gARSWELLCo,i.imiua ' BiiokbliidorM. P«»Ti!ns. , TORONTO I9IT0PU1I' OF CAN, .- . . ORONTO, OM Frontispiece to KSOWLKnr.K. Volume XSWII '10'" M.3J TriaiiKiili N.G.C.5yt>. Position of Nebula K.A. 1" ^.'S'". Decl. + JO' Ap. 60ins. (l-524m.) F.L. 299ins. (7-5m.) Exp. S* 50". l-ounlt:(! 1 y K;Ui.:.J A. I'roclor, .531. With which is incorporated Hardwicke's Science Gossip, and the Illustrated Scientific News. A Monthly Record of Science. CONDUCTED BY Wilfred Mark Webb, F.L.S., and E. S. Grew, M.A. Let Knowledge grow from more to more." — Tennyson. Volume XXX\4l New Series, \'olume XI. 1914. London : Knowledge Publishing Company, Limited, 83, Avenue Chambers (42, Bloomsbur>- Square), W.C. ^ ^ . INDEX. ABSORPTION AND .-UDSORPTION, 375 Acetylene, Acetic acid from, 398 Acid, Blue perchromic, 186 from acct>'lene. Acetic, 398 in plants, Prussic, 331 or P>'rogallol, P\r<)gallic, 336 Acids and vegetation, Sulphurous and sulphuric, 306 -, Soaps from naphthenic, 148 Actinium emanation. Molecular weight of, 34 Adams's photographs. The late Mr, Frank- lin, 66 Adriatic, Marine vegetation of the, 146 , Plankton (flagellates and green algae) of the, 306, 330 Adsorption, Absorption and, 375 Aeronautics, Wireless telegraph^' in, 279 Aeroplanes, Testing aneroids for use on, 400 , The Schilowsky gyroscope applied to ships and, 209 .\ir in plant physiology. Use of liquid, 28 , Liquid, 333 records at Batavia, Remarkable upper, 189 research. Upper, 115 Air-sac in a Lemur, Pecuhar, 194 Albedo, The Earth's, 65 Alchemical Society, The, 128 Algae and sponges, SyTiibiosis between, 112 , Diastase in red, 186 ) of the Adriatic, Plankton (flagellates and green, 306, 330 , S>'mbiosis between freshwater mol- luscs and, 397 Alkaloids and colour changes, 323 Alleghany di%-ide. The, 31 Alloys, Komenckiture of, 67, 148 , The colour of metals and, 268 -Mmanac" for 1916, "The Nautical, 184 Alps, Vegetation above the snow-Une in the, 112 Altruism, Infectious, 340 Ahiminium, and Duralumin, Exposure tests of copper, commercial, 30 in the vegetable kingdom. Dis- tribution of, 268 America and the dyestuff industry, 431 America, Earthquakes in North, 210 American Entomological Societv, The, 284 reflectors. Great, 27 goatsuckers. New family of, 406 Ancestry of domestic fowls, 376 Andes, Pillow-lavas in the, 269 Aneroids for use on aeroplanes. Testing, 400 .\nglo-Swedish antarctic expedition. An, 221 Animals, Chemical test of pregnancy in, 220 , Protective changes of colour in, 195 Antarctic expedition. An Anglo-Swedish, 221 Expedition, The Imperial, 114, 372 — — nematodes, 194 Antiquities, Egyptian metal, 68 Ants, Caterpillar reared by, 231 Aporeine and its salts, 3'70 Arc, The Twilight, 296 Archipelago, Vegetation of the Arctic- American, 146 Arctic-American Archipelago, Vegetation of the, 14G Arctic expeditions, lU-fated, 399 ArgylLshire, Abnormal stream transport 'in Perthshire and, 188 Arithmetic, Russian peasants', 203, 254, 301, 323, 419 Arsenic, The forms of, 29 Astronomical Society of the Pacific, The October Journal of the. 27 , The London, 284 Astronomj' and modern novelists, 121 , Meteoric, 96 Notes, 26, 65, 111, 145, 184, 219, 266, 305, 329, 369, 394, 430 Atkinson, Helen A. S., 419 Atlantic coastUne, Permanence of the, 268 Atomic hypothesis, The present position of the, 344 weight of lead, 376 Austraha, Federal capital of, 269 Australian weather forecasts, 432 Autotomy in Linckia, 73 Axon, T., 50 BACTERIA,DENITR1FYING MARINE, 66 • , The purple sulphur, 185 Badgky, W. F., 108 Balloon ascents at L'pavon during 1913, Pilot, 150 Ballstone, 308 Barclav, J. Gurnev, 108 Barlo\v, E. W,, 419 Barnard's observations of Halley's Comet, Professor, 329 Novae, Professor, 266 Batavia, Remarkable upper-air records at, 189 Bather, Dr. F. A., 329 Beads, Platinum metals in cupellation, 114 Bee, Tropism of horned, 35 Beeswax of the Viking period, 29 Beetle, The water-, 222, 270 Beetles, Myrmecophilous, 73 , Respiration in water-, 315 Benham, Charles E., 45, 351 Bickerton, Professor A. W., 10, 55, 83, 140 Binocular microscope. The, 226 Biogeography of the tsetse-fly, 68 Birds, Bright colours of male, 406 , Luminous, 50 Bivalves, How cuttlefishes deal with crabs and, 35 Black Sea ports, Russian wheat and the, 68 Blood films. Notes on, 32 Bones, Cetacean pelvic, 153 Botany, Ehzabethan, 60 Notes, 27, 66, 112, 146, 185, 267, 306, 330, 370, 397 BoweU, E. W., 373 British Association, 1913, Economics at the. 60 grants, 14 , The Australian meeting of the, 375 Folk Museum, A, 136 British Journal of Photography, The diamond jubilee of The, 314 British Rainfall, 1913, 401 Brittany, Frilled shark off the coast of, 406 Britton, L., 195 Bronze, 220 Bruce, Dr. WUhara S., 92 Burke, John Butler, 304 Butterfield, \\. Ruskin, 136 CACTI, TRANSPIRATION IN, 398 Cairns, J. E., 61 Calcium carbonate. The solubility of, 147 Canada, Archaean geology in, 431 Cancer, Coal-tar, pitch and, 39S Cape Observatory," Sir David Gill's " History of the, 27, 66 Carbon dioxide, Carbon and, 332 Carbonate, The solubiUty of calcium, 147 Caspian Sea, A recent lowering of the level of the, 187 Castor seeds, Detection of, 371 Caterpillar reared by ants, 231 Caucasus, Travel in the, 30 Cavers, Professor F., 27, 66, 112, 146, 185, 267, 306, 330, 370, 397 Cell-dimensions in dwarf plants, 66 Cement works, Estimation of the dust fall near, 332 Cetacean pelvic bones, 153 Chambers, W. F. D., 260 Charts, Variable star, 298 Cheavin, W. Harold S., 225, 270, 313, 336, 374, 402, 435 Chemistrv and the war, 370 Notes, 29, 67, 113, 147, 186, 220, •268, 306, 332, 370, 398, 431 , Engineering and Metallurgical, 29. 67, 114, 148, 187, 220, 268, 307, 333, 371 of the Radio-elements, The, 24 forest. The, 50 tobacco and nicotine. Some notes on the, 46 , Some interesting features of photo- 389 Chinese flea-trap, 36 Chlorine in rain and snow. The nitrogen and, 268 Clandge, The Rev. J. T. W., 204 INDEX. Climate as tested by fossil plants, 190 , Effect of the Gulf Stream on our, 270 Climatic belts, The shifting of the, 188 Cloud-burst in Malta, October 16th, 1913, 400 Coal-tar, pitch and cancer, 398 Cohen, Israel, 211, 292 Coinage bronze by volatilisation, The estimation of zinc in, 148 Colloidal solutions of the radio-elements, 401 Collodion emulsion. Transparencies on, 192 Colour changes. Alkaloids and, 323 in animals, Protective changes of, 195 of metals and allo>^. The, 268 C.>louration of a sea-urchin, 36 Colours of male birds. Bright, 406 Combustion, Surface, 333 Comet, A new, 65 Dcla\-an's, 112, 369, 394 . Encke's, 394 , Professor Barnard's observations of HaUevs, 329 Comets, 184. 220, 266, 305 by M. Fehx de Roy, Extract from a letter on, 266 Comments, 81 Condenser tubes. Corrosion of, 371 Conductor in a magnetic field. Lecture illustration of a moving, 193 Cooke, Death of Dr. M. C. 435 Coordinates for star-places. Use of Galac- tic, 26 Copepod from a novel host. New parasitic, 231 Copper, Commercial Aluminium, and duralumin. Exposure tests of, 30 steel. 30 Correspondence, 24, 50, 88, 107, 133, 153, 195, 203, 254, 295, 301, 304, 323, 381, 419 Corrosion of condenser tubes, 371 iron, 68 Cortie, The Rev. A. L., 1 Cotton and weather, 308 Cotyledons, Dicotvledons with one or several, 332 Crab, Gall-forming, 376 , The tube of the pistol, 118 Crat« and bivalves. How cuttlefishes deal with, 35 Crommelin, A. C. D., 25, 26, 63, 65, 109, 111, 134, 145, 166, 184, 219, 232, 252, 266, 302, 305, 324, 329, 369, 377, 392, 394, 428, 430 Crustacean, Flying, 376 Crustaceans, Orientation in swimming, 340 Cryptodromia and its sponge, 73 Curator," " A provincial, 50 Curves, A new method of producing stereoscopic harmonograph, 45 Cuttlefishes deal with crabs and bivalves. How, 35 Cuttriss, Frank, 420 DAGUERREOTYPES, RESTORING TARNISHED, 152 Darhng, Charles R.. 201 Davidson, The Rev. M., 181, 301, 415 Day, The longest, 381 Decarburisation during the hardening of steel dies. A curious case of, 307 Delavans Comet, 112, 369, 396 Dennett, Frank C, 36, 79, 11 9, 123, 180, 206, 244, 315, 326, 379, 391. 427 Denning, \V. F., 96, 133, 352 Depigmentation, Darkness and, 231 De Roy, Extract from a letter on comets by M. Felix, 266 Deserts, 431 D'Estcrrc's observatory at Tatsfield, Mr., 145 Diamond jubilee of The British Journal of Photography, 314 Dicotvledons with one or several cotyle- dons, 332 Disintegration series, The branching of the, 376 Disturbances, Solar surface, 1 Dogs, Inheritance in short-tailed and tailless, 118 Dogs, Spelling, 35 Doncaster, Great rainstorm at, 32 Dorton, The water of, 307 Dragon-fly, The, 432 Drawing, Stereoscopic, 351 , lo convert a photograph into a Une, 71 Drew, J. G., 323 Drops and globules. Some further experi- ments with liquid, 201 Drought of last summer in the United States, The great heat and, 150 resistance in ferns, 267 Duralumin, Exposure tests of copper, commercial aluminium and, 30 Dust explosion. Paper, 67 fall near cement works. Estimation of the, 332 storms on the atmospheric potential gradient. Influence of, 270 Dyestuff industry, America and the, 431 EARTH DRYING UP ? IS THE, 149. 189 , The cleaning of polycistinous, 152 , The rate of erosion and the age of the, 31 with solar observatories, GirdUng the, 236 Earthquakes in North America, 210 Earth's albedo. The, 65 crust. The strength of the, 371 Earwig, The common, 373, 401, 432 Earwigs, Maternal care in, 194 Eclipse and its predecessors. The coming, 265 of August 21st, 1914, The total solar, 111, 305, 369, 394 , The war and the solar, 330 viewed in its partial phase from Hampstead, The solar, 357 Economics at the British Association, 1913, 60 Edinburgh, Meteorological conference at, 116, 334 Education, Museums and, 89, 154, 259 Eels in the North Sea, Young sand, 194 Egerton, .Mfred C, 34, 72 Egg continued outside the mother. De- velopment of a rabbit's, 119 Eggar, W. D., 193 Eg}-ptian metal antiquities, 68 Electric discharge ? Can the rare gases be produced by, 436 Electrical nomenclature, 231 Electric-cell photometer. The, 65 Electromagnets, Powerful, 403 EUminators, " H>'po," 34 EUzabethan botany, 60 Emanation, Molecular weight of actinium, 34 Embryos, Photographing. 