Ffar heumns lefere te looue at bear headis hed Giunenty bokis Lelad in blak ar red Of Aristotle 2% his philosa-phie be onrp a turhe or fede or gay sxuitie a 9 a Pid) eAear bh AP. on Basle ¢ Pr iy fae i i 8. Na 4 Pa ‘| \ é ; ‘ yee ‘Vi ii Ve Laat eres : ; pul ees) 1 aa Aa ’ - b ) 4 oe a ; , j Bs & » b "Sra ATUR AP WEEKLY ILLUSTRATED JOURNAL OF SCIENCE VOEUNEE,* ii MAY to NOVEMBER 1870 “ To the solid ground Of Nature trusts the mind that builds for aye.” —WORDSWORTH VF ondow MAGCMIELAN AND CO 1879 LONDON ;: -R. CLAY, SONS, AND TAYLOR, PRINTERS, BREAD STREET HILL IND EX Abel (Pro!.) History of Explosive Agents, 326 Abyssinian Expedition, the Natural History of the, 29 Adams’ ‘‘ Travels of a Naturalist in J Aéronautical Society, 132, 266 Airica, the Swallows of, 74 Airican Monitors and their Geographical Distribution, 39 Air Pollution from Chem. Works, A. E. Fletcher (Br. A.), 441 Alcohol, the Effects of, on the Human Body, 93 Alcohois, some Reactions of, 113 Alcoholic Extract of Cynoyiossum officinale, 156 America, Science Schools and Museums in, 289 American Government Eclipse Expedition, the, 517, 590 American Museum of Natural History, 289 American Natural History, 186 Ammoniacal Amalgam, on the Constitution of, 135 Ammoniacal Salts, quantitative determination of the, 204 Ancient Lakes of Western Asterica, J. S. Newberry, 385 Andaman Islands, gradually sinking, 13 Andamanese, 328 Anderson’s University, 212 Anemone nemorosa, infested by a fungus, 368 Anglo-Saxon Conquest, Correspondence on the, 48, 66, 103 Animal Fibre, Separation of, from Vegetable, 52 Animal Life, Forms of, 80, 206 Animal Mechanics, some Elementary Principles in, 114 Anneloids Dredged in the Expedition of H.M.S. Porcupine, Dr. M‘Intosh, F.L.S. (Br. A.), 465 Antholite discovered by Mr. C, P, Peaclr, W. Carruthers (Br. A.), 505 Anthropological Society, 37, 133, 153, 266 Anthropology of Lancashire, Dr. Beddoe (Br. A.), 467 Aplanatic Searcher, an, G. W. Royston Pigott (R. Soc.), 16 Aqueous Solutions, Specific Gravities of, 151 Arbutin, Constitution of, 487 Archer (Prof.), Arrangement of Specimens in Natural History Museums, 465 Arctic Ice, the Physics of, 265 Arisaig, Nova Scotia, Geology of, Rey. D. Honeyman, 95 Armenians of Southern India, the, 133 Army Medical Museum, Washington, 290 Aromatic Glycol, by A. Naquet, 337 Artificial Alzarine, W. H. Perkins, Journal of the Chemical Society, 114 Assays of Gold and Silver Bullion, the Manipulations of, 95 Atlases, New, 207 Atmosphere, Researches on the, by Dr. Sigerson, 203 Atmospheric Currents, J. K. Laughton (Br. A,), 447 Aurora Borealis, the, 515, 520 Australia, the Snakes of, by A. Giinther, 64 Aymara Indians of Bolivia and Peru, 266 Aztec Remains, 477 F.R.S. (Br. A.), 463; Baker (B.) on the Strength of Beams, Columns, and Arches, 139 Balfour’s Class Book of Botany, 162 Balloons, 380 Barberry, Fertilisation of the, by T. H. Farrer, 164 Barlow (W. H.), Resistance of Flexure in Beams (R. Soc.), 114 Barometer, the new Form of, 396 Barometric Prediction of Weather, by F. Galton (Br. A.), 510, Barracks, Indian, 304 Bastian (H. C.), the Heterogeneous Evolution of Living Things, 170, 193, 219; Reply to Prof. Huxley's Liverpool Address, 410, 431; Letter on the Evolution of Life, 492 Bath, Denudation of the Oolites of, W. S. Mitchell (Br. A.), 505 Beale (L. S.), Prof., Letter on Spontaneous Generation, 254 Bechtinger’s (Dr.) Ost Afrika, 45 Beke (Charles) on the Sources of the Nile, 6 Bennett (A. W.), Leonardo da Vinci as a Botanist, 42; Hooker's British Flora, 292 ; Wheat Rust and Berberry Rust, 318 ; Pro- tandry and Protogyny in British Plants (Br. A.), 482 apan and Manchuria,” 352 | | | Bentham (G.) on the Progress of Botany during 1869, 91, 100. | Benzile, the Optical Properties of, 134 Bergeret’s ‘‘ De l’abus des boissons alcooliques,”’ 100 Berkeley (M. J.) on Roumeguere on Fungi, 185; on Wheat Rust and Barberry Rust, 318 Berlin: German Chemical Society, 19, 40, 75, 116, 156, 288, 308, 366; Royal Prussian Academy of Sciences, 39, 155, 268; Working Men’s Club, 429 Bidston Observatory, Liverpool, 390 Biological Section, British Association, 423, 442, 464, 481, 505, 527 Bird of Paradise, Twelve-wired, Letter by A. R. Wallace, 234 Birds’ Nests, 189 Boiler Explosions, Report of the Committee on (Br. A.), 448 Bolley (Dr.), 361 Bone Caves of the Wye, Rev. W. S. Symonds (Br. A.), 481 Book Shelf, Our, 5, 23, 45, 65, 83, 99, 121, 139, 162, 186, 208, 234, 253, 273, 295, 342, 331, 352 Boston Natural History Society, 135, 180, 268 Botanical Department of the British Museum, Annual Report of the, 398 Botany, the Progress of, during 1869, by G. Bentham, F.R.S., OI, 112 Brackish Water Foraminifera, H. B. Brady (Br. A.), 527 Brady (G. S.), Protective Adaptation in Marine Animals, 376 Brazil, the Glaciation of, by A. R. Wallace, 310 Brenner’s (Madame) Gymnastics for Ladies, 208 Brett (John) on Natural Science at the Royal Academy, 157 Brighton and Sussex Natural History Society, 57, 154, 246 Bristol Observing Astronomical Society, 267, 347, 507 British Association, the, 399, 416, 437, 460, 479, 501, 526 British Coniferze, the, W. Carruthers (Br. A.), 464 British Edible Fungi, by C. J. Robinson, 518 British Islands, Temperature of the, 307 Buddhist, the Modern, 372 Busk (George), The Species of Rhinoceros whose remains were discovered in a fissure cavern at Oreston in 1816 (Geological Society), 36 | Calamites of the Coal Measures, Prof, Williamson (Br.A.), 423 | Cambridge, Physical Science at, by Sedley Taylor, 28; Philo- sophical Society, 57, 134 | Camerer’s (Dr.) Investigations on the Sense of Taste, 455 | Canada, Yearbook of, for 1870, 90 | Captain, Loss of the, 398 | Carbon, Varieties of, 131 Carbonic Anhydride, the combination of, with Water and Am monia, 365 a Cardiff Naturalists’ Society, 38 Carp and Toads, 59, 67, 101 Carpenter (Dr. W. B.) on the Cretaceous Epoch, 100; Lecture on the Deep Sea, 107; on the Gulf Stream, 334; on recent Deep-sea Explorations, 513 Cartesian, the, with two imaginary axial foci, Prof. Cayley, 202 Catlin’s American Geology, by T. Rupert Jones, 371 Caverns, the formation of, H. P. Maleton, 103 | Cayley (Prof.), a Ninth Memoir on Quantics (Rayal Soc.), 152 ; the Cartesian, with two imaginary Axial Foci, 202 Central America, Ruined Cities of, Carmichael (Br. A.), 138 Chamouni, 28 | Cheesewring, anticipated Destruction of the, 101 Chemical Section (Br. A.), 422, 440, 463, 480, 503 Chemical Society, 37, 95, 133, 179 Chessau, Prize Medals, of the Geographical Society, 109 “* Choice and Chance,” by Prof. W. S. Jevons, 4 “¢Chromatic Octave,” Correspondence on the, 102, 188 Cinnamic Acid, Some derivatives of, 487 Clouds, New Classification of, by Prof. Poey, 382 Clydesdale during the Glacial Epoch, 38 | Coal-getting Machine, New, 346 ; Jones's, 346 1V Coal Measures of Scotland, the Geology of the, 345 Cockroach, the, 435 Cocoa, by John R. Jackson, 497 Codrington (T.) on the Superficial Deposits of the South of Hampshire and the Isle of Wight (Geol. Soc.), 178 Coffee, by J. R. Jackson, 126 Coleoptera, Plateau on the Flight of, 244 Colour-Blindness, Correspondence on, 256, 314, 355, 452 Columbia College, New York, 289 Comets, Tails of, 25 Copals, 37 Coral, a new species of, by W. S. Kent (Br. A.), 505 Cornell University, 289, 380 Cornish Minerals, Analysis of two, 37 Cornish and other Pumping Engines, the Duty of, 345 Corona, the, 141, 164, 277 Cosmical Physics, by Prof. Balfour Stewart, 499 Cotteau et Triger’s Echinides du Départemente de la Sarthe, 352 Council of the British Association, Report of the, 418 Cox (Samuel S.), ‘‘Search for Winter Sunbeams,” 5 Cranial Cavity, the Temperature of the, 192 Cretaceous Epoch, by Dr. W. B. Carpenter, 100 Cross Fertilisation, 28, 355 Crystals of Potassia Racemate, 130 Crystallisation of a Double Salt, J. Berger Spence (Br. A.), 441 Cuckows’ Eggs, 188, 314 Curves, the Intersection of, 203 Cushat, Special Modification of Colour in the, 314 Cutaneous Nerves, the Termination of, 93 Dartmoor, Prehistoric Antiquities of, 133 Darwin and the French Institute, 309 Darwin before the French Academy, 261, 298 Dawkins (W. Boyd) on Fossil Mammals in North America, 119, 232 ; on Platycnemic Men in Denbighshire, 506 Dawson (J. W.), Precarboniferous Flora of North-eastern America (R. Soc.), 35; Primitive Vegetation of the Earth, 85 ; Sigil- laria, Calamites, Calamodendron (Geol. Soc.), 95 Deep-sea Climates, by Prof. Wyville Thomson, 257 Deep-sea Thermometers, 73 Deep-sea Explorations, the Geological Bearings of recent, by Dr. C, B. Carpenter, 513 eo eabetehire, Platyenemic Men in, Dawkins and Busk (Br. A.), 50 Depraved Appetite, extraordinary instance of, 90 Derby Free Public Museum, Liverpool, 389 De Rance (C. E.), Geology of country around Liverpool, 391 Devon and Cornwall, Archzeology and Geology of, 154 Devonshire, the Geology of, 376 Diamond, the Combustibility of the, 39 Diatomacez, Notes on, 135 Digestion, the Physiology of, by H. Power, 238 Discosaurus and its Allies, 248 Donkin’s Acoustics, by C. Foster, 253 Dublin: Royal Irish Academy, 58, 155, 203, 307; Royal Society, 155 ; Royal Geological and Zoological Societies, 155 ; Natural History Society, 58, 155; Royal Geological Society, 58; Institution of Civil Engineers of Ireland, 58 Duchenne’s Researches on the Appearance Presented by Sections of the Nervous Centres, 108 _ Dust and Disease, 143 Earth, the Primitive Vegetation of the, by J. W. Dawson, 85 ; External Configuration of the, 397 Earwaker (J. P.) on a Geological Discovery in Liverpool, 397 Echinoderms of the Porcupine Expedition, W. Thomson, 464 Eclipse of December, Expedition to Observe, 74; Action of Government, 409 Economic Museum, Liverpool, 397 J-conomic Section, Br. A., 428, 468 Edinburgh : Royal Physical Society, 58 ; Botanical Society, 38, 267 ; Institute of Engineers, 95 ; Meteorological Society, 306 Edwards (Prof. A. Mead), ‘‘ Notes on Diatomace ” (Boston | Natural History Society), 135 Electrical Phenomena and Theories, Prof. Tyndall’s Lectures on, 243 Electric Currents, 115 Electroscopic Experiments, a cause of error in, Sir C. Wheat- stone (Royal Society), 17 Energy, by Dr. Balfour Stewart, 79, 183, 279; the Dissipation of, 435 | Engineering College for the Indian Service, INDEX 316, 353, 374 A “ English Cyclopzdia,” Correspondence on the, 83, 187, 297 3. English Physiology, Letter by T. M. Braidwood, 413 English Plantations, New Trees and Shrubs for, 68 | Entomological inquiries, Letter by T. W. Webb, 298 Entomological Society, 55, 153, 306 Ethnological and Anthropological Department, Br. A., 446, 466 Ethnological Society, 56, 94, 133, 153, 266, 287 Ethnology of Britain, Address by Prof. Huxley, 56; Influence of the Norman Conquest on, Rev. Dr. Nicholas, 56 Ethylamines, the Preparation of, on a large scale, 40 Etna in Winter, 142 Euclid as a Text-Book, 65, 141, 164 | Euphorbia, Cross-fertilisation and Law of Sex in, 248 Evans (J.), Stone Implements from Burma, 104; Address to Eth. and Anth, Department (Br. A.), 446 Everard's “ Birds of Marlborough,” 208 | Evolution of Life, the, H. C. Bastian, 492 Explosives, the Science of, 49 Explosive Agents, the History of, 326 Extension of the Coal-fields beneath the newer Formations of England, Edward Hull (Br.A.), 463 Farrer (T. H.) on Fertilisation of the Barberry, 164 Fermentation, 179 Finkelstein (B.), on Hoppe-Seyler’s ‘‘ Handbuch,” 5 Fish, Keen Sight of, 67 Fish Torpedo, the, 475 | Fishes of the Tertiary Shales of Green River, 96 Fizeau’s Experiments on “* Newton’s Rings,” I’oster, 105 Flight, Pettigrew and Marey’s Views of, 166 Flint Lake Ore from the River Gravel of the Irwell, John Plant (Br. A.), 506 Flintshire and part of Devonshire, the Mountain Limestone of, G. H. Morton (Br. A.), 526 Flower (W. H.) on the New Natural History Museum, 61 Fluid in Plants, a method of ascertaining the rate of extent of, 5t Geobes (David), the Aymara Indians of Boliviaand Peru (Eth. S.), 266 ; Voleinoes, 283, 336; the External Configuration of the Earth, 397; the Utilisation of Sewage, 503 Fossil and Recent Bones, Composition of, 52 Fossil Corals, Report on Slicing and Photographing of (Br. A.), 423; British, Prof. P. M. Duncan (Br.A.), 441 Fossil Crustacee, H. Woodward (Br. A.), 464 Fossil Elephants from Malta, by Dr. Leith Adams (Br. A.), 441 Fossil Mammals in N. America, W. Boyd Dawkins, 119, 252 Fossil Oysters, by T. W. Flower, 22 Fossils of Kiltorcan, Report on the, W. H. Bailey (Br. A.), 423 Foster (G. C.) on Fizeau’s Experiments on Newton’s Rings, 105 ; on the Intended Engineering College, 316, 374; on Donkin’s Acoustics, 253 Foster (M.), Velocity of Thought, 2 ; Choice of a Microscope, 255 Gasteropeda, the British Fossil, Lobley (Br. A.), 526 Gatling Gun, the, 302, 358 Geikie (A.) on the Ice Age in Switzerland, 310 Geikie (J.), Geology of the Coal Measures ot Scotland, 345 General Committee of Br. A., Resolutions of the, 439 Geographical Distribution of Various Diseases in England, 33 Geographical Section (Br. A.), 427, 447, 467, 483, 506 Geographical Society, 17 ; Prize Medals of the, by Chessar, 109 Geological Section (Br.A.), 422, 441, 463, 480, 503, 526 Geological Society, 36, 94, 178, 245, 265 Geological Systems and Endemic Diseases, Dr. Moffat, Br. A., 481 Gerardin’s (Prof.) efforts to purify the Water of the Croult, 169 Gerold’s (Dr. Hugo), Ophthalmologische Physic, 209 Gervais’ ‘‘ Zoologie et Paleontologie générales,” 23 Girard’s (Jules) “* La Chambre noire et le Microscope,” 65 Glacial Action in Canada, 246 Glacial Phenomena, in the Central District of England, Rev. H. W. Crosskey (Br. A.), 504; of Western Lancashire and Cheshire, 276 Glaciated Surface of Triassic Rocks near Liverpool (Br.A.), 422 Glasgow Geological Society, 38 Glyceric Tribromhydrine, 387 Gneissoid series in Nova Scotia and New Brunswick, TI. Vule Hind (Geol. Soc.), 36 = Gould (B. A.), a New Observatory in S. Hemisphere, 305 Gould’s (John) ‘‘ Birds of Asia,” 23 Gottingen Royal Society of Sciences, 156, 268 INDEX Government and the Eclipse Expedition, 409, 512 Grape Sugar, a new Acid from, 19 ; Estimation of, 487 Great Tunnel through the Alps, by Prof. Ansted (Br.A.), 481 Grisons, Red Snow in the, 169 Guattari Atmospheric Telegraph, the, 257 Gulf Stream, Correspondence on the, 334, 353, 374 Gulf of Suez, Marine Mollusca of the, R. McAndrew (Br.A.), 464 Guns and Gunpowder, 378 Giinther (A.) on the Snakes of Australia, 64; on Modern Angling, 512 Hzematozoon, the Embryonal Development of the, Dr. Cobbold, (Br. A.), 528 Hairy Structure of various Families of Dicotyledons, 19 Hammering and Stone-driving Machinery, Dr. J. H. Lloyd (Br. A.), 507 Harrison (W. H.) on Curious Facts in Molecular Physics, 7 Harvard Museum, 138 Harveian Oration, the, 242 Haughton (Rev. S.) the Geological Effects of the Opening of | the Suez and Darien Canals, 58; Animal Mechanics (R. Soc.), 114; Natural Laws of Muscular Exertion, 324 Haute Savoie, Temperature of, 90 Haze accompanying Auroral Display, the, 453 Heart, Magnitude of the Areas of the Orifices of the, 14 Heat Engine, New, A. W. Bickerton (Br. A.), 483 Heavy Forgings, Production of, Lieut.-Col. Clay (Br. A.), 506 Height and Weight, by E. Lankester, 230 Henocque’s Investigations on the Mode in which Nerves termi- nate in Smooth Muscular Tissue, 93 Hereditary Deformities, 493 Herschel’s (Sir John) Meteorology, 140 Heterogeneous Evolution of Living Things, by H. C, Bastian, 170, 193, 219 Hibberd’s (Shirley) Rustic Adornments for Homes of Taste, 140 Higher Hydrocarbons of Coal-tar, 366 Hind (H.Y.), on Two Gneissoid Series in Nova Scotiaand New Brunswick (Geological Society), 36 Hinks (Rev. W.) on the Darwinian Theory, 108, 127 Hirschwald’s Reactions-Schema fiir die Qualitative Analyse, 274 | Hofmann (Prof.) on Substituted Melamines, 155 Holly Berries, 103; and Birds, 103, 274, 356, 374 Hooker’s British Flora, by A. W. Bennett, 293 ; Letter on, by Henry Reeks, 335 Hopkins versus Delaunay, 264 Hoppe-Seyler’s ‘‘ Handbuch,” B. Finkelstein, 5 Horse-Chestnut, derivation of the term, 212, 277, 297, 313 Hugel, Baron, 356 Hulke (J. W.), Plesiosaurian Remains obtained by Mr. J. C. Mansel, in Kimmeridge Bay, Dorset (Geol, Soc.), 245 Humphrey (Prof.), Case of Asymmetry in the Human Body, 134 Huxley (Prof.) on the Ethnology of Britain, 56; on the Chief Modifications of Mankind and their Geographical Distribution (Ethnological Society), 153 ; on some Observations of Prof. Haeckel, 187 ; Opening Address to the British Association, 400; Remarks on Mr. Gladstone, 414; Speech before the | Working Men of Liverpool, 415 ; Speech on Vivisection, 466 ; Letter on Dr. Bastian and Spontaneous Generation, 473 Huyton, Remarks on the Fossils from the Railway Cutting at, Carruthers (Br. A.), 527 Hydraulic Bucketing Engine for Graving Docks and Sewerage, Percy Westmacott (Br. A.), 506 Hydrogenium Amalgam, Paper by Mr, O. Loew, 367 Ice Age in Switzerland, the, by A. Geikie, 310 Ice Marks in Newfoundland, 246 Ice, Prismatic Structure in, 141 Ichthyological Notes, W. Andrews (Dublin Nat. Hist. Soc.), 58 India, the Races of, 73; the Armenians of, 133 Tnfusoria, 246 Ingleby’s ‘‘ Reflections, Historical and Critical,” &c., 373 Insects and Swallows, 495 Institution of Civil Engineers, 134 Treland, Crustacea of the West Coast of, 155; the Kelts of, 266 Towa State University, Scientific Instruction at the, 382 Irish Cairns, &c., Dr. Conwell (Br. A.), 505 Iron and Steel, Papers on, by W. Mattieu Williams, 322, 363; the condition of Carbon in, 395 Tron and Steel Institute, Second Provincial Meeting of, 394 Tssel’s (Arturo) Malacologia del Mar Rosso, $3 | Isthmus of Panama, Lines for Ship Canals across, General W. Heine, 506 Jack (William) on Miiller’s ‘‘ Physics and Meteorology,” 272 Jackson (John R.) on Coffee, 126; on Tea, 215; on Cocoa, 497 Jahrbuch der K. K. geologischen Reichsanstalt, 163 Jahresbericht tiber die Fortschritte der Chemie, 353 Jeffreys (J. Gwyn) on Issel’s Malacologia del mar Rosso, $3 | Jersey, Relics of Non-historic Times in, by Lieutenant Oliver, 166. Jevons (Prof. W. S.) on ‘* Choice and Chance,” 4 ; on the Na- tural Laws of Muscular Exertion, 158 ; Opening Address to Section F (Br. A.), 428 | Jones (T. Rupert) on Catlin’s ‘‘ American Geology,” 371 Jones’s (T. Grafton) Coal-getting Machine, 346 Johnson’s (S. W.) ‘‘ How Crops Feed,” 373 Johnston’s (W. and A. K.) Illustrations for Bot. Lectures, 35 Jupiter’s Cloud Belts, Letter by R. A. Proctor, 236 Kangaroos, Paraplegia in, 143; Parturition of, 155, 211, 313 Kant’s Distinction between Affection and Function, 296; be- tween Sensibility and Understanding, 355, 375 Karl Koch on Tree-cultivation, by D. Oliver, 351 | Karsten, Harms and Weyer’s “‘ Einleitung in die Physik,” 99 Kepler, the Monument to, 240 Kent’s Cavern, Exploration of, W. Pengelly (Br. A.), 441 | Kerry, on some Corries and their Rock-basins in, 155 | King (Major Ross), Aboriginal Tribes of the Nilgini Hills, 37 King and Romney on ‘‘ Eozobn Canadense,”’ 209 Kingfisher, the Meal of a, 356 Kingsley (Rev. C.) on strange Noises heard at Sea, off Grey- town, 46 ; on Mirage, 414 Kirk (Dr.) on Copals, 37 Lake District, Green Slates and Porphyries of the, Prof. Hark- ness and Dr. Nicholson (Br. A.) 480 Lake of Geneva and the Mediterranean Sea, Colour of, by Prof. Tyndall, 489 Lamé, Professor, 52 Lancashire Alkali Trade, W. Gossage (Br. A.), 480 Language, the Origin of, Correspondence on, 48, 66, 103 Lankester (Dr. E.) on the Extract of Meat, 62; on Height and Weight, 230 ; on the representation of Science and Art at the School Board, 509 Lankester (E, Ray) on the Microscope, 213 ; Colour of the Sky, 235; Carpsand Toads, 67; Nicholson’s Manual of Zoology, 490 ; a Stock-form of the Parasitic Flat-worms (Br. A.), 527; Worms from Thames Mud (Br. A.), 527; Methzemoglobin (Br. A.), 528; the action of certain Vapours and Gases on the Red-Blood Corpuscles (Br. A.), 528 Learned Societies, the Building for the, 21; House Accommoda- | tion for, 429 Lectures, the Gresham, 15 Leeds Philosophical and Literary Society, 75 Left -handedness, 25, IOI Leonardo da Vinci as a Botanist, by A. W. Bennett, 43 | Light, Ponderable Molecules and Dispersion of, 327 Linnzean Society, 37, 94 Liquid Drops, the Formation of, 18 Liverpool : the Museums and Scientific Institutions of, 389 ; the Geology of the Country around, by C. E. De Rance, 391 ; Geo- logical Discovery in, by J. P. Earwaker, 387 Liverpool, Sewage of, J. N. Shoolbred (Br. A.), 483 Llandudno, Glacial and Post-glacial Beds in the neighbourhood Ofpbi ae) Etalll (Br As); 527 Lockyer (J. N.) on Spectroscopic Observations of the Sun (Royal Soc.), 131 | Loew (O.) on Hydrogenium Amalgam, 367 Lofoten Islands, the Geology of, 245 | Login (T.), Abrading and Transporting Power of Water, 72 Longevity in Men and Animals, by H. Power, 98 Lower Silurian Trilobites, 94 Lunar Activity or Quiescence, Paper by W. R. Birt (Br. A.), 462 | Machine Guns, 358 | Maclachlan’s (Robert) Catalogue of British Neuroptera, 45 | Macvicar’s Sketch of a Philosophy, 295 | Magnus, Heinrich Gustay, 143 Malet’s (H. P.) ‘‘Interior of the Earth,” 121 vi INDEX the Principal Geological Changes in Europe since the of, Prof. P. M. Duncan (Br. A.), 446 Man, Appearance Manchester, Ashpit System of, Literary and Philosophical Society, 56 Mankind, Chief Modifications and Geographical Distribution of, by Prof. Huxley (Eth. Soc.), 153; the Early History of, by A. R. Wallace, 350; Earliest Traces of, in North America, by Dr. J. S. Newberry, 366 Manners (Admiral R. H.), 84 Mantegazza’s ( Prof.) Researches on th Flowers on the Production of Atmospheric Ozone, Mapother’s (E. D.) ‘f The Body and its Health,” 13 Marine Animals, Protective Adaptation in, G. S. Brady, 376 Marl-slate of Midderidge, Durham, Dorypierus Hofmanni, Germar, from the, 246 Maskelyne (N. S.), on Whence come Meteorites ? 77 Mastication, 238 Mathematical and Physical Science Section (Br. A.), 419, 440, 479, 501, 526 Mathematical Society, 73, 202 Mathematical Theory of Combined Streams, Prof. NV Rankine (Br. A.), 440, 462 Matter, the Continuity of the Gaseous and the Liquid States of, by Prof. James Thomson, 278 Matthiessen (Augustus), 517 Mauritius, New Observatory at the, 201 Maxwell’s (Prof. Clerk) Opening Address to Section A (Br. A.), e Action of the Essence of 108 J. M. 419 McDonnell (Dr. R.), Speech on the Transmission of certain Sensations through the Nerves and their Interception, 466 Meat, On the Extract of, by Dr. E. Lankester, 62 Mechanical Science Section (Br. A.), 448, 483, 506, 528 Mechanical Ventilation, the Economical Advantages of, 346 Medical Schools of England and Germany, the, by Prof. S. Stricker, 349, 369 Mediterranean Coast, Changes of Level on, G. Maw (Br. A.), 423 Meenas of Central India, the, 129 Megalithic Monuments in Britain, A. S. Lewis (Br. A.), 467 Melbourne, the Flagstaff Observatory at, 303 Mercury, the Extinction and Reducing Power of, 388 Mereuryditolyl, 487 Merkel’s ‘‘ Die Zonula Ciliaris,” 374 Messagete and Sace, H. H. Howorth (Br. A.), 467 Meteor of August 15, the, 357 Meteorites : Whence do they Come? 77, 209 Meteorological Investigations, the Improvement of, 451 Meteorological Society, 266 Meteorology of June, 1870, by John T. Hall, 214 Meteorology and Magnetism, Pamphlets on, by Dr. Balfour Stewart, 252 Methzmoglobin, Note on, E. Ray Lankester (Br. A.), 528 Methyl Compounds, Dr. B. W. Richardson (Br. A.), 466 Meunier (Dr. Stanislas), on Whence come Meteorites? 209 Microscope, the, by E. Ray Lankester, 213 ; Choice of a, by M. Foster, 255 Middle Drift of East Anglia, Seams of Hard Sandstone, J. E. Taylor (Br. A.), 503 A Mier’s (John) Contributions to Botany, 187 Miller (Prof. W. A.), Lecture on Aniline and the various Pro- ducts of Coal-Tar, 70; Death of, 517. Millon (E.) Sa Vie et Travaux de Chimie, &c., 140 Mills (E. J.) on Naumann’s Thermo-Chemistry, 120 Milne-Edwards’ Lecons, 122 Mineral Chemistry, the Province of, by T. E. Thorpe, 304 Mineral Oil Works, 346 Mirage in the Firth of Forth, 263, 296 Mirages, 337, 375» 39, 414, 435 Mississippi, the Surface Geology of the Basin of the Great Lakes and Valleys of the, 177 Mistletoe on the Oak, 399 Mitrailleur, the, 359 Mivart (St. George) on the Vertebrate Skeleton, 291 Mixed Fabrics, Discrimination of Fibres in, J. Spiller (Br. A.), 480 Modern Angling, by A. Giinther, 512 Molecular Physics, Curious Facts in, by W. H. Harrison, 7 Molgula, Larve state of, A. Hancock (Br. A.), 505 Molgula Tubulosa, Development of, 130 Moncriefi’s Hydro-pneumatic Gun Carriage, 339 Montreal Natural History Society, 76 | Moon, Apparent size of the, Correspondence on, 27, 122 Alderman Rumney (Br. A.), 4833 | Morocco, the Races of, 133 Moniis (Prof.), Testimonial to, 317 | Moser’s (Von. S. T.) Lehrbuch der Ghemie, 65 Mud Fish, the New Australian, by P. L. Sclater, 106 Mulberry Tree, the, by C. J. Robinson, 67 Miiller’s Physics and Meteorology, by W. Jack, 272 Murchison’s (Sir R.) Address at the Anniversary Meeting of the Geogr. Society, 70; Address to Section E (Br. A.) 427 Muscular Contraction, Kliinder’s Investigations into the Time occupied in, 343 Muscular Exertion, the Natural Laws of, by the Rev. Samuel Haughton, 158 ; by Prof. W.S. Jevons, 324 Music, Racial Aspects of, Mr. Kaines (Br. A.), 467 Naquet, H., Aromatic Glycol, 3373 Swallows’ Nests, 377 Natural History : Curious Fact in, 33 ; New Museum, by W. H. Flower, 61; Collections, 97, 118; Museums, 138, 493; in Schools, 249; Societies, 461; Principles to be Observed in the Establishment of a National Museum of, 455, 465 Naumann on Thermo-Electricity, by E. J. Mills, 120 Newberry, Earliest Traces of Man in North America, 366 ; Ancient Lakes of Western America, 385 New Observatory in the Southern Hemisphere, Gould, 305 New York Lyceum of Natural History, 135, 366, 388 New Zealand Institute, the, 160, 508; Wellington Philosophical Society, 59, 365, 508 Newton’s (Prof.) Speech on Natural History Museumis, 465 Nicholson (Dr. H. Alleyne), Lower Portion of the Gréen-slates and Porphyries of the Lake District (Geol. Soc.), 245 Nicholson’s Manual of Zoology, by E. R. Lankester, 490 Niger, Upper Waters of the, Wingwood Reade (Br. A.), 467 Nilgiri Hills, the Aboriginal Tribes of, 37 Norfolk and Suffolk, the Forest-Bed and the Chillesford Clay in, 178 Norfolk and Norwich Naturalists’ Society, 488 North American Indians, Aptitude of, for Agriculture, James Heywood (Br. A.), 468 North of England Institute of Mining and Mechanical Engineers, Meeting at Glasgow, 345 Nuttall’s Dictionary of Terms, 337 Observations, of Temperature and Pressure in Gas Analyses, 152; of Shooting Stars (Br.A.), 479 Odling (Prof.) on the Platinum Ammonia Compounds, 133 Oliver’s (Prof.) Guide-Book to the Royal Botanic Gardens and Pleasure Grounds, Kew, 169 ; on Karl Koch on Tree-cultiva- tion, 351 Ophthalmoscope, a New Form of, by H. Power, 54 Oppenheim (A.) on Heinrich Gustav Magnus, 143 Organic Bodies, Chem. Constitution and Crystalline Form of, 76 Organic Matter, Contained in Air, 113; in Water, 179 Origin of Species and of Language, Letter by William Taylor, 435 Osten Sacken (Baron), Trans-Narym Couniry (Geogr. Soc.), 17 Osteology of Chlamydophorus Truncatus, E, Atkinson (Br. A.), 464 Ottoman Turks, Dr. Beddoe (Br.A.), 467 Ovals of Des Cartes, 74 Owens College, Manchester, 449 Oysters of the Chalk, T. R. KR. Stebbing, 65 Ozone and Autozone, 487 Ozone developed by Humidity and Electricity, 473 Page’s Introductory Text Book of Physical Geography, 140 Palzontological Aspects of the Middle Glacial Formation of the East of England, S. V. Wood and F. Harmer (Br. A.), 504 Palzozoic Rocks of the Western States of America, new species and genera of fossils from, 247 Parasites, Prof. von Beneden (Br. A.), 527 Parasitic Flat-worms, E. Ray Lankester (Br. A.), 527 Parhelia, 163 Paris Academy of Sciences, 18, 39, 59, 115, 134, 179, 203, 2 268, 287, 307, 328, 348, 365, 3 3 488 mae Pasteur’s Researches on the Diseases of Silkworms, by Prof. Tyndall, 1&1 Patent Law, the, 95 Peabody Institute, Baltimore, 290; Academy of Science, Salem, Massachusetts, 290 Pearly Nautilus, H. Woodward (Br.A.), 505 ‘a INDEX Vil Perry (S. J.) on Terrestrial Magnetism, 124 Persia, the pre-Turkish Frontages of, H. Howorth (Br. A.), 528. | : Petermann (Augustus) on the Sources of the Nile, 13, 47 Pettigrew’s (A.) Handy Book of Bees, by A. R. Wallace, 82; | Philadelphia, American Phi! Soc., 60, 96; Academy of Sciences, 290 Philology and Darwinism, 66, 103, 435 Photography, Application of, to Military Purposes, 236 Physiology, Outlines of, 139 Plain Cylindrical Boilers, the Efficiency and Durability of, 396 Plateau on the Flight of Coleoptera, 244 : ; Playfair (Dr. Lyon), Address to Birmingmam and Midland Insti- tute, 453; Address to at the Social Science Congress, 459 Poey’s (Prof.) New Classification of Clouds, 382 Polarised Light, transmission of through Uniaxal Crystals, by H. L. Russell, 299 Polygala, Fertilisation of, letter by W. E. Hart, 274 Pontobdella, M. Vaillant’s Anatomical Investigation of, 93 Popular Physiology, 272 Port Elizabeth, Electric Time Signal at, Varley (Br. A.), 452 Portland, Beaches of, W. Pengelly (Br. A.), 502 : Power (H.) on Longevity in Man and Animals, 98 ; Digestion, 238 ; a New Form of Ophthalmoscope, 54 Pozzuoli, Changes of Level at, F. Fox Tuckett, 493 Precarboniferous Floras of North-Eastern America, Paper by J. W. Dawson (Royal Soc.), 35 Pre-glacial Deposits of West Lancashire and Cheshire, 246 Primitive Man, 311 Pritchard (Prof. C.) on “Other Worlds than Ours,” 161 Proctor (R. A.) on the Corona, 164, 277; Jupiter’s Cloud Belts, 236 ; the Source of Solar Energy, 275, 315 ; the Resolvability of Star-Groups Regarded as a Test of Distance, 74 Proctor’s “Other Worlds than Ours,” by C. Pritchard, 161 ; Correspondence respecting, 190, 209 Products Accompanying Formation of Chloral from Alcohol, 19 Progress of Chemistry, 353 Protandry and Protogyny in British Plants, Bennett, 482 Psychology in England, by Professor G, Croom Robertson, 331 Pumping and Winding Machinery, 395 Pye-Smith (Dr. H.) on Forms of Animal Life, 80, 206 Quantics, a ninth Memoir on, by Prof. Cayley, F.R.S., 152 Quartz Implement from St. George’s Sound, H. Woodward (Br. A), 506 Quekett Microscopical Club, 287 Race in Music, 153 Rainfall Committee, Report of the (Br. A.), 507 Rainfall, C. Chambers, F.R.S. (Br. A.), 526 | Rankine (Prof. W. J. M.) on the Thermo-dynamic Acceleration | and Retardation of Streams, 440 ; onthe Mathematical Theory | of Combined Streams (Br. A.), 440, 462; on Stream-lines in connection with Naval Architecture, 460 Red-Blood Corpuscles, the action of certain vapours and gases on the, E. Ray Lankester (Br. A.), 528 Regenerative Hot-Blast Stoves for Blast Furnaces, 134 Reproduction by Spontaneous Fission in the Hydroida, Prot. Allman (Br. A.), 481 ~ Russell (W. H. L.) on Transmission of Polarised Light through Uniaxal Crystals, 299 Sabine (Sir Edward), Conversazione of, 8 Salad Herbs, our, by C. J. Robinson, 317 Scandinavian Skulls, 47, 103 Schleiden’s Fiir Baum und Wald, 234 School Board, the Representation of Science and Art at the, by Dr. E. Lankester, 509 Schools, Natural History in, 249 Science and Art Department, the, 269, 316 Science and Mathematics, Elementary Teaching of, 205 Science and Military Surgery, 329 Scientific Administration, 449 | Scientific Education, 41; of Women, 117, 165, 305 | Scientific Research, letter by C. Biggs, 354; the State and, 24 Scientific Serials, 15, 35, 55, 93, 113, 130, 152, 177, 202, 244, __ 265, 286, 305, 313, 327, 346, 364, 387, 487, 507 Sclater (P. L.) on Recent Accessions to the Zoological Society’s Gardens, 9, 146; on Certain Principles to be Observed in the Establishment of National Museums of Natural History (Br. A.), 455; on the New Australian Mud-Fish, 106 Scottish Gold Fields, the Matrix of the Gold in, Dr. Bryce (Br. A.), 504 Sea, Illumination of the, 165 ; StrangeNoises heard at, 25, 46, 356 Secchi (Father) and Mr. Lockyer, 128 Sewers in Running Sand, Reade and Goodison (Br. A.), 483 Sheffield Scientific School, New Hayen, 289 Shooting Stars of August, 365 Sicily, Newer Tertiary Fossils in, Jeffreys (Br. A.), 503 Silkworms, Pasteur’s Researches on the Diseases of, by Prof. Tyndall, 181 Simpson (Sir J. Y.) on Modern Aneesthetics, 52 Skin, the Composition of the, 387 Sky, the Colour of the, Correspondence on, 7, 48, 235 Smallwood (Dr., Montreal) on some Phenomena of the Solar Eclipse of August 1869, 76 Smithsonian Institution, Washington, 290 Snake-bite, Prof. Halford’s Methed of dealing with, 381 Solar Energy, the Source of, 255, 275, 295, 315 Soluble Garnet, 282 Sonnenschein and Nesbitt’s “ Arithmetic,” 186 Sources of the Nile, 6, 13, 26, 47, 77 Sourel’s (L.) ‘The Bottom of the Sea,” 65 South Wales Coal-field, the Geological Features of the, 395 Southern Chili, Tertiary Coal Fields of, G. A. Lebour (Br. A.), 464 Spontaneous Generation, Correspondence on, 234, 254, 276, 296 ; Bastian’s Facts and Reasonings concerning, 170, 193, 219; Prof. Huxley on, 400, 473; Reply to Prof. Huxley on, 410, 431, 492 : Sporangia of Ferns from the Coal Measures, W. Carruthers (Br. A), 505 Spottiswoode’s Paper on the Mechanical Description of a nodal bicircular Quartic, 74 | Stars, the Extinction of, 211 Religion, the Philosophy of, among the Lower Grades of Man- | kind, by E. B. Tylor (Geogr. Soc.), 18 Robertson (P. S.) on the Flowering and Fruiting of Aucuda japonica (Edin. Bot. Soc.), 58 Robertson (Prof. G: Croom) on Psychology in England, 331 Robertson’s Daily Readings in Natural Science, 253 Robinson (C. J.) on the Mulberry Tree, 67 ; on our Salad Herbs, 317; on British Edible Fungi, 518 - Rodwell (Geo. F.) on an Unpublished Italian MS. of the Seven— teenth Century, 370 Address to Section D (Br. A.), 423, 442 Roscoe’s (Prof. H. E.) Address to Section B (Br. A.), 406 - Rotundity of the Earth, The, 214, 236 - Roumeguere on Fungi, by M. J. Berkeley, 185 Royal Academy, Natural Science at the, by John Brett, 157 Royal College of Surgeons, Annual Report of the, 320 Royal Institution, 17, 36 Royal Society, 16, 35, 73, 93, 114, 131, 152 Royal Society of Literature, 287 - Royston-Pigott (G. W.), on an Aplanatic Searcher (R. Soc.), 16 Rugby School Nat. Hist. Soc., Third Annual Report of, 89 4 —Ss Rolleston (Prof. ), Classical and Scientific Training, 250; Opening | Statistical Society, 266 Steam Power, Meter, Ashton and Storey’s, Mr. Ashton (Br. A.), 528 Steel, New Process for Making, 397 | Stewart (Dr. Balfour) on What is Energy? 