO. 1 271, VOL. 4q] to which e.xception may justly be taken. The writer appears to have depended almost entirely upon the exist- ence of descriptive physiological works for his material. The result is that the book represents simply a compila- tion of physiological facts, and in no sense can it be described as a guide to physiological practice. The South Kensington examinations, both elementary and advanced, attempt, as far as their opportunities permit, to test the practical acquaintance of a candidate with the subject in which he presents himself for examination. This is very frequently found to be non-existent, and most usually the reason of this is that the teacher himself is not in a position to act as an instructor in the practical work of a subject he professes to teach. There exists a large number of books which give the minimum of the required amount of physiological fact necessary to impart to his pupils, and upon these alone he usually depends. This class of books gives the teacher no information as to the best way to demonstrate practically the facts he teaches, for the reason generally that the writers themselves are unacquainted with the methods. These books are the class which we would wish to see abolished from our elementary science schools ; they are necessarily un- reliable, and they always tempt the teacher who uses them to depend upon a wholly artificial knowledge of little practical value whatever. What advantage is it to a student to know that if fibrin be " placed in gastric juice and the mixture kept at a temperature of about 40^ C. . . . in about an hour the fibrin will be in great part dis- solved " .^ By itself this is simply a naked fact (though stated in the way the writer puts it, it can hardly be called a fact). The whole process could be shown the student in the most simple way on the lecture table, and unless he actually sees the change produced by the gastric juice, he can, as a rule, have but an imperfect idea of what really occurs. All these books that aim at being guides to elementary science teaching should have so much simple instruction as to the methods to be adopted to actually show the different processes described, as can be done, having re- gard to the opportunities of an elementary science school. In physiology a very considerable knowledge can be imparted simply by demonstration, and to ignore this and depend simply upon oral description is to teach physiology in a way that, we are glad to say, is rapidly becoming obsolete. If this volume were supplemented with practical demonstration, it might serve a useful pur- pose. But the divorce from practical acquaintance with the subject is frequently emphasised. In referring to coagulation, the writer says that " by adding to plasma about 14 per cent, of a saturated solution of sodium chloride a white flaky sticky precipitate of fibrinogen is thrown down." The author intends to be precise, but there is a considerable difference between the statement above and the actual fact, viz. that solid sodium chloride should be added so that it becomes dissolved to the ex- tent of 14 per cent. Later, in treating of the absorption of food, the author commits himself to the following statement : " We know of a physical process called filtration, by which is meant the passage of fluids through the pores of a membrane under pressure. Substances that may be obtained in the form of crystals, or 432 NATURE [March 8, 1894 crystalloids, as they are termed, filter easily when in solution. Glue-like substances, or colloids, as they are termed, filter with difficulty." Statements like these are calculated to mislead a student as to the differences between simple filtration and dialysis. On the whole the book gives a large amount of in- formation in a very small compass, and this is, speaking generally, accurate. One of the best features is the wealth of illustration, selected from well-known text- books, which it possesses. J. S. Edkins. OUR BOOK SHELF. Light : an Elementary Text-book^ Theoretical an d Practical, for Colleges and Schools. By R. T. Glaze - brook, M.A., F.R.S. (Cambridge: University Press, 1894.) The best foundation upon which a student of science can build is elementary physics, for the necessity of accurate observation and correct reasoning is impressed upon him from the very beginning. Mere book-work has no value in training the mind in this direction : lectures illustrated with experiments may lead to the desired end if the teacher take care that the inferences to be drawn from the experimentation are quite clear ; but best of all methods, by far, is to let the student perform the experi- ments himself, to mark the result, and then reason out the explanation. The advantages to be derived from such practical work are incalculable, yet the small num- ber of physical laboratories in our schools and colleges at the present time shows that its importance has not been fully recognised. There are, however, signs of improvement. Judging from the increasing number of books dealing more or less with practical physics, interest in that subject is developing. Mr. Glazebrook's two volumes, that on " Heat," recently noticed in these columns, and the one now before us, help to extend the practical method of teaching. Believing with most scientific educationalists that courses of practical instruc- tion are necessary to the proper understanding of funda- mental principles, Mr. Glazebrook gives, in the volume under review, clear