274 Emerods, mice, and the plague, 406 Emulsion, Transparencies on collodion, 192 Encke's Comet, 394 Engineering and Metallurgical Chemistry Notes, 29, 67, 114, 148, 187, 220, 268. 307, 333, 371 problems of stress and strain. The application of polarised hght to, 193 England, Connection between the summer rainfall at Havana and the winter rainfall in the south-west of, 269 English Channel, Plankton (vegetable) of the, 267 W'oodlahd and Timber Industries Exhibition, 1914, 5 Entomological Society, The American, 284 Erosion, 107 and the age of the earth. The rate of, 31 , Man and the rate of, 188 Evolution among penguins. Social, 376 , Conservation in, 194 of sieve tubes, 332 Exhibition, The Nature Photographic Society's, 9 , The Physical Society's, 9 , 1914, EngUsh Woodland and Tim- ber Industries, 5 Expedition, The Imperial Antarctic, 114, 372 Expeditions, Ill-fated arctic, 399 Exploration, 371 Explosion, Paper dust, 67 Explosive flowers. An orchid with, 146 Eyes that shine at night, 193 FALIvLAND ISLANDS, VEGETATION OF THE, 147 Feathers with hollow shafts, 427 Fermentation and the respiration of plants. 187 Fern, A heterosporous fossil, 186 Ferns, Drought resistance in, 267 Films, Notes on blood, 32 Fire-damp whistle. A, 220 Fish, Remarkable cj-prinodont, 119 Fislies on the Paris market. Deep-water, 72 (Flagellates and green algae) of the Adriatic, Plankton, 306, 330 Flea-trap, Chinese, 30 Fleas, Endurance and longevity of, 118 Fleck, .\lcxander, 24, 376, 404, 439 Flies, Ox-warble, 406 Flora, A new freshwater, 331 Selborniensis. 359, 387 Flowering plants. The origin of, 185 Flowers, An orchid with explosive, 146 Fly, Biogeographv of the tsetse-, 68 — '—, Ox warble-,' 406 , The flight of the house, 193 Folk Museum. A British, 136 Folklore mu.seums, 196 Forest, The chemistry of the, SO Formaldelivde on living plants. Action of, 28 ' Fossil fern, A heterosporous, 186 plants. Climate as tested by, 190 track of a dying lobster, The, 329 Fowls, Ancestry of domestic, 376 Freezmg of water, The, 88 Fremantlc, High tide at, 88, 133, 153, 29.=) Freshwater flora, A new, 331 mite, A rare, 335 molluscs and algae. Symbiosis be- tween, 397 Frisian Islands, Vegetation of the East, 113 Fuel, The future of oil, 114 Function, Structural modification and specialisation of, 245 ixnicx. Fungi and humus-formation. Soil, 66 , Soil. 28 , Spore-dispersal in the larger, ! 124, 168 Fungus-infested moss, A, 225 -)-RAYS. SPECTRUM of, 340 , The origin of the, 404 Galactic coordinates for star-places, Use of, 26 Gall-forming crab, 376 Gas, Petroleum spirit from natural, 67 Gases be produced by electric discharge ? Can the rare, 436 Gazette Astronomique, The, 424 Gegenschein, The, 27 Geneva, Deep-water snails of the lake of, 405 Genus Porphyridium, The algal, 331 Geographical research, 333 Geography, 188 Note's, 30. 68, 114, 149. 187, 220, 268, 307. 333, 371, 399, 431 of the war area, 399 Geologv in Canada, Archaean. 431 Geology Notes, 31, 68, 115, 149. 188, 221, 269, 308, 333, 371, 399. 431 of South Georgia. 115 Georgia. The geolog\- of South. 115 Gilbert Centenan,- Fund. Lawcs and, 54 Gill's " History of the Cape Observatory," Sir David] 27, 66 Ginkgo biloba, 88 Giza Zoological Gardens. 358 Glass labels, Ground, 32, 151 Globules, Some further experiments with liquid drops and, 201 Gnat, The common. 309, 336 Gnetales and their affinities. The, 370 Goatsuckers, New famil)- of American, 406 Gornold, W., 88. 203 Gradenwitz, Alfred, 231 Grafts, Some interesting, 424 Graphite, Sulphuretted hydrogen from artificial, 148 Gra\-itation, 61, 108 Gravitative differentiation, 400 Gravity lever. Specific, 35 Gray, H. John, 60 Gulf Stream on our cUmate, Effect of the, 270 Gulls killed by hail, 372 Gusts, Wind, 70 Gyroscope applied to ships and aero- planes. The Schilowsk>% 209 mono-rail system, The Schilowskv, 131 HAEMOCYTO METER. DARK- GROUND ILLUMINATION FOR THE. 33 Haig. Harold A., 245 Hail, Gulls killed by. 372 Hair. Evolution of mammaUan. 105 Hairs and hair pigments. On, 161 Hall, MaxweU, 296 Halley's Comet, Professor Barnard's ob- servations of, 329 Hampstead Scientific Society, 195 , The solar eclipse of August 21st, 1914, viewed in its partial phase from, 357 Harmonograph curves, A new method of producing stereoscopic, 45 Hastings, Somerville, 98, 124, 168, 319 Haughton. John L., 216, 239 Havana and the winter rainfall in the south-west of England, Connection between the summer rainfall at, 269 Hawaiian lava flows. Plant invasion on, 370 Heat and drought of last summer in the United States, The great, 150 of soUds, Specific, 340 Helium stars. Professor Kapteyn on the distance of the galactic. 369 Helix riipestris, The radula of, 190 Hemisphere. Weather map of the Northern, 151 Hibernation of meadow jumping mouse, 439 Higginson. George N., 419 Home, A strange, 405 Hornets, Poison of, 36 Horticulturists, A cool house for tropical, 6 Horwood, A. R., 301 Humus-formation, Soil fungi and. 66 "Hurstcot," 88 Hydrogen a-particlcs. 404 Hydrogen from artificial grapliite. Sul- phuretted. 148 " Hv'po " eliminators, 34 . Further tests for the presence of, 34 , Sodium thiosulphate. 117 Hypothesis. The nebular. 149 , The present position of the atomic, 344 Hyrax, Habits of, 406 ICE-SHEET, THE METEOROLOGICAL CONDITIONS OF AN, 69 Igneous rocks, Saturated and unsatu- rated, 69 Illumination for the haemocytometer, Dark-ground, 33 of opaque objects under low-power objectives. Photo-micrography, 313 Imperial Antarctic Expedition, The, 114, 372 In-breeding, Measurement of intensity of, 153 Indicators. 374 Infusorians. So-called senescence of. 274 Insects. The stridulating organs of, 70 Intoxicating male parent. Effect of, 72 Iron, Corrosion of, 68 . NickeUde of, 220 • , Porosity of, 114 , Recrv'staUisation of deformed, 268 JAMESON, H. LYSTER, 41 Jams, Microscopical and colloidal examin- ation of, 175 Jewish Race, Phj'sical conditions of the, 211. 292 Johnston. The Rev. G. T., 203 JoUand, G. T., 153 Jupiter, The ninth satellite of, 430 , — Planet, 145, 383 Jupiter's red spot in 1913, 298 KANGAROOS. TREE. 231 Kapteyn on the distance of the galactic helium stars, Professor. 369 Keen. Gilbert R., 50 LABELS, GROUND GLASS, 32, 151 Larkman, A. E., 295 Lava, The ascent of, 68 Lavas, Vesicular sediments and sedi- mentary infiUings in, 31 Lawes and Gilbert Centenary Fund. 54 Lead, Atomic weight of, 376 Lecture illustration of a moving conductor in a magnetic field, 193 Leggett, Bernard, 279 Leigh-Sharpe, W. Harold, 326 Lemur, Pecuhar air-sac in a, 194 Lenses, Photo-micrography by means of short-focus photographic, 229 Lever, Specific gravity, 35 Lice on Seals, 118 Lichen, A wandering, 319 Lichens, Perfumes of, 113, 196 Life, Some fruitless efforts to synthesise, 304 , Tenacity of, 194 , The origin of, 24 Light of the stars, The total number and total, 305 , The Zodiacal, 204 to engineering problems of stress and strain. The application of polarised, 193 Lightning, 339 and trees, 372 Lily, The May, 301 Limpet's feeding habits, 439 Linckia, Autotomv in, 73 Ling, PhiUp H, 1'21 Liquid air in plant physiologj'. Use of, 28 drops and globules, Some further experiments with. 201 Lobster, The fossil track of a dying, 329 withdraws the muscles from its claws. How a moulting. 405 Lomax-Earp, Charles. 254 London Astronomical Society, The, 284 , June 14th, The thunderstorm in South, 308 Museum, The, 50 parks, 82 , The Zoological Society of, 95 McHENRY, H. H., 389 Magnetic field. Lecture illustration of a moving conductor in a, 193 Male parent, Effect of intoxicating, 72 Males in a species of spider. Two kinds of, 118 Malta, October 16th, 1913, Cloud-burst in, 400 MammaUan hair, Evolution of, 405 Man and the rate of erosion, 188 Mangrove trees. Transpiration and osmo- tic pressure in, 397 Map of the Northern Hemisphere, Weather, 151 of the World, The International 1 : 1.000.000, 115 Marriage, Ernest, 175 Marriott, William, 32, 69, 115, 150, 189, 221, 269, 308, 334, 372, 400, 432 Mars, 184, 394 Martin. Gerald Hargrave, 344 May Lily, The, 301 Measurement of intensity of inbreeding, 153 Mechanism of oxidation processes, 67 Medal. Award of the Symons gold. 32 Media, New mounting, 373 Meicury, November 7th, 1914, The transit of, 419, 424 Metal antiquities, Egyptian, 68 INDEX. Metals and alloys. The colour of, 268 at low temperatures. The electrical resistance of, 314 in cupellation beads. Platinum, 114 in warships, 187 — — The intercrv-stalline cohesion of, 30 Metallurgical Chemistrv Notes.Ensiineering and. 29, 07, 111, 148, 187. 220, 268, 307, 333, 371 Meteor Orbits, 415 Meteoric Astronomy. 96 Meteorological conditions of an ice-sheet. The, 69 Conference at Edinburgh, 116, 334 Office, The, 372 Meteorology .Votes. 32, 69, 115, 150. 189, 221, 269. 308, 334, 372, 400. 432 Meteors. 181, 352 Metz, C. 117 Mice, and the plague, Emerods, 406 Microscope, The binocular, 226 The Twin. 116 Microscopical and colloidal examination of jams. 175 Club. The Quekett. 33. 71. 117, 151, 191, 226, 273. 309. 335. 435 Society, The Royal, 71 ^Ucroscopy■ Notes, 32, 70. 116, 151, 190, 222. 270, 309. 335. 373. 401, 432 Migration routes. 153 MiiUbar : What is a. 222 MiUipede's nest. 340 Minerals. The saturation of. 399 Mirrors for photographic purposes, Silyering, 402 Mitchell, C. Ainsworth, 29, 67, 113. 147, 186. 220. 268. 306. 332. 370. 398. 431 Jlite, A rare freshwater. 335 ^lolluscs and algae. Symbiosis between freshwater. 397 Mono-rail system. The Schilowsky Gyro- scope. 131 Montell. Texas. Torrential rainfall at. 32 Moss, A fungus-infested. 225 Moth. The golden-eight. 72 Motions in the line of sight. 65 Mounting media. New. 373 Mouse, Hibernation of meadow jumping, 439 Museum. A British Folk. 136 Museum. The London. 50 Museums and Education. 89, 154, 259 . Folk-lore, 196 , The public utiUty of. 81 Myrmecopha^'idac. Complete toothlcssness of. 340 MyrmecophUous beetles, 73 NAPHTHEXIC ACIDS, SOAPS FROM, 148 Napier Tercentenary Celebration, 97 Nature Photographic Society's Exhibition, The, 9 Reserves, The Society foi the pro- motion of. 82 Nebular h\-pothesis. The, 149 Necturus, Decapitated \oung, 274 Negatives, The rapid drying of, 152 Nematodes, Antarctic. 