79, 183, 270; on Mattieu Williams’ ‘‘ Fuel of the Sun,” 99 ; on Pamphlets on Meteorology and Magnetism, 252 ; on the Flagstaff Observa- tory at Melbourne, 303 ; on Cosmical Physics, 499 Storms in the Bay of Bengal, Origin of, 151 Stone Implements from Burma, by J. Evans, 104 Strachey (G.) on Scandinavian Skulls, 47 Strath, Isle of Skye, some Points in the Geology of, Profs, King and Rowney (Br. A.), 481 Stream Lines and Naval Archit., Prof. Rankine (Br. A.), 460 Stricker (Prof. S.) on the Medical Schools of England and Ger- many, 349, 369 Suez Canal, on the Reported Current in the, by F, Galton, 189 Suffolk’s Microscopical Manipulation, 273 Sulphur, a new Acid of, 387 Super-Saturation, Letter by J. G. by C. Tomlinson on, 335 Surface Oceanic Life, 92 Grenfell on, 276; Letter Vill Sun, the Physical Constituticn of the, 34; the, 67, £9, 123, 160; Evidence as to Spots on the, derived from Mr. Lockyer’s Method of Spectroscopic Observation, 74 ; Spectroscopic Observations of the, by J. N. Lockyer, F.R.S., 131; the Fuel of the, 451; Prof. Zollner on the Tempera- ture and Physical Constitution of the, 522 Swallow Holes in Mountain Limestone, Miall (Br. A.), 528 Swallows’ Nests, by A. Naquet, 377 Syro-Egyptian Society, 203, 287 Tannin, the Effect of, on Cotton, 452 Tar Pavement, the Manufacture of, 303 Taylor (Sedley) on Physical Science at Cambridge, 28 Tea, by J. R. Jackson, 215 Telegraph Coils, S. A. Varley (Br. A.), 462 Telegraphy, Novel, by Fleeming Jenkin, 12 Telfairia pedata, 521 Temperature of the British Islands, 307 Tetrabromide of Carbon, 37 Terrestrial Magnetism, S. J. Perry on, 125 Thalium, the position of, in the series of elementary bodies, 156 | Thermal Springs in the Fens of Cambridgeshire, F. W. Harmer (Br. A.), 584 ; ; Thermo-dynamic Acceleration and Retardation of Streams, by Prof. W. J. M. Rankine (Br. A.), 440 Thiophenol, Conversion of, into Phenylic Disulphide, 487 Thome’s “ Das Gesetz der vermiedenen Selbstbefruchtung bei den héheren Pflanzen,” 334 Thomson (Prof. Tames) on the Continuity of the Gaseous and Liquid States of Matter, 278 Thomson (Sir William), Letter by, 56 Thomson (Wyville) on Deep-sea Climates, 257 Thorpe (T. E.) on the Province of Mineral Chemistry, 304 Thought, the Velocity of, by M. Foster, 2 Tideswell Dale, an altered Clay-bed and Sections in, 246 Tomlinson (C.), Letter on Supersaturated Solutions, 335 Tower Subway, the, 33 Training, Classical and Scientific, 250 Transactions of the Woolhope Naturalists’ Field Club, 187 Trans-Narym Country, An Expedition to the, 17 Trees, the Tendency of, to bend towards the East, by L. Trouvelet (Boston Natural History Society), 180 Trequair (Prof. R. H.), Paper on the Scales of Calamoichthys calabaricus, 155 Truro, Royal Institution of, Cornwall, 154 ‘Turret Ships, the Stability of, 494 Tyler (E. B.) on the Philosophy of Religion among the Lower Races of Mankind, 18 ; on Taunton College School, 48 Tyndall (Prof.) on Pasteur’s Researches on the Diseases of Silk- worms, 181; Lectures of, at the Royal Institution, on Elec- trical Phenomena and Theories, 243; on the Colour of the Lake of Geneva and the Mediterranean Sea, 489 Underground Temperature Committee (Br. A.), Third Report of, 484 Unit of Length, the, 137 U. S. Coast Survey, Soundings and Dredgings by the, 169 University College, Faculty of Science in, 377 Unpublished Italian MS. of the Seventeenth Century, by George F. Rodwell, 370 Upper Silurian Strata in Roxburgh and Dumfries, C. Lapworth (Br. A.), 484 Utilisation of Sewage, D. Forbes (Br. A.), 503 INDEX Pinkish Colour of | Variegation, Nature of the Phenomena of, 89 Vegetable Fossils from Victoria, 245 Venus, the Transit of, and the Artarctic Regions, 29 ; the Coming Transits of, 343 Vertebrate Skeleton, the, by St. George Mivart, 291 Victoria Institute, 154 Vienna: Imperial Academy of Sciences, 19, 59, 268 ; Imperial Geological Institution, 19 Vignoles (C. B.), Address to Section G (Br. A.), 448 Virchow (Prof.) on Portrait or Facial Urns, 128 Vivisection, Prof. Huxley on, 466 Volcanic Agency v. Denudation, 375 Volcano Tongariro, New Zealand, Eruption of, 477 Volcanoes, by David Forbes, F.R.S., 283 Von Graefe, 277 Wallace (A. R) on Pettigrew’s Handy-book of Bees, 82; on a Twelve-wired Bird of Paradise, 234; on the Early History of Mankind, 350; Speech on the Arrangement of Specimens in a Natural History Museum, 465; on Natural Selection, 471; on the Glaciation of Brazil, 510 Waller (Dr. A.), 436 Walz (Dr. I.), Extinction and Reducing Power of Mercury, 388 Wanklyn’s (Prof. J. A.) Letter on Spontaneous Generation, 234 War, 229; the Science of, 339, 358, 378 Waterspout off Calais, 342 | Water, the Abrading and Transporting Power of, by T. Login, 72; Analysis, 293, 315, 308; Different forms of, 38 Wealden, the Age of, E. W. Judd (Br. A.), 481 Weldon’s Process for the Manufacture of Chlorine, W. Weldon (Br. A.), 440 Whalebone Whales of the Southern Hemisphere, J. E. Gray, F.R.S. (Br. A.), 527 What is a Boulder? Letter by C. T. Woodward, 66 Wheat Rust and Barberry Rust, by A. W. Bennett and M. J. Berkeley, 318 | Wheatstone (Sir C.) on a Cause of Error in Electroscopic Ex- periments (Royal Soc.), 17 White Mustard Seed, Paper by Prof. H. Will (Vienna Acad. of Sc.), 19 Williams’ (W. Mattieu) “ The Fuel of the Sun,” by Dr. Balfour Stewart, 99; on Iron and Steel, 322, 363 ; on the Intended Engineering College, 353 Winlock (Prof.), his Plan for Photographing the Sun, 301 Woodward (H.), Note on the Palpus and other Appendages of Asaphus from the Trenton Limestone, 94 Wooster’s (David) “Mrs. Loudon’s First Book of Botany,” 23 Working Men’s College, Letter by W. Rossiter, 475 Wormell’s Geometry and Mensuration, J. M. Wilson, 313 Worms from Thames Mud, by E. Ray Lankester, 527 Xanthidia in Flint, 66 Yale, a Word about, 470 Yellow Rain, a fall of, 166 Yeo’s (J. Burney) Notes of a Season at St. Moritz, 274 | Zollner (Prof.) on the Sun’s Temperature and Physical Con- stitution, 522 Zoological Society's Gardens, Recent Accessions to, by P. L, Sclater, 9, 146 Zoological Society, 37, 74, 132, 154, 287 Zoology and Botany, department of, at Br. A., 466 a | Sept. 15, 1870] NATORE Ixxix BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. Authors of papers read at the Liverpool Meeting of the British Association are requested to favour the Editor of “NATURE” with copies or abstracts of their com- munications as soon as possible, addressed to him at the Post Office in the Reception Room, as by these means alone can an accurate and early notice be insured. The Editor appeals to men of Science to aid him in his attempt to give an account of their investigations to their fellow-workers throughout the world. A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. “© To the solid ground Of Nature trusts the mind which builds for aye.” —WORDSWORTH, One of the leading objects of this periodical is to awaken in the public mind a@ move lively interest in Science. With this end in view it provides original Articles and Reviews, written by Scientific men, and illustrated when necessary, expounding the brand resulis of scientific research, discussing the most recent scientific discoveries, and pointing out the bearing of Science upon civilization and progress, and its claims to move general recognition, as well as to a higher place in the educational system of the country. There will also be found in “NATURE” complete Abstracts of all important Papers communicated 10 British, American, and Continental Scientific Societies and | periodicals, and Reports of the Meetings of Scientific Bodies at home and abroad. In the columns devoted to Correspondence an opportunity is afforded for the discussion IXxx | of scientific questions of general and popular interest. NATURE | Sept. 15, 1870. The Fournal has now been nearly a year in existence, and having helped to promote many of the objects which all scientific workers have at heart, has, it is hoped, already made good its claim to the support of all who really desire the advancement of Science. Appended is a List of ~ some» of the eminent men who have already contributed to the pages of “ NATURE,” or have otherwise aided to establish it. ABEL, F. A., F.R.S., H.AZ. Chem. Dep. Woolwich. Acassiz, Pror. L., Museum of Comparative Zoology, Harvard College. ANDREWS, Pro. T., F.R.S. Queen’s Univ. Dublin. BasTIAN, Pro. H. C., F.R.S. University Coll. BENNETT, A. W., F.L.S. BERTHELOT, PROF., Collége de France, Paris. BONNEY, REV. T. G., Caméridye. Busk, PROF. G., F.R.S. CARRUTHERS, W., F.L.S. British Museum, CLIFTON, PRor. R. B. Oxford. COBBOLD, T. SPENCER, F.R.S. CROOKES, WILLIAM, F.R.S. Dattas, W. S., F.L.S. Geological Society. Dana, Pror. J. D. Newhaven, Conn. U.S.A. DaRwIN, C., F.R.S. DawkKINs, W. Boyp, F.R.S. Owens Coll. Mane. Dumas, J. B. Sec. Imperial Acad. of Sciences, Paris. EVANS, J., F.R.S. Secretary Geological Society. FARRAR, REv. F. W., F.R.S. Harrow School. FLowER, Pror. W. H,, F.R.S. Roy. Coll. of Surg. Forbes, Davin, F.R.S. FosTER, Dr. C. LE NEVE, Predmont. FOSTER, PROF. MICHAEL, Royal Lustitution. Foster, Pror. G. Carey, F.R.S.' Univer. Coll. FRANKLAND, PROF. E., F.R.S. Roy. Coll. of Chem. GALLOWAY, PRO). R. College of Science, Dublin, GALTON, DOUGLAS, F.R.S: GBIKIE, A., F.R.A. Geol. Survey of Scotland. GoRE, G, F.R.S. GranT, PRor. R., F.R.S. Direc. Glasgow Obser. Grove, W. R, F.2.S., Q.C. HARCOURT, A. VERNON, F.R.S. Sec. Cher. Soc. HAUGHTON, REV. PROF:, F.R.S. Zrin. Coll. Dublin. Hirst, PRoOF., F_R.S. Gen. Sec. British Assoc. Hooker, ‘Dr. J. D., F.R.S. Director Royal Gardens, Kew. HuMPuRY, PROF., F.R.S. Cambridge. HUXLEY, PRor. T. H., F.R.S. Pres. Geol. Soc. JACK, PROF. Owens College, Manchester. Jerrreys, J. Gwyn, F.R.S. JENKIN, PRoF. H. C. FLEEMING, F.RS, Edinburgh University, JEvons, Pror. W. S., date of Owens College, Mane. — Jones, Dr. H. BENCE, F.R.S. Sec. Royai Inst. JOULE, 9:72: RS: KEKULE, Pror. Chemisches Institut, Bonn. KINGSLEY, REV. CANON. LANKESTER, DR. E., F.R.S. LANKESTER, E. Ray. Lrvi, LEONI, F.S.S. LEWES, G. H. LIVEING, Pror. G. D.; F.C.S. Cambridge. LUBBOCK, SIR JOHN, BART., F.R:S. MACMILLAN, Rey. H. MaGNus, Pror. (¢he late), Berlin. MaIN, P. T. Cambridge University. MARKHAM, CLEMENTS, Secretary R.G.S. MASKELYNE, N. S., F.R.S. British Museum. MATTHIESSEN, Pror. A., F.R.S. S# Bartholomew's Hospital. MURCHISON, SIR RODERICK I., BART., F.R.S. President Geog. Soc.,; Direc. Geol. Survey. NEWTON, PROF. ALFRED, F.R.S. Cambridge. ODLING, PRoF., F.R.S. Royal Institution. OLIVER, PROF. D., F.R.S. Royal Gard. Kew. OPPENHEIM, Dr. A. Berlin. PENGELLY, WILLIAM, F-.R.S. PHILLIPS, PRor. J., F.R.S. Oxford. PRESTWICH, J., F.R.S. PRITCHARD, REv. C.,.F.R.S. Procror, R. A., F.R.A.S. QUETELET, DR. A. Secretary Royal Academy of Science? Brussels, : RAMSAY, PROF. A. C., F.RS. Geol. Survey. RCDWELL, G. F., F.GS.- , =f ROLLESTON, PRor. G., F.R.S. Oaford. eit, ; Roscok, ProF. H. E., F.R.S. Owens Coll, Mane. % SCLATER, P. L., F:R.S. See. Zoological Society. SHARPEY, DR., Secretary Royal Society. Sorby, HG) Fikes; . ey SPOTTISWOODE, ‘W., V.P.R.S~ ; . STAINTON, H. T., F.R.S. E STEWART, BALFOUR, F.R.S. Direc. Kew Observatory. STONE, E. J., Reyal Cbservatory, Greenwich. STRICKER, PROF. S. University of Vienna. os Sepi. 15, 1870 | “NA TURE STUART, JAMES, Trinity College, Cambridge. SYLVESTER, PROF. J. J., F.R.S. oe Military Academy, Woolwich. Symons, G. J., F.M.S. TAIt, Pror. P. G. Edinburgh Ugh eeE THOMSON, PROF. SIR W., F-R-.S. Glasgow OEE ‘TRISTRAM, REy. H: B., F-L-S. TyLorR, EDWARD B., F.R.S. TYNDALL, PROF. J., F.R.S. Royal Institution. WALLACE, A. R., F.RG.S. WILLIAMSON, Pror. A., F.R.S. Pres. Chem. WILSON, J. M., Rugby School. WoopwarbD, H., F.G.S. British Museum. WRIGHT, DR. PERCEVAL, Dublin University. Soc. the last few montis :—. The Progress of Paleontology._Further Evidence on the Affinity between the Dinosaurian Reptiles and Birds.—The Forefathers of the English People. PROFESSOR HUXLEY, Dust and Disease.—Pasteur’s Researches on the Dis- eases of Silkworms. PROFESSOR TYNDALL, F.R.S. Madsen’s Danish Antiquities. Str JoHN Lupgock, F.R.S, Lectures to Working -Men.—Scientific Education in Germany. PROrESSOR ROSCOE, F.R.S, The Relative Value of Class PROFESSOR ROLLESTON, ical and Scientific Training. RES. Deductions from Darwin's EOS —Natural Laws of Muscular Exertion. ° PROFESSOR STANLEY JEVONS. The Velocity of Thought.. PROFESSOR MICHAEL FOSTER. Newfon’s Rings. PROFESSOR G. Cary FOSTER, F:R.S. Fossil Mammals of North America. W. Boyp DawkINs, F.R.S. The Deep Sea Dredging Expedition.—The Food cf Oceanic Animals. J. GwyN JEFFREYS, F-.R.S. Measurement of Geological Time. Hereditary Genius. A. R. WALLACE, F.R-.G.S. Spontaneous Generation. Dr. H. C. BasTIAN, F.R.S. _ The Size of Atoms. PROFESSOR SIR WILLIAM THOMSON, F.R.S. The Continuity of the Liquid and Gaseous States of Matter. PROFESSOR JAMES THOMSON, F.R.S. Thé following are among the Articles yee sall which have appeared in “NATURE” during | What is Energy ?—The Flagstaff Observat bourne. at Mel- ’ PROFESSOR BALFOUR STF _RT, F.R.S. On Fungi. Rev. J. M. BERKELEY, F.R.S. Height and Weight.—The Extract of Meat. Dr. E. LANKESTER, F-R.S. | Deep Sea Climates. PROFESSOR WYVILLE THOMSON, F.R.S. Psychology in England. PROFESSOR G. CROOM ROBERTSON, Volcanoes. | : : DaVID ForBES, F.R.S. The Medical Schools of England and Germany. PROFESSOR STRICKER (of Vienna), The Natural Laws of Muscular Exertion. --The Labour- ing Force of the Human Heart. Rey. PROFESSOR S. HAUGHTON, M.D. F.R.S. The Temperature and Animal Life of the Deep Sea. Dr. CARPENTER, F.R.S. | ‘The Origin of Blood-letting. E. R. LANKESTER, F.R.S. The Polarization of Light. W. H. S. RUSSELL, HsRES? Original. Scientific Research in Relation to Employ- | ment for Workmen. GEORGE GORE, F.R.S. The Physical Constitution of the Sun. DR. GOULD (U.S.A.) The Snakes of Australia. Dr, GUNTHER, F.R.S. Whence come Meteorites ? PROFESSOR N. S. MASKELYNE, F.R.S, Ixxxii NATURE [Sept. 15, 1870 nee EEEUUEEEEE EEE EIEN IESE S SSSR! The Primitive Vegetation of the Earth. The Geology of the Holy Land.—The Geological PRINCIPAL Dawson, F.R.S. (AZontreal), Structure of some Alpine Lake Basins. ARCHIBALD GEIKIE, F.R.S. The Australian Mud Fish, Dr. P. S. SCLATER, F.RS, Leonardo da Vinci as a Botanist.—Wheat Rust and Terrestrial Magnetism. Berberry Rust. Rev. S. J. PERRY. A. W. BENNETT, F.L.S. Electrification of an Island. Spectroscopic Observations of the Sun. PROFESSOR FLEEMING JENKIN, F.RS. | J. NorRMAN LOCKYER, F.R.S The aim of the proprietors of “NATURE” ts to make it the accredited organ of Science among the English-speaking peoples, and ‘the above list will show a part of the generous aid they have already received in their enterprise. NOTICE.—The Post Office regulations on and after October Ist, allowing News- papers and Periodicals to go by Post at reduced rates, the Publishers of “ NATURE” undertake to forward the Weekly Numbers by Post on the following terms :— Sa, cies V carlyegyb- oats kee oe ni Ee Cameo Half Yearly . r= -70"16 Quarterly . Hele 10) Subscriptions may be forwarded either direct to the Publishers, 16, BEDFORD STREET, W.C., or through any Bookseller, “NATURE” is published every Thursday, price Fourpence, and in Monthly Parts, 1s. 4d. and 1s. 8d. VOLUME TI. now ready, handsomely bound in cloth, royal 8vo. 10s. 6d. Books for Review, communications respecting Advertisements, the purchase of copies, and other business, to be addressed to the Publishing Office, 16, BEDFORD STREET, COVENT GARDEN, W.C, MACMILLAN & CO, LONDON: ah A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE “© 7 the solid ground Of Nature trusts the mind which builds for aye.” —WV ORDSWORTIT THURSDAY, MAY 5, 1870 TO OUR READERS HE opportunity afforded by the commencement of a new volume is one we cannot allow to pass by without a few remarks on the work on which we are engaged, although it may be that such a course is not strictly in accordance with precedent, but our excuse lies in this—our journal is not according to precedent. For, in fact, six months ago a scientific journal, in which the leaders of scientific thought, in this and other lands, gave week by week an account of their own and others’ labours to their fellows and the general public, was a thing of the future, and, in the general opinion, to attempt to start such a journal was almost to end in- signal failure. “Science is so small, her victories are so few,” said some, “that a weekly account of them certain _is altogether beside the question—the well would run dry.” Others said: ‘‘Science is large, it is true, but her followers are not numerous. You may perhaps number your readers by hundreds, if you take care to appeal to scientific men only ; but as for the outside world, they care nothing for science.” On the other hand it was held that a popular scientific weekly journal would, be a certain success under certain con- ditions—some such as these: in the first place, the articles were to be light as air; each fact was to be clothed in a delicate atmosphere of adjective and imagery; next, each page was to be studded with beautiful pictures, correctness both in text and illustra- tion giving way to a certain more or less subdued sensationalism ; and lastly, and above all, every care was to be taken to spare the reader the least trouble in the matter of thinking. We confess that we should have shrunk from our vor. IT | task in the face of such advice as this, had there not been certain Signs of the Times which did not seem difficult to read, and which were more in harmony with the encouragements we received to undertake it , and now that the first volume has been completed, we have the satisfaction of knowing that none of these gloomy forebodings have been realised. A consideration of the facts brings us at once to our first duty, which is to tender to the scientific men, both at home and abroad, who have assisted us, our best thanks for all their help in the work we have | undertaken. We willingly acknowledge the small part we have borne in what has been done. Thanks are | due, not only for criticism and the contributions which have already appeared, but for many others which—Nature is so large, and our journal is so small —we have not as yet been able to place before our readers. It has been our endeavour to carry out our programme by making the journal useful to workers in science ; worthy therefore of their perusal, and there- fore, again, worthy of their contributions : and by thus extending our appeal beyond the limits of the scientific world on the one hand, and endeavouring to keep up the dignity of science herself on the other, we have already met with an encouraging response. Our subscribers now number nearly five thousand ; that is, we have, on a moderate estimate, fifteen thou- sand readers. Though we think this an emphatic success, we shall not be satisfied if the increasing interest in Science, and an increased knowledge of the periodical, do not in a short time double our present circulation, and we trust not only that each worker will urge his neighbours to send us facts, but that each of our present readers will form a nucleus of new ones. We state this, not only because the statement is almost due to our contributors as a justification of our demands upon their time, but because it indicates B 2 NATURE [Atay 5, 1870 the work—we had almost said the noble work—which lies before them. Surely at a time when England would gain so much by the scientific education, not only of her Workmen but of her Ministers, an attempt to place Science before the Public, week by week, as Politics, Art, Music, and a hundred other things are placed before them, must not be suffered to flag; when the number of science-teachers and science-students is daily increasing, and the necessity for combined action and representation among scientific men themselves is being more and more felt, the popularisation of science becomes more important than ever, and every effort to gain these ends deserves a larger encourage- ment, for the most “ practical man” will now soon be made to feel that Science dogs his every footstep, meets him at every turn, and twines itself round his life ; nay, it may soon become evident that such a practical thing as a stagnation of trade may in some way be traced to the neglect of science. Hence our endeavour in the future will be not only to make our journal a necessity in the Studies of the more thoughtful, and in our Schools, but a welcome visitor inthe Homes of all who care for aught that is beautiful and true in the world around them. EDITOR THE VELOCITY OF THOUGHT i A® quick as thought” is a common proverb, and pro- bably not a few persons feel inclined to regard the speed of mental operations as beyond our powers of mea- surement. Apart, however, from those minds which take their owners so long in making up because they are so great, rough experience clearly shows that ordinary think- ing does take time ; and as soon as mental processes were brought to work in connection with delicate instru- ments and exact calculations, it became obvious that the time they consumed was a matter for serious considera- tion. A well-known instance of this is the “per- sonal equation” of the astronomers. When a person watching the movement of a star, makes a signal the instant he sees it, or the instant it seems to him to crossa certain line, it is found that a definite fraction of a second always elapses between the actual falling of the image of the star on the observer’s eye, and the making of the signal—a fraction, moreover, varying somewhat with different observers, and with the same observer under differing mental conditions. Of late years considerable progress has been made towards an accurate knowledge of this mental time. A typical bodily action, involving mental effort, may be regarded as made up of three terms ; of sensations tra- velling towards the brain, of processes thereby set up within the brain, and of resultant motor impulses tra- velling from the brain towards the muscles which are about to be used. Our first task is to ascertain how much time is consumed in each of these terms; we may after- wards try to measure the velocity of the various stages and parts into which each term may be further sub- divided. The velocity of motor impulses is by far the simplest case of the three, and has already been made out pretty satisfactorily. We can assert, for instance, that in frogs a motor impulse, the message of the will to the muscle, travels at about the rate of 28 metres a second, while in man it moves at about 33 metres. The method by which this result is obtained may be described in its simplest form somewhat as follows :— The muscle which in the frog corresponds to the calf of the leg, may be prepared with about two inches of its proper nerve still attached to it. Ifa galvanic current be brought to bear on the nerve close to the muscle, a motor impulse is set up in the nerve, and a contraction of the muscle follows. Between the exact moment when the current breaks into the nerve, and the exact moment when the muscle begins to contract, a certain time elapses. This time is measured in this way :—A blackened elass cylinder, made to revolve very rapidly, is fitted with two delicate levers, the points of which just touch the blackened surface at some little distance apart from each other. So long as the levers remain perfectly motionless, they trace on the revolving cylinder two parallel, hori- zontal, unbroken lines ; and any movement of either is in- dicated at once by an upward (or downward) deviation from the horizontal line. These levers further are so arranged (as may readily be done) that the one lever is moved by the entrance of the very galvanic current which gives rise to the motor impulse in the nerve, and thus marks the beginning of that motor impulse; while the other is moved by the muscle directly this begins to con- tract, and thus marks the beginning of the muscular con- traction. Taking note of the direction in which the cylinder is revolving, it is found that the mark of the setting-up of the motor impulse is always some little distance ahead of the mark of the muscular contraction ; it only remains to be ascertained to what interval of time that distance of space on the cylinder corresponds. Did we know the actual rate at which the cylinder revolves this might be calculated, but an easier method is to bring a vibrating tuning-fork, of known pitch, to bear very lightly sideways on the cylinder, above or between the - two levers. As the cylinder revolves, and the tuning- fork vibrates, the latter will mark on the former a hori- zontal line, made up of minute, uniform waves correspond- ing to the vibrations. In any given distance, as for instance in the distance between the two marks made by the levers, we may count the number of waves. These will give us the number of vibrations made by the tuning-fork in the interval ; and knowing how many vibrations the tuning-fork makes in a second, we can easily tell to what fraction of a second the number of vibrations counted corresponds. Thus, if the tuning-fork vibrates roo times a second, and in the interval between the marks of the two levers we count ten waves, we can tell that the time between the two marks, @.e. the time between the setting- up of the motor impulse and the beginning of the muscular contraction, was 3/5 of a second. Having ascertained this, the next step is to repeat the experiment exactly in the same way, except that the galvanic current is brought to bear upon the nerve, not close to the muscle, but as far off as possible at the May 5, 1870] NATURE 3 furthest point of the two inches of nerve. The motor impulse has then to travel along the two inches of nerve before it reaches the point at which, in the former ex- periment, it was first set up. On examination, it is found that the interval of time elapsing between the setting up of the motor impulse and the commencement of the muscular contraction is greater in this case than in the preceding. Suppose it is 4 of a second—we infer from this that it took the motor impulse ;}, of a second to travel along the two inches of nerve: that is to say, the rate at which it travelled was one inch in 5}, of a second. By observations of this kind it has been firmly estab- lished that motor impulses travel along the nerves of a frog at the rate of 28 metres a second, and by a very ingenious application of the same method to the arm of a living man, Helmholtz and Baxt have ascertained that the velocity of our own motor impulses is about 33 metres a second.