descriptions of experiments, the explanations of the theory underlying the work, and the deductions to be made from the results. The theoretical portion of the book could very well form the subject of short lectures preceding the laboratory work, in which the principles expounded at such times could be experi- mentally tested. The book abounds with diagrams of the kind that appertain to treatises on light. To the artistic mind these figures lack beauty, but they possess the qualification of clearness ; and that is sufficient to commend them to the student of optics. Teachers who require a book on light, suitable for the class-room and the laboratory, would do well to adopt Mr. Glazebrook's work. Beni Hasan. Part ii. By P. E. Newberry. With appen- dix, plans, and measurements of the Tombs, by G. W. Eraser. (London: Kegan Paul, 1893.) Some two or three months ago we called the attention of readers of Nature to the first part of Mr. Newberry's work on the rock-hewn Xllth dynasty tombs at Beni Hasan m Upper Egypt, and we have now the pleasure to record the appearance of the second and concluding portion of this valuable book. We have already described the general scope of the publication, and the plan upon which it has been carried out, and it therefore only remains for us to state the contents of the part before us. Employing the same method of arrangement, Mr. Newberry describes tombs Nos. 15-39, and he gives lists of all the members of the households of the Egyptian NO. 1271, VOL. 49] noblemen who were buried at Beni Hasan ; the general remarks which he makes upon them are interesting and to the point. Too much praise cannot be given to the thirty-seven plates which illustrate the text, for they give the reader an accurate idea of the general appearance of the scenes painted upon the walls of the tombs. Mr. G. W. Eraser's "Report" (pp. 71-85) is also a very useful addition to the book, and the copies of Greek and Coptic graffti on pp. 65-68 will be welcome for several reasons. We are glad to see that the system of transliteration of Egyptian texts has been much modified, especially as the non-expert will now be able to gain some idea of its meaning and use. It is a great pity, however, that the system as represented in Dr. Birch's " Egyptian Texts" was not wholly adopted. LETTERS TO THE EDITOR. \The Editor does not hold himself responsible for opinions ex- pressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part t»/ NATURE. No notice is taken of anonymous co7nmunications.'\ Great Auk's Egg. In your last issue (p. 412), I observe a letter from Prof. Newton, in which he gives his version of the history of the egg of this extinct bird, which was recently sold by auction for ;^3i5. There is no doubt that the egg was brought to this country by Yarrell, who purchased it in France some time before 1838, in which year it was figured by Hewitson in his well-known work on birds' eggs. But the question is, where- abouts in France did he find it? Prof. Newton, who well remembers it in the collection of Yarrell, says : " He told me, as he told others of his friends, that he bought it in Pai-is, in a little curiosity shop of mean appearance," and that he paid twa francs for it. He adds that the only "variant" of this story deserving of consideration, is to the effect that the price was five instead of two francs. If this were the only "variant," it would not be worth further discussion. But there is a very different story told of it in Mr. Symington Grieve's important work on " The Great Auk, its history, archaeology, and remains," pub- lished in 1885. At p. 105 of this volume, Mr. Grieve writes of this very egg ■■ — " The following curious story, which is well-known to ornitho- logists, is so remarkable that we repeat it, and give a copy of Mr. R. Champley's original note, dated June I, i860 : Mr. Bond [who became the purchaser of the egg in question upon Yarrell's death] says to R. C. — Yarrell told him that, walking near a village near Boulogne, he met a fishwoman having some guillemot's eggs. He asked her if she had any more ; she said she had at her house. He went, when he saw hanging over the chimney-piece four wild swans' [eggs], with a great auk's [egg] hanging in the centre. She asked two francs each for them. He bought the auk's, and two swans'. She said her husband brought it from the fisheries. The great auk's egg sold at Stevens's sale to Mr. Gardner for ;i^2l, [and was] sold again by him to Mr. Bond for ;^26. Copied by R. Champley at Mr. Bond's, by whom the history was told." Here then we have an important "variant" of Prof. New- ton's version ; and as it was taken down in writing in i860, within four years of Yarrell's death, from the lips of the the late Mr. Bond, who had it frjm Yarrell himself, it seems to me that it ought not to be passed over in silence. At any rate, it affords some justification to the writers referred to by Prof. Newton (see the Titnes of February 23), who, comment- ing upon the recent remarkable sale, have naturally repeated the only history they could find of this egg, namely, that published in the latest book on the subject. J. E. Harting. On M. Mercadier's Test of the Relative Validity of the Electrostatic and Electromagnetic Systems of Dimensions. In connection with the clear exposition of the true dimensions of electrical units given by Prof. Kuckerin Nature of the 22nd ult. it is well to bear in mind that Maxwell long before the publi- March 8, 1894] NA TURE 433