194 Nereidae of Plymouth by means of their parapodia. On the identification of the, 326 Nickelide of iron, 220 Nicotine, Some notes on the chemistry of tobacco and, 46 Kicteribia, 190 Nitrogen and chlorine in rain and snow, The, 268 Nitrogen, Phenomena shown by active, 186 , The active modification of, 268 The fixation of, 29 Nomenclature, Electrical, 231 of alloys, 67, 148 , Zoological, 255 North Sea, Young sand-eels in the, 194 Notes. 26, 65. Ill, 145, 184, 219, 266, 305, 329, 369. 394. 430 Notices. 39, 80, 120, 159, 198, 237, 278, 318, 349, 382, 414, 440 Nottingham, Rainfall at, 150 Novae. Professor Barnard's observations of. 266 Novelists, Astronomy and modern, 121 OBITUARY, 27, 111 Objective. A new Zeiss. 151 Objectives. Photo - micrography. Il- lumination of opaque objects under low power, 313 Obscn^atorics, Girdling the Earth with solar, 236 Observatory- at Tatsfield, Mr, D'Esterre's, 145 , Sir David Gill's History of the Cape, 27, 66 , Stonyhurst College, 123 Oil and its utilisation. Whale, 113 fuel. The future of, 114 Okapi, The hving. 119 Olcott, WilUam Tyler, 298 OUgochaete, Remarkable epizoic, 405 Onflow. H.. 161 Orbits. Meteor. 415 Orchid with explosive flowers. An, 146 Ore. The production of steel direct from, 307 Organisms. Productivity of. 376 Organs of insects. The stridulating, 70 Orobanches. 62 Osmosis. 375 Osmotic pressure in mangrove trees. Transpiration and. 397 Oxidation processes, Mechanism of, 67 Ox warble-fUes. 406 Oxalate, Development with ferrous. 436 Oysters. Competition between Portuguese oysters and common, 153 PACIFIC. THE OCTOBER JOURNAL OF THE ASTRONOMICAL SOCIETY OF THE. 27 Palaeobotany : Its past and its future, 15 Palestine. The wild wheat of, 27 PangoUn. Malayan, 405 Paper-dust explosion, 67 Paper — " Satista." A new photographic printing. 273 Parapodia. On the identification of the nereidae of Plymouth by means of their, 326 Parasitism in the yellow-rattle tribe, 398 Paris market, Deepwater fishes on the, 72 Parks, London. 82 Parr. W. Alfred. 357 Paternal care. 405 Paulson. Robert. 319 Pearl-production, Artificially induced, 41 Pelvic bones. Cetacean, 153 Penguins. Social evolution among, 376 Perchromic acid. Blue, 186 Perfumes of lichens. 113. 196 Perthshire and .Vrgyllshirc, Abnormal stream transport in, 188 Petitfourt, E. J.. 323 Petrie, W. M. FUnders, 196 Petroleum spirit from natural gas. 67 Phenological observations. 1913, 221 Phenomena shown by active nitrogen. 186 Phenomenon, A planetar^^ 50 Phillips. The Rev. Theodore. 383 Photo-chentistrv. Some interesting features of] 389 Phonograph records. Enlarging and re- ducing. 231 Phosphorus. New salts of, 29 Phosphorus. Two new modifications of. 398 Photograph into a line drawing. To con- vert a. 71 Photographic printing paper — " Satista." A new. 273 purposes. Silvering mirrors for, 402 Society's Exhibition. The Nature. 9 Photographs. The late Mr. Franklin Adams's, 66 Photography, Diamond jubilee of The British Journal of. 314 Photography Notes. 34. 71. 117. 152. 192, 229. 273, 313, 336, 374, 402, 436 Photometer. The clcctric-ceU, 65 Photo-micrography by means of short- focus photographic lenses, 229 Illumination of opaque objects under low-power objectives, 313 Photo-microscopy, 190 Physical conditions of the Jewish race, ' 211, 292 Society's Exhibition, The. 9 Physics Notes. 34, 72, 193, 230, 314, 339, 375, 403. 436 Physiology. Use of liquid air in plant, 28 Pigmentation and assimilation in plant-, 112 Pillow-lavas in the Andes, 269 Pilot balloon ascents at Upavon during 1913, 150 Piltdown, Further discoveries at, 221, 400 Pistol crab. The tube of the. 118 Pitch and cancer, Coal-tar, 398 Plague, Emerods, mice, and the, 406 Planet Jupiter, The, 145, 383 Planetary- phenomenon. A, 50 Plankton (flagellates and green algae) of the Adriatic, 306. 330 (vegetable) of the Enghsli Channel, 267 Plant invasion on Hawaiian lava flows, 370 physiology-. Use of hquid air in, 28 Plants, Action of formaldehyde on hving, 28 • and carbon dioxide, 332 , Cell-dimensions in dwarf, 66 , Climate as tested hy fossil, 190 , Fermentation and the respiration of, 187 . Pigmentation and assimilation in, 112 Prussic acid in, 331 ■ . The origin of flowering. 185 Platinum metals in cupellation beads, 114 Plumage question. The, 81 Plumages in a male tragopan, Sequence of, 340 Ph'mouth by means of their parapodia. On the identification of the nereidae of, 326 Poison of hornets, 36 Polarised Ught to engineering problems of stress and strain. The apphcation of, 193 Pole-lathe, The, 364, 409 Polycistinous earth. The cleaning of, 152 Porphyridium, The algal genus, 331 Portuguese oysters and common oysters. Competition between, 153 Ports. Russian wheat and the Black Sea, 68 INDEX. Printing paper — " Satista," A new photo- graphic, 273 Proctor, Mary. 236 Production and profit-sharing. Co-oper- ative, 153 Profit-sharing, Co-operative production and, 153 Prussic acid in plants, 331 P>'rogalUc acid or " p\Togallol," 336 Pj'rogallol, Method of preparing. 374 , PjTogallic acid or, 336 QUANTUM THEORY, THE. 339 Quekett Microscopical Club, The, 33. 71, 117, 151, 191, 226, 273, 309, 335 RABBIT'S EGG CONTINUED OUT- SIDE THE MOTHER, DEV'ELOP- MENT OF A, 119 Radiation, Production of soft rontgen, 403 Radio-activity, 376. 404, 439 Radio-elements, Colloidal solutions of the, 404 elements. The chemistry of, 24 -telegraphic investigation, 132 Radium. Sources of. 439 Radula of Helix rupestris. The. 190 Rain and snow. The nitrogen and chlorine in, 268 Rainbows seen at once, Six, 116 Rainfall at Havana and the winter rain- fall in the south-west of England, Connection between the summer. 269 at MontcU. Texas. Torrential, 32 at Nottingham. 150 Rainfall, British, 1913, 401 Rainfall, Diurnal variation in the amount of, 69 , The economic value of tropical, 187 , Wind direction and, 372 Rainstorm at Doncaster, Great, 32 Rats, Inbreeding in, 231 Records, Enlarging and reducing phono- graph, 231 Redgrove, H. Stanley, 24, 46, 60 Reflectors, Great American, 27 Reproduction in yeasts. Sexual. 67 Reproducrivity, 73 Reserves, The Societj- for the Promotion of Nature, 82 Respiration of plants, Fermentation and the, 187 , Remarkable, 35 Reviews, 37, 73. 105, 156, 196, 234, 274, 316, 341, 380, 409, 439 Archaeology-, 196 Art, 156 Astronomv, 156, 234, 274, 316, 341, 380, 409 Biography, 196 Biolog>-. 105, 316, 410 Botanv, 73, 157, 234, 410 Chemistry-, 105. 157. 197, 235. 274, 316, '341. 380, 413. 439 Dress, 105 Ecology', 105 Economics, 74, 317 Education, 105 Engineering, 157, 275 Entomolog>-, 197 Forestr\', 74 Fungi, 106 Geographv, 37. 197, 380 Geology, 235, 275. 381 Reviews (cont.) — Gilbert White, 74 Histology, 37 History. 413 of Science, 413 Horticulture, 197 Hvgiene, 37 Medicine. 341 Meteorology, 275 Mineralogy', 342, 381 Mollusca, 158 Natural Histon', 74, 106, 276 Ornithology-, 236, 342 Perspective, 77 Petrolog\', 77 Photography, 106, 158, 342 Physical chemistr\-, 317 Phvsical geographv. 198 Physics. 78, 106, 276, 440 Polar Exploration, 440 Psychology, 158 Reference Books, 107 Sociology, 343 Spectroscopy, 198 Spinning tops, 381 Telegraphy, 78 Theologv.'78 Waves, 343 Wild Life in Crete, 107 Year Books, 38 Zo61og^•. 37. 107.236.277 Ridpath, C. H. E., 88 River-capture, An example of, 307 Roberts, J. H. T., 193 Rocks, Genetic classification of, 333, 371 Rocks, Saturated and unsaturated igneous, 69 Roe, T. B., 196 Rontgen radiation. Production of soft, 403 Rose, Ernest George, 50 Rotifers, Intelligence of parasitic, 191, 270 Rousselet, C. F., 191. 273 Rowan, WilUani, 53 Royal Microscopical Society, The, 71 Rupert-Jones. John A., 153 Russian peasants' arithmetic, 203, 254, 301, 323, 419 wheat and the Black Sea ports, 68 ST. SWTTHIN'S DAY AND SUBSE- QUENT WEATHER, 334 Salamander, The breeding of the, 194 Salmon in freshwater. King, 439 Salts, Aporeine and its, 370 of phosphorus. New, 29 Sandstorm at TuUa, Texas, Remarkable, 335 Satellite of Jupiter, The ninth, 430 " Satista," A new photographic printing paper — , 273 Saturn's satellites. Rotation periods of, 430 Schilowsky gjToscope applied to ships and aeroplanes. The, 209 Mono-rail system. The, 131 Scott, A., 399, 431 Scottish Zoological Park. The, 92 Sea route to Siberia, The, 269 Seagrave, F. E., 265 Sea-urchin, Coloration of a, 36 Seals, Lice on, 118 Sediments and sedimentary infillings in lavas. Vesicular, 31 Seeds, Detection of castor, 371 Selborne Magasine, The, 394 Selborniensis, Flora, 359. 387 Senior. Edgar, 34, 71, 117, 152. 192. 229, 273. 313. 336. 374. 402. 436 Sexual reproduction in yeasts. 67 Shark off the coast of Brittany, Frilled. 406 Shepherd. R., 153 Sheppard, T.. 196 Ships and aeroplanes, The Schilowsky gjTOSCope apphed to, 209 Shrews, Side glands of. 405 Shrimp, The fairj'. 165 Siberia, The sea route to, 269 Sidereal centre. The, 287 Sieve tubes. Evolution of, 332 Sight, Motions in the hne of, 65 Silvering. Manipulations in. 403 mirrors for photographic purposes, 402 Sts-, The face of the, 25, 63, 109, 134, 166, 232, 252, 302, 324, 377, 392, 428 Smith, T. F., 226 Snails of the I^ke of Geneva, Deepwater 405 Snow-Une in the Alps. Vegetation above the, 112 Snow, The nitrogen and chlorine in rain and, 268 Soaps from naphthenic acids, 148 Soar, Chas. D., 335 Societies, 284 Sodium thiosulphate ("Hj-po"), 117 Soil fungi, 28 and humus-formation, 66 Solar Disturbances, 36, 79, 119, 123, 180. 206, 244. 315. 326, 379, 391, 427 ecUpse of August 21st, 1 91 4, The total, HI, 305, 366, 394 , 1914. \-iewed in its partial phase from Hampstead, The, 357 , The war and the, 330 obsen.'atories. Girdling the earth with, 236 surface disturbances, 1 SoUds, Specific heat of, 340 Southport, HoUday weather at, 334 Spectrometer, The ;tr-iay, 436 Spectroscopic apparatus. Simple, 230 Spectroscopy for beginners. Stellar, 10, 55, 83,' 140 Spectrum of 7-rays, 340 Spider, Two kinds of males in a species of, 118 Spirit from natural gas. Petroleum, 67 Sponge, Cry-ptodromia and its, 73 Sponges in waterworks, 152 • , Symbiosis between algae and, 112 Spore-dispersal in the larger fungi, 98, 124, 168 Stanley, F., 230 Star charts. Variable, 298 motions. Studies on, 330 places. Use of galactic coordinates for, 26 Stars, Professor Kapteyn on the distance of the galactic heUum, 369 , The total number and total hght of the, 305 , Variable, 216, 239 Stebbine, The Rev. Thomas R. R., 255 Steel, Copper, 30 dies, A curious case of decarburisation during the hardening of, 307 direct from ore, The production of, 307 Steels, Local surface-hardening of high- tensUe, 187 Stellar parallaxes. Statistics of. 430 Stellar sj-stem. The, 219 Stenhouse, T., 29, 67, 114, 148, 187, 220, 268, 307, 333, 371 Stereoscopic drawing, 351 harmonograph curves, A new method of producing, 45 Stevens, A.. 30, 68, 114, 133, 149, 187, 220, 268, 307, 333. 