* Speaking roughly this may be put down as about 100 feet in a second, a speed which is surpassed by many birds on the wing, which is nearly reached by the running of fleet quadrupeds, and even by man in the movements of his arm, and which is infinitely slower than the passage of a galvanic current. This is what we might expect from what we know of the complex nature of nervous action. When a nervous impulse, set up by the act of volition, or by any other means, travels along a nerve, at each step there are many molecular changes, not only electrical, but chemical, and the analogy of the transit is not somuch with that of a simple galvanic current, as with that of a telegraphic message carried along a line almost made up of repeating stations. It has been found, moreover, that the velocity of the impulse depends, to some extent, on its intensity. Weak impulses, set up by slight causes of excitement, travel more slowly than strong ones. The contraction of a muscle offers us an excellent ob- jective sign of the motor impulse having arrived at its destination ; and, all muscles behaving pretty much the same towards their exciting motor impulses, the results obtained by different observers show a remarkable agree- ment. With regard to the velocity of sensations or sensory impulses, the case is very different ; here we have no objective sign of the sensation having reached the brain, and are consequently driven to roundabout methods of research. We may attack the problem in this way. Suppose that, say by a galvanic shock, an impression is made on the skin of the brow, and the person feeling it at once makes a signal by making or breaking a galvanic current. It is very easy to bring both currents into con- nection with a revolving cylinder and levers, so that we can estimate by means of a tuning-fork, as before, the time which elapses between the shock being given to the brow and the making of the signal. We shall then get the whole “ physiological time,” as it is called (a very bad name), taken up by the passage of the sensation from the brow to the brain, by the resulting cerebral action, in- cluding the starting of a volitional impulse, and by the passage of the impulse along the nerve of the arm and * Quite recently M. Place has determined the rate to be 53 metres per second, This discordance is too great to be allowed to remain long unex- plained, and we are very glad to hear that Helmholtz has repeated his ex- riments, employing a new method of experiment, the results of which we ope will soon be published, hand, together with the muscular contractions which make the signal. We may then repeat exactly as before, with the exception that the shock is applied to the foot, for instance, instead of the brow. When this is done, it is found that the whole physiological time is greater in the second case than in the first ; but the chief difference to account for the longer time is, that in the first case the sensation of the shock travels along a short tract of nerve (from the brow to the brain), and in the second case through a longer tract (from the foot to the brain). We may conclude, then, that the excess of time is taken up by the transit of the sensation through the distance by which the sensory nerves of the foot exceed in length those of the brow. And from this we can calculate the rate at which the sensation moves. Unfortunately, however, the results obtained by this method are by no means accordant ; they vary as much as from 26 to 94 metres per second. Upon reflection, this is not to be wondered at. The skin is not equally sentient in all places, and the same shock might produce a weak shock (travelling more slowly) in one place, and a stronger one (travelling more quickly) in another. Then, again, the mental actions involved in the making the signal may take place more readily in connection with sensations from certain parts of the body than from others. In fact, there are so many variables in the data for calculation that though the observations hitherto made seem to show that sensory impressions travel more rapidly than motor impulses (44 metres per second), we shall not greatly err if we consider the matter as yet undecided. By a similar method of observation certain other con- clusions have been arrived at, though the analysis of the particulars is not yet within our reach. Thus nearly all observers are agreed about the comparative amount of physiological time required for the sensations of sight, hearing, and touch. If, for instance, the impression to be signalled be an object seen, a sound heard, or a galvanic shock felt on the brow, while the same signal is made in all three cases, it is found that the physiological time is longest in the case of sight, shorter in the case of hearing, shortest of all in the case of touch. Between the appear- ance of the object seen (for instance, an electric spark) and the making of the signal, about 1; between the sound and the signal, ; between the touch and signal, + of a second, is found to intervene. This general fact seems quite clear and settled ; but if we ask ourselves the question, why is it so? where, in the case of light, for instance, does the delay take place? we meet at once with difficulties. The differences certainly cannot be accounted for by differences in length between the optic, auditory, and brow nerves. The retardation in the case of sight as compared with touch may take place in the retina during the conversion of the waves of light into visual impressions, or may be due to a specifically lower rate of conduction in the optic nerve, or may arise in the nervous centre itself through the sensations of light being imperfectly connected with the volitional mecha- nism in the brain put to work in the making of the signal. One observer (Wittich) has attempted to settle the first of these questions by stimulating the optic nerve, not by light, but directly by a galvanic current, and has found that the physiological time was thereby decidedly less- ened ; while conversely, by substituting a prick or pressure 4 NATURE | May 5, 1870 on the skin for a galvanic shock, the physiological time of touch was lengthened. But there is one element, that of intensity (which we have every reason to think makes itself felt in sensory impressions, and especially in cerebral actions even more than in motor impulses), that disturbs all these calculations, and thus causes the matter to be left in considerable uncertainty. How can we, for instance, compare the intensity of vision with that either of hearing or of touch? The sensory term, therefore, of a complete mental action is far less clearly understood than the motor term ; and we may naturally conclude that the middle cerebral term is still less known. Nevertheless, here too it is possible to arrive at general results. We can, for instance, estimate the time required for the mental operation of deciding between two or more events, and of willing to act in accordance with the decision. Thus, if a galvanic shock be given to one foot, and the signal be made with the hand of the same side, a certain physiological time is consumed in the act. But if the apparatus be so arranged that the shock may be given to either foot, and it be required that the person experimenting, not knowing beforehand to which foot the shock is coming, must give the signal with the hand of the same side as the foot which receives {the shock, a distinctly longer physiological time is found to be necessary. The difference between the two cases, which, according to Donders, amounts to zits, or about }; of a second, gives the time taken up in the mental act of recognising the side affected and choosing the side for the signal. A similar method may be employed in reference to light. Thus we know the physiological time required for any one to make a signal on seeing a light. But Donders found that when matters were arranged so that a red light was to be signalled with the left hand and a white with the right, the observer not knowing which colour was about to be shown, an extension of the physiological time by jib of a second was required for the additional mental labour. This of course was after a correction (amounting to ;%o Of a second) had been made for the greater facility in using the right hand. The time thus taken up in recognising and willing, was reduced in some further observations of Donders, by the use of a more appropriate signal. The object looked for was a letter illuminated suddenly by an electric spark, and the observer had to call out the name of the letter, his cry being registered by a phonautograph, the revolving cylinder of which was also marked by the current giving rise to the electric spark. When the observer had to choose between two letters, the physiological time was rather shorter than when the signal was made by the hand ; but when a choice of five letters was presented, the time was lengthened, the duration of the mental act amounting in this case to qf of a second. When the exciting cause was a sound answered by a sound, the increase of the physiological time was much shortened. Thus, the choice between two sounds and the determination to answer required about 7$§5 of a second ; while, when the choice lay between five different sounds, ziSs of a second was required. In these observations two persons sat before the phonautograph, one answering the other, while the voices of both were registered on the same revolving cylinder. | These observations may be regarded as the beginnings of a new line of inquiry, and it is obvious that by a proper combination of changes various mental factors may be eliminated and their duration ascertained. For instance, when one person utters a sound, the nature of which has been previously arranged, the time elapsing before the answer is given corresponds to the time required for simple recognition and volition. When, however, the first person has leave to utter any one, say of five, given sounds, and the second person to make answer by the same sound to any and every one of the five which he thus may hear, the mental process is much more com- plex. There is in this case first the perception and recog- nition of sound, then the bare volition towards an answer, and finally the choice and combination of certain motor impulses which are to be set going, in order that the appropriate sound may be made in answer. All this latter part of the cerebral labour may, however, be reduced to a minimum by arranging that though any one of five sounds may be given out, answer shall be made to a particular one only, The respondent then puts certain parts of his brain in communication with the origin of certain out- going nerves; he assumes the attitude, physical and mental, of one about to utter the expected sound. To use a metaphor, all the trains are laid, and there is only need for the match to be applied. When he hears any of the four sounds other than the one he has to answer, he has only to remain quiet. The mental labour actually em- ployed when the sound at last is heard is limited almost to a recognition of the sound, and the rise of what we may venture to call a bare volitional impulse. When this is done, the time is very considerably shortened. In this way Donders found, as a mean of numerous observations, that the second of these cases required 73%, of a second, and the third only ;3%5 over and above the first. That is to: say, while the complex act of recognition, rise of volitional impulse, and inauguration of an actual volition, with the setting free of co-ordinated motor impulses, took z$$q Of a second, the simple recognition and rise of volitional im- pulse took 7325 only. We infer, therefore, that the full inauguration of the volition took $3339 =73$5- In rough language, it took 4; of a second to think, and rather less to will. We may fairly expect interesting and curious results from a continuation of these researches. Two sources of error have, however, to be guarded against. One, and that most readily appreciated and cared for, refers to exactitude in the instruments employed ; the other, far more dangerous and less readily borne in mind, is the danger of getting wrong in drawing averages from a number of exceedingly small and variable differences. M. FOSTER CHOICE AND CHANCE Choice and Chance. By the Rev. Wm. Allen Whitworth, M.A., Fellow of St. John’s College, Cambridge. 2nd ed. Enlarged. 1870. (Deighton, Bell & Co.) E shou!d think that not a few copies of the first edition of this work must have been purchased under the im- pression that it was an interesting story ; and itis surprising that so neat and suggestive a title had not been long ago appropriated by some needy novelist. This work, how- ever, is a very able elementary treatise on those puzzling branches of mathematics which treat of combinations 4 4 = May 5, 1870] NATURE 5 permutations, and probabilities. The earlier chapters are quite within the comprehension of a schoolboy witha moderate knowledge of arithmetic ; the appendices, which treat of distributions, derangements, the disadvantage of gambling, and a proof of the Binomial Theorem, founded purely on the doctrine of combinations, require some knowledge of algebra in the reader. So great is the clear- ness with which Mr. Whitworth states and explains the problems throughout, that it is almost impossible to mis- understand him. The appendix in which the disadvan- tage of gambling is demonstrated is very interesting, and often novel ; and his explanation of the Petersburg problem is the most satisfactory which we have met. Our only regret concerning the work is that Mr. Whit- worth has not attempted more. Though the doctrines of combinations and probabilities lie at the basis of all mathematical and physical science, their value is chiefly theoretical, and it is hardly likely that time can be spared for their study in a school education. Had Mr. Whit- worth enlarged his work so as to make it a pretty com- plete handbook of the theory of probabilities, he would have performed a great service to science. It is strange how little attention has been paid at Cambridge to the theory of probabilities. If we except Mr. Todhunter’s valuable history, and Mr. Airy’s special work upon its ap- plication to observations, we cannot call to mind any recent separate work devoted to rendering the subject of probabilities accessible to students. Mr. De Morgan’s article in the Encyclopaedia Metropolitana, his excellent work in the Cabinet Cyclopzedia, the Useful Knowledge Society’s essay, Galloway’s treatise, and the translations of Quetelet’s work, are what we have to depend upon as introductions to the subject ; but they are all twenty or thirty years old at least, and difficult to meet with, Mr. Venn’s logic of chance, being purely metaphysical, is not to be counted. We wish that Mr. Whitworth, or some mathematician at once as able, and possessed of as clear a style of exposition, would fill this gap in mathematical literature by producing a student’s handbook of proba- bilities, including the theory of errors, the method of least squares, &c., with some of the applications to practice. W. S. JEVONS OUR BOOK SHELF F. Hoppe-Seyler. Handbuch der physiologischen wu. patho- logischen Analyse. Third edition. (Berlin, 1870.) WHILST modern chemical literature is abundantly sup- plied with publications on the analysis of mineral sub- stances, works on the methods of chemical investigation of the products of animal life are comparatively few. Physiological chemistry is still in its infancy. By far the greatest number of the substances occurring in the animal body have as yet to be discovered, and even those already known exhibit but in few instances such characteristic re- actions as serve for their detection and quantitative esti- mation equal in reliability to those we find in mineral chemistry. But however incomplete the analytical methods of the physiological chemist may be, they are highly valuable, not merely from a scientific, but also from a practical point of view, inasmuch as they aid the physi- cian in the detection of those important changes in the chemical composition of animal fluids and excreta, which almost invariably accompany certain forms of disease. The scientific man as well as the medical practitioner will, therefore, take an equal interest in the re-publication in an enlarged form of a work on the application of chemical analysis to physiology and pathology, which has proved very valuable in its former editions. The “Handbook” of Mr. Hoppe-Seyler’s is adapted to the use of the advanced medical student as well as of the physician. That part of the book treating on the analysis, properly speaking, of animal fluids, tissues, &c., is preceded by some very useful chapters on the employ- ment of chemical and physical apparatus ; on re-agents and the mode of ascertaining the purity of the same ; and on the composition, the properties, and detection of inorganic and organic chemical compounds occurring in the animal body. The great attention paid to the optical properties, of the various substances occurring in the body to the methods of their examination by means of the polariscope and spectroscope, forms a very remark- able and important feature of the book. Physiological chemistry claims a large share of the results which natural science owes to the application of these instruments, and a more extensive use of optical methods of research will certainly lead to further important discoveries. The author does not include the analysis of gaseous products, nor does he give an account of the methods used for the de- tection of poisons. The detection of blood-spots on wood, cloth, &c., is treated in an appendix. A chromolithograph, representing the spectra of the alkali metals, the absorp- tion bands of hamoglobine, and various tables and engra- vings, contribute to the usefulness of the work. B. FINKELSTEIN Search for Winter Sunbeams in the Raviera, Corsica, Algiers, and Spain. With numerous illustrations. By Samuel S. Cox. (London: Sampson Low, Son, and Marston. NewYork: D. Appleton and Co.) THISs interesting book will be welcome to those who are seeking to find a home ina sunnier clime than our own The author points out the beauties and the medicinal qualities of the south. In his preliminary chapter he ex- plains the title, “ Sunbeams,” giving the functions of light, music of light, analogy between light and sound, speaking especially of the life-giving power of the golden sunbeam. Quoting Prof. Maury’s thoughts on light, he says, “that the organs of the human ear are so ordered that they cannot comprehend colour any more than the eyes can see sounds ; yet, that we may hear over again the song of the morning stars, for light has its gamut of music ! The high notes vibrate with the violet of the spectrum, and the red extremity sounds the bass ; and though the ear may not catch the song that the rose, lily, and violet sing, it may, for aught we know, be to the humming-bird the butterfly, and the bee, more enchanting than that which ‘Prospero’s Ariel’ sung to the shipwrecked mariner.” The author rapidly describes the well-known winter resorts, Nice, Mentone (of which, with its lovely flowers and fruits, he draws a most inviting picture), Monaco, with its roulette table, myths, and beautiful scenery; then comes Corsica, its chief town, Ajaccio, being renowned as the birthplace of Napoleon. Many interesting facts are here given of his mother, Madame Letitia, with incidents of his boyhood. The author then proceeds to Africa, passing through Algiers, visits the Kabyle people and Arabs, giving a description of the Blidah orange orchards, Algerine desert, the magnificent cedars and oaks on Mount Atlas, the Arab and Moorish women, different interesting old tombs, mosaics, and inscriptions, Our author travels on to Spain and compares it with Algiers. Arrived at Murcia he witnesses a bull-fight, then he visits the Alhambra with its graceful architecture ; ez route for Madrid he passes many curious towns and castles. The following is a description of one :—“A mist obscured the mountains above. That old Moorish castle near the hill of the Pharos is called the Alcazaba. Its Puerta de la Cava is renowned, if not in history, in legend, as the scene of the suicide of Count Julian’s daugh- ter, whose woes brought on the Moorish invasion, and whose Iliad has been sung in prose by Irving. This castle is hid under a veil, even as Irving dropped over its rigid outlines the drapery of his genius, The mist lifts a little. We see a streak of sunlight on a bleak, bright mountain ahead of us. We pass by gar- dens of immense fig-trees. The mountains begin to shine 6 NATURE | May 5, 1870 white. We are in the vine-hills again. . . . Cactus, oleander, orange, and pomegranate—all these appear.” He then passes through the Basque country, St. Sebastian, and Biarritz, which the author considers “ the very pearl of a summer resort.” The work is ended with a fable recorded by Ford : “When San Ferdinand captured Seville from the Moor and bore the conquest to heaven, the Virgin desired her champion to ask from the Supernal Power any favour for Spain. The King asked for a fine climate and sweet sun : they were conceded. For brave men and beautiful women: conceded. For oil, wine, and all the fruits and goods of this teeming earth. This request was granted. ‘Then will it please the beauteous Queen of Heaven to grant unto Spain a good Govern- ment ?? ‘Nay, nay, that can never be. The angels would then desert heaven for Spain !’” The book is plentifully interspersed with good illus- trations. : LETTERS TO THE EDITOR [ The Editor does not hold himself responsible for opinions expressed by his Correspondents. No notice is taken of anonymous communications. | The Sources of the Nile From Mr. Keith Johnston’s communication to NATURE of the 14th April, it appears that he agrees with me in opinion—though quite independently of me and by a different process of reasoning --that the great river Kassabi, Kassavi, or Kasai, of South- Western Africa, instead of flowing to the north and north-west, as it has hitherto been shown to do in all maps, has its course north-eastward as far as about the meridian of 27°30’ east of Greenwich, where it is joined by the river system of the Cham- beze. Such being the case, the only material question between us is with respect to the lower course of the united stream of the two rivers, which Mr. Johnston carries round by a sharp curve to the north-west and west, so as to join the Zairé or Congo river, whereas I regard it as continuing northwards, and uniting with the Albert Nyanza, so as to form the upper course of the Nile. While thus disputing the claim of the Kassavi and Chambeze to be the head-streams of the Nile, Mr, Keith Johnston adyo- cates the rival claim of ‘‘the feeders of Lake Liemba.” Ido not, however, understand him to mean that these rivers, four in number, are to be considered the head-streams of the main body of the Nile, or to be anything but tributaries of that river, as is, in fact, shown in the map accompanying his paper. It being upon this point that the whole difference between us really hinges, I beg to be allowed to offer the following observations on the subject. Dr. Livingstone, the discoverer of Lake Liemba, describes it as lying at an elevation of 2,800 feet above the sea, on the northern slope of the Balungu upland, ina hollow with preci- pitous sides 2,000 feet down, and as going away in a river-like prolongation, two miles wide, N.N.W., to Tanganyika, of which he rightly considers it to be an arm ; the difficulty with respect to the elevation of the latter having been removed by Mr. Findlay, who makes it to be 2,800 feet, or the same as that of Lake Liemba. Captain Burton, the discoverer of Tanganyika, says respecting this great lake: ‘‘ The general formation suggests, as in the case of the Dead Sea, the idea of a volcano of depression—not like the Nyanza or Ukerewe formed by the drainage of mountains. Judging from the eye, the walls of this basin rise in an almost continuous curtain, rarely waving and infracted, to 2,000 or 3,000 feet above the water-level ;” from which description it is evident that Liemba and Tanganyika are portions of one continuous fissure or ‘‘crack” in the table-land, of which table-land the elevation is 5,000 feet, or perhaps more, above the ocean.—Dr. Livingstone says 4,000 to 6,000 feet, sloping towards the north and west, but he had not seen any part of it under 3,000 feet of altitude. Further, Lake Tanganyika is described by Dr. Living- stone as passing northwards, bya river named Loanda, into Lake Chowambe, which lake he identifies with Sir Samuel Baker's Albert Nyanza. The last-named expanse of water was found by its discoverer to have an elevation of 2,720 feet above the ocean, with a pre- cipitous cliff of 1,200 to 1,500 feet on the east shore, whilst on the opposite side the faint blue mountains rose about 7,000 feet above the water-level. The Albert Nyanza is, however, in nowise a continuation of the system of which Liemba and Tanganyika form parts; for whilst the direction of these two lakes is from north to south, or nearly so, the general bearing of the Albert Nyanza is from about north-east to south-west ; so that, as is shown on Mr. Keith Johnston’s map, the former joins the latter at an angle of 45°; whilst the main body of water extends probably a hundred miles beyond the junction, or to about the 28th meridian, And the Albert Nyanza does not terminate here ; for, in the latitude of Karagwe, between 1° and 2° S., it was said by the natives to turn to the west, in which direction its extent was unknown even to Rumanika, the King of Karagwe. Quite independently, then, of the question of the junction of the joint stream of the Kassavi and Chambeze with the Nile, there is this preliminary question, which I would propound for Mr. Keith Johnston’s consideration and answer :—Where would he place, even if only conjecturally, the head of this unknown western extension of the Albert Nyanza?—or, in other words, where would he trace the western limits of the Upper Nile basin ? : As regards his objection to ‘‘ the northward wall-like continua- tion of the Mossamba mountains on the 20th meridian to beyond the equator,” shown in my sketch-map of the Upper Nile basin, in Part xv. (for March 1st last) of the ‘‘Illustrated Travels,” I must explain that the same is so marked merely conjecturally, and that I do not think of maintaining it against—I will not say proof—but any reasonable argument. In my former maps of 1849, 1859, and 1864, I placed the conjectural western limits of the basin of the river somewhere about that meridian on or near the equator, thence continuing to about 10° N. lat., where the line was made to curve inwards towards the valley of the river. When I found the Kassavi, which I look on as the head-stream of the Nile, actually rising in the Mossamba mountains, on about the meridian thus indicated, I naturally extended my con- jectural limits of the basin of the river along the same meridian from the equator southwards. But I repeat that, beyond what we actually know, all the rest is purely conjectural. If there is reason to carry the limits of the basins of the rivers of the West Coast of Africa to the east of the 20th meridian, on the equator or even as far south as the fifth parallel of south latitude, I have nothing to object to it, except that care must be taken to leave sufficient space for the western flank of the basin of the River Nile. And this brings me to what I regard as an insurmountable ob- jection to Mr. Keith Johnston’s hypothesis. By causing, as he does, the Kassavi and Chambeze, after their union on the me- ridian of 27° 30’, to make a curve round to the north-west and west, so as to form the main-stream of the Congo River, he actually brings the course of this supposed river within 150 miles of the south-western extremity of the Albert Nyanza, as laid down onhis own map. But to enable him to do this, he must, in de- fiance of Sir Samuel Baker’s authority, deny the great westerly extension of this immense body of water ; and by closing it up in that direction he renders it merely a ‘‘ back-water” to Tanga- nyika, as Captain Speke imagined it to be to his Victoria Nyanza, instead of its being the main-stream ofthe Nile. Mr. Keith Johnston evidently has misgivings on this head, for he says : *‘ If, however, the Albert Nyanza prove to have a great south-westerly extension, this one difficulty would be removed,”-—namely, the sole diffi- culty in the way of the junction of the Kassavi and Chambeze with the Nile, for which I contend. The argument founded on the comparative levels of Lakes Moero and Tanganyika I fail to appreciate. If the upland, 2,000ft. below which Liemba and Tanganyika lie, has a general elevation of 5,000ft., the waters of Lake Moero, instead of pass- ing as they do through the crack in the mountains of Rua, could not by any possibility unite with those of Tanganyika, except by means of a similar crack in the mountains forming the western side of the latter; unless, indeed, Moero were supposed to lie on the upper level, to which supposition Mr. Johnston’s argument is diametrically opposed. In support of my own argument that the united stream of the Kassavi and the Chambeze continues northwards to” join the Nile, instead of turning round to the north- west and west to join the Congo, I have really nothing to add. My opponent himself carries the joint stream for me to within 150 miles of the known south-western extremity of the Albert Nyanza: it is for him to show how the two are to be May 5, 1870 | NATURE : prevented from uniting. But in doing so he must bear in mind that the waters of Ulenge, made by him to be the recipient of the Kassavi, as well as of the Chambeze, are said by some of Livingstone’s native informants to flow N.N.W. into Chowambe or Albert Nyanza, and that for the westerly extension of this body of water we have the authority of Baker. On the subject of the Congo I have little to say. If it should be found that north of the fifth parallel of south latitude the basin of that river requires to be carried further eastward than the 20th meridian, I see no objection to it. Only I am bound to remark, that I do not consider there is any war- rant for representing the Congo as a river having a low alluvial valley extending some 500 or 600 miles inland. I have not examined the subject of this river very closely, but my im- pression is, that, like the other rivers of the West Coast of Africa south of the equator, the rise of the level of its bed is rapid, and that it becomes considerable within a short distance from the ocean ; so that there would not be sufficient fall for the waters of Ulenge in 27°30’ E. long. to join it. And, further, I cannot but entertain the opinion that the volume of water of the Congo has been greatly over estimated ; in support of which opinion I will cite the following passages, in pages 147 and 148, of Captain Tuckey’s Narrative :—‘‘ At the further end of the banza we unexpectedly saw the fall almost under our feet, and were not less surprised than disappointed at finding, instead of a second Niagara, which the description of the natives and_ their horror of it had given us reason to expect, @ comparative brook bubbling over its stony bed .... The principal idea that the fall creates is, that the quantity of water which flows over it isby no means equal to the volume of the river below it ; and yet, as we know there is not at this season a tributary stream sufficient to turn a mill below the fall, we can hardly account for this volume, unless we suppose, as Dr. Smith sug- gests, the existence of subterranean communications or caverns filled with water.” Doesthis look like the lower course of the supposed second great river of Africa, with a basin of which the area is estimated to measure $00,000 square miles ? On a reconsideration, then, of the whole subject, I see no reason whatever to go from the opinion I have expressed, that the rivers Kassavi and Chambeze unite to form the upper course of the Albert Nyanza; that is to say, the main stream of the Nile ; and as the former of those two rivers has the more direct course, and its source is the most remote of all, it is entitled to the honour which I claim for it, of being the hitherto undis- covered head of the great river of Egypt. Bekesbourne, April 22 CHARLES BEKE P.S., April 26.