371 Stone, J. Harris, 6, 131, 209 Stonyhurst College Observatory-, 123 INDEX. Stopes. Marie C, 15 Storms on the atmospheric potential gradient. Influence of dust, 270 Stream transport in Perthshire and Argj-ll- shire, Abnormal, 188 type, A new, 115 valleys, T>T)es of, 371 Sudan, Thunderstorms in the, 400 Suess, The late Eduard. 220 Sulphur bacteria. The purple, 185 Sulphuretted hydrogen from artificial graphite, 148 Sulphuric acids and vegetation. Sul- phurous and, 306 Summer in the United States, The great heat and drought of last, 150 Summer rainfall at Havana and the winter rainfall in tlie south-west of England, Connection between the, 209 Sun, The remarkable quiescence of the. 112 Surface combustion, 333 Swedish Antarctic expedition. An Anglo-, 221 Symons gold medal. Award of the, 32 TAR, PITCH AND CANCER, COAL-, 398 Tatsfield, llr. D'Esterre's observatory' at, 145 Telegraphy in aeronautics. Wireless, 279 Temperature change at great heights. Daily, 32 Tern colony. Some observations on a, 53 Terns plunging below the surface, 315 Tsetse-fiy, Biogeography of the, 68 Thiosulphate (" Hj-po ") Sodium, 117 Thompson, H. Stuart, 62 Thomson, Professor J. Arthur, 35, 72, 118, 152, 193, 231, 274, 315, 310, 376, 405, 439 Thorp, Death of Mr. Thomas, 314 Thunderstorm in South London, June 14th. The, 30.S Thunderstorms in the Sudan, 400 Tide at Fremantle, High, 88, 133, 153, 295 Tides, Single, 203 Timber Industries Exhibition, 1914, Eng- lish Woodland and, 5 Tobacco and nicotine. Some notes on the chemistry of, 46 Toothlessness of myrmecophagidae. Com- plete, 340 Tragopan, Sequence of plumages in a male, 340 Transparencies on collodion emulsion, 192 Trees, Lightning and, 372 , Transpiration and osmotic pressure in mangrove, 397 Tribe, Parasitism in the yellow-rattle, 398 Tropical horticulturists, A cool house for, 6 Tropism of horned bee, 35 Tubes, Corrosion of condenser, 371 , Evolution of sieve, 332 Tulia, Texas, Remarkable sandstorm at, 335 Twihght arc. The, 296 Tj'rreU, G. W., 31, 68, 115, 149, 188, 221, 269, 308. 333, 371, 399, 431 UNITED STATES, THE GREAT HEAT AND DROUGHT OF LAST SUM- MER IN THE, 150 University appointment, 314 Upavon during 1913, Pilot balloon ascents at, 150 VALLEYS, TYPES OF STREAM, 371 Vegetable kingdom. Distribution of aluminium in the, 268 Vegetation above the snow-Une in the Alps, 112 of the Adriatic, Marine, 146 • Arctic -American Archi- pelago, 146 • East Frisian Islands, 113 Falkland Islands, 147 , Sulphurous and sulphuric acids and, 306 Verne, Jules, 121 Viking period, Beeswax of the, 29 Vincent, J. H., 314, 339, 375, 403, 436 Vision, Intermittent, 35 ^'olcanic activity. The role of water in, 149 WALKEY. O. R., 287 War and the solar ecUpse, The, 330 area. Geography of the, 399 , Chemistrj' and the. 370 Warble-fly, Ox, 406 Warships^ Metals in, 187 Wasps' nest. Diary of a, 133 Wasps, Weight-lifting power of, 315 Water-beetle, The, 222, 270 beetles. Respiration in, 315 Water fishes on the Paris market. Deep-, 72 in volcanic activity. The role of, 149 of Dorton, The, 307 , The freezing of, 88 Waterspout at close range, 69 Waterworks, Sponges in, 152 Weather at Southport, Holiday, 334 Weather forecasts, Australian, 432 , Cotton and, 308 map of the northern hemisphere, 151 , St. Swithin's Day and subsequent, 334 Web, The spinning of a, 420 Webb, Wilfred Mark, 89, 154, 165, 259, 364, 409, 427 Whale oil and its utilisation. 113 Wheat and the Black Sea ports. Russian, 68 of Palestine, The wild, 27 Wliite, Portraits of Gilbert, 250 Wild Life, 349. 439 Wilkinson, M. C, 50 Wilson, Latimer J., 298 Wind direction and rainfall, 372 gusts, 70 Winter rainfall in the south-west of Eng- land, Connection between the summer rainfall at Havana and the, 269 Wireless telegraphy in aeronautics, 279 Woodland and Timber Industries Ex- hibition, Enghsh. 5 World, The International 1 : 1,000,000 map of the, 115 Worm, A hardy, 340 Worthington, James H., 424 A"-RADIATION (WITH SOME NEW EFFECTS), CONTINUITY AND, 260 X-rav spectrometer. The, 436 A^-rays. 72 YEASTS, SEXUAL REPRODUCTION IN, 67 Yellow-rattle tribe, Parasitism in the, 398 ZEISS OBJECTIVE, A NEW, 151 Zinc in coinage bronze by volatilisation. The estimation of, 148 Zodiacal Light, Tlie, 204 Zoological Gardens, Giza, 358 nomenclature, 255 Park, The Scottish, 92 Society of Ia)ndon, The, 95 Zoology Notes, 35, 72, 118, 152, 193, 231, 275, 315, 340. 376, 405, 439 Printed for the Proprietors (Knowledge Publishing Company, Limited,) by John King, Ealing and Uxbridge. Knowledge. Wit which is incorporated Hardwicke's Science Gossip, and the Ilhistrated Scientific News. A Monthly Record of Science. Conducted bv Wilfred Mark Webb, F.L.S., and E. S. Grew, M.A. JANUARY, 1914. SOLAR SURFACE DISTURBANCES. By THE KE\'. A. L. CORTIE, S.J., F.R.A.S. The statistical study of sunspots and faculae, their enumeration, and the determination of their positions and areas is all-important, since physical science depends on the sure foundations of exact measurement. In addition to this, the study of the life-histories of the spot-groups and the faculae associated with them, and, further, their co- ordination with the phenomena observed in the solar atmosphere, are no less necessarj' if the phj^sics of the Sun and the mode of action of the forces which are in evidence in such disturbances are to be adequately comprehended. Were an observer to examine the Sun's surface at times when sun- spots are plentiful, he would be at once struck by the variety of appearances which the spots presented : some as groups of small dots ; some as well- developed round spots ; others, again, as a brace of more or less developed spots ; and others of a medley of spots following a well-defined leader. And yet there is a unity in their seeming variety ; for by a comparative study of thousands of sun- spots drawn at the Stonyhurst Observatory during the last thirty years it appears that by far the greater number of sunspot groups follow the same phases in their birth, development, and decay, and that the dissimilarit\' of forms seen on any one day is but a passing type in an orderly progression in the life-history of a group of sunspots. Nor are the individual groups themselves isolated phenomena, but are frequently linked with other gi-oups, which will sometimes disturb, cither inter- mittently or continuously and successively, the same region of the Sun's surface for long periods of time. These disturbed regions are mostly in the form of narrow strips of the surface, containing an area comprised within some 20- in longitude by 5" in latitude, about five thousand six hundred millions of square miles, or one four-hundredth of the Sun's total surface area. For instance, a region of the Sun's surface between the limits 112" and 133° longitude and 9^ to 13= south latitude, was inter- mittently disturbed from January 1st to July 31st, 1897, and then almost continuously from January 1 9th to July 29th, 1 898. A still larger area, extend- ing from 249^ to 281= longitude and 13- to 27= south latitude, was the seat of continuous dis- turbance for five hundred and twentj'-seven days, from September 25th, 1891, to March 5th, 1893, and of intermittent disturbance for months after- wards. During this period four spot-groups of the the largest dimensions and thirteen of smaller size appeared on this portion of the Sun's surface. Such successive disturbances in close proximity to one another are nearly always concomitant with series of magnetic disturbances on the Earth, culminating at times in a magnetic storm of the first order of magnitude. Such was the ver>' great magnetic storm of March 15th, 1898, which was KNOWLEDGE. January. 1914. one of successive sets of magnetic disturbances, occurring in sympathy with the presentment to the Earth, at each of eight synodical solar rotations, of the area of the Sun already referred to as dis- turbed during the months January to July, 1898. In these cases the magnetic action of the Sun, which is a condition of the occurrence of a storm upon Earth, would seem to be gradual and cumulative, until it attains a disturbing climax. Disturbed areas of the Sun, associated with like series of magnetic storms, have, in the cases of the total solar eclipses of I8OP1, 1898, 1905, and 1908, been identified with bundles of streamers in the Sun's corona, apparently diverging from the foci of solar disturbance. This concordance is suggestive, as an indication of the mode of propagation of the Sun's influence operative in magnetic storms. But leaving aside for the present these questions of wider import, it is proposed to describe in detail the life-history of a typical outburst of sunspots and the accompanying faculae. The appearance of a sunspot group is generally preceded bj- a few flecks of compact brilliant faculae. presumably the signs of an upheaval of the solar surface or photosphere. But as the disturbance ma}' be associated with others, as has been already explained, the spot, when it appears, may be born amidst spreading and diffuse faculae, which do not properly belong to it, but to a pre- ceding disturbance in approximately the same region. The discriminating note is that its own faculae are, in the earlier stages of its life-history, brilliant and compact and closely massed round the newly born spot. The propagation of wave- motion when a stone is dropped into a pond, bears an analogy to the spreading of the faculae around a sunspot disturbance. In the illustrations (from a series of drawings in the Stonyhurst collection) which illustrate this article the spot group will be seen on September 7th, 1884, (see Figure 