—Since the foregoing was written, Mr. Keith Johnston has obligingly sent me a copy of his ‘‘ Map of the Lake Region of Eastern Africa,” with notes, just published, in which I find a categorical answer to my question respecting the western limits of the Upper Nile Basin. He traces them as coming from the south of Lake Liemba and its feeders, and running close along the western side of Tanganyika as far as its northern end, where he gives them a curve to the westward not more than sufficient to include the south-western of the Albert Nyanza, and thence continuing along the high mountains on the west side of that body of water, the westerly extension of which, reported by Baker, he ignores entirely. To these views I need not reiterate my objections. Cabs Why is the Sky Blue? CAN any of your readers inform me why the sky is blue? Is it that the predominant colour of sunlight being orange, the regions devoid of sunlight appear of the complementary colour? If so, the planets of Sirius and Vega would have a black sky, those of Betelgeux a green sky, while those of the double stars would have different coloured skies at different times, according to their position with respect to their two luminaries. Or again, is the blueness merely the colour of our atmosphere, as Prof. Tyndall’s experiments have led some to believe? In favour of the former explanation, is the fact that the maximum intensity of the light of the solar spectrum is in the orange, and indeed that the sun /ooks orange, and if we close our eyes after gazing a moment at him when high up in the sky, we see a blue image. When the sun is low, his colour changes from orange to red, and this would explain the green tintsso often seen in the cloudless parts of the sky at sunset. Possibly Mr. Glaisher, who has seen the sky through a thinner stratum of air than most of us, could help us to a solution. ALN, Hampstead, April 24 Curious Facts in Molecular Physics Some of the phenomena of photography present features of a very curious nature, yet seem to be very little knowr. to philoso- phers who devote their time to researches in molecular physics. For instance, when a glass plate coated with collodion con- taining an iodide—say iodide of cadmium—is dipped into a “bath” solution of nitrate of silver, strength twenty-five grains to the ounce, in from three to four minutes a good dense preci- pitate of yellow iodide of silver is formed in the spongy collodion film, and the plate is ready for photographic use. But, let a plate be covered with collodion containing bromide of cadmium, (ten grains to the ounce) instead of iodide of cadmium, an immersion of ten or fifteen minutes is necessary to obtain a good film of bromide of silver, though the collodion skin upon the glass surface is only of the same thickness as in the former in- stance, and not only is this much longer immersion necessary, but the nitrate of silver solution must be increased in strength to about sixty grains to the ounce to get the best results. When the strength of the nitrate of silver is only twenty-five grains to the ounce, the bromide of silver forms more on the surface of the collodion than within it, and sometimes breaks away in scales from the collodion, and falls to the bottom of the bath. Lastly, let chloride of cadmium be used instead of the bromide in the collodion, the strength of the nitrate of silver must be increased to about one hundred grains to the ounce of water, and an immersion of thirty or forty-five minutes is necessary to get a good photographic precipitate of chloride of silver. In this case, when a weak nitrate of silver solution is used, an uneven preci- pitate is formed upon the plate, and the tendency to burst out ot film in scales is seen as in the former instance. The three kinds of films just described vary in their photo- graphic properties. The iodide of silver film requires the shortest exposure in the camera to produce a good picture, the bromide of silver film requires a longer exposure, and the chloride of silver film requires the most prolonged exposure to light of all. Again, the iodide of silver film is more liable than the others to spots and markings, when there are particles of dust or other impurities on the glass plate or in the solution used ; bromide of silver is not nearly so delicately sensitive to such disturbing influences; the chloride of silver film is even less sensitive in this respect than the bromide surface. The reason of the differences of time of exposure just men- tioned may possibly be accounted for on the supposition that chlorine binds itself to silver with more force than is exerted by bromine, and that the atom of bromine clings to the atom of silver with more tenacity than iodine clings to the metal. Hence the waves of light have more work to do in beating chlorine from silver than in beating iodine from silver. One very beau- tiful experiment, first made by Mr. M. Carey Lea, of Philadel- phia, tends to prove that light will widen the distance between the hypothetical swinging atoms of iodine and silver, and that in darkness the atoms, with their attraction for each other thus par- tially overcome, will gradually fall together again. He prepared a film of absolutely pure dry iodide of silver, upon a glass plate, which film in the process of preparation had not been allowed to come into contact with the slightest trace of organic matter, in the washing water, or by any other means. On exposing such a film to light under a negative, and then applying what is known as the ‘‘alkaline developer,” a picture came out ; but if instead of developing the picture, the exposed plate were allowed to rest a day or two in the dark, the latent image died out, the film, so far as is known, returned to its primitive condition, and on expostue under another negative, a picture from it could be brought out, with no traceof the image impressed for a time through the first negative. The alkaline developer seems to ‘drink up” the iodine where its cohesion to the silver is loosened, thereby leaving a dark deposit of metallic silver, but where the light has not somewhat beaten the atoms asunder, the developer has no action, unless its strength be increased till it blackens the whole plate, whether the light has acted upon the film or not. The alkaline developer consists of a weak solution of pyrogallic acid, rendered alkaline by the addition of a few drops of carbonate of soda, This is but one instance among many of the facilities offered by photographic phenomena to those who are trying to peer into the penumbral philosophical region of molecular physics. WILLIAM H. HARRISON 8 NATURE [ May 5, 1870 SIR EDWARD SABINE’S CONVERSAZIONE HATEVER may be said by those to whom the grapes are sour, the gathering which- met at Bur- lington House on April 23 to greet the President of the Royal Society, under animating circumstances, can hardly fail of beneficial results, whether regarded from the social, the moral, or the scientific point of view. It would not be easy to devise a happier way of bringing novelties at once under practical criticism—of making the outliers of science acquainted with the centre, of enabling investigators to compare operations and dis- cuss facts and speculations, and of giving occasion for re- newal of intercourse and removal of misunderstandings. As usual, the range of articles exhibited was wide enough to include different branches of science, from astronomy to natural history, and from electro-magnetism to physiology, with achievements of fine art, and of arts mechanical. In an exhausted hydrogen tube placed across the poles of an elec- tro-magnet, Mr. C.F. Varley produced a beautiful luminous arc, the dimensions of which he could vary at pleasure bya change in the size of the negative pole, and occasion a change of direction by a slight elevation of one end of the tube. Spectroscopy, as we have more than once had occasion to record, owes much to the constructive skill of Mr. Browning. We shall return, on a future occasion, to his new automatic spectroscope. Mr. C. W. Siemens’s Electrical Resistance Pyrometer well maintains the reputation of the inventor for applica- tion of philosophical principles to mechanical uses. It is the very salamander of pyrometers, and will measure the temperature of the most highly heated fiery furnace ; which must render it indispensable in operations where intense heat is required, and to all experimentalists who know the imperfections of the pyrometer in ordinary use. The construction of the new instrument is based on the physical fact that the resistance of pure metals to the electric current increases with increase of temperature in a simple absolute ratio. A platinum wire of known re- sistance is coiled upon a small cylinder of fireclay, and is covered by a tube of the same metal, which protects the wire from the destructive action of flame, without pre- venting access of heat. Thus constructed, the pyrometer is placed in the furnace, and is connected by wires with a Daniell’s battery of two cells, and with a compact Resist- ance-measurer, specially devised by Mr. Siemens, on which the observer makes observations at his ease. As the fire burns, the electrical resistance of the platinum coil rapidly increases, communicates its progress to the measurer on which the indications of temperature may be read off as entirely trustworthy, even up to the melting point of platinum. The importance of such an instru- ment as this cannot fail to be recognised by practical men, whether among natural philosophers or workers in the pyrotechnic arts ; and, for our part, we cordially wel- come this new pyrometer as a logical sequence from the inventor of the regenerative gas-furnace with its fierce heat-producing capabilities. Mr. Jerry Barrett, who relieves his hours at the easel with natural philosophy, exhibited an auxiliary air-pump, which appears to produce that essential desideratum, a perfect Torricellian vacuum, To an ordinary air-pump he attaches an air-chamber or reservoir, and, communicating therewith, two cylindrical glass vessels charged with mercury, and connected by a V tube, On working the pump the pressure of the air in the lower vessels compels the mercury to rise and fill the upper one, in which an ingeniously contrived platinum valve plays an important part. By continuing the process of filling and emptying (the details of which are not easy to describe), the desired vacuum is eventually obtained, and the exhausted tube on the top of the pump is ready for experiment. We learn that a well-known experimentalist was so favourably im- pressed by the capabilities of this pump that he intends to have anumber of large tubes made for a series of experi- ments. Inthese days of busy telegraphy, Mr. J. Parnell’s new secondary battery is worth attention. It isso constructed as to be capable of alarge amount of heavy work, having forty cells, each containing a pair of copper plates immersed in a solution of the impure carbonate of sodium, known in commerce as “soda.” By this employment of an alkali, the electromotive force produced is supposed to depend on the electrolytic reduction of the sodium. The battery is arranged inten compound cells of four couples each, and ischarged by a small battery of five Grove cells, and afterthe connection has been established for a few seconds, a com- mutator of peculiar construction is brought into play, and excites the whole forty cells to activity. It is thought that a battery so constructed, which can be energised at pleasure by a brief communication with the small Grove, will be found of service in telegraphing through lines of great resistance. Rear-Admiral Inglefield’s contrivance for making the water in which a ship floats do the work of steering appeals to every Englishman, for are we not all interested in our navy, whether Royal or commercial? It is a con- trivance which involves a large economy, for instead of a number of men labouring at two wheels, and with relieving tackles, it requires one small wheel only, and one man to steer the largest ship afloat ; estimating roughly the pressure of the water as half a pouna per square inch for every foot of the ship’s draught. Ad- miral Inglefield admits the water through the bottom by a “Kingston valve” into a cylinder placed at the stern. The piston of this cylinder works a double-action force- pump, which sends the water to two hydraulic cylinders ; these are connected with a tiller four feet in length, and thus, by movements of the small steering wheel, the ship is easily steered. Trials made with this apparatus on board the Achilles, one of the largest vessels in the navy, proved satisfactory ; and in an improved form it is to be fitted to the Fethz Bulend,a corvette now building for the Turkish Government. Unfortunately for the visitors to the conversazione, the model exhibited, owing to lateness of delivery, could not be shown in work; but there was a skeleton of the corvette’s stern, showing the position of the apparatus, and near it stood one of the small steering- wheels, By this and Admiral Ingletield’s explanations, the naval men present could form an opinion of the new method, compare it with the existing method, and mark how surely the helm could be kept hard over during full speed, and how rapid and easy were its movements generally. Mr. J. B. Rogers exhibited his life-saving apparatus, by which he has obtained the prize long offered by the Ship- wrecked Mariners’ Society, and furnished means of rescue, which, judging from the trials made near Portsmouth under authority of the Admiralty, are likely to render valuable service. With a mortar and a small charge of powder he throws out an anchor from the shore, and by means of the double rope thereto attached, a lifeboat can be hauled out through a heavy surf in weather when it would be impossible to launch her in the usual way ; and with the further advantage that the hauling need not be done by the crew of the boat, who would consequently be fresh for their laborious task of rowing out to the ship in distress. The Meteorological Office of the Board of Trade in carrying out their scheme of “ ocean statistics,” from which great advantage may be anticipated to navigation and to meteorological science, have constructed two charts, the value of which all whose business it is to go down to the sea in ships will appreciate. The wind chart is the first instalment of a series intended to show the best route for crossing the line in each month of the year. To facilitate reference, it is ruled in squares each represent- ing a degree, with the direction and force of the prevailing May 5, 1870] NATURE 9 winds. This is, we believe, the first attempt to show the force of the wind in a chart of this nature. The area embraced lies between the equator and 10°N. and 20° and 30° W., and contains the observations of five years for the month of November. When the other eleven months of _ the year are represented each by a chart, mariners will be able to choose a way across “the Doldrums” where they may be likely to find the most favourable winds and currents. From this it will be understocd that the current chart is constructed in a similar style. Principal Dawson, of M‘Gill College, Montreal, who has just arrived with a fine collection of fossils, could not have desired a better opportunity for exhibiting them than was afforded by the conversazione. There, while showing his specimens to the éife of the scientific world, he could talk to them about the geological survey of. Canada, and the Peninsula of Gaspé, with its cliffs of ‘‘ Upper Silurian,” 600 feet in height, its ‘‘ Devonian sandstones” and “lower carbo- niferous deposits, and its arched rocks forming magnificent coast scenery. Among those fossils are two large tree- stems, Protavites Logani,a species of Psilophyton, anda Cyclostigma, the latter a genus previously met with no- where but in the Devonian rocks of Ireland. Other kinds include Cordaites, Psaronius, Antholithes, Asterophyllites, and a variety of ferns; and occurring in the animal remains, we find Cephalaspis, the first of the kind yet found in America, and AZachairacanthus, and other large fishes. As Dr. Dawson is to read a paper on these im- portant fossils at the Royal Society this evening, we may hope to see their story told in due time with suitable illustrations in the “ Philosophical Transactions.” Dr. Carpenter exhibited with microscopes, with the actual specimens, and with a considerable breadth of well-executed diagrams, some of his treasures from the “deep, deep sea.” In friendly neighbourhood, Prof. Tennant showed fossil specimens of some of the same creatures. And not far distant were hung Lieut. Palmer’s clever drawings of living animals from the surface of the sea, captured in the China Sea, the Indian Ocean, and the Atlantic. These drawings testify to Lieut. Palmer’s skill and industry. The animals are represented life-size and in their natural colours. Among them we observed the Glodzgerina, which may, perhaps, be taken as evidence that this creature does not, as some have supposed, exclusively inhabit the bottom of the sea. Considering that there is always room for natural history researches, the Admiralty should be able to find such employment for Lieut. Palmer as would exer- cise his artistic faculty and his habit of observation. We are far from having exhausted the subject, but we must close here. Need we pause to draw a moral, or to point out that in such a conversazione as we have attempted to describe there is a tangible gain to science? It is well for inventors and experimentalists that they should hear what contemporaries say of their schemes and experi- ments, and much can be said and done with advantage amid the free talk of a general gathering which could not be permitted in the formal meeting of a scientific society. Let proper discrimination be used in the selection of articles for exhibition : science will then continue to benefit by soirées. RECENT ACCESSIONS TO THE ZOOLOGICAL SOCIETY S GARDENS Toe collection of living animals belonging to the Zoological Society of London and kept in their gardens in the Regent’s Park contains, as most of the readers of NATURE are probably aware, by far the largest and most nearly complete living series of representatives of the various classes of Vertebrate animals that has ever been brought together in one spot. Great as the exertions that have been made of late years in some of the corre- sponding establishments on the Continent, the sister societies have never succeeded in rivalling the English collection as a whole, although they have occasionally bid fair to surpass it in some particular point. The whole number of animals in the Zoological Society’s Gardens usually somewhat exceeds two thousand—on the first of January last it was 2,031—consisting of 598 mammals, 1,245 birds, and 170 reptiles and batrachians, besides the fishes in the aquarium, which do not appear to be included in the annual census. Constant additions are made to the series, not only by purchase, but also by gifts of correspondents in every part of the world, and by exchange with the continental establishments. By these means the collection is kept up to its normalstandard—the death-rate, as in all living zoological collections, being, in spite of every care and precaution, extremely heavy. During the past month of March go additions are recorded in the Society’s register as having been made to the Menagerie. 33 of these were by gift, 33 by purchase, 4 by exchange, 5 by birth, and 15 were animals received ‘‘on deposit.” The decrease during the same period by death and departures was 96, showing a total loss to the collection during the month of 6 individuals. The most noticeable amongst the acquisitions to the Menagerie in March last were the four following :— (1). Examples of two very fine new pheasants, recently discovered in Upper Assam by the well-known Indian ornithologist, Dr. J. C. Jerdon, and named by him Lopho- phorus sclateri, and Ceriornis bly(hit. These birds are both of very great interest, not only as being brilliant ad- ditions to the two magnificent groups to which they belong, but also as being ¢yfzca/ specimens, 2.¢., the identical speci- mens upon whichDr. Jerdon has founded these two species. The “ Monaul,” or Impeyan pheasant of the southern slopes of the Himalaya, is one of the best known of Indian game-birds, and at the same time one of the most mag- nificently-coloured birds of British India, insomuch that Mr. Gould has chosen it as the representative bird for the cover of the numbers of his great work on the ‘‘ Birds of Asia.” For many years this bird was believed to stand quite alone, and to be the sole existing representative of the genus Lophophorus. A short time ago, however, Monsignor Chauveau, titular Bishop of Lhassa, who has recently found it necessary to retire from his Tibetan diocese into the confines of China, sent home from 7Zua- tsten-liew, in the western part of the province of Sechuen, where he has taken up his abode, a collection of birds, amongst which were a pair of a very fine new species of Impeyan pheasant. These specimens, after being named in France Lophophorus Lhuyst, in compliment to M. Drouyn de Lhuys, the Minister of Foreign Affairs, whom we suppose the describer was anxious, for some good reason, to propitiate, passed into the collection of the British Museum, where they may be now seen in the Ornithological Gallery. It was thus proved that a second Impeyan pheasant is found on the northern slopes of the great central range of Asia, where it doubt- less occupies a corresponding elevation and fulfils similar functions in the economy of nature to the well- known bird of the Indian Himalayas. The discovery of the present bird by Dr. Jerdon, which, although somewhat different in certain details of structure from the two former, belongs strictly to the same genus, serves to further prove to us how much still remains to be done in zoological discovery, even amongst what are gene- rally supposed to be the best-known divisions of the Verte- brata. Being crestless, Sclater’s Impeyan, which has been named by Dr. Jerdon after the secretary of the Zoological Society of London, renders the old generic term /opho- phorus \ess applicable to the group. But in other points it does not materially differ, and at any rate is sufficiently near the common Impeyan to induce the only known in- dividual of Sclater’s Impeyan now in the Zoological So- ciety’s gardens to be quite ready to associate with a female of the latter which had been placed along with him, 10 , : 3 i aved Dr. Jerdon discovered this new bird during his resi- | dence at Shillong, a new sanitarium recently opened on the Khasya hills. The single example known was ob- tained from the Mishmees, a wild tribe which inhabits the hills of Upper Assam, by Major Montagu, of the Bengal Staff Corps, who, on being informed of the value of his acquisition, most liberally presented this unique specimen to the Zoological Society. The new Tragopan which arrived in the Society’s Gardens along with the last named bird, is hardly of less interest to the naturalist, and to the general observer amuch more brilliant species in colour. It is likewise a gift of Major Montagu to the Society, having been obtained by him in the same district as the new Impeyan. The two Tragopans or “ Argus Pheasants,” as they are usually termed by Indian sportsmen, one of which NAT- URE [ May 5,.1870 to keep alive in this country members of the great | fruit-eating families of the Old-world and New-world Tropics—such as !the Hornbills (Bucerotide), the Co- | tingas (Cofingide,) and others. Continued experience | has, however, shown that the difficulties, formerly supposed to be insuperable, may be overcome by careful ' attention to dietand other matters, and in the case of the | Hornbills the Zoological Society has succeeded in a very | remarkable degree, some four or five of the finest species of the group having been successfully introduced into their aviaries, and kept in excellent health andcondition. The most remarkable representatives of this group in the Society’s Gardens at the present moment are, perhaps, the | great Concave-casqued Hornbills (Buceros bicornis). Apair of these fine birds have inhabited one of the compartments of the large Eastern Aviary ever since the summer of 1864, THE PLAIT-BILLED HORNBILL (Ceriornis melanocephaia) inhabits the western Himalayas, and the other (C. sa¢yra) the Himalayas of Nipaland Sikim, have long been known as among the most splendid forms of the Gallinaceous order. ‘The present bird, which has been named by Dr. Jerdon Ceriornis blythit, after one of the most distinguished of Indian naturalists, forms a third Indian species of the genus. ‘There are likewise two Chinese Tragopans known—making in all five members of | the group. Ofone of these latter—Temminck’s Tragopan (C. temminckit}—there are several pairs now in the Zoo- logical Society’s Gardens, and both this and the Cerzorns satyra have bred there in former years. (2). Four young Hornbills belonging to three species (Buceros bicornis, B. plicatus, and B. gractlis), received March 18th. A few years ago it was supposed to be impossible | andstillshow nosymptoms of yielding to theinclemencies of the English climate. There are, indeed, great hopes of these birds breeding here, in which case the British public might have an opportunity of becoming acquainted with the very singular manners and customs of the Hornbills during the breeding season. No sooner has the hen commenced the labour of incubation, say several trustworthy observers on this subject, than the male walls up the hole in the hollow tree in which the hen is sitting on her eggs, until there is only room for the point of her bill to protrude, so that until her young birds are hatched she remains confined to her nest, and is in the meantime assiduously fed by her mate, who devotes himself entirely to this object. This | habit has been testified to not only by Tickell, Layard, and other Indian naturalists concerning some of the Asiatic species, but is also spoken of by Dr. Livingstone May 35, 1870] NATURE 4 il & in the case of Hornbills met with during his African explorations, and there appears to be no doubt of its authenticity. In Sumatra, in 1862, Mr, Wallace heard the same story from his hunters, and was taken to see a nest of the Concave-casqued Hornbill, in which, after the male bird had been ‘shot while in the act of feeding its mate, the female was discovered walled up. “With great difficulty,” Mr. Wallace tells us, “I persuaded some natives to climb up the tree, and bring me the bird. This they did, alive, and along with ita young one, apparently not many days old, and a most remarkable object. Lt was about the size of a half-grown duckling, but opposite sexes of a rather smaller bird, the Plait-billed Hornbill (2. plzécatus), which is found in the Burmese peninsula, Sumatra and Java. The male, as in many other species, has the head and neck white or pale rufous, while the female these parts are black, like the rest of the body. It will be also remarked that the colour of the naked skin of the throat is not alike in the two sexes. Thefourth and smallest bird is a female of the Slender Hornbill (Buceros gracilis.) Neither of these two last-named species have been previously exhibited in the Society’s collection, which now contains twelve Hornbills of eight different species. THE BURROWING OWL so flabby and semi-transparent as to resemble a bladder of jelly, furnished with head, legs, and rudimentary wings, but with not a sign of a feather, except a few lines of points indicating where they would come.” It would be certainly very delightful to be able to wit- ness this imprisoning process in the Zoological Society’s Gardens, and a fine moral lesson would at the same time be administered to such of the British matrons as are in the habit of running about neglecting their infant children. Of the four Hornbills last received, one only belongs to the large species I have just spoken of. Two are the | (3.) Four Burrowing Owls (Pholeoptynx cunicularia), presented by George Wilks, Esq., C.M.Z.S., of Buenos Ayres. The Burrowing Owl is an American species of Day-Owl, well-known for its abnormal habits, and widely distributed in the New World. In the prairies of the far West, it lives in the “villages” of the Prairie-dog (Arctomys ludovicianus), residing in the forsaken burrows. “The burrow selected,” says the well-known naturalist, Audu- bon, “is usually at the foot of a wormwood-bush (A7- temiséa), upon the summit of which the owl often perches, and stands for a considerable while. On being approached they utter a low chattering sound, start, and skim along fee NATURE [May 5, 1870 the plain fora considerable distance. When winged they make for the nearest burrow, and when once within it, it is impossible to dislodge them.” It is commonly said that rattlesnakes are likewise abundant in these “ Prairie-dog villages,” and that the beast, bird, and reptile, may not unfrequently be seen here in harmonious juxtaposition. In the pampas of South America, this little owl associates with another Burrowing rodent, which lives in communi- ties in a similar manner to the Prairie-dog. This is the Vizcacha (Lagostomus trichodactylus). During the open day, Mr. Darwin tells us, but more especially in the evening, these owls may be seen in the pampas of the Argentine Republic in every direction, standing by pairs on the hillock next to their hole. If disturbed, they either retreat under-ground, or move with an undulatory flight to a short distance, and then turning round, steadily gaze at their pursuer. The Burrowing Owl is, however, perfectly capable of making its own burrow, as Mr. Darwin tells us it always does where the Vizcacha is not found, and as it has done in the Zoological Society’s Gardens. The first individual of this species which was received in 1868 from the same donor, was no sooner placed in a cage with a sandy floor than, “true to its habits, it excavated a hole in the soil at the bottom, into which it always retreated when threatened.” The same habit may be witnessed on alarming the specimens of this bird now in the Society’s gardens, although the burrow in the present instance has been, at all events partially, made artificially for their use. (4.) An example of a rather rare Antelope from Western Africa—the Woodloving Antelope (Cephalophus sylvicul- tyix)—received in exchange March 24th. This is a representative of a group of Antelopes of small size which are found only in tropical or subtropical Africa, and are peculiar for having a little tuft of hair between their horns, as their generic name imports. Some eighteen or twenty species of this genus are known to science, and several of them are usually represented in the Zoological Society’s collection. But the present animal, which is well marked by its white dorsal streak, has not been pre- viously received alive by the Society. P. L. SCLATER NOVEL TELEGRAPHY — ELECTRIFICATION OF AN ISLAND CURIOUS discovery has been made by Mr. Gott, the superintendent of the French company’s telegraph station at the little island of St. Pierre Miquelon. There are two telegraph stations on the island. One, worked in connection with the Anglo-American company’s lines by an American company, receives messages from Newfound- land and sends them on to Sydney, using for the latter purpose a powerful battery and the ordinary Morse signals. The second station is worked by the French Trans- atlantic Company, and is furnished with exceedingly deli- cate receiving instruments, the invention of Sir William Thomson, and used to receive messages from Brest and Duxbury. These very sensitive instruments were found to be seriously affected by earth-currents ; ze., currents de- pending on some rapid changes in the electrical condition of the island ; these numerous changes caused currents to flow in and out of the French company’s cables, interfering very much with the currents indicating true signals. This phenomenon is not an uncommon one, and the inconve- nience was removed by laying an insulated wire about three miles long back from the station to the sea, in which a large metal plate was immersed ; this plate is used in practice as the earth of the St. Pierre station, the changes in the electrical condition or potential of the sea being small and slow, in comparison with those of the dry rocky soil of St. Pierre. After this had been done, it was found that part of the so-called earth-currents had been due to the signals sent bythe American company into their own lines, for when the delicate receiving instrument was placed between the earth at the French station and the earth at the sea, so as to bein circuit with the three miles of insu- lated wire, the messages sent by the rival com- pany were clearly indicated, so clearly indeed, that they have been automatically recorded by i Sir William Thomson’s syphon recorder. An- nexed is a facsimile of a small part of the message concerning the loss of the steamship Oneida, stolen in this manner. It must be clearly understood that the Ameri- can lines come nowhere into contact, or even into the neighbourhood of the French line. The two stations are several hundred yards apart, and yet messages sent at one station are dis- tinctly read at the other station ; the only con- nection between the two being through the earth ; and it is quite clear that they would be so re- : ~ ceived and read at fifty stations in the neighbour- ? ™ hood all at once. The explanation is obvious ‘S enough: the potential of the ground in the neigh- ae bourhood of the stations is alternately raised and lowered by the powerful battery used to send the American signals. The potential of the sea at the other end of the short insulated line re- mains almost if not wholly unaffected by these, and thus the island acts like a sort of great Leyden jar, continually charged by the American battery, and discharged in part through the short insulated French line. Each time the American operator depresses his sending key, he not only sends a current through his lines, but electrifies the whole island, and this elec- trification is detected and recorded by the rival company’s instruments. No similar experiment could be made in the neighbourhood of a station from which many simultaneous signals were being sent; but it is perfectly clear that unless special precautions are taken at isolated stations, an inquisitive neigh- bour owning a short insulated wire might steal all messages without making any connection line. Stealing messages by attaching an in- strument to the line was a familiar incident in the American War ; but now messages may be stolen with perfect secrecy by persons who no- where come within a quarter of a mile of the line. Luckily, the remedy is simple enough. ~ = i All owners of important isolated stations should use earth-plates at sea, and at sea only. This plan was devised by Mr. C. Varley many years ago to eliminate what we may term