1) appear- ing as a few small dots in some old branching faculae, but surrounded bj' a bright ring of the faculae which properly belong to it. The few small spots marking the region of a disturbance are soon joined by others, which gradually form a train consisting of a principal leader spot and a trailer. This phase generally occurs from five to seven days after the first appearance of the spot, the faculae remaining compact and bright about the group. The beginning and the progress of this stage in the spot's life- history are illustrated in the present case in the drawings of September 10th and September 12th (see Figures 2 and 3). Two. groups of spots are showTi on the drawing of September 10th (see Figure 2) : it is the upper one of the two with which we are concerned, and the subsequent development of which is shown in the succeeding pictures. This is the period in the life-history of a spot-group of great internal activity, which is completed when the spots which fill up the space between the two main spots disappear, leaving the leader and the trailer of the group. It is in this space, between the two main spots, that vivid reversals of the hydrogen lines are frequently seen in the spectroscope. The two main spots arc also at this stage often affected by proper motions, independent of and superadded to their normal drift across the Sun's surface proper to the latitude in which they may have appeared. For it is well known, since the classical researches of Carrington on sunspots, that a spot in latitude 1-f^ north or south will have a normal angular velocity of 14"-2 a day in longitude, while spots in higher latitudes will travel more slowly, and those in lower latitudes more quickly. This inequality of rotational velocity with latitude is one of the many puzzles of solar physics. But the proper motion to which reference is now made is something beyond the normal drift, the leader spot frequently advancing forward in longitude, and the following spot receding in an opposite direction, as if the two spots were exercising a repellent action upon each other. The faculae now begin to branch out from the centre of disturbance, becoming at the same time less brilliant. They sometimes embrace vast areas of the solar surface. The drawing of September 1 5th (see Figure 4) illustrates the beginning of this tendency to spread in the faculae, which is seen also in those of the ne.xt two days. The spot-group is now approaching the Sun's west limb, and on September 17th (see Figure 6) the leader spot, at the Greenwich mean time indicated, is actuall}' on the limb. Is it a saucer-like cavity in the limb, or is it an eminence blocking out the view of a continuous limb ? Might not the pen- umbra of a sunspot represent the shelving sides of a shallowdepression.andthe umbra a central eminence something like the central peak of a lunar crater ? The next drawing, that of October 5th (see Figure 7) shows the group after it has passed round the invisible hemisphere of the Sun, and after its reappearance at the east limb. It will be noticed that the following one of the two spots is breaking up. This usually occurs until it is finally absorbed in or covered by the photosphere, leaving the leader as a single round spot. It may persist in this steady state for another two rotations, surrounded by extensive, though comparatively faint, faculae. This spot also is gradually broken up and dis- appears as a few small dots, or a single small round spot, recalling, except for the form of the accompanying faculae, its first beginnings ; for, whereas the faculae were then compact and bright, they are now diffuse and not so brilliant. This phase is shown in the third reappearance of the spot in the drawing of November 1st (see Figure 8), when one minute spot is seen in the enveloping faculae. At the next rotation, in the drawing of November 28th (see Figure 9), an extensive area of faculae alone remains to mark the seat of the spot disturbance. But the next day a new, though associated, disturbance appears in almost the same latitude, and some two degrees behind in longitude, which is figured when approaching the west Jantary, 1914. ;\"o\vLi:i)(;i:. 1 . - ':■:,: -1. lull '■-^ , riGLKl. J. Sept. IJlh. 1S^4. I'K.LKl- 4. Sept. litl:. LSS4. I'K.lKi; 5. Si-pt. Ibth. 1^N4. llh. 12h. JOiii. I2h. iOiii. ::% m- OK-Auixos (^r sL'Nsi'irrs m.vdi: in thi-: vi:.\r is,s4. from ihf. s'iuNVHUK>i ui;>i;u\ Aium C(jLLi:cri()N. KNOWLEDGE. January, 1914. iGUKh y. Nov. 2,-s. is.st, i.'ii. ui DK.\\VIN(;S OF SUNSl'crj'S NLADI-: IN Till; \1:AK l^M. 1 KO.M llli, SroNVilLKsr OBSia':\'.\TUKY COLIJX iujn. January, 1914. KNOWLKPr,?:. limb on December 6th (see Figure 11). It is com- paratively easy, therefore, for one who studies the surface of the Sun, and who applies the criteria of the form of the spot-group and of the surrounding faculae, to discriminate between old and new disturbances. Should the spot-group also be in one of its earlier stages of development when it comes into view on the Sun's east limb, it is possible to give the appro.ximate date of its first appearance on the invisible hemisphere of the Sun. The different phases of the life-histories of spots have been summarised in a series of types, with suitable subdivisions, which it is beyond our scope to dis- cuss. These types, as a short description of a spot- group, have been adopted at the solar observatories of Kodaikanal, Tortosa, and Stonyhurst, whence they originated. The group of spots which has been described in the present article can be recog- nised as group 1480, mean longitude 15-38 and latitude -|- 14-02, and the recurrent group 1501, mean longitude 15-18 and latitude -|- 14-18 of the Greenwich sunspot volumes, and the second group which appeared in the same region as group 1547, mean longitude 13-03 and latitude -|- 13-52. ENGLISH WOODLAND AND TIMBER INDUSTRIE.S EXHIBITION. l'J14 Ax important and representative exhibition ol woodland and timber industries will be held in London this year, under the auspices of the " English Forestry Association." Invitations to cooperate will be extended to all bodies interested in the subject, and it is hoped to obtain the enthusiastic support of all concerned with English Timber and Underwood, so that a real effort may be made to improve the present unsatisfactory position of affairs. A special feature of the exhibition will be practical illustrations — showing the men at work — of the Woodland Industries which the Association are organising and encouraging, and especially those dealing with the conversion of coppice and poles. By organisation and up-to-date methods, effec- tive steps are being taken to compete with foreign supplies, and the Association have spent consider- able time in investigating the directions in which such competition maj' be most successful. No industry will be exhibited which in their opinion is not capable of being made a commercial success. The importance of woodland industries in pro- viding work for agricultural districts during the winter months cannot be over-estimated, and it is deplorable that in the past such valuable sources of rural employment have been lost for want of organisation. The decay of these woodland industries has contributed very considerably to rural depopulation, and their successful revival would have an important influence upon small holdings and similar movements to attract the labourer back to the land. Steps have alreadj' been taken to revive the wooden barrel-hoop industry. Contrary to popular belief there is still a very large demand in this country for these hoops, which are manufactured from Hazel and other Underwood. Other local industries are being extended and organised for the consumption of other classes of Underwood. Another special feature of the Exhibition will be illustrations of the present uses and markets for English Timber, and great emphasis will be laid upon new ones that might now be cultivated. The " English Forestry Association " was formed some years ago to take up the whole question of the marketing and commercial utilisation of English Timber and Underwood. After several years of investigation the Council are satisfied that proper markets for all classes of English Timber and Underwood exist, and can be cultivated, pro- viding that landowners and land agents will cooperate with them. \Vherever sufficient and proper supplies can be ensured, a greatly increased demand is being organised for all classes of English Timber and Underwood, and especially for Oak, Larch, and Scots Pine. At the coming exhibition all these points will be illustrated, and in order to secure the best results the Council of the " English Forestry Association " invite particulars from Landowners, Land Agents, Timber Merchants and others interested in Wood- land Industries. During the course of the Exhibition, Conferences will be held to discuss important points, and especially with a view of extending the uses of English timber or the goods manufactured from it, as well as to endeavour to overcome some of the initial difficulties. The Association are publishing leaflets dealing with the many important points with which they are immediately concerned. The " English Forestry Association " wish to emphasise that they are not a trading association, they do not as a body buy or sell timber, nor charge commission on the sale. Their object is to encourage the use and demand for English Timber and I'nderwood, and to organise its marketing and assist in its sale, leaving it to the recognised channels to negotiate and to supply that demand. They are not aware of any legitimate interest which will be prejudiced by the steps which they advocate and they invite all who are interested to communicate with the Honorarj' Secretary, " English Forestry Association," Farnham Common, Slough, Bucks, with a view to making the coming exhibition a success, and helping them to prove that British Timber and British goods, manu- factured by British labour, can compete successfully with foreign productions. A COOL HOUSE FOR TROPICAL HORTICULTURISTS. By J. HARRIS STONE, M.A., F.L.S., F.C.S A nurseryman's business in the Southern States of America is very different in character from what it is here. The reason is not far to seek. The climatic conditions are much more trjdng, extremes of heat and cold not unfrequently occur, requiring the utmost skill of the scientific gardener to combat and overcome if commercial success is to attend his expenditure of time and money. Practically quite a new wholesale florist's business has been inaugurated at Dickinson, in Galveston County, Texas, by Mr. Erik E. Stone, who emigrated to the United States some years ago. Mr. Stone had had no previous knowledge of gardening beyond the ordinary amateur's interest in flowers, but he received the ordinary all-round education at Bedford Grammar School, and was always particularly interested in natural history, and especially botany. Taking up a farm of many acres, about nine miles from the thriving port of Galveston, he gradually formed it into a nursery- garden, and took to raising chiefly gardenias, which he grew in long hedges, sending the odorous white blooms all over the States. He would take orders for these blossoms by the thousand, and has supphed requests for as many as ten thousand at a time for the shops at St. Louis, Chicago, and New York. White flowers, he soon found, had a more constant and larger demand than any others ; so he concentrated his attention on the supply of such for weddings and funerals all over the States, but strictly as a wholesale merchant. To do a retail trade in flowers, as well as a wholesale, is not politic there, and the latter is more constant and paying. His difficulty was to keep up his supply to meet the demand all the year round. Flowers are such seasonable commodities that he found he must depart from the usual stereotyped methods in order to be able to meet the trade necessities at all times of the year — winter as well as summer. One of his inventions is a cool house for a hot climate. It is like other greenhouses in so far as the frame goes, but it is different in that it is exactly the opposite of the usual warm house for cool climates. Each house is thirty feet by a hundred, constructed of the well-known Foley pipe frame, with no benches, but four lines of support. The common complaint in Mr. Stone's locality is that the ordinary form of greenhouse gets too hot in the summer. After thinking the matter out for himself he had a special roof built on a standard frame (see Figure 12). Shade was what he wanted. This is how he got it. At the end of the house are three sash bars to carry the glass in the ordinary way ; then a bar is admitted and the frame set in ; two frames are not glazed, but filled with roofing felt ; then three more runs of glass ; then a felt frame, and so on, to the other end of the house. Laths of wood are nailed on to a wooden framework, with the width of a lath between and on the sides as well. The beds are bordered with creosoted wood, which, Mr. Stone tells us, does not injure the plants. These lath-houses keep the hot sun off in summer and the plants warm in winter, and he finds they are admirable for producing all the year round the graceful spray=5 of Asparagus plumosus nanus, which are in constant demand. Mr. Stone says : " I do not raise the plants to sell, but only the sprays, which are cut from them as they mature and are shipped to florists all over the States, who use them in making up flower designs and decorations. The sprays are put up in bunches of twelve or twenty-five, accord- ing to the market they are for, and wet paper tied round the stems to keep them on long journeys. They are put up in special boxes, holding from three hundred to five hundred sprays each, or twenty-five to forty-two bunches of twelve sprays. The boxes are well lined wdth old newspapers first. I buy my newspapers by the hundred pounds, and use quantities of them. There is a reason for this — not because the old papers are cheap, but that there has not 3'ct been found anything so good to hold moisture in and keep hot and cold air out. Nothing beats an old newspaper when it comes to packing plants or flowers." Mr. Stone raises his Asparagus plumosus plants from seeds, and cuts from them in two years, when they will produce good sprays for four or five years. In winter the tops often get frozen off, but the plants put up new shoots in about six weeks or two months, according to the weather, the roots being very seldom killed. Figure 13 shows the interior of one of these shade-houses, where each compartment of plants is numbered. The history of each of the groups is carefullj- recorded, the manure used and general treatment, and so on, in order that the best and most economical method may be evolved and the inferior discarded. Mr. Stone, to use the American expression, is doing a " bumper " business at Dickinson, and a \nsit to his glasshouses, lath-houses, beds, and hot and cool houses makes one feel inclined to go in for this delightful business. There is a sj'stcm in the way things are run about the place, for every detail is under the personal supervision of the proprietor, and must be done just right, or else it is considered worse than useless. Among the omamental|trees and shrubs grown by Mr. Stone are several varieties of cedars, camphor trees. Jamary, 1914. KNOWLKDGK. Figure 12. General view of part of Mr. E. E. Stout's Nursery at Dickinson in (iaiseslon County, Texas, U.S..^., showing roof of a Shade-house in the foreground. FiGL'RE 13. Shade-house invented by .Mr. E. E. Stone for growing all the year round the .Asparagus Feni. KNOWLEDGE. Jani-^ry. 1914. Fiom a t>lu^ti\^7af:i iy CliarUi Mac, Fir.rKK 14. Ttthninis sp. with poUinia of Asclcpuis syriiicti :itt;'.clied U) its Utel and proboscis. X 7. January, loi (. knowledcp:. Arabian tallow trees of the Loras variety, Mexican single tube-roses, and jessamines. Under the lath- houses and combination houses he has always about fifteen thou'^and Asparagus plumosus plants alone. From his thousand young jessamine trees, blooming this past season for the second time, he shipped more than half a million blossoms. So well did he realise from these that he has made arrangements to plant several thousand more of the plants, and engage in growing the flowers foi the market in a more extensive way. About the gardens there are four gas-engines, lifting water into the high-level tanks and operating the complete workshop of the place. For sport Mr. Stone has almost at his doors plenty of wild- duck shooting and alligator hunting, so that he combines pleasure with his other and more remunerative occupations. THE PHYSICAL SOCIETY'S EXHIBITION. The Physical Society of London held their ninth Annual Exhibition of Electrical, Optical, and other Physical apparatus, at the Imperial College of Science, on December 16th, \')\'A. Experimental demonstrations were given at intervals throughout the afternoon and evening of the Band Spectrum of Helium, of lonisation by Collision, of the Interference of X-rays by crystals, and many other interesting phenomena ; while in the two lecture-theatres, Professor J. A. Fleming, D.Sc, F.R.S., discoursed on the l^roduction of Vibrations on Loaded and Unloaded Strings, and Mr. Louis Brennan, C.B., on the " Iridiscope " and some Experiments on Soap Films. The latter lecturer made an appeal to the aesthetic as well as the scientific sense, for the colours displayed by the delicate films ingeniously stretched on the iridi- scope were exquisite both in their variety and intensity. These colours, as explained by Mr. Brennan, are due to interference and accordingly change with the ever-varying thickness, or rather thinness, of the soap films, which although almost inconceivably thin nevertheless exhibit such marvellous tenacity that they will endure a fairly strong blast from a blowpipe before rupturing. Curious and very beautiful effects were produced when the lecturer introduced a hair, the ends of which had previously been cemented together, into the film. On applying the blowpipe to the centre of the ring thus formed the film was ruptured within the circle, so that a round hole, bounded by the hair, was produced. This hole could be made to swim about the film in a remarkable way by blowing upon it, and when two holes w'cre pro- duced in the manner described the result was very curious indeed, the two round vacuities revolving about each other something after the fashion of a double star. A vast array of instrumental exhibits was to be seen in the various rooms, and astronomers in particular found much to interest them in the display of astrophysical apparatus. Messrs. R. and ]. Beck, Ltd. showed, in addition to their well- known microscopes, several examples of Thorpe diffraction gratings — replicas of the Rowland's Gratings cast in celluloid from the original rulings — viewed under the microscope. Microscopes of various patterns were exhibited by Messrs. Zeiss, Leitz, and Swift, the new binocu- lar microscope available for objectives of the highest powers (including oil-immersion objectives) of Messrs. E. Leitz attracting especial attention. A slide of Trypanosomes was exhibited under one of these, and all the details of this micro- organism were shown with wonderful precision. An interesting instrument exhibited by the courtesy of Messrs. Vickers, Ltd., was the " Ripo- graph." This was a copy, with additions, of an instrument designed and made at the I^oyal Air- craft Factory. The apparatus, when carried on an aeroplane, records, simultaneously, nine different quantities, and thus enables the behaviour of the aeroplane to be thoroughly examined. Messrs. A. C. Cossor, Ltd., showed new forms of X-ray tubes with Iridium Targets, and with Lithium glass. Other interesting apparatus by Messrs. Adam Hilger, Ltd., and Messrs. Newton & Company, attracted much attention. The first-named firm showed their Quartz Monochromatic Illuminator of large effective aperture for the ultra-violet, reading from 200 a/m to 700 /ul/ul direct in wave-lengths, and their ingenious Spectro-Comparator, especially designed for the accurate comparison and measure- ment of spectrograms. Practical utility was duly considered in many of the exhibits, and mention must be made of the installations shown by the Marconi Wireless Telegraph Company, Ltd. ; but one of the items most calculated to benefit the man in the street was perhaps the demonstration given by Messrs. Clifford C. Paterson and B. P. Dudding of a proposal for mitigating the dazzle caused by motor car head-lights. THE NATURE PHOTOGRAPHIC SOCIETY'S EXHIBITION. We have the pleasure of reproducing (see Figure 1 4 on page 8) another interesting picture which was shown at the Nature Photographic Society's Exhibition, of which we gave an account in the last number of " Knowledge." It is by Mr. Charles Macnamara, of a species of gadfly, bearing pollinia on its feet. STELLAR SPECTROSCOPY EOR BEGINNERS. III. Bv PROFESSOR A. W. BICKERTOX, A.R.S.M. The Spectroscope. Spectroscopes are of two principal kinds, generally called " integrating" and " analysing " ; but, as the spectroscope used in analyses is generally an integrating one, perhaps the best terms to use Figure 15. Figure 16. would be "integrating" and "differentiating" spectroscopes. The former presents all the rays from an object collected together. The differentiating spectroscope allows the several parts of an object to be examined separately. The camera, or tele- scope, armed with a prism, but not having a slit, is a differential spectroscope. Or the object to be examined may have its image focused upon the slit of a spectroscope, so that different parts of the object may be separately examined. An integrating spectroscope then becomes analysing or differential. An interesting example of this change is the mode of looking at the so-called long and short lines of an element. If an electric arc be placed at right angles in front of the slit of a spectroscope the whole hght will show on the spectrogram. If a lens be interposed as in Figure 1 6 the middle or each end can be separately examined. The diagram shows the middle of the arc being examined. Figures 15 and 16 show the very different effect on the various overtones. Stars have no disc ; hence, c\en without a slit, all spectrograms of stars are integrated. The parts of a star cannot be differentiated. In fact, the spectrum of a star is a straight line, and the Fraunhofer lines but black dots. A cylindrical lens is used in the eyepiece of the telescope to make these dots into lines. When spectrograms— that is, photospectra — are taken, the plate is sometimes moved at right angles to the spectrum, or the plate rocked to give width to the lines in an enlargement. All the spectra in the plates of the first article are integrated spectra. Mr. Worthington's spectruni that was given in the December number of " Knowledge " is a differentiated one. Divergent Rays. During an eclipse of the Sun along a shaded path every chink of the foliage that allows a sun- beam to pass through produces an image on the path of the eclipsed Sun. A very pretty way of showing an eclipse of the Sun is to cover a window with brown paper and pierce small holes of any shape through the paper. If a white screen be placed across the rays at some distance from the holes, images of the eclipse are seen, no matter what are the shapes of the holes, whether they be round or square or triangular. The image gets bigger and less like the hole the farther the screen is from the opening. The rays diverge in the same way from a spectroscope slit, and a lens is used to make the rays entering the prism parallel : this is called a collimating lens. After passing the prism a small telescope is used to bring the parallel rays of each tint to its focus. As the rays are differently bent the telescope has to be moved around in order to see each in succession. Half the length of the slit may be covered with a totally reflecting prism to bring into comparison I-IGURli 17. light Irom a known source. This enables an element to be recognised. Figure 15 represents the arrange- ment ; only two wave-lengths are shown, red and green ; a perspective picture of the whole apparatus J.WIAUV, 1914. Kxo\VLi:r)r,i-:. From ipectro^mms taken Spectra showing the point of light of the star drawn out into horizontal lines by a prism ; the black vertical lines are a series of dots, each one produced by a shift of the image of the star on the photographic plate. From spectrograms by William Huggiris. Tulse Hill. Figure 19. Example of integrated spectra : the light is collected from the whole of the luminous body. KNO\\Li:nGK. J.wi-AUY, ion. '(■■■■iiiiiii I'rom spfctro^^rant!, by Figure 20. IVi/liam lliiggim, Ttihe Hill. I- 1 0111 spirtru^yaiin !■ FlGL-Rli 21. lyiJiuim //Kg^iiis, Tube lUll. Siifctrograins showing well the cicliujlc hanuojiic cluuaLhr oi Ihr overtones of thi: eleinonl liyilrogen. January. 1914. KNOWLEDGE. 13 is shown in Figure 1 7. In this, a scale is reflected instead of a known element. Cross wires are placed in the telescope, and a graduated scale is attached to the stand to enable the exact position of the line to be read off. Observing Power. 1 once had a student who could see lines in the ultra-violet part of the spectrum of which no one else could see a sign. To test liim we read the vernier scale, and then let him tix the cross wires over the ultra-\iolet line again, and the reading was exactly the same as before. Some students are slightly colour-blind, and have a great difficulty in reading the red end of the spectrum. Besides these there are other great differences in observing power, both telescopic and spectroscopic. Some observers can catch a faint point of light like a planet's moon or a small asteroid, and others such delicate lines as the complex markings on Mars. Training has an immense deal of importance in this respect. A person for weeks may not see the so-called canals on Mars, yet when once they are seen they are afterwards easily recognised and drawn, and differently trained observers will draw them alike. Probabh', however, the full compre- hension of a good working hypothesis is the very best aid of all in the discovery of truths of any kind. Of course, there is seeing what one looks for when it is not there. There are many ways of testing such false seeing, such as comparison of different observers' drawings, and photography. There are also researches in which the eye is best, and others in which the photographic film is altogether the most powerful, as already noticed. Gratings and W.a.ve-lengths. Before studying celestial phenomena we had best understand the effect on light of gratings as well as prisms.' Sometimes in early morning brilliant colours are seen flashing from sunlit dewdrops. The water sphere is sorting the light into its constituents. The beauty of sunlight pulled to pieces is seen in the diamond and the lustres of chandeliers : these are all examples of prismatic colours, but sunlight can be pulled to pieces, by closely ruled lines cedled " gratings.' The loveliness of a grating is seen in mother-of-pearl and in the rainbow button, both of which are covered with fine, close, parallel lines. The colours of a prism are due to the different refractions of the waves. The colours of a diffraction grating are due to the effect of two waves of light on each other, and is called " interference," or " diffraction. " Interference effects are also seen in the colours of a soap-bubble, in the changing tints when steel is tempered, and when oil is placed on water. These are called the colours of thin plates. A very pretty way of studying these phenomena is to overload one of Professor Boys's Rainbow Tops, and keep spinning it ; then care- fully noticing the successive changes of colour at the centre. An extraordinary number of important phenomena can be learnt from this wonderful toy. The Explan.\tion of Interference and Differentiation. Suppose two equal impulses be given to a particle of ether, one to push it up and the other to press it down ; clearly the particle stands still. If we ha\e two sources of the same pure tint, the two impulses may push the ether particle the same way and increase the intensity of the light ; or they may be half a wave-length different in phase — then the colour is obliterated. Suppose we have white light made of pure green and pure red, and there is a reflection from the front and back surface of the film of a bubble ; the two reflections of the red may be half a wave-length different, and will interfere and be destroyed ; the green would then show. Suppose the film became thinner, and the two green reflections were half a wave-length out ; the green would be destroyed and the red would show. Thus is explained the colours of thin plates. In the case of a grating of thousands of close lines the light tends to spread fanwise through each space ; the oblique reflection, or transmission from the different openings or surfaces, will be half a wave-length out for some tints, and whole wave- lengths different for others. With common white light the exact angle at which the reflection, or transmitted beams, are whole wave-lengths out give brilhant colours. These various wave-lengths are collected by a lens (see Figure 22). A different wave - length would be focused in a different position, as a different angle would produce a whole wave-length. Maps of Spectra. Prisms of different glass bend the light in different ratios ; hence prismatic dispersion tells us but little of the actual lengths of the wave, and spectra maps prepared from them are of much less value than grating maps. Fraunhofer noticed this, and took extraordinary trouble to prepare gratings so accurate as to enable him to measure the waves of light. This wonderful genius, who was apprenticed to a looking-glass maker, died before the age of forty ; yet he laid the foundations of modern spectroscopy.. He mapped five hundred and seventy-six of tlie Sun's lines ; was the first to make and use gratings for perfect spectra and to measure the wave- lengths of light. He suggested that the D lines were produced by sodium, and made most wonderful microscopic and telescopic lenses, so that his epitaph, " He brought the stars nearer, " was well deserved, even more so than anyone would then have thought. Notice the scales in Figure 423 in "Knowledge," Volume XXXVI (1913). Ihe di\isions vary in length because the photographs were taken through a prism. In modern day^ Fraunholcr s spectra maps have 14 KNOWLEDGE. January. 101-1. been greatly improved by many, especially by Angstrom and Rowland. Wave-lexgth Units. Gratings are made of glass and of metal. Fraun- hofer drew exquisitely close lines, with a diamond, on glass. Our modern gratings run from ten thousand to twenty thousand lines to the inch. A table, or map, of solar lines, numbering over Figure 22. twenty thousand, has been prepared by Rowland. Angstrom used as units of wave-lengths the ten millionth part of a millimetre : these are called tenth metres," or J-n of a metre, also called Angstrom units, and are signified by A.U. Thus the crimson hydrogen line, the line indicated by Fraunhofer as C, and now more usually as H.,, has wave-length 6563 A.U. ; and D, the longest yellow sodium line, has 5896 A.U. Rowland divided the A.U. units into one thousand parts ; and the two above lines, C and D, became, with greater precision, C 6563'954 and D 5896' 154. The ordinary range of the spectrum is indicated by the distance from the line A 7594 A.U. to the broad diffused line of calcium K 3934 A.U. In the November and December numbers of " Knowledge " the scales attached to the several spectra show the Angstrom units, and also show that these spectra are chiefly of short wave-lengths ; the ordinary photographic plate being, as already explained, much more sensitive to the short than to the long wave-lengths. It is well to remember that there are two ways of looking at the dimensions of waves : their frequency and length. The greater the frequency the shorter the wave. It is the wave-length that is generally used, but sometimes in studying the systems of the spectrum line of an element the frequency throws light on the harmonic character of over- tones. The shorter the wave-length the greater the frequency, and vice versa. The relations are well shown by the curve called the rectangular hyper- bola (see F'igure 23). The upright lines represent wave-frequencies, and the horizontal lines the wave- lengths. A few lines are drawn showing the approximate relations. The Y square and the R and V rectangles are all equal in area. In all cases the rectangles made by multiplying the two are equal to one another. The parabola and rectangular hyperbola are extremely useful in spectroscopy, and, in fact, in physics generally. A few words will be said about these conies in the next article. A first look at stellar spectrograms (the wonderful photographic cyphers by which the stars tell us their story) seems to show us a hopeless jumble of lines, and to the eye they are bands of many colours on a continuous spectrum. Some lines are bright and some dark ; some broad and diffused ; some sharp and narrow. Except the wonderful hydrogen band seen in the pre-solar stars in " Knowledge," Volume XXXVI (1913), Figure 423, all the fines seem to be without order ; but the clear and obvious harmony in the black bands in those stars furnished a first key to unlock the mysteries. Key after key has been found since. All is not yet understood ; but already a wonderful order has evolved from the apparent Figure 23. chaos. When astronomers also use the powerful cosmic key of the third body, the cipher of the com- plex stellar spectrum will be an open book, telling us in its first amazing outlines the cycle of the eternal heavens. BRITISH ASSOCIATION GRANTS. The Council of the British Association, acting under authority of the General Committee, has made the following grants out of the gift of £10,000 made to the Association for scientific purposes by Sir J. K. Caird at the Dundee meeting of the Association last year. 1. ;i500 to the Committee on Radiotelegraphic Investigations. 2. An annual grant of £lOO to the Committee on Seismological Investigations, which is carrying on the work of the late Professor John Milne, F.R.S. 3. An annual grant of ;ilOO to the Committee appointed to select and assist investigators to carry on worii at the zoological station at Naples. 4. £250 towards the cost of the magnetic re-survey of the British Isles, which has been undertaken by the Royal Society and the British Association in collaboration. PALAEOBOTANY : ITS PAST AND ITS FUTURE. Rv MARIE r. STOPES, D.Sc, Pii.D. Fellow and Lecturer in Palaeobotany at University College, University of London. Thf.re was once a time when anthropology claimed privilege as " the youngest of the sciences." To-day Palaeobotany holds that inglorious place. Indeed, Palaeobotany is so exceedingly young a science that I fear that most people, even most palaeobotanists, will scarcely allow that it exists independently at all. This is because it is one of the borderland studies whose boundaries lie between several others, and consequently it is partially known to each of the more condensed, older- established provinces whose territory it touches. Palaeobotany is thus comparable to physical chemistry or astral physics ; it is a new science resulting from the combination and extension of two or more older ones. The botanical side of our science has safely passed through its early struggles, and, thanks to the work of a number of distinguished men, some of whom I shall have occasion to mention later, is to-day eagerly claimed by its once antagonistic step-mother, Botany. The geological side of the subject is still rather scornfully annexed by Geology, and the rest of the science — what might be called the cement of the whole superstructure — is neglected by both Palaeophytologia's step-parents, and left in the hands of one or two isolated people. I do not know whether anyone has ever quite clearly, unequivocally, and determinedly enunciated the fact that Palaeobotany is an independent science. In any case, that is what I wish now to emphasise ; indeed, an attempt to drive that statement home is the raison d'etre of this paper. Palaeobotany has already passed through three main phases of its development : the first, when fossil plants were supposed to be the spontaneous ornamentations of stones by an exuberant Nature which blindly disported itself ; the second, when they were realised as being the remains of extinct life, but were described without the light of a fundamental and unifying hypothesis ; and the third, when a scientific knowledge of their structure made comparison with recent plants possible, and it was realised that they threw light on the evolution both of the living plants and the existing continents. In this phase we are now at work. As we are all evolutionists the past as well as the future of our science interests us, and with the past let me deal first, dallying a while in the delightful shades of the tortuous paths of mediaeval progress. On turning to the early books on geological and botanical science it is rather surprising to find how few and scanty are the references to plant fossils. It seems unlikely that even the most primitive people could never have noticed such striking objects as the ribbed casts of Calamites. Sometimes the trunks are washed out of cliffs, so that they look like pillars from an ancient temple ; and even the smaller branches, preserved as deeply ribbed sandstone casts, are so conspicuous that it seems certain they must have attracted the attention even of savages. Yet the only fossil known to me whose history indicates that it may possibly have interested prehistoric man is Cyadeoidea etrnsca, a specimen which Capellini describes as having been found while excavating an Etruscan tomb. Leonardo da Vinci, in the early sixteenth century, was perhaps the first to give anything like a scientific explanation of fossils (see Richter's Ed., 1883), but he does not specially mention fossil plants. In the edition of Gerard's " Herbal " published in 1597, there is one reference to mineralised wood, which he calls Ligna Lapidea and figures as a stump standing in water. His words are worth quoting : " Among the wonders of England this is one of great admiration, and contrary unto man's reason and capacitie, that there should bee a kinde of Wood alterable into the hardnesse of a stone called Stonie Wood, or rather a kinde of water, which hardeneth Wood and other things into the nature and matter of stones." In the old literature to which I have had access there is a long gap of nearly a century from 1597 before there occur other references worth quoting. Even at a time when the petrifications of animal shells were exciting much discussion the early references to plant fossils were few and scanty. I think this is not perhaps surprising. To the unscientific and uncritical minds of the fifteenth and sixteenth centuries there must have seemed nothing unnatural in the impression of a fern or leaf upon a rock. In autumn one may often find leaves closely adhering to stones in a way that is suggestive of a fossil impression, and such a comparison would have immediately lulled a mediaeval mind had it noticed a fossil plant. As vegetation covers the rocks and soil there would have appeared nothing very startUng in the dis- covery of leaves printed on a piece of rock while * Inaugural Lecture at University College, London. Dr. TeaU, F.R.S., F.G.S., Director of H.M. Geological Survey, in the chair. 15 16 KNOWLEDGE. January, 1914. it was soft or wet. What stirred the first enquiries into the nature of fossils and led to elaborate discussions about the Flood were sea-shells found high and dry on the hillsides. Robert Hooke's famous explorations with his microscope led him to take an interest in fossil wood, and in his " Micrographia " (1665) we find a plate illustrating part of a section of petrified wood so far as he could see its structure. He devotes five pages to a careful considei^ation of this and other fossils, and concludes that such " figur'd stones " should be collected and studied furtlier. In 1693 John Ray, in his "Three Physico- Theological Discourses," devotes some time to demonstrating that wanton ornament is