natural earth-currents, and now it should be used to avoid the production of artificial earth-currents which may be improperly made use of. FLEEMING JENKIN NOTES WE regret to hear that Baron Liebig is very ill. WE are informed that Messrs. Lyon Playfair, C.B., M.P., B. Samuelson, M.P., and Dr. W. A. Miller, will probably be among the members of the Royal Commission to inquire into the Present State of Science in this country. PRINCIPAL DAwsoN, of Montreal, who is now ona visit to this country, will deliver the Bakerian Lecture to-night before the Royal Society. The subject is the Pre-carboniferous Flora of North Eastern America, The opportunity of listening to so emi- nent a geologist on a subject which he has made especially his own, will doubtless draw together a large assembly of our men of science anxious to do honour to their distinguished con/rére. THE following gentlemen have been appointed by the Uni- versity of London examiners and assistant examiners for 1870- between his instrument and the cable or land — Jay 5, 1870 | MATORE aS 1871 in the various branches of science:—Logic and Moral Uosophy: Rey. Mark Pattison, B.D., and Prof. G. Croom Obertson, M.A. Political Economy: Prof. W. Stanley Jevons, A., and Prof. T. E. Cliffe Leslie, LL.B. Mathematics and atural Philosophy: Prof. H. J. S. Smith, M.A., F.R.S., and we Sylvester, M.A., F.R.S. Experimental Philosophy: Prof. W. G. Adams, M.A., and Prof. G. Carey Foster, B.A., F.R.S. emistry : Dr. Matthiessen, F.R.S., and Prof. Odling, M.B., ER.S. Botany and Vegetable Physiology: Joseph Dalton ‘Hooker, M.D., LL.D., F.R.S., and Thomas Thomson, M.D., F.RS. Geology and Palxontology: Prof. Duncan, M.B., F.R.S., and Prof. Morris, F.G.S. Practice of Medicine : John Syer Bristowe, M.D., and Prof. J. Russell Reynolds, M.D., F.R.S. Surgery: Prof. John Birkett, F.R.C.S., and F. Le Gros Clark, F.R.C.S. Anatomy : Prof. William Turner, M.B., F.RS.E., and Prof. John Wood, F.R.C.S. Physiology, Com- parative Anatomy. and Zoology : Michael Foster, M.D., B.A-, and Henry Power, M.B. Obstetric Medicine: Robert Barnes, M.D., and Prof. W. H. Graily Hewitt, M.D. Materia Medica and Pharmaceutical Chemistry: Thomas R. Fraser, M.D., B.R.S.E., and Prof. Alfred Baring Garrod, M.D., F.R.S. Forensic Medicine: E. Headlam Greenhow, M.D., and Thomas Stevenson, M.D. PROFEssOR AGASSIZ is still seriously ill. WE are rejoiced to hear that M. Janssen is to be provided with instruments wherewith to continue his observations on the sun by means of the new method. This was announced at the last meeting of the Paris Academy by M. Faye, who remarked : **F1 quelques mois il livrera 4 la Science cent fois plus de données précieuses que les astronomes n’ auraient pu en recueillir, ayant lui, par observation ordinaire des eclipses totales d’une vingtaine de siecles.” THE number of entries for the Examination for Women at the London University, which takes place during the current week, is 17, against 9 last year. Of these, 12 will be examined in London, and 5 at Cheltenham. Dr. A. VOELCKER and Mr. H, M, Jenkins, Secretary to the Royal Agricultural Society, reprint, from the Journal of the Society, a Report on the Agriculture of Belgium, containing much valuable information on its soil and climate, geological features, modes of agriculture, and rural economy. “ THE Body and its Health, a Book for Primary Schools,” by E, D. Mapother, M.D., is a little elementary book on human hysiology, prepared with greater care and attention to accuracy io is usually the case with primary scientific hand-books. It contains in a small space, and published at a low price, a mass of such information as ought to form a portion of the curriculum of all schools, both for boys and girls, and is illustrated by good woodcuts THE “‘Repertorium fiir Meteorologie,” issued by the Imperial Academy of St. Petersburg, in the form of a 4to. volume, edited by Dr. H. Wild, Director of the Physical Central Observatory, contains a mss of tables respecting the meteorological pheno- mena of Russa, and a variety of other information. WE have on our table the reports of several provincial scien- tific societies, aid other papers of a like nature :—The Proceed- ings of the Beryickshire Naturalists’ Club, for 1869; Trans- actions of the Norfolk and Norwich Naturalists’ Society for 1869-70; the 37th Annual Report of the Royal Cornwall Poly- technic Society for'1869 ; and the Geology, Botany, and Zoology of the Neighbourhood of Alnwick, by George Tate, F.G.S, They all show the zeal with which the pursuit of natural history is followed in the provinces ; these local societies have been the nursery of many 4 genuine naturalist who has rendered. important service to the study of Nature. _ Amonc the objicts of interest exhibited at the soirée of the Linnean Society on the 27th ult., was a collection of plants \ ‘ \ made by Mr. W. W. Saunders, arranged in pairs; the plants forming each pair belonged to entirely different natural orders, but were so remarkably alike in the general form, and even in the marking of the foliage, as to be barely distinguishable even to a practised eye. One of the most strikingly “ mimetic” pairs were a Conifer and a Selaginella, belonging to the two sub-kingdoms of flowering and flowerless plants. ACCORDING to Mr. Kurtz, the Curator of the Herbarium of the Calcutta Botanical Gardens, the Andaman Islands are gra- dually sinking, the rate of subsidence being about one foot in a century. This inference is founded on the fact that trunks of trees still rooted in the ground may be seen in the water of the straits which separate the islands, belonging to species which never grow in mangrove swamps, but which are only found further inland. It is even possible to “trace in several places the stumps of the sunken trees in the sea, up to the state when the trees are just dying by the influence of the sea-water, and the subsequent change of the soil by the formation of the man- grove swamp.” At the rate of subsidence indicated by Mr. Kurtz, a thousand years must elapse before the extensive convict establishment maintained on these islands will be in immediate danger of submersion. In a forthcoming number of his ‘‘ Geographische Mittheilung- en,” by means of a map and a memoir, the geographer Peter- mann gives his rendering of the information contained in Dr. Livingstone’s recent letters, taken in connection with the former travels of the Portuguese in Central South Africa. The new real geography of this map agrees remarkably well, in its general features, with a chart which lately appeared in this journal, There is, however, one main point of difference. A river named Luvivi was crossed by Pombeiro Baptista in his route to the Cazembe’s town from that of the Muata Yanyo, and is distinctly stated by him to run into the Luapula, the river which is now known to unite Lakes Bangeweolo and Moero. Livingstone says that a large river named Zw/ia drains the western side of the great valley, and takes up the waters of Ulenge in the west of Tanganyika. On the foundation of the resemblance of these names—surely a very weak one in a region where duplicate river names are frequent—Dr. Petermann discards the Pom- beiros statement, and uniting the Luviri with the Lufira, carries a great river through the midst of the country separating the valleys ruled over by the Muata Yanvo and the Cazembe, which all travellers here agree is a mountainous desert, and which the road joining these territories bends far southward to avoid. Again.: The country of Usango is said by Livingstone to be on the east of the plateau which rises south of Tanganyika ; on this map it is indicated to westward of that lake ; and Lake Liemba, instead of being shown on the northern slope of that upland, is represented as lying in a valley directly continuing that of Tanganyika, The uncertainty as to the identity of the Chowambe Lake with the Albert Nyanza, and consequently of the union of Tanganyika with the Nile system, is considered too great to admit of any solution of the Nile problem as yet, and any attempt at this is characterised as plucking unripe fruit. This part also contains a very interesting account of a voyage by a Norwegian fisher named Captain E. H. Johannesen, who, in the summer of 1869, sailed completely round the island of Novaia Zemlia and through the Kara Sea, This gulf, believed till now to be con- stantly choked up by impenetrable ice-park, has been called the ““ice-cellar” of the North Pole. In place of this, Johannesen found a mild atmosphere off the north-east of Novaia Zemlia, and throughout the whole Kara Gulf in July and August no ice was visible, but a heavy roll of the open sea came up from the south-east. Mr. B. WILLIAMSON, one of the Fellows of Trinity College, Dublin, is preparing a “Treatise on Mechanics,” which will shortly be issued by the University Press. 14 NATURE [AZay 5, 1870 Mr. JAMES GLAIsHER has given two lectures for the “Sunday Lecture Society” on the evenings of April 24th and May Ist., on ‘The Balloon” and on ‘‘Rain.” In the latter he gave an interesting account of how rain is derived and how measured ; some most carefully prepared tables were exhibited, together with diagrams and some excellent photographs of the varied forms of snow crystals. The lecture for May 8th will be by Mr. Henry Moody on ‘*The Prevention of Infectious Diseases.” The importance of this subject, in reference to the great object of the society, the social welfare of mankind, will be illustrated by the example of Bristol. From being one of the most unhealthy, Bristol has become one of the most healthy of cities. In the summer and autumn of 1832 the ravages there by cholera were enormous ; the deaths alone approaching to 1000! In 1866, on the contrary, when the poor at the East-end of London were dying by hundreds, the deaths in Bristol were but 26 ; and it will be pointed out that this vast difference has arisen from the pre- cautions and general sanatory measures adopted by the inhabitants and authorities of the City of Bristol. M. QUENAULT reports the discovery at Hauteville-sur-mer, near toa rock called Maulieu, of a bed of vegetable mould in which repose trunks of trees, still holding by their roots, along with a layer of turf, At high tide this bed is covered to the depth of about twelve inches. The oak alone has preserved its hard- ness, the other woods having become quite soft, but still presery- ing their colour and even their bark. He supposes the immer- sion to have taken place in the eighth century. THE ninth reunion of the learned societies of the Sorbonne took place on the 20th of April, when M. Le Verrier was ap- pointed president, M. Milne-Edwards vice-president, and M. Blanchard, secretary of the Section of Sciences ; M. le Marquis de la Grange, president, M. Léon Renier, vice-president, and M. Chabouillet, secretary of the Section of Archeology ; M. Amédée Thierry, president, and M. Hippeau, secretary of the Section of History. M. Le Verrier stated that the lectures in- stituted at the Sorbonne, which have already been in existence ten years, have had already the most beneficial results ; they have formed bonds between the savants of France and of the other countries of Europe, and have contributed to raise scientific and literary labours to a higher and higher platform. WE have received Washington papers of the 13th, 14th, and 15th of April, containinga report of the 13th semi-annual ses- sion of the National Academy of Sciences, held in that city. The most important papers read were: ‘‘On the coming transits of Venus,” by Prof. Simon Newcomb; ‘On meri- dional arcs, measured in connection with the United States coast survey,” by Mr. J. E. Hilgard; ‘*Craniological ob- servations,” by Dr. George Otis; ‘‘ The Northmen in Greenland,” by Dr. Hayes ; ‘ Considerations of the apparent inequalities of long periods in the moon’s mean motion,” by Prof. S. Newcomb ; ‘‘On the influence of the interior structure of the earth on precession and nutation,” by Prof, J. G. Barnard ; “On a new classification of clouds,” by Prof, Poey, of Havana ; “On fluctuations of the barometer,” by Dr. B. F. Craig. Prof. Joseph Henry occupied the chair. We purpose giving abstracts of some of these pages on a future occasion. A NATURAL History Society has recently been established at Winchester College ; and a Botanical Section has been formed in connection with the Hants and Winchester Scientific and Literary Society. Mr. LLEWELLYNN Jewirr has issued a prospectus of a pro- posed publication, by subscription, of an entirely new, large, and comprehensive history, topography, and genealogy of the county of Derby. A PAPER appears in the last number of the “‘ Proceedings of the Royal Society,” by Dr. Herbert Davies, on the law which regu- lates the relative magnitude of the areas of the four orifices of the heart. He remarks that although to ordinary observation these orifices appear to exhibit no mutual relationship of size, there can be no doubt that an instrument so accurate in the adaptation of its valvular apparatus, and so exact in the working of its different parts, must reveal on close examination the existence of laws which not only determine the force required to be impressed upon the blood traversing its chambers, but also the relative sizes of these apertures to one another. On _ converting Dr. Peacock’s measurements of the circumference of the several orifices into numbers representing these areas it is found that in the male the respective mean areas are Tricuspid : . P : 1j sq. inch, Pulmonic : A f , I yt Mitral . 2 5 . ; se + Aortic . 5 . and on pushing the inquiry further, it is found that there is a dis- tinct law presiding over them which is discovered on comparing the ratios of the areas of corresponding orifices. Thus— Area of tricuspid 1.78 = —— = 1°4 nearl Area of mitral 1.27 4 y Areaofpulmonic _ 1 _ / Area of aortic a ae 1°3 nearly or in other words, the area of the tricuspid appears from these calculations to bear nearly the same relation to the area of the mitral, which the area of the pulmonic does to that of the aortic orifice ; z.¢., were the tricuspid, for example, twice the size of the mitral orifice in area, the pulmonic would be twice the size of the aortic orifice in area, the two ratios differing | from each other only by one-tenth. The same law probably holds in the hearts of most animals, the areas of the four orifices bearing an exact mathematical relationship to each other, so that if the areas of any three of the openings be known, the area of the fourth orifice can be correctly calculated. A know- ledge of this law, it is obvious, may prove of great impor- tance in estimating the amount of contraction or dilatation of orifice which may be present in disease. Dr. Davis then proceeds to give the reasons for this arrangement, for which — we must refer our readers to the original. TuatT the white corpuscles of the blood can pass through the - walls of the blood-vessels is now admitted by so many observers, — that it may fairly be regarded as an established fact. But the entrance of a solid body from the outside of the capillaries into their interior has, so far as we know, only been observed in one or two exceptional instances. Quite recently, however, M. _ Saviotti has published a paper in the Cenfra/é/att, in which he describes the passage of entire pigment cells from the paren- chyma of the web of the foot of the frog through the walls of — the capillaries and smaller veins, into their lumen, where having arrived, they are swept away by the blood current as < pheno- menon of common occurrence, and easily followed. To render this evident he excites local inflammation in the w:b by the application of a dilute (2 per cent.) solution of sulphuric acid. After the lapse of some time the pigment cells of the part affected are found to have congregated together round the minute yessels in a somewhat contracted condition, their long branching process Lecoming materially shorten:d. The con- tractility which these cells are known to possess, however, is not entirely abrogated. One or more of the processes may be seen to insinuate itself through the wall of the adjacent capillary. After penetration it may become much elongated, and be even altogether carried away by the current cf blood, to the movements of which for a time it offers an impediment ; or it may, so to speak, drag after it the rest of the cell, which after remaining a little while adherent to the inner surface of the vessel at the point where it has entered, is swept, or itself swims away. Is not this a singular fact? Of whct nature must the capillary wall be, that will thus admit the irgress and egress of ay 5, 1870] NATURE T5 ‘solid bodies, and yet retain the red blood corpuscles even under _ increase of pressure. _ M. E. LeFevre is engaged upon a monograph of the species ‘ofthe genus CZythva, inhabiting Europe and its confines (including the Mediterranean region). As many new species have been dis- Beoyercd, especially in Algeria and the East, since the publication of Lacordaire’s memoir in 1848, M. Lefévre will be thankful tr the loan of specimens of new or rare species, and for any information as to their geographical distribution. M. Lefevre’s address is 28, Rue Constantine, Paris-Plaisance. WE quote the following from the Scotsman, of May 2 :— “tA correspondent writes: ‘In Inverleith Row on Saturday night, exactly at a quarter-past eleven o’clock, my attention was attracted by a sudden and strange brightness overspreading every- thing around. Instinctively turning my eyes upwards, a grand sight met my gaze. A meteor of remarkable size, brilliancy, and distinctness, was seen shooting from the heavens, from about the zenith, and descending earthwards in a southerly direction. The form of this interesting object seemed elliptical, and it was of a bright yellow hue. It had a clearly-defined apex or point, which was of a deep red colour, and appeared to glow and sparkle ina wonderful manner. The phenomenon was visible for about two seconds, and lighted up everything around me. The night was fine and clear, with a decidedly frosty air, and there was a light, steady breeze blowing from the north-west at the time.” On the same subject our Dunbar correspondent writes: ‘A very brilliant meteor was observed here about eleven o’clock on Saturday night. When first seen, the meteor had the appearance of a star of the first magnitude, As it approached, however, it gradually increased in size until it assumed the appearance of a ball of five or six inches in diameter, and changing its colour from a pale silvery white to a bright blue flame. As it still increased, sparks seemed to be emitted from the circumference, giving it the appearance of being surrounded with a peculiar halo of dense silvery rays. It continued in this state for a second or two, and then shot across the heavens in a southerly direction, the ball increasing in brilliancy as it travelled, and leaving behind it a long train of lurid-coloured flame. From the time it was first seen approaching until it vanished about five or six seconds elapsed. The night was clear and cold at the time.’ ” ———<——— THE GRESHAM LECTURES HE Lectures (three in number) were delivered by Dr. Symes Thompson, during the past week, at the Gresham College, Basinghall-street. The first was occupied with the consideration of Cough, an account being given of its etiology varieties, and general principles of treatment. The second was devoted to Tonics; whilst of the third, which treated of Climate and Health Resorts, we give an epitome as likely to prove interesting to some of our readers. Dr. Thompson remarked that the Romans very early discovered the use of mineral waters, as shown by many of their relics being found in the neighbour- hood of such springs ; whilst at Wiesbaden, tablets have been found with votive inscriptions. Some of the more common ingredients of mineral waters were then described, and their chemical properties demonstrated, including carbonic acid, iron, sulphuretted hydrogen, &c. The properties of ozone were then discussed in connection with pure air, and the lecturer _ passed on to the consideration of climate and health resorts, and said that it was a great mistake to suppose that any particular place was the best for a particular malady, for there is no specific action in the air of any place; and the physician, in recommending a resort to patients, had regard to the kind of climate there found, a dry climate being suitable for most bronchial membranes, and a moist climate for the reverse state of the membranes, and an approximation to such different climates can be obtained in our rooms. Ifthe patient be feverish and excitable, he should be sent to an exciting varied climate ; or, if languid and torpid, not to a quiet, mild, uniform climate. These two kinds of climate are obtainable at the south of France ; for at Nice the climate is bright and exciting, while in the neighbourhood of the Pyrenees, at Pau, the atmosphere is very still, and eminently suitable to patients suffering from irri- table membranes. The great advantage gained by persons going abroad is no doubt the regular daily outdoor exercise, not obtain- able in the varied winter of our island, but foundin Algiers, Riviera, Mentone, Nice, &c., at that season. Together with exer- cise may be linked the advantage derived from breathing pure air. There are, however, many places in England where almost the same benefit may be enjoyed. It was the former practice in cases of lung-disease, to shut up patients in close rooms, with fire burning, all through the winter, the consequence being that they became like hothouse plants, and on the first exposure to the open air in spring all these advantages were lost. Acting on the same principle, consumptive patients up to 20 years ago were sent to Madeira. Three years ago the inhabitants of Madeira, wishing to re-establish the value of their climate in lung-disease, solicited the authorities of the Brompton Hospital for Consumption to send them out patients as a matter of experiment. Twenty patients were sent out, and only those who were likely to be benefited by the climate of Madeira, being all in an advanced stage of lung-disease. Of this num- ber I patient died suddenly, although up to the time of his death he seemed to be benefiting by the change ; 4 were worse ; 6 were stationary, and 7 were markedly benefited ; 2 very much benefited. This has been regarded by some as unsuccessful ; but Dr. Thomp- son was of different opinion, and thought it indicated that Madeira is a useful climate in certain cases. Since Madeira has been abandoned there has been a revulsion of feeling in favour of Canada as a resort for consumptives, but that this is no new doctrine is seen from the fact that the value of cold climates for consumption was advocated by Baron Larrey, Napoleon Bona- parte’s physician. There are disadvantages as wellas advantages in the most favoured health resorts; such as the dry, hot ‘‘ mistral’ of Nice, orthe dry, dusty ‘‘ brickfielder” of Melbourne,—winds which patients dislike as much as our east wind. Purity of air or ab- sence of dust is of very great importance ; and for this reason it is now the practice to send patients suffering from chest-disease for a long sea-voyage. It constantly happens that sick people— in whom the disease is far advanced—press their medical men to send them on a sea-voyage ; but in their case the remedy has come too late, and so it happens that the death-rate at Melbourne is exceedingly high—more than half the deaths being due to con- sumption. Dampness favours consumption; so that dry air is another desideratum which can be obtained at certain altitudes —so that in certain districts it is found possible to resort to mountain-tops, where consumption does not occur. In the neighbourhood of the equator the so-called ‘‘immunity-level” is at a height of 9,000 feet ; at Algiers, 6,000 feet ; at London, 3,000 feet. The chief resorts in Europe are the Swiss mountains, where English people often go to spend the winter, in perpetual snow, but yet in anatmosphere so pure and clear that the most delicate invalids can go out in theopen air. In Norway, Russia, &c., the immunity-level is only 1,000 feet above the sea. SCIENTIFIC SERIALS THE May number of the Journal of Botany, British and Foreign, commences with the first part of a Clavis Agaricinorum by the well-known fungologist, Mr. Worthington Smith. The general classification of the Agarics adopted by Fries and Berkeley is followed ; but several new sub-genera are proposed. An ingenious tabular view accompanies the paper, presenting the salient features of the series and sub-genera of this vast genus at a glance. Dr. Seemann continues his revision of the natural order Bignontacee ; while the Hon. J. L. Warren contributes a paper on a sub-division of Rubus, a most intricate genus, to which he has paid special attention ; and Dr. H. Trimen a description of a new British Cad/itriche. Other short notes and notices fill up the number, which maintains the interest for British botanists especially, promised on the commencement of the new series. The Revue des Cours Scientifigues for April 23rd contains a report of an interesting address delivered before the University of Berlin, by M. du Bois Reymond on the Organisation of Uni- versities ; the conclusion of Fotherly’s address to the Hunterian Society, and report of a lecture by M. Claude Bernard, on Suf- focation by Charcoal. The number for April 30th is entirely occupied by M. Bouley’s lecture at the Sorbonne, on Madness, and the conclusion of M. Bernard’s lecture. 16 NATURE [May 5, 1870 THE third number of the new Italian Geological Journal, or Bollettino, published by the ‘*Comitato Geologico d'Italia,” opens with M. Igino Cocchi’s paper on the stratified rocks of the isle of Elba. It especially relates to the lower secondary, eocene, cretaceous, and post pliocene strata, and is illustrated with engravings. Among the bibliographical notices, Professor Omboni’s work on the Geology of Italy, with eight maps, is well spoken of, ‘The number also comprises translations of extracts from foreign memoirs. THE American Naturalist, Vol, 1V., No. 2, April 1870.— The April number of this Journal contains three exceedingly interesting articles, namely, a report on the Sea Otters of the north-west coast of America and Aleutian islands, by Captain C. M. Scammon ; a paper on Parasitic Insects, from the able hand of Dr. A. S. Packard ; and some notes on the Fresh- water Fish of New Jersey, by Dr. C. C. Abbott, which con- tains many valuable remarks. The last two papers are illustrated. —Dr. W. Wood contributes a popular article on Falconry.—The usual reviews and short miscellaneous notices complete the contents of the number. SOCIETIES AND ACADEMIES LONDON Royal Society.—April 28.—‘‘ On the Organs of Visionin the Common Mole.” By Robert James Lee. ‘On an Aplanatic Searcher, and its Effects in improving High Power Definition in the Microscope.” By G, W. Royston-Pigott, M.A., M.D. The Aplanatic Searcheris intended to improve the penetration, amplify magnifying power, intensify definition, and raise the objective somewhat further from its dangerous proximity to the delicate covering-glass indispensable to the observation of objects under very high powers. The inquiry into the practica- bility of improving the performance of microscopic _ object- glasses of the very finest known quality was suggested by an accidental resolution in 1862 of the Podura markings into black beads. ‘This led to a search for the cause of defective definition, if any existed. A variety of first-class objectives, from the +; to the 4, failed to show the beading, although most carefully constructed by Messrs. Powell and Lealand. Experiments having been instituted on the nature of the errors, it was found that the instrument required a better distribution of power ; instead of depending upon the deepest eyepieces and most powerful objectives hitherto constructed, that better effects could be produced by regulating a more gradual bending or re- fraction of the excentrical rays emanating from a_ brilliant microscopic origin of light. It then appeared that delusive images, which the writer has ventured to name e/do/a*, exist in close proximity to the best focal point (where the least circle of confusion finds its focus). I. That these images, possessing extraordinary characters, exist principally above or below the best focal point, according as the objective spherical aberration is positive or negative. II. That test-images may be formed of a high order of delicacy and accurate portraiture in miniature, by employing an objective of twice the focal depth, or, rather, half the focal length, of the observing objective. III. That such test-images (which may be obtained con- veniently two thousand times less than a known original) are formed (under precautions) with a remarkable freedom from aberration, which appears to be reduced in the miniature to a minimum. IV. The beauty or indistinctness with which they are dis- played (especially on the immersion system) is a marvellous test of the correction of the observing objective, but an indifferent one of the image-forming objective used to produce the testing miniature. These results enable the observer to compare the known with the unknown. By observing a variety of brilliant images of known objects, as gauze, lace, an ivory thermometer, and sparkles of mercury, all formed in the focus of the objective to be tested with the microscope properly adjusted so that the axes of the two objectives may be coincident, and their cor- rections suitably manipulated, it is practicable to compare known delusions with suspected phenomena. It was then observed (by means of such appliances) that the ~ From eidwXov, a false spectral image. aberration developed by high-power eyepieces and a lengthened” tube followed a peculiar law. A. A lengthened tube increased aberration faster than it gained power (roughly, the aberration varied ‘as v*, while the power varied as 7). B. As the image was formed by the objective at points nearer to it than the standard distance of nine inches, for which the best English glasses are corrected, the writer found the aberration diminished faster than the power was lost, by shortening the body of the instrument. | C. The aberration became negatively affected, and required a_ positive compensation. | D. Frequent consideration of the equations for aplanatism— suggested the idea of searching the axis of the instrument for- aplanatic foci, and that many such foci would probably be found | to exist in proportion to the number of terms in the equations (involving curvatures and positions). ‘ E. The law was then ascertained that power could be raised, and definition intensified, by positively correcting the searching lenses in proportion as they approached the objective, at the © same time applying a similar correction to the observing objec- | tive. The chief results hitherto obtained may be thus summarised. — The aplanatic searcher increases the power of the microscope from two and a half to five times the usual power obtained with a third or C eye-piece of one inch focal length. The eighth thus acquires the power of a twenty-fifth, the penetration of a one- fourth. And at the same time the lowest possible eyepiece (3-inch focus) is substituted for the deep eye-piece formed of minute lenses, and guarded with a minutely perforated cap. The writer lately exhibited to Messrs. Powell and Lealand a brilliant definition, under a power of four thousand diameters, with their new ‘eighth immersion” lens, by means of the searcher and low eyepiece. The traverse of the aplanatic searcher introduces remarkable chromatic corrections displayed in the unexpected colouring developed in microscopic test objects. The singular properties, or rather phenomena, shown by eidola, enable the practised observer in many cases to distinguish between true and delusive appearances, especially when aided by the aberrameter applied to the objective to display excentrical aberration by cutting off excentrical rays. Eidola are symmetrically placed on each side of the best focal point, as ascertained by the aberrameter when the compensations have attained a delicate balance of opposite corrections. If the beading, for instance, of a test object exists in two contiguous parallel planes, the eidolon of one set is commingled with the true image of the other. But the upper or lower set may be separately displayed, either by depressing the false eidola of the lower stratum, or elevating the eidola of the upper. For when the eidola of two contiguous strata are intermingled, correct definition is impossible so long as the aperture of the objective remains considerable. One other result accrues : when an objective, otherwise excellent, cannot be further corrected, the component glasses being already closely screwed up together, a further correction can be applied by means of the adjustments of the aplanatic searcher itself, all of which are essentially conjugate with the actions of the objective and the variable positions of its compo- nent lenses; so that if dx be the traversing movements of the objective lenses, dz that of the searcher, F the focal distance of the image from the objective when 6x vanishes, / the focal distance of the virtual image formed by the facet lenses of the objective, then , a ~ (7) The appendix refers to plates illustrating the mechanical arrangements for the discrimination of eidola and true images, and for traversing the lenses of the aplanatic searcher. ‘The plates also show the course of the optical pencils, spurious disks of residuary aberration and imperfect definition, as well as some examples of ‘‘ high-power resolution ” of the Podura and Lepisma beading, as well as the amount of amplification May 5, 1870] MATURE 17 ‘obtained by Camera Lucida outline drawings of a given scale. On a Cause of Error in Electroscopic Experiments.” By Sir Charles Wheatstone, F.R.S. _ Toarrive at accurate conclusions from the indications of an electroscope or electrometer, it is necessary to be aware of all the sources of error which may occasion these indications to be misinterpreted. In the course of some experiments on electrical ‘conduction and induction which I have recently resumed, I was “frequently delayed by what at first appeared to be very puzzling ‘results. Qccasionally I found that I could not discharge the electrometer with my finger, or only to a certain degree, and that “it was necessary, before commencing another experiment, to “place myself in communication with a gas-pipe which entered ‘the room. TElow I became charged I could not at that time explain ; the following chain of observations and experiments, however, soon led me to‘the true solution. I was sitting at a fable not far from the fireplace, with the electrometer (one of Peltier’s construction) before me, and was engaged in experi- menting with disks of various substances. To ensure that the one I -had in hand, which was of tortoise-shell, ‘should be perfectly dry, I rose and held it for a minute before the fire; returning and placing it on the plate of the electrometer, I was surprised to find that it had apparently acquired a strong charge, deflecting the index of the electro- meter beyond go”. I found that the same thing took place with every disk I thus presented to the fire, whether of metal or any - other substance. My first impression was that the disk had been rendered electrical by heat, though it would have been extraordinary that, if so, such a result had not been observed before ; but on placing it in contact with a vessel of boiling water, or heating it by a gas-lamp, no such effect was produced. I next conjectured that the phenomenon might arise from a difference in the electrical state of the air in the room and at the top of the chimney ; and to put this to the proof, I adjourned to the adjacent room where there was no fire, and bringing my disk to the fireplace I obtained precisely the same result. That this conjecture, however, was not tenable was soon evident, be- cause I was able to produce the same deviation of the needle of the electrometer by bringing my disk near any part of the wall of the room. This seemed to indicate that different parts of the yoom were in different electrical states ; but this again was dis- proved by finding that when the positions of the electrometer and the place where the disk was supposed to be charged were interchanged, the charge of the electrometer was still always negative. The last resource was to assume that my body had become charged by walking across the carpeted room, though the effect was produced even by the most careful treading. This ultimately proved to be the case; for resuming my seat at the table and scraping my foot on the rug, I was able at will to move the index to its greatest extent. Before I proceed further I may state that a gold-leaf electro- meter shows the phenomena as readily. When I first observed these effects the weather was frosty; but they present them- selves, as I have subsequently found, almost equally well in all states of the weather, provided the room be perfectly dry. I will now proceed to state the conditions which are necessary for the complete success of the experiments, and the absence of which has prevented them from being hitherto observed in the striking manner in which they have appeared to me. The most essential condition appears to be that the boot or shoe of the experimenter must have a thin sole and be perfectly dry; a surface polished by wear seems to augment the effect. By rubbing the sole of the boot against the carpet or rug, the elec- tricities are separated, the carpet assumes the positive state and the sole the negative state; the former being a tolerable insu- lator, prevents the positive electricity from running away to the earth, while the sole of the foot, being a much better conductor, readily allows the charge of negative electricity to pass into the body. So effective is the excitation, that if three persons hold each other by the hands, and the first rubs the carpet with his . foot while the third touches the plate of the electrometer with his finger, a strong charge is communicated to the instrument. Eyen approaching the electrometer by the hand or body, it becomes charged by induction at some distance. A stronger effect is produced on the index of the instrument if, _ after rubbing the foot against the carpet, it be immediately raised from it. When the two are in contact, the electricities are in some degree coerced or dissimulated ; but when they are sepa- rated, the whole of the negative electricity becomes free and ex- pands itself in the body, A single stamp on the carpet followed by an immediate removal of the foot causes the index of the elec- trometer to advance several degrees, and by a reiteration of such stamps the index advances 30° or 40°. The opposite electrical states of the carpet and the sole of the boot were thus shown : after rubbing, I removed the boot from the carpet, and placed on the latter a proo&plate (¢.e. a small disk of metal with an in- sulating handle), and then transferred it to the plate of the elec- trometer : strong positive electricity was manifested. Performing the same operation with the sole of the boot, a very small charge was carried, by reason of its ready escape into the body. The negative charge assumed by sole-leather when rubbed with ani- mal hair was thus rendered evident. I placed on the plate of the electrometer a disk of sole-leather and brushed it lightly with a thick camel’s-hair pencil ; a negative charge was communicated to the electrometer, which charge was principally one of conduc- tion, on account of the very imperfect insulating power of the leather. Various materials, as India-rubber, gutta-percha, &c., were substituted for the sole of the boot ; metal plates were also tried; all communicated negative electricity to the body. Woollen stockings are a great impediment to the transmission of electricity from the boot ; when these experiments were made I wore cotton ones. When I substituted for the electrometer a long wire galvanometer, such as is usually employed in physio- logical experiments, the needle was made to advance several degrees. At the meeting of the British Association at Dublin in 1857, Professor Loomis, of New York, attracted great attention by his account of some remarkable electrical phenomena observed in certain houses in that city. It appears that in unusually cold and dry winters, in rooms provided with thick carpets and heated by stoves or hot-air apparatus to 70°, electrical phenomena of great intensity are sometimes produced. A lady walking along a carpeted floor drewa spark one quarter of an inch in length be- tween two metal balls, one attached to a gas-pipe, the other touched by her hand; she also fired ether, ignited a gaslight, charged a Leyden jar, and repelled and attracted pith-balls similarly or dissimilarly electrified. Some of these statement were received with great incredulity at the time both here and abroad, but they have since been abundantly confirmed by the Professor himself and by others. (See Silliman’s American Journal of Science, July 1858.) My experiments show that these phenomena are exceptional only in degree. The striking effects observed by Professor Loo- mis were feeble unless the thermometer was below the freezing- point, and most energetic when near zero, the thermometer in the room standing at 70°. Those observed by myself succeed in almost any weather, when all the necessary conditions are ful- filled. Some of these conditions must frequently be present, and experimentalists cannot be too much on their guard against the occurrence of these abnormal effects. I think I have donea service to them, especially to those engaged in the delicate inves- tigations of animal electricity, by drawing their attention to the subject. Royal Institution, May 2. Annual meeting.—Sir Henry Holland, Bart, M.D., D.C.L., F.R.S., President, in the chair. The annual report of the Committee of Visitors for the year 1869 was read and adopted. The books and pamphlets pre- sented in 1869 amounted to 255 volumes, making, with those purchased by the managers, a total of 388 volumes added to the library in the year, exclusive of periodicals. Forty-seven new members were elected in 1869. Sixty-three lectures and nine- teen evening discourses were delivered during the year 1869. The following gentlemen were unanimously elected as officers for the ensuing year :—President : Sir Henry Holland, Bart., M.D., D.C.L., F.R.S. Treasurer: William Spottiswoode, age F.R.S. Secretary: Henry Bence Jones, M.A.,,M.D., ~RAS. Royal Geographical Society, April 25.—Sir R. IL Murchison, Bart., President, in the chair. The following new Fellows were elected :—Baron Osten Sacken, Secretary to the Imperial Geographical Society, St. Petersburg (Hon. Corresponding Member) ; Thomas M. Blackie; Lieutenant Evelyn Baring, R.A. ; Colonel Shuckburgh Denniss; George B. Hudson ; Lord Lawrence, G.C.B.; and John Fenton Taylor. A paper was read, entitled “ An Expedition to the Trans- Narym Country,” by Baron Osten Sacken. This paper, which had been translated from the Russian by Mr. Delmar Morgan, contained a narrative of a journey, undertaken for the purpose of a reconnaissance survey, by General Poltoratsky, across the 18 Thian-Shan Mountains to the vicinity of Kashgar. This territory became part of the Russian dominions by the treaty of Pekin in 1860, by which the frontier line was fixed as extending from the east of Lake Issyk-Kul, along the southern spur of the Celestial Mountains, to the Khokand country ; but the terrritory had never yet been visited by a European. Starting from Fort Vernoé, north of Lake Issyk-Kul, the party turned the western end of the lake, and then marched nearly due south. The country was very mountainous and picturesque, five distinct lines of elevation belonging to the Thian-Shan system being crossed in succession, some of them by passes upwards of 12,000 feet in height. The intervening valleys are traversed by streams, forming the head-waters of the Jaxartes, the largest of which is the Narym ; and on the elevated ridges lie two beautiful alpine lakes, the Sou-Kul and the Chatir-Kul. Game is very abundant along the banks of the rivers, and the country is but thinly peopled by tribes of Kirghizes. The Russians did not gain possession of the new territory without a severe struggle with the forces of the neighbouring indepen- dent state of Khokand, who, in October 1860, marched an army of 40,co> men against the small Russian force, but were defeated. Baron Osten Sacken paid great attention to the botany of the country passed through, and noted the various zones of vegetation, from the wooded lower slopes of the Thian-Shan to the treeless plains below the snow-line. The alpine flora he described as extremely rich and beautiful in colour and form—amongst the plants he mentioned Anemone narcissifiora, Ranunculi, Geraniums, Potentillas, Gentians, and other genera—showing a great resemblance between the pro- ductions of the Thian-Shan and the Himalaya, The expedition reached to within two marches of Kashgar, and then returned to Fort Vernoé. A second paper, on “ Recent Russian Explorations in Turkistan,” was read by Mr. Delmar Morgan. In the discussion which followed, M. Bartholomei, of the Russian Legation, spoke of the friendly rivalry which now prevailed between Russians and English in the exploration of Central Asia. Sir Henry Rawlinson enumerated three new expeditions to different parts of Turkistan, in which the Russians were now engaged, and the scientific results of which were freely communicated ; and he congratulated the President, Sir Roderick Murchison, on the actual realisation of his anticipations of former years, when Russia and England would be friendly rivals in completing our acquaintance with the geography of the respective boundaries of each in their Eastern possessions. Ethnological Society, April 26.—Prof. Huxley, F.R.S., in the chair.—Dr. Donovan read a paper on ‘* The importance to the Ethnologist of a careful study of the Characters of the Brain.” —Mr. E. B. Tylor then read a communication ‘*On the Philosophy of Religion among the Lower Races of Mankind.” Generalising from the lower religions of the world, the author stated the principle on which, in his view, was developed the philosophy of what may be called Natural Religion. Taking the doctrine of spiritual beings as the minimum definition of religion, he described it as azimism, a term which fits with the theory put forward, that the conception of the soul as recog- nised by the lower races, is the starting-point of their religious philosophy. Sucha soul, combining the ideas of ghost and vital principle, explains the phenomena of life, disease, dreams, visions, &c. This idea is extended to animals and inanimate objects, which are considered to have souls capable of appearing after death or destruction. On the analogy of the body and soul, the actions of nature are explained on the animistic theory as worked or controlled by soul-like spiritual beings. Of these beings an immense number are held to be actually human souls ormanes. To such beings are ascribed the phenomena of disease, especially epilepsy and mania. Similar in nature, though different in function, are the spirits of trees, springs, &c. Hence the savage polytheist rises to expanded conceptions of greater deities, as Sun and Moon, At an early period he separates the cause of good from that ofevil, and hence Dualism is rooted deeply in the religion of the lower races. The cul- minating conception of a Supreme Deity is well known to many of the lower races.—The President, Mr. Pusey, Mr. Howorth, and Dr. Hyde Clarke, joined in the discussion on this paper. N.B.—It should have been stated in the report of the last meeting, that the paper ‘On the Danish Element in the Popu- lation of Cleveland” was written by the Rev. J. C, Atkinson, of Danby. NATURE | May 5, 1870 PARIS Academy of Sciences, April 25.—M. Chasles presented a note by M. H. Durrande, on surfaces of the fourth order, and a communication from Mr. Spottiswoode concerning a theorem brought before the Academy on the 21st of March last, and of which he now gives the following enunciation :—‘‘ Every point of a surface is sextactic in ten of the sections made by the planes of a bundle of which the axis passes through the point.” —M. de Saint Venant presented a memoir on the pressure of soils, containing a comparison of his estimates from the rational consideration of the limit of equilibrium, and by the employ- ment of the so-called principle of least resistance of Moseley. —Several papers on subjects connected with physics were read. M. Becquerel communicated some experimental researches by MM. Lucas and Cazin, upon the duration of the electric spark. M. Jamin presented a note by M. A. Tréve, on electric cur- rents, containing some curious and interesting experiments on _ the action of currents in opposite directions, and when crossed in vacuum-tubes. A note by M. Rénou, on the latent heat of ice, deduced from the experiments of Laplace and Lavoisier, was communicated by M. C. Sainte-Claire Deville. The author referred toa note by M. Jamin, in which the correctness of the experiments made by Laplace and Lavoisier was maintained, and- stated that the accordance of results obtained by M. Jamin could only be fortuitous, as the thermometers employed by the old experimenters were inaccurate.—M. H. Sainte-Claire Deville” presented a note on the formation of liquid drops, by M.— Duclaux. The author described experiments with distilled water, and with alcohols of different strengths, and stated that — in the formation of drops phenomena of cohesion have but little action. Drops of water are formed much more rapidly in vapour — of alcohol than in the air, and yet the amount of alcohol dis-— solved is very small, and hence the author concluded that the effect is produced only upon a very thin superficial layer of the © drop, the tension of which constitutes the resisting power deter-— mining the size ofthe drop. He extended these considerations to the formation of emulsions, and to various liquids in the organ- | ism.—A paper on the fixed characteristic notes of the different vowels, by M. R. Kceenig, was presented by M. Regnault. The — author discussed the results obtained by MM. Helmholtz and Donders, and gave the following as that of his own investigations into the musical notes of the vowels. OU oO A E I (sib)2 (sib)3.—s(sib)4a.~—(siD)5—(si)6 giving in round numbers of simple vibrations : 450, 900, 1,800, — 3,600, 7,200.—Numerous papers relating to astronomical subjects “ were communicated, and M, Delaunay read a note on the dis- covery of a new telescopic planet at the Observatory of Marseilles — on the 19th April. This is the 110th asteroid of the group be- tween Mars and Jupiter, and M. Delaunay proposes for it the — name of Zydia. Its position on the 19th April, at ro" 33™ 135, mean time at Marseilles, was as follows :— 121 2™ 30°, 22. +6° 50’, 38”. 8 in right ascension — IS 77 in declination + 2”, 20 Magnitude 12 — 13. M. Faye presented three memoirs, namely: a report on the operations of M. Respighi in spectral observation of the solar protuberances ; a note on the recent experiments of M. Willner on the spectra of hydrogen, oxygen, and nitrogen, with reference to those of the solar protuberances; and a note on the processes of photographic observation proposed by M. Paschen for the coming transit of Venus.—A letter from Father Secchi on the results of some spectral observations of the sun was also read.—M. Delaunay presented, on the part of M. Flammarion, a reply to the objections raised by M. G. Quesneville to his law of the rotatory movement of the planets——M. Chapelas presented a note ona luminous meteor of great brilliancy ob- served at Paris on the night of the r9th of April. This meteor passed from near ¢ Herculis to the neighbourhood of 5 « ¢ Cephei, describing a trajectory from S. to N. of 48°. Its colour was green, and it had a long train. Its disappearance was preceded by three noiseless explosions, accompanied by flashes which illuminated the hills round Paris. Its apparent size was 6 or 7 times that of Jupiter.—The subject of arctic explorations was treated by M. C. Grad, who suggested as an untried route for attempting to reach the North Pole, the passage through the Sea of Kara and the Siberian Ocean.—The chemical papers were the following: Researches upon new platinic derivatives — Horary movements i Wie 5, 1870 | NATURE 19 of the phosphorus-bases, by MM. A. Cahours and H. Gall; on . the utilisation of the secondary products obtained in the manu- facture of chloral, for the preparation of the «thylamines on a Targe scale, by M. A. W. Hofmann ; thermical investigations of iodic acid, by M. A. Ditte, communicated by M. H. Sainte- Claire Deville ; and thermical investigations of the states of sul- phur, by M. Berthelot, presented by M. Balard.—M. A. Béchamp communicated a memoir on geological “ microzymas ” of various origin, in which he described the action of different rocks in pro- ducing alteration and fermentation of starch-paste, and sugar. He maintained that in all limestones, from the Great Oolite to the most recent Tertiaries, there exist living organisms (for which he has proposed the name of ALicrozymas), of the nature of the molecular granules observed in certain fer- mentations, and that these are the agents which produce the changes described by him. He stated that pure carbonate of lime has no such action.—M. Milne-Edwards presented a note by M. Jourdain on the mode of action of chloroform, upon the irritability of the stamens of Afahonia. Exposure for from 1 to 3 minutes to the vapour of chloroform was said to destroy tem- porarily the irritability of the stamens ; exposure for 10 minutes or a quarter of an hour kills the portion of the plant subjected to it.—A note on the primitive type of the mammalia, by M. A. Roujou was read.—M. C. Robin communicated a note by M. Girard-Teulon on the law of the rotations of the eye-ball in the associated movements of the eyes, in which the author supported the views of Donders, in opposition to those of Helmholtz and Listing, and indicated what, in his opinion, had led the latter writers to a false conclusion.—The Abbé Richard communi- cated an account of the discovery of a workshop for the manu- facture of flint instruments in Palestine. —This workshop is near the village of El-Bire (the ancient Beéroth), about twelve kilometers from Jerusalem; the author found aches, scrapers, Knives, and saws, the last said by him to be very remarkable. — Besides these, and two papers on medical and surgical subjects, seyeral notes were read of which the titles only are given. VIENNA Imperial Academy of Sciences, Feb. 3.—Prof. P. Red- tenbacher presented on the part of Prof. H. Will, ‘‘ An investi- gation of white mustard seed.” In place of the myronate of potash of black mustard seed, the white mustard contains si7- albine, decomposable into sugar, a sulphocyanic compound and an acid sulphate. The sulphocyanic compound contains the radical akrinyle C7 H? O, and when freed from sul- phur and treated as nitryle with alkali furnishes ammonia and the salt of an acid = C8 H8 0%, which melts at 277° F., and is not identical with any known acid of the same formula. The acid sulphate contains sinapisine, and the author contrasts the products of black and white mustard as follows :— Myronate of Potash. Sugar. Mustard Oil. Sulphate of Potash, be to H78 N'S? KO = C6 H** O06 +. C+ HS NS SO+ K H esi: ume Salsintect 2. C3° H#4 N? S? O0'6 = C6 H*? O6 + C2 H7 NOS + SO4 (C6 H™ NOS) H February 10.—Mr. Joseph Rauter forwarded a memoir on the ‘‘ Developmental history of some of the hairy structures of plants belonging to various families of Dicotyledons.” He noticed that insome cases the hairs are simple products of the epidermal cells; whilst in others, although the first rudiment of the hair takes its origin from an epidermal cell, at a later period the subjacent parenchyma and the neighbouring epider- mal cells take part ints structure ; and in others, again—such as the spines and glandular hairs of roses—the first rudiment of the structure springs from the subcuticular tissue. As examples of the first mode of development, he cites the woolly hairs of Ribes, Rosa, &c., the stellate hairs of Hieracium pilosella, and the glandular hairs of Aieracium, Azalea, &c. ; of the second, the stings of the nettle, the clinging hairs of the hop, and some other forms.—Dr. Boué presented the first portion of his minera- logico-geognostic observations made during his travels in Turkey in Europe, and relating to North Albania, Bosnia, Hergezo- wina, and Turkish Croatia.—Prof. J. Redtenbacher communi- nicated the results of an investigation of some Austrian hydraulic magnesian lime which had been made in his labora- ‘tory by M. P. G. Hauenschild. The material contained about “sixty per cent. of carbonate of lime, and thirty per cent. of car- bonate of magnesia; when burnt at about 752° F. it furnished an excellent hydraulic cement.—Prof. Hlasivetz made a preli- Minary communication ‘* Upon a new acid from grape sugar.” He referred to his discovery of lactonic acid by the treatment + of sugar of milk with bromine, and indicated that the only difference between the two bodies consists in the presence of one more atom of oxygen in the acid. A _ similar acid was produced by treating other sugars with bromine, but the hydro- bromic acid formed in the reaction prevented its separation. The author induced M. Habermann to treat grape sugar with chlorine instead of bromine, and he has obtained the expected acid, having the formula C°H!O7.—Dr. S. L. Schenk commu- nicated a memoir “On the distribution of gluten in the wheat- grain,” and Prof. Lang some ‘ Crystallographic-optical deter- minations” relating to thirteen substances, chiefly of organic origin. Imperial Geological Institution, April 5.—Th. Fuchs on the fossil shells of the Congeria-beds from Radmanest, near Lugas (Banat). A comparatively large number of species (48, 32 of them hitherto unknown in Austria), but of small size, characterise this fauna, and correspond to the fauna of the so- called Upper Steppen-Kalk (limestone of Odessa) in southern Russia. The small amygdaloid Congeria simplex, recently described by Barbot de Marny, which alone forms whole beds of the Odessa-limestone, is also found abundantly in Radmanest. Among the small Cardiadz of the Odessa-limestone, some species differ from the usnal type of the genus by possessing a sinuated pallial line. Very interesting is therefore the discovery of a new species of Congeria at Radmanest, which differs in the same way from the generic type of Congeria.—Ch. v. Hauer on the coking of brown coal. A series of experiments with the brown coal from Fohnsdorf (Styria) gave very sati factory results. Cokes were obtained with a heating power equal to that of the cokes of good black coal; the proportion of sulphur was essentially diminished, and the cokes are firm enough to support the pressure of a high furnace. V. Hauer thinks that, mixed with cokes ot black coal, they would be applicable to the smelting of iron, a problem the solution of which would be of the utmost impor- tance for the iron manufacturers in the Alpine iron districts. April 23.—Ferd. Baron y. Andrian on the Volcanic Rocks or the Bosphorus. An accurate investigation of the geological relations, the mineralogical characters, and the chemical consti- tution of these rocks, which border the mouth of the Bosphorus to the Black Sea, served to distinguish a series of different varieties which in part are almost perfectly identical with the trachytic rocks of Hungary and Transylvania. In both coun- tries generally three types may be distinguished, viz. : green andesites and dacites ; black augit-andesites, and rhyalithes.— Prof. Ch. Zittel from Munich contributed some remarks on the tithonic strata. His important memoir on the fossils of the Stramberg limestone will be followed within a few weeks by another on the fossils of the cliff limestone (Klippenkalk) otf the enyirons of Rogoznik and Csarsztyn (Galicia), and the tithonic cephalopod-limestone of Southern Tyrol and Italy. His studies have brought him to the conclusion that an exact line of demarcation does not exist between the Jur- assic and the Cretaceous formation. Prof. Ch. Hoffmann of Pesth announced the discovery of ‘Triassic fossils in the older Dolomite—and limestone-rocks of the environs of Ofen, which had formerly been thought to belong to the Rhaetic series. M. Ch. Paul has examined the Lignite-beds of western Slavonia. In a thickness of more than 6 feet they are to be found along a line of 15 German miles in length, they belong to the upper Miocene formation (Congeria or fresh- water beds of the Vienna Basin), which contains many fossils, among them chiefly to be noticed a very large new species of Unio.—Dr. Em. Tietze, of Breslau, spoke about the fossils of the carboniferous limestone of Silesia. Nearly two hundred different species have been found therein, they will be described in a special memoir.—M. Fr. Posepny on the lead-mines of Raihl in Carinthia. The ores are imbedded in irregular masses in a stratified limestone of Triassic age. They form neither layers nor true veins, but are dependent on dislocations in the limestone-strata, and the over-lying schists, BERLIN German Chemical Society, March 28.—M. G. Kramer has investigated the products accompanying the formation of chloral from alcohol. Besides chloride of ethyl already recog- nised by Hofmann, both chloride of ethylene, and chloride of ethylidene, as also the monochlorinated substitution compound of both have been isolated. Chlorinated chloride of ethylene C, H, Cl, boils at 115° and yields with potash C, H, Cl, boiling at 37° and transforming itself into a solid polymeric modification, 20 Chloride of ethylidene and ammonia produce collidene. Professor Hofmann, in continuance of former researches, has transformed methylated and amylated sulpho-ureas into trimethy- lated and triamylated melamines by the action of oxide of mercury. This reaction however is but secondary, the first products being substituted (neutral) cyanamides, which by repeated evaporisa- tion become suddenly transformed into alealine melamides. The ethylic, and the phenylic sulpho-ureas behave in the same manner. The transformation consists in three molecules of cyanamide uniting into one of melamine— 3 C H(C, H,) N = C, H; (C, Hs)5 Ng The same chemist, in conjunction with Dr. Olshausen, publishes researches on polymeric modifications of cyanetholine, and its homologues. These researches are connected with the foregoing paper by the following consideration. A certain analogy between ethylcyanamide C N (C, H;) H N and cyanetholine— CN (C, Hs) O allows us to predict that the latter will treble, in the same way that the former does. This has been found to be the case. By passing chloride of cyanogen into methylate of sodium, the cyanetholine of the methylic series (an oil) forms at the same time, with crystals of the formula— (CN); (C Hah $08 cyanurate of methyl. These crystals fuse at 134° but are transformed by distillation into the isomeric compound— (COs IN, (C Hy) fusing at 175°. The former treated with potash yields cyanuric acid, and methylic alcohol ; the latter carbonic acid and methylamine. The former, treated with ammonia, forms the dimethylic ether of amido-cyanuric acid— C H; O C,N, ;C H,O H, N The same compound is formed (together with cyanurate of methyl) when chloride of cyanogen is passed into methylate of sodium, and may be separated from the cyanurate, by the action of ether, in which it is insoluble. The circumstance that the corresponding ethyl-compound dissolves in ether, renders the investigation of the transformation of cyanetholine more difficult. Analogous results have been obtained when chloride of cyanogen was passed into amylate and phenylate of sodium. Professor Rammelsberg, in a paper on the phosphates of thallium, stated that isomorphism exists between 1. H Tl, PO, H, O and H, Na PO, H, O 2. Hy Tl PO,y and H (NH,) . PO, 3. H Tl, PO, and Hy (N-Hy) PO, This he considers as the first proof of the isomorphism of hydrogen with monatomic metals. The same is stated of a phosphoborate of magnesium found in the saltlayers of Liineburg, and analysed by Nollner, who gives it the formula Mg B, Oy. 2 H Mg PO,, De Koninck and Marquardt have investigated Bryonicine, one of the two bases contained in the roots of Bryonia dioica, and give it the formula C,, H; N O,. P. Marquardt described polybromides of tetraethyl ammonium. Dr. Coninck described modifications of Bunsen’s sucking appa- ratus for filtering, and of Mitscherlich’s potash bulbs for combus- tion. M. Ballo recommends the preparation of binitronaphthol by oxydising naphthylamin with nitric acid. By the action of mono- brominated naphthalin on rosaniline, he has produced a violet colouring matter, not yet analysed. W. Doer has prepared azonaphthaline by heating nitronaphthaline with zinc powder. ¥’. Rochleder has found four new colouring substances in madder, Cy, Hg Oy, isalizarine; and its homologue, a very similar substance, C,; Hj, O,; a third called hydrisalizarin, Cy, H,5 Og, and a fourth, homologous with the foregoing, Cyy Hy) Og. The proportions in which these substances occur in madder are minute. N. Bunge on electrolysis communicates that nitrophe- nate of potassium yields to the anode nitrophenol and oxygen. Thiacetic acid and thiobenzoic acid yield bisulphide of acetyle, and bisulphide of benzoyl. But stilphocyanide of potassium, instead of yielding bisulphide of cyanogen, gives pseudo-sulphocyanogen. L. Henry has proved the identity of tribromhydrine of glycerine with the tribromide of allyle, from which it has hitherto been considered to differ. N. Lubarin, in submitting chloraluric acid to a renewed investigation, has arrived at the conclusion that it is impure parabanic acid mixed with chloride of ammonium. A. Ladenburg has found that, in support of Dr. Wanklyn’s opinion, acetic ether perectly free from water is not attacked by sodium NATURE [May 5, 187¢ below 100” C., and that inthis reaction no evolution of gas takes place. For decomposing the water and alcohol generally con tained in what is called pure acetic ether, the chlorides of silicium: or of phosphorus were employed. Lastly, M. Vogel reported on Camuzet’s experiments on gun-cotton, which differ so entirely, from everything hitherto asserted, that they require confirmation, | According to Camuzet, water dissolves the greater part of gun= cotton, separating at the same time the remaining part into a floc culent mass (the explosive ingredient of gun-cotton), and agranu-_ lar non-explosive powder, which falls to the bottom of the vessel, DIARY THURSDAY, May 5 Rovat Sociery, at 8.30 —On the Pre-Carboniferous Flora of North-Eas ern America, and more especially on that o! the Erian (Devonian) Peris (Bakerian Lecture): Principal Dawson, I’.R.S. ‘ Soctery of ANTIQUARTIES, at 8.30.—On the Date of the Discovery of the American Continent, by John and Sebastian Cabot: R. H. Major, F.S.A. LINNEAN Socrrry, at 8. Cuemicat Sociery, at 8. Roya InstirurTion, at 3.—Electricity: Prof. Tyndall. FRIDAY, Mayv6. : Royat InstiTuTioN, at 8.—Star-grouping ; star-drift; star-mist: R. A, Proctor. SATURDAY, May 7. Rovat InstiTruTron, at 3.—Comets: Prot. Grant. MONDAY, May 09. ROvAL GEOGRAPHICAL Society, at 8.30. Lonpon InstrrvTion, at 4.—Botany: Prof. Bentley. TUESDAY, May vo. ETHNOLOGICAL Society, at 8.30.—(Special meeting at the Museum of Practical Geology). Opening address: Prof. Huxley. On the Influence of the Norman Conquest inthe Ethnology of Britain : Rev. Dr. Nichol InsTITUTION OF CivIL ENGINEERS, at 8.—Discussion on the Strength of Iron and Steel. _ Recent Improvements in Regenerative Hot Ble Stoves, for Blast Furnances: E. A. Cowper. Roya INSTrTUTIoN, at 3.—On the Principles of Moral and Political Philo= sophy : Prof. Blackie. 7 PuoToGrapruic Socrery, at 8. - WEDNESDAY, May 11. GEOLOGICAL Society, at 8. Roya Microscoricat Soctety, at 8.—On a new form of Binocular and Stereoscopic Microscope: Mr. Samuel Holmes. ARCHAZOLOGICAL ASSOCIATION, at 8. THURSDAY, May 12. ~- Royat InstrTuTION, at 3.—Electricity: Prof. Tyndall. ;: ZoOLoGIcAL Society, at 8.30.—Notes on some points in the anatomy of certain Kingfishers: Dr. Cunningham.—On the-taxonomic charact afforded by the muscular sheath of the cesophagus in Sauropsida and other Vertebrates: Mr. George Gulliver.—Notes on the myology of Platydactylus Faponicus: Mr. Alfred Sanders.—On the Hirundinide of the Ethiopian region: Mr. R. B. Sharpe. 1 Lonpon MATHEMATICAL Society, at 8.—On the Mechanical deseription of a nodal bicireular Quartic: Prof. Cayley.—Concerning the ovals of Des Cartes: Mr. S. Roberts. BOOKS RECEIVED. ~ EnGitsH.—Choice and Chance: Rev. W. A. Whitworth (Deighton and Bell).—Blanford’s Natural History of Abyssinia (Macmillan and Co.),—The Lifted and Subsided Rocks of America, by Catlin (Triibner and Co.).—The Yosemite Guide-book: J. D. Whitney. ForeiGn (through Williams and Norgate).—Ornithologie Nordost Afrikas Th. von. Heuglin: Elektrische Untersuchungen, achte Abhandlungen iber die thermoelektrischen Eigenschaften des Topases: W. G. Hanke.—Bestim: mung der Sonnenparallaxe durch Venus-voriibergange vor der Sonnenscheibe : P. A. Hansen.-—La_psychologie anglaise contemporaine: T, H. Ribot.— Das Verhalten der Eigenwarme in Krankheiten: D, C. A. Wunderlich. Verhandlungen der k. k. Zoologisch-botanischer Gesellschaft in Wien 1869.— Berichte iiber die Vorhandlungen Ost Afrika. * CONTENTS To Our Reavers. By THE Epiror. .... - Tue Vetocity of THouGuTt. By Dr. M. Foster. Cuotce anp CHance. By Proressor STANLEY JEVONS Qur Boor SHELF_= « 5% 6 & 8 Eine & & 5 2 LETTERS TO THE EpITOR :— The Sources of the Nile.—Dr. Cuartes Beke . Why is the Sky Blue? panto oi) NN ale * er Curious Facts in Molecular Physics—W. H. Harrison Str Epwarp Sapinet’s CONVERSAZIONE « eae 3 al Recent Accessrons TO THE ZOOLOGICAL SocreTy’s GARDENS (With tustrations) By P. L. SCLATER, 4 Novet_ TELEGRAPHY—ELECTRIFICATION OF AN ISLAND.—PROF. | FLEEMING JENKIN, F.R.G. 2... 5 . 4 3 | Nomad 6 aco s Bs pean eas ee ae Gas o =e Tue GrespAmM LEGTURES. - =. * 2 6 © 4s 6 2 1 Seeete SéreTihiC SERIATS. 5 SR ee ee | SOCIETIES AND ACADEMIES. . » . 8 © © «© © © = © © © © & Diary AND Books RECEIVED. . . . «© 6 es « i arty _bpratum.—By an error of the press, Prof. Duncan’s Table of Madreporaria dredged up in the ‘Porcupine’ Expedition(No. 26, p. 660), was designated ** Madreporaria of the Red Sea,” instead of the ‘“‘ Deep Sea.” : The INDEX and CONTENTS for Vol. I., will be published with an early number. NATURE THURSDAY, MAY 12, 1870 A BUILDING FOR THE LEARNED SOCIETIES ge Statistical Society has done good service to the cause of science in convening representatives of the learned societies, to consider whether it would not be possible to obtain a building for their accommodation worthy of the high position they occupy in this great metropolis. At this moment several societies are under notice to quit, others scarcely know where to look for shelter, and many more are utterly unable to find suffi- cient room for their libraries, instruments, and museums, though they pay a large portion of their income in rent and taxes. Itis calculated that, jointly, upwards of 2,000/.a year is now paid in rent, enough, one would think, if pro- perly managed, to supply most ample accommodation for very many societies, to say nothing of the great economy in service that would result from the joint occupation of a proper building. But so long as nothing is done to bring about some understanding and co-operation among the different societies, the evil is irremediable. Nor is it purely a question of finance. Many abstain from joining a learned society when its place of meeting is either incon- veniently situated, or-altogether too small for the usual attendance at the ordinary meetings. Not a few mem- bers of more than one society are unnecessarily driven from one place to another. The libraries for reference are not half utilised. Co-operation among men of science is almost impossible, and the action of each society is rendered thereby comparatively feeble and ineffective. On every ground, whether of convenience, economy, or utility, the learned societies would do well if they could combine in erecting a building sufficiently capacious for their joint accommodation. Some learned societies have no reason to complain. The Royal Society, the Linnean, the Royal Astro- nomical, the Geological, the Chemical, the Society of Antiquaries, and a few others, are well accommodated, and a solid structure is being raised for them in Picca- dilly. Those whose wants are yet to be supplied are the Statistical Society, the Institute of Actuaries, the Mathematical, Meteorological, Ethnological, Anthropologi- cal, Geographical, Archzeological, and Juridical Societies, the Social Science Association, and as many more; and it is for them to consider whether it is better to go on as they are doing, paying one, two, or four hundred pounds a year each for their present rooms, or whether they would not do better by combining together for the erection of a proper building for them all. In calculating how many societies could unite for such a purpose, we must take into account the kindred character of their labour and inquiries. The statisticians, actuaries, and mathemati- cians might well meet together, and so it would be fitting that the antiquaries and archzologists should have a com- mon habitation. But not so those that have nothing in common, Then the number of members and the space re- quired for meetings, libraries, and museums are important elements. The Geographical Society, with its map- rooms and extensive library, would require space enough for a dozen other societies. And further, the frequency of meetings must be considered, whenrat the most only VOL. II. 2 three or four commodious halls could be secured in any one building. We scarcely imagine, in fact, that any large number of societies could well be united in one building, and that will be a source of difficulty, especially in a financial aspect. But why should there be any financial difficulty ? Surely the erection of one or more buildings for purposes of science is a duty which may well rest with the Govern- ment. Nowhere does the State do so little for science as in this country. The estimates for 1870-71 give the entire sum to be applied to the learned societies at 2,370/.—a sum distributed among very few of them. Of this 5007. goes to the Royal Geographical Society, to provide suitable rooms in which to hold their meetings, and to exhibit to the public, free of charge, their collec- tion of maps ; 300/. is given to the Royal Society of Edin- burgh ; 500/. to the Royal Academy of Music ; and 7o/, to the Irish Academy of Music. In addition to this 160,000/. are appropriated to a building for certain learned societies in Burlington House; but it will serve for very few of them; and if we are rightly informed, the Government will reoccupy all the buildings in Somerset House now used by learned societies. The chairman of the meeting at the Statistical Society stated that communications had passed between himself and the Chancellor of the Exchequer, and that no en- couragement whatever was given for any application of this nature. But it is the clear duty of the societies not to rest satisfied with this, but to get a decided expression of opinion on the subject. By no means should the most natural and proper channel for obtaining the requi- site sum for a building so essential to the well-being of the country be neglected. But supposing the Government should turn a deaf ear to the application of the learned societies, are there no means available within these bodies themselves for getting the amount? It has been estimated that the probable cost of a building sufficiently commodious, though not ornamental, in some eligible locality near Charing-cross, will be, with the ground-rent, 30,000/. to 40,0007. Why should not a joint-stock company be formed for the pur- pose, and a large number of shares be taken up by the members of the societies interested ? Some societies have moreover an accumulated fund of considerable impor- tance. The Geographical Society has, it is understood, upwards of 20,c00/. What more natural than to apply such investments in a palace of science, with an income so well guaranteed by the rental of the learned societies ? The financial part of the question must be carefully but fearlessly approached. No insurmountable difficulties stand in the way of obtaining any reasonable amount for such a purpose. What we want is a prompt and vigorous action on the part of the learned bodies. Heaven helps those who help themselves. The delegates at the meeting at the Statistical Society unanimously resolved in favour of co-operation on the subject, but by an unfortunate introduction of too cautious a spirit, they let the oppor- tunity slip without naming a committee to prosecute the necessary inquiries and to digest a suitable scheme. Such a committee could not have committed the parties to any course of action. Its object would have been to place the proposal on a’ practical basis, so as to Cc 22 enable the societies to come to a right decision. As it is, the Conference decided to invite the societies— first, to confirm by their separate vote the joint resolve of their delegates, and then to give proof of their in- terest in the attainment of the object by nominating one or more members to act on a committee to be ap- pointed for the purpose. The evil of such a course is, that much valuable time is lost in correspondence and negotiation before any practical step is taken in the matter. After all, however, the delay may be useful in ripening opinion on the subject. What is wanted in the steps eventually to be taken is energy of purpose and prompti- tude of action, for we are sure that the object in view will be eminently conducive to the welfare and progress of Science in the United Kingdom. FOSSIL OYSTERS Monographie du Genre Ostrea—Terrain Cretacé. Par Henri Coquand, Docteur és-Sciences, Professeur de Geologie et Mineralogie. (Paris: Baillitre, 1869.) ‘Oa the many able geologists whom France has pro- duced, few have had better opportunities of observa- tion, or have availed themselves of them to better pur- pose, than the author of this monograph. Distinguished alike by his skill and long experience asa paleontologist, and by his extensive knowledge of practical geology, M. Coquand has laboured long and well, and far and wide—not only in Provence, and Italy, and Germany, but in far distant regions in Spain and Africa, in valleys and mountains never before resounding to the blows of the geologist’s hammer, Those who are only acquainted with the chalk as it is seen exposed in quarries and cuttings on the green downs and wolds of England, can form but a very imperfect notion of its true character. As M. Coquand has shown ina paper lately read before the Geological Society of London,* the chalk of England, extensive as we are accustomed to regard it, is but a fragment when compared with that which is seen in the South of France. The utmost thick- ness of the English Cretaceous beds is found to be about goo feet, while in Provence the same, or rather the equiva- lent beds are more than 4,000 feet thick. In England we are accustomed to arrange the chalk into three or four divi- sions, while in France their more extended development re- quires an entirely different arrangement, and thus we find no less than eleven different beds, the character and limits of which are now ascertained with great accuracy. The French strata being thus so much more largely developed than the English, the character of the fauna is, as might be expected, infinitely more varied. The difference of nearly three thousand feet is principally yepresented in France by several marine and freshwater beds altogether unknown in England. In some places, as at La Cadiére and Martigues, we find extensive beds of Hippurites and Radiolites—fossils almost unknown in England, lying ranged in close order as when they lived; and again, while we have been accustomed to regard the chalk as altogether of marine origin, we find in Provence a district of about 250 square miles, in which the upper chalk strata of England and the Charentes of France are represented by freshwater deposits 1,400 feet thick. These contain several hundred species of land and fresh- * Quarterly Journal G. S., Aug. 1869, vol. 25, part 3. NATURE | AZay 12, 1870 water shells unknown elsewhere, associated with beds of lignite as compact as our own Newcastle coal, and like it worked extensively for fuel. Both from the palzontological and the geological evidence it would seem as if, at some time, while our Cretaceous deposits were interrupted and stationary, others of great magnitude, with a succession of fauna essentially differing, as well from our own as from each other, were accumulating in the South of France, alternately depressed and elevated—sometimes a deep sea, sometimes a great lake, and not improbably at one time dry land. After a careful study of the Cretaceous systems of many countries, M. Coquand, undeterred by the dread of taking charge of a family at once so numerous and so troublesome, has now been induced to prepare this mono- graph of all the Cretaceous oysters wherever found, to be followed by like monographs of the Tertiary, Jurassic, Triassic, and Permian formations. It is, we believe, the first, or at least the most important attempt to give a | synopsis of any one genus occupying so extensive a range. The results of M. Coquand’s researches are sufficiently striking ; he describes no less than 255 distinct species of chalk oysters (including Gryphea and Exogyra), and of these he has given excellent figures in an atlas of 75 plates, in folio. As regards England, he has disclosed the poverty of the land as compared with our neighbours. Our chalk oyster beds have been examined as assiduously as the French, but they have been found much less prolific, While France possesses 115 well-marked species, England. according to Mr. Morris’s catalogue, can show but 25, all of which, except one (O. triangularis of Woodward), seem to be found also in France. Nor is the range of some species less remarkable than their abundance. Two of them (vesiculosa, and ungulata or Zarva) appear to be altogether cosmopolitan ; the former being found alike in England, France, Algeria, Belgium, Spain, Poland, Russia, Sweden, North America, and Mexico ; and the latter having been also traced through all these countries (except Poland and Mexico), and extending its range also to India. But while some species are thus prone to wander, othe are to be noted for their domestic habits. Out of 49 American species, five only have been met with in Europe; and of 27 in Russia, and 23 in Spain, no less than 1o in each of these countries are not found elsewhere. It seems evident from our author’s observations, that so far as these fossils are concerned the several zones of chalk which he has described are divided by “a hard and fast line,” marking the limits of each as clearly as the Tertiaries are separable from the Secondary rocks. Of the several Dordonien species, not one is found in the Campanien beds, and of ninety-five found in the Cam- panien none are found in the lower beds, and the same observation applies to each of the seven or eight inferior deposits. Although it transcends all our powers of cal- culation to form even a conjecture, much less an approxi- mate estimate of the ages of ages that should be allowed for the creation (or, if that word be not allowable, for the introduction or evolution) of these various forms, and the extinction of their predecessors, we may yet gather from these materials a somewhat better, although still utterly inadequate notion of the extreme deliberation, so to speak, exhibited in building up this portion of the earth’s fabric. May 12, 1870] NATURE as M. Coquand’s memoir can hardly fail to be welcomed as a valuable addition to our paleontological and geological literature, both for what it is, and for what it suggests. Monographs of the fossils of any one country can only be regarded as so many JZémozres pour servir—words and lines, rather than pages—of the geological record. In- complete as that vast history must ever remain, it would be found far more available than it is if we could have a synopsis like the present of every important genus. Owing to their wide range, and the usually good state of preser- vation in which they are found, the study of these fossils cannot fail to be of value with reference to some ques- tions of much present interest. As compared with the fauna of the Cretaceous seas, the fossil mammals of the Quaternary period, to which reference is so often made in these discussions, afford but very imperfect materials for testing the various theories which are from time to time put forward as to the succession of species. These Quaternary beds usually exhibit but broken fragments— disjecta membra, which, while lying on the surface, or tossed about in company with river or deluge gravels, have been subjected to so many chances and changes that the order of succession is often difficult, if not im- possible, to ascertain; while, on the other hand, the fossils of the chalk, slowly accumulating during countless ages in the quiet depths of their seas, exhibit the exact order in which their multitudinous genera and species successively made their appearance and, having endured for their appointed seasons, finally disappeared. If we could have monographs of other important families arranged upon a plan as comprehensive as M. Coquand’s, how much less unsatisfactory might our speculations be upon the perplexed and perplexing questions of the origin, distribution, and extinction of species. When we con- sider the subjects of this memoir, their great variety and wide dispersion, although we might perhaps think it possible that, as we have heard, an oyster should be “ crossed in love,” we find it difficult to imagine the crea- ture as existing under such conditions that one species, while engaged in “the struggle for existence,” should starve out and extinguish another ; or that any process of “ natu- ral selection” should avail to alter the formation of the hinge as well as the internal and external structure of the shell. Indeed, if any such change did occur, it must have been er saltum, since with these mollusks, numerous as they are, there are no forms that can fairly be recog- nised as transitional ; for just as each zone or region of the chalk is marked by the presence of its peculiar fauna, so each species of this numerous family has a character of its own ; it is saz generis, apparently without ancestors and without descendants. If, indeed, all the members of this great family, by virtue of some law or process of evolution, did descend from one common ancestor, we should expect to find their forms varied and numerous, instead of being, as to our sorrow we find them, more simple and far less numerous; so that instead of being permitted to choose from the two hundred and fifty-five kinds described by M. Coquand, we are reduced to the pitiful allowance of one poor “xa¢cve,” and from what we see and hear of /z# it seems not unlikely that he is to be the last of his race, and that ere long, Oysters, like Mastodons will be things of the past. J. W. FLOWER OUR BOOK SHELF Mrs. Loudon's First Book of Botany, for Schools and Young Persons. New edition, revised and cnlarged. By David Wooster. (London: Bell and Daldy, 1870.) WE wish we could speak more favourably of this prettily got-up little book. Mrs. Loudon’s writings did good service in cultivating a love of plants among the last genera- tion ; but when a new edition of an old manual is brought out, with the date of the current year on the title-page, ; and an editor’s name as having “revised” it, we expect | that it will be corrected by the light of the present state of scientific knowledge. In the present instance this has not been adequately done; of the inadequacy we may give but two instances. At p. 18 prickles are described as metamorphosed leaves, instead of, as they really are, indurated hairs, or processes of the epidermis. But a more serious erroneous description occurs in the case of the spores of ferns, which are said to differ from seeds “in not requiring to be fertilised by pollen” (do seeds require to be fertilised by pollen?) The reader is left to suppose that the young fern-plant springs direct from the spore, no reference whatever being made to the recent discoveries of the functions of the ~ro-thallium, archegonia, and anztheridia. The arrangement is good, as also are some of the illustrations ; but the book cannot be used as a manual by teachers or lecturers, without the errors being corrected from some other handbook. A. W.B. The Birds of Asia. By John Gould, F.R.S. THE twenty-second part of this magnificent work has just been issued to the subscribers. It contains fifteen plates coloured by hand, including the great alced, four owls, two pheasants, three buntings, three piculets, Franklin’s barbet, and the long-billed wren, accompanied by letter- press descriptions. Among so much that is beautiful and interesting, it is very difficult to particularise ; but we can- not help referring to the charming little owlet dedicated to the late Sir Benjamin Brodie, the eminent surgeon, and named Azthene Brodie. Among the peculiarities of the bay owl found in Nepaul and the northern confines of India, Mr. Gould notices its friendship for wild animals, living on good terms with the tiger, and sometimes alight- ing on its back. We learn that one of the pheasants, the Chinese Crossoftilon, or Dallas’s eared pheasant, is now domesticated in our Zoological Gardens ; also that some eggs have been hatched there, and that female birds may be purchased for 157. The long-billed wren (Rzmaztor malacoptilus, Blyth), a small reddish-brown bird, with a droll apology for a tail, is said to be excessively rare, and one of the most curious and highly-interesting species in the Indian avi-fauna. Zoologie et Paleontologie générales. Par Paul Gervais, Prof. d’Anatomie Comparée au Museum d'Histoire naturelle de Paris. Premiére Série. 4to. Planches 50. (Paris: Bertrand, 1867— 69.) THIS handsome volume, with its carefully executed plates, is, as the author states, an endeavour to make the treasures accumulated in the Museum of Natural History available for the advance of science. The present part is occupied with the consideration of various living and fossil verte- brated animals, and is introduced by a long account of the arguments, most of them familiar to our readers, re- specting the duration of man’s habitation of the earth, together with minute descriptions of bones of the animals found in various caverns in France. The second chapter treats of the Fossils of Armissan (Aude) ; the third of animals living at the present time in the French posses- sions in the North of Africa ; the fourth of some fossil reptiles of the secondary period, especially including the archzopteryx ; the fifth and last considers the different species of fossil reptiles. 24 NATURE [May 12, 1870 ee || aEnEEane LETTERS TO THE EDITOR [The Editor does not hold himself responsible for opinions expressed by his Correspondents, No notice is taken of anonymous communications. ] The late Captain Brome A SHORT time since I announced in your columns the decease of Captain Fred. Brome, late of Gibraltar, and well known to many of your geological readers for his great and successful labours in the exploration of the caves and fissures of the Rock. Ithen stated that Captain Brome had left a widow and eight children, wholly unprovided for ; and this is literally the case. My object in this communication is to state that his numerous and warm friends in Gibraltar, and at Weedon where he died, have already commenced the collection of a fund for the relief and maintenance of his helpless widow and family, and to request that you will allow me space to say, that I shall be happy to receive and forward any contributions in aid of this fund. Captain Brome was for twenty-two years Governor of the Military Prison at Gibraltar, from which post he was displaced towards the end of 1868. His removal to England last year with his large family necessarily involved him in considerable expense, incurred in the hope that his new appointment at Weedon might afford him a home and some prospect of providing for his children’s education. These hopes, however, were destroyed in less than twelve months by the announcement that the prison at Weedon was to be disestablished. The anxiety lest he should thus be left without prospect of employment, and, as he feared, without any provision for the wants of his family, caused him such distress that, although a strong and energetic man and in the prime of life, he gradually sank, and died from mental depression on the 4th of March. It is impossible to conceive a case more deserving of sympathy and support than that of his unhappy widow and children, or one more deserving of recognition by all lovers of science than that of Captain Brome, who had gratuitously devoted several years of his life, and the most unwearied personal labour, simply because he believed, and truly believed that he was promoting a scientific object. Subscriptions will be received by me, and, I am kindly per- mitted to say, by Mr. W. S. Dallas, at the apartments of the Geological Society, Somerset House. 32, Harley Street, May 6, Gro, Busk Relations of the State to Scientific Research.—II. ScIENTIFIC men are of three kinds: the young, the middle aged, and the old. It is difficult to say which needs help the most ; but there is one work in which they can all severally take part, and from which they can each obtain that comfortable leisure which is the one thing needful for original research, That work is simply the work of teaching. And here let me not be misunderstood, By teaching science, I do not mean the miserable practices now carried on, but teaching on a scale commensurate with the great needs of a great nation, and in a way calculated to bring about the blessings that follow inevitably on true, thorough scientific knowledge. To illustrate my meaning, let me take a particular science, chemistry, as an example. Of the whole population of England there will certainly be a certain number of men whose minds are so set on chemistry that they would be willing to accept, while in the prime of life, with gladness the offer of posts which, while taking up about half their time in teaching chemistry, would _enable them to devote the entire other half to original work, and yet bring up their families in decency and order. What the exact number of such men would be, I do not care to know ; it probably would never be very great ; it certainly would neyer exceed the demand for men to fill chairs of chemistry at properly organised laboratories established at various points all over the kingdom. Now a livelihood may be gained, and even a fortune made, by teaching, but this can never be done by working half time. But such a man as we are picturing must work half time only; and therefore the receipts from his actual teaching must be subsidised from elsewhere—the chair must be endowed by the Government, either local or imperial. The occupant of such a chair would not be an idler. No idler would seek a post which would always entail a large amount of labour, and never would bring wealth. At the very worst, eyen if he did no original work, he would earn his salary by teaching. If he taught badly, that is a thing which can readily be recognised by competent persons, and he could be dismissed. The very desire of a man to take such a position would be of itself almost a guarantee that he would perform its duties properly, and bring forth the fruit expected of him, And calling to mind the well-known law of human nature that the more work a man has to do, the more he over-abounds in work, we may feel sure that the half life which teaching leaves to such a man will be filled with a whole life’s exertion. The work of such a man would lie almost exclusively in the way of systematic lectures and general superintendence of the laboratory. I need hardly say that that ought to be a small part only of the total teaching done in the place. There must be attached to the professor two, three, or more recognised assis- tants, who would be always in the laboratory, who would per- sonally direct and nurse the students, who would carry on original work, partly on their own account and partly on behalf of their master, and who would receive a moderate fixed salary, sufficient to enable them to live without having to look to any other extraneous sources of income. Such men would of course be embryonic professors ; and I know of no more pressing need than this, of finding livelihoods for young promising men in the inter- val between the studentship and the professorship. I weep when I think of how many admirable young men become outcasts to science for lack of these. It has been so with myself: full of zeal for science in my youth, and, whatis more important, rich in the germs of large ideas, which I have since seen flourishing in other men’s minds and bringing forth fruit of fame, I could find no rest- ing place. I threw myself into practical money-getting life, with the hope that after a while my gains would provide me a com- fortable afternoon of old age, in which I might return to my former love. I now have both time and money; but, alas! my mind has grown stiff in the ways of the world: the old ideas of my youth are now vain shadows which I cannot grasp. I find myself a wretched puddler, full of egotistic hobbies, productive of little oddities and trifling curiosities, but bringing forth nothing of real value or permanent worth, The young men make fun of me, and the"chief men treat me with a courtesy which is at once patronizing and forced. What is true of chemistry is, with minor differences, true of the other sciences. Under such a scheme as I have pictured, both young and middle-aged would be provided for, With a sufficient number of laboratories, some large and some small, some with eminent, some with ‘useful men at their head, some with many, some with few assistants, it would come to pass that on the one hand the younger men would work under the bene- ficial influence of their chiefs,}while on the other the men full of thoughts would find heads and hands near them to carry out their ideas. Is it not a crying shame that at the present time such a man as Huxley is completely isolated from the younger biological workers, and instead of, like Cuvier, having a large laboratory manned by an enthusiastic body of scholars, ready to dissect everything after its kind, is penned up in an abominable den in Jermyn Street, and distracted by the demands of triflers ; has, in fact, to work upon the world through the bars of a prison cage? Is it not also a shame that one of the acknowledged fore- most teachers of mathematics in Europe, in the focus of our national life, should feel himself compelled to forsake the work of teach- ing for a subordinate unscientific appointment in a University, when his right place would have been as instructor of the rising mathematicians of England ? But besides teaching, there is the task of examining the taught. And here again is a source of easy livelihood. I do not mean such kind of examinations as are carried on at present; that wretched system of papers, worked through at the rate of so many dozen a day and paid for at so much a hundred—work done by steam and ending in smoke. I mean a thorough system of practical examinations, carried on slowly and quietly, by a staff of professors and their assistants, and paid for in respect of the immense contingencies that hang upon the result and of the vast responsibilities of the examiners. I haye not space to dwell on this; but it is a point which wants working out thoroughly and well. The task of examining ought to be one of the richest sources of income to a large number of scientific men, instead as now the odd pence of a few. I maintain, then, that teaching and examining combined would support all the young and middle-aged scientific men in this country that have sound reasons for devoting themselves to a scientific life, and support them honourably and productively. | May 12, 1870] NATURE 25 Touching the old, little need be said. Every man who has filled one of the above posts worthily while he had force to work ought to be pensioned when he gets old. The matter lies in a ~ nutshell and needs no more words. But there will always be a few old men who for their eminence and their services would require special provision, and that not so much on their own account as for the sake of the younger men of their time. There ought to be some rewards for a scientific life, but they shouid be few and very carefully allotted. At all times, moreover, there will be a few, avery few men whose genius ought to receive plenteous and present recognition. Such men with the older distinguished men might form a small consulting body whose services in the way of advice would be at the command of Government, and the members of which would draw salaries on a scale feebly imita- tive of those of other Government officials. I believe the legal advisers of Government are pretty well paid, and yet scientific advice is altogether unrewarded. Such men would be then at liberty to work out their ideas; the best means being, of course, taken to choose those men only into whose soul the iron of science has entered, men whom it is impossible to keep from work. Two more remarks and I have done. It may be objected that this scheme would make scientific success in large measure dependent on the power of teaching, and that original work would thereby go to the wall. I reply that that is altogether a fallacy, and if I had time I could show it. Lastly, the question of expense of apparatus and other means of inquiry is altogether a secondary one. Government ought of course largely to provide these ; but there would be no difficulty in distributing them on a plan similar to that of the grant to the Royal Society. It is the question of “ scientific careers” that is the pressing one, and the one most difficult to settle. In Sicco Tails of Comets In NATURE of 16th December, Prof. Tait advances the opinion that the tail of a comet consists of nothing but meteorites ; mentioning in proof of this that the orbits of the August and November meteors have been determined, and found to be identical with those of two known comets. I do not question the importance of this most remarkable fact, but I think the older opinion, that the tail of a comet is gaseous, is demonstrably true. Sir John Herschel, in his ‘‘ Elements of Astronomy,” remarks with wonder how the tail, in the comet’s perihelion passage, is whisked round in apparent defiance of the law of inertia, so as always to keep pointing away from the sun. Were the comet an assemblage of meteorites this would be impossible ; the tail would, in that case, always lie parallel to the direction of the comet’s orbit. The fact just mentioned as to the perihelion motion of the tail is, to my mind, a conclusive proof that the tail is not formed once for all, but is a cloud which is constantly in process of formation, and as constantly evaporated. This view is supported by the fact that Halley’s Comet was seen to increase in apparent magnitude as it receded from the sun, in conse- quence, as was suggested, of the conversion of invisible vapour into visible cloud as the heat grew less intense. Dr. Tyndall’s suggestion, that the tail may be a cloud produced by actinic precipitation from an invisible atmosphere is, to my” mind, the only plausible suggestion yet made on the subject. JosEPH JOHN MuRPHY Old Forge, Dummurry, Co. Antrim, May 4 Left-Handedness In reference to the letters which lately appeared in your periodical on ‘* Right and Left-handedness,” I beg to draw your attention to some remarks of Professor Hyrtl, the celebrated anatomist of Vienna, which were published several years ago, and the substance of which I now quote from the 4th edition of Lis ‘‘ Handbuch der topographischen Anatomie,” 2 vol. 1860. “It happens in the proportion of about two ina hundred cases that the left subclavian artery has its origin defore the right, and in these cases left-handedness exists, as it also often actually does in the case of complete transposition of the internal organs (Pro- fessor Hyrtl describes two cases), and it is found that the propor- tion of left-handed to right-handed persons is also about 2 to 100. Professor Hyrtl thinks that ordinarily the blood is sent into the right subclayian under a greater pressure than into the left, on ac- count of the relative position of these vessels, that in consequence of the greater supply of blood the muscles are better nourished and stronger, and that therefore the right extremity is more used. In cases of anomalous origin of the left subclavian, &c., the re- verse occurs, and therefore the left hand is employed in prefer- ence. Kensington, May 3 ADOLF BERNHARD MEYER Strange Noises heard at Sea off Grey Town IN submitting the following to the notice of your readers, I am guided only by the desire of seeking a solution of what to me and to many others appears a very curious phenomenon. The facts related can be vouched for by numbers of the officers and crews of any of the R. M. Company’s ships. I must premise that this phenomenon only takes place with iron vessels, and then only when at anchor off the port of Grey Town. At least, I have never heard of its occurring elsewhere, and I have made many inquiries. Grey Town is a small place, containing but few inhabitants, situated at the mouth of the river St. Juan, which separates Nicaragua from Costa Rica, and empties itself into the Atlantic, lat. 10° 54’ N., and long. 83° 41’ W. In this town there are no belfries or factories of any kind. Owing to a shallow bar, vessels cannot enter the harbour or river, and are therefore ; obliged to anchor in from seven to eight fathoms of water, about two miles from the beach, the bottom consisting of a heavy dark ‘sand and mud containing much vegetable matter brought down by the river. Now, while at anchor in this situation, we hear, commencing with a marvellous punctuality at about midnight, a pecu- liar metallic vibratory sound, of sufficient loudness to awaken a great majority of the ship’s crew, however tired they may be after a hard day’s work. This sound continues for about two hours with but one or two very short intervals. It was first noticed some few years ago in the iron-built vessels Wye, Tyne, Eider,and Danube. It has never been heard on board the coppered-wooden vessels Zrent, Thames, Tumar, or Solent. These were steamers formerly employed on the branch of the Company’s Intercolonial service, and when any of their officers or crew told of the wonderful music heard on board at Grey Town, it was generally treated as ‘fa yarn’ or hoax. Well, for the last two years the company’s large Transatlantic ships have called at Grey Town, and remained there on such occasions for from five tosix days. We have thus all had ample epportunity of hearing for ourselves. When first heard by the negro sailors they were more frightened than astonished, and they at once gave way to superstitious fears of ghosts and Obeihism. By English sailors it was considered to be caused by the trumpet fish, or what they called such (certainly not the Centriscus scolopax, which does not even exist here). They in- vented a fish to account for it. But if caused by any kind of fish, why only at one place, and why only at certain hours of the night? Everything on board is as still from two to four, as from twelve to two o’clock, yet the sound is heard between twelve and two, but not between two and four. The ship is undoubtedly one of the principal instruments in its production. She is in fact for the time being converted into a great musical sounding board. It is by no means easy to describe this sound, and each listener gives a somewhat different account of it. It is musical, metallic, with a certain cadence, and a one-two- three time tendency of beat. It is heard most distinctly over open hatchways, over the engine-room, through the coal-shoots, and close round the outside of the ship. It cannot be fixed at any one place, always appearing to recede from the observer. On applying the ear to the side of an open bunker, one fancies that it is proceeding from the very bottom of the hold. Very different were the comparisons made by the different listeners. The blowing of a conch shell by fishermen at a distance, a shell held to the ear, an zolian harp, the whirr or buzzing sound of wheel machinery in rapid motion, the vibration of a large bell when the first and louder part of the sound has ceased, the echo of chimes in the belfry, the ricocheting of a stone on ice, the wind blowing over telegraph wires, have all been assigned as bearing a more or less close resemblance ; it is louder on the second than the first, and reaches its acme on the third night; calm weather and smooth water favour itsdevelopment. The rippling of the water alongside and the breaking of the surf on the shore are heard quite distinct from it, 26 NATURE | May 12, 1870 What is, then, this nocturnal music? Is it the result ofa molecular change or vibration in the iron acted on by some galvanic agent peculiar to Grey Town ? for bear in mind that it is heard nowhere else, not at Colon, some 250 miles distant on the same coast, not at Porto Bello, Carthagena, or St. Marta. The inhabitants on shore know nothing of it. If any of your numerous readers can assign a likely cause, will they be pleased to state by what means, if any, its accuracy may be tested? If required, I can forward a specimen of the mud and sand taken from the anchor. CHARLES DENNEHY, M.R.C.S.1L, R.M.S. Shannon [Our correspondent should dredge.—Ep. ] The Newly-Discovered Sources of the Nile RELUCTANT as I am to meddle with geographical discoveries made by the ‘high #77077 road,’ I cannot refrain from protesting against erroneous statements, which, if left uncontradicted, may acquire currency. The zealous geographer of former times sought for truth and accuracy. ‘Treasuring truth, his knowledge in- creased with his information. But fashions are now changed. It has been found that one who starts in ignorance may every day alight on some novelty and wonder ; and that since anything may be proved by data made for the purpose, the best mode of treating preceding information is to corrupt, change, and distort it as the case may require, so that instead of fettering invention, it may serve as proof of endless new discoveries. Captains Burton and Speke examined the northern end of what they called Lake Tanganyika. They saw it narrowing to a point and enclosed by hills, called by the latter officer the Mountains of the Moon. Six rivers, they learned, flowed into it from those hills. They did not examine nor approach the southern end of the lake ; they differed in their accounts of it ; and Captain Burton, in writing that it was often circumnayvigated by the Arabs, made a state- ment repugnant to common sense. The pedlar Arabs cross the lake in ill-built boats, with savage crews, navigating only in day- light. They navigate it no more than is absolutely necessary for their trade with the interior, and not for pleasure or scientific purposes. Captain Speke measured the altitude of the lake, and on his second journey, going to a great extent over the same ground, he saw no reason to be dissatisfied with his previous hypsometrical observations, The result of his observation at Gondokoro was thought to prove the accuracy of his instruments. Yet the account given of the northern end of the lake is now rejected, while that of the southern end is obstinately adhered to ; and as to the elevation of the lake, the @ gviov7 geographers find it convenient to add 1,000 feet to that assigned by Captain Speke. Among the geographers of the new school, no one holds a higher rank than Dr. Beke. In devoting his labours to the mystery of the Nile, he very properly began at the base. He first adjusted the Mountains of the Moon and their everlasting snows. A warm admirer of Ptolemy, he nevertheless found it expedient to correct a mistake of the old Grecian, who thought that those mountains extended from W. to FE. inlat. 12°30'S., whereas Dr. Beke discovered that they actually lie in a meridional line across the equator, and not far from the eastern coast. With the boldness of genius he set this chain of mountains, on the alleged authority of the East African missionaries, in a region where these missionaries emphatically declare that there is nothing of the kind. But having removed the Mountains of the Moon from the famed Land of the Moon, he now unaccountably removes the sources of the Nile as far as possible from the mountains supposed to give birth to them. He places them 1,000 miles S. W. of those mountains, on the eastern frontier of Benguela ; and this he does, forsooth, because Dr. Livingstone announces the discovery of the real Lakes of the Nile (a batch of 20), just where Ptolemy set them, between Jat. 10° and 12° S, Had Dr. Livingstone an opportunity of looking at Ptolemy’s map he would have therein seen only two lakes, nine degrees asunder, and respectively in lats. 6° and 7°. But with time to study and understand his author, he would also have perceived that the positions thus indicated in false graduation are really close to the equator, respectively in 11’ N. and 39’ S. In Dr. Livingstone such a mistake is not surprising ; in Dr. Beke it is inexcusable. But the latter, being inspired with a new hypothe- tical discovery, eagerly seizes on anything that will help him to develope it. The river Casabi he deems the chief, as being also the most remote source of the Nile. Its course eastward he concludes on the authority of Ladislaus Magyar, whose scientific attainments and reliability he, of course, rates highly, But the career of the Hungarian proves only his leaning to savage life. From the Brazilian navy Ladislaus passed into the service of the King of Calibar; and thence again he made his way to the interior of Benguela, where, marrying the daughter of a chief, he found himself in a short time the leader of a band of expert hunters. In 1850 he started, with his wife and 280 armed followers, on an excursion to the interior. The province of Kiboque, in which are the sources of the great river Casabi, was soon reached. Its forests, he says, extend far and wide, in lat. 6°S. But as the province in question reaches little north of the 12th parallel, it is evident that the Hungarian’s science deserted him at first starting. He continued his march through Bunda, south of the river Lungobungo, in lat. 10° 6’ (13° would be nearer the truth), and at length after a 33 days’ march, crossing the Liambegi, he arrived at Ya Quilem, in Kilunda. Now, the Portuguese traveller, Graca, travelling from Bihé in a parallel route, arrived in 33 days at Catende, 100 miles west of the Liambegi, so that we cannot doubt that Ya Quilem was not far east of that river, and not to the north, but probably much to the south of the 11th parallel. Yet Ladislaus places it in 4° 41' S.! Such is the science on which Dr. Beke relies. When the latter says that in lat. 6° 30’ Ladislaus learned the eastward course of the Casabi, he totally misrepresents the facts. The Hungarian was much further south when he embraced the belief that the great river runs to Nyanza and Lake Mofo (near the Cazembe), that is, that it occupies the valley of the Luapula. Graca, who followed the river down a long way to the north, states his opinion (entirely mistaken by Mr. Keith Johnston), that the Casabi and Lulua are the head-waters of the Rios de Sena (the Zambeze). To these two foolish attempts at a great discovery must be added a third. Dr. Livingstone proclaimed that the Luapula flows into the Liambegi, and deforming their names, he reckoned among its tributaries rivers which run into the Lulua. If the concurrent and invariable testimony of three centuries can make anything certain, it is certain that the Casabi falls into the river of Congo, commonly called the Zaire. From the first visit of the Portu- guese to Congo to the present day, the natives, when interro- gated respecting the origin of their great river, have always answered that it comes from the Lake (Lobale) a-Kilunda (of Kilunda). This is properly the name of the country about the head-waters of the Liambegi, but the Portuguese, copied by Dr. Livingstone, apply it much more widely. The Casabi certainly does not rise in Kilunda, but it receives many streams from it, and unites with the Lulua, which is swelled by many more. The chief river of Kilunda is, we believe, the Lualaba, which turns westward to join the Lulua, while 8 or ro days’ journey further east the Luviri, a smaller, but still an important river, flows north-east- ward to the Luapula. Between them, in about the meridian of 25° E., isa well-marked water-parting. The Lualaba is bordered by extensive sait marshes. One of its afiluents—the Luigila—is said to flow over a bed of rock-salt. Hence, the Lulua or Lolo, which collects these waters, is, as its name implies, a salt river, and remarkable for its excellent fish. Lake Dilolo (the cerebral d here takes the place of 7), has, for the same reason, an equal reputation. Fish, salt, and copper are the products which chiefly support the trade of the African interior, and the great emporium of this trade is Katanga, on the River Luviri. T now turn to Mr. Keith Johnston, who rejects, but not on the best. grounds, Dr. Beke’s hypothesis that the Casabi is the source of the Nile, and at the same time proposes another equally objectionable, namely, that the Chambezi, that is, the Luapula, flows round by the north and west into the river of Congo. Surely such extravagant conjectures would never be brought forward if, in the quarters that exercise an influence on geography, fair play were allowed to the information and common sense of all parties. An ignorant and overbearing patronage has the power of spreading darkness around. Mr. K. Johnston unfortunately fixed his attention on a sentence of Dr. Livingstone’s letter, which is fitted only to mislead-—a sen- tence, the dangerous indistinctness of which was pointed out by me in an early number of this paper (NATURE No. 3). Dr. L. plainly says that the Luapula flows down north past the town of the Cazembe, and 12 wiles delow it, enters lake Moero. The traveller here states not what he saw, for the Luapula is some miles west of the Cazembe’s town, but what he miscon- ceived. He may have meant that twelve miles from the town, towards the S.W., the river issues from the lake. It is easy to show that Lake Moero (a name made for convenience by strangers, but not used by the natives) lies to the S.W. of the Cazembe. Dr. L., when he first visited the Cazembe, May 12, 1870} passed (northwards) up the east side of the lake. He tells the difficulties created by the flooded rivers at its north end ; one of these was the Luo, mentioned, as I have else- where pointed out, by the Portuguese as five days’ distant from the Cazembe. Again, further north Dr. L. had to wade through the Chungu near an old_ site of the chiet’s town and where Larcerda died. Now, Father Pinto, when he left the Cazembe on his way homewards, did not reach the Chungu where he disinterred Lacerda’s bones (sub- sequently lost in the retreat), till the 3rd day. Thus it is quite evident that the north end of Lake Moero is ‘south of the Cazembe’s residence. With respect to the course of the Luapula northwards, Mr. K. Johnston may frest assured that Dr. L.’s statements have not the slightest foundation. The Luapula does not take the name of Lualaba, nor does it join the Luviri towardsthe north. That the Chambezi falls into the Luapula was ascertained ,by Dr. Lacerda 70 years ago, and all that Dr. Livingstone has ascertained is that his own views on the subject were erroneous. As to the further course of these rivers let us take the evidently unbiassed evidence of the Arabs who met Dr. Livingstone in the interior of Africa, and a brief account of whose travels appeared in the transactions of the Geographical Society of Bombay, 1862. From the western shore they travelled in 27 days to the broad river Maroongo. ‘This is the Luapula, which, by strangers reaching it from the north, is named after the Arungo, who dwell on its western side. ‘‘ Roonda (Lunda) is on the banks of the Rooapoora, which runs north to Tanganyika.” Here the rude observers confound the river which does reach the Nyanza, with Lake Mofo. Neither need we be- lieve that the place is called Lunda by the natives. But this among African traders is a wide-spread name. By the Portuguese and their native agents the dominions of the Muata-ya-Nvo and of the Cazembe are all called Lunda. ‘‘25 days west (SW) of the Cazembe are the copper mines and the town Katanga. ‘The river Rafira (Luviri) flows past Katanga, and joins the Rooa- poora to the N.” There is much reason for believing that the Luviri flows south-eastwards from Kanyika, but perhaps the author’s meaning is that the river wheels round to the north. Dr. Livingstone saw nothing of Lake Bangweolo. Lake Moero he saw only on the east and north, and not connectedly ; most of his statements respecting its size, &c., must be due to hearsay. The mountains that he speaks of are the hills Chimpire, noted in two groups by the Portuguese. It is remarkable that when in his missionary travels he met with the name Mpire, a hill, he supposed it to be the Sichuana numeral mbili, éwo (hills), a | flagrant mistake. The Portuguese reported that the elevated country on the way to the Cazembe lies in ridges, with pools of water in the successive hollows. They learned that there was a great marsh at the confluence of the Chambeze and Luapula. Further north they saw numerous swamps and lagoons, and heard of more. They were told that to the west lay the great lagoon which Caetano Pereira spent a whole day in wading through. This was Carucuize, the nucleus of the Moero, The pombeiros, or native commercial travellers from Angola to the Cazembe, marched down the eastern bank of the Luapula five days before they turned eastward to Lake Mofo. That river, therefore, does not ordinarily flow through a lake. Dr. Living- stone evidently found the country in a state of unusual flood, with the fens and lagoons united into great lakes. From the dis- trict of the Fumo Moiro, at thenorth-east margin of the flood, he has made the name of the lake. As he finds every pool to belong to the system of the Nile, it is natural that, in his exalted imagina- tion, the hills should rise into mountains. The Alunda, or Balunda as he calls them, being originally from the banks of the Lualaba, nourish a superstitious regard for that river. While the traveller, therefore, thought of nothing but the Nile, his native hearers knew of no great rivers but the Lualaba and its immediate neighbours, the Luviri and Luburi (in the printed letter misread Soburi.) His inquiries pointed to the N. or N.E. ; they answered respecting the S.W. They mistook the object of his ardent curiosity, and he was only too ready to misinterpret their communicativeness. Hence the confusion of rivers, right and left, the lakes Ulenge, Chowambe, &c., of which the less said at present the better. After such a conclusion it may perhaps be consolatory to remark that it would be labour thown away to lead all the great rivers of south tropical Africa to the river of Gondokoro. Dr. Peney, who studied the character of this stream, found that it varied often, but that it never rose in flood more than two feet above its mean level. This increase in a wide spreading river near the equator barely suffices to com- NATURE pensate the loss by evaporation. Consequently, the floods at Gondokoro have no perceptible effect on the river a few degrees lower down. The river of Gondokoro, therefore, contributing nothing whatever to the floods of Egypt, must be regarded as a very subordinate branch of the Nile. Dr. Beke wonders (NATURE, No. 9) why I give the name Nyanza to Lake Tanganyika. He here touches upon an im- portant subject, interesting in its bearing both on geography and on the intrigues of geographical coteries. The assertion that in the name Lake Tanganyika there lurks some fraudulence, will of course be received with incredulity, and therefore its justification will be impossible without some historical development. But if encouraged, I am prepared to show that, with respect to the lake, the geographical world labours under a delusion designedly produced. Wie Daic: Apparent Size of the Moon My original intention was to put together several vere cause, which might be found, concurrently, to contribute to the univer- sal impression that the moon’s disc is larger or smaller, accord- ing as it is nearer to the horizon, or to the meridian. I shall content myself, however, with calling attention to what I am now persuaded is the nature of that impression. ‘‘ Sweet are the uses of adversity.” An attack of hemiopsia is always serious, and may be dangerous (see NATURE, Feb. 24th, 1870; p. 444). I think I owe to it the discovery (for such it was to me), that the variable standard of angular magaitude which infects our visual judgment, can be detected in a small room as certainly as in view of the celestial vault. The distressing affection which suc- ceeds the hemiopsia, as soon as it forms a broken arch around the central hole of the retina, is an instructive spectre in regard to the question I am considering. Being referred to two equally distant sites on the wall of the room, one horizontal and the other consi- derably elevated, the spectre seems larger in the former than in the latter. I soon proved that this was no accident case. I extem- porised a very rough experiment on this wise—I placed a disc 141 inches in diameter on the wall 7 feet from the ground, and selected a horizon so that the base of the disc and the horizon were equidistant from a fixed point of observation. I found the disc was about 30° above the horizon. I now took six persons successively, and made each person take an observation from that point, first looking at the disc, and then transferring it in mind to the horizon, where I carefully marked the estimated size. The maximum was 133, the minimum 108, and the mean 12h inches. This result is, of course, equivalent to saying that had an equal-sized disc been placed on the horizon, its diameter would, taking the average, have appeared to be 1$ inch greater than when elevated 30° above it. I think it is worth while making this experiment with greater accuracy, and with a greater number of persons. I have no doubt Mr. Abbott’s view of the case would be fully borne out. But I do not understand why the augmentation on the horizon is so much greater in the case of the moon and the sun; nor yet why the rising sun does not present so striking an augmentation as the rising moon. The augmentation of the latter may be partly an effect of external conditions ; but the fact of augmentation, in what I have called visual judgment, is a question for the physiologist. I should much like to know what, for instance, such an authority as Helmholtz has to say on the matter. The great fault of physicists, me judice, is, and ever was, their inability to see more than one side or aspect of a subject. Metaphysicians, on the contrary, may see all round it, but do not see all sides clearly. Mr. R. A. Proctor (NATURE, March 3rd, 1870; p. 462) affords me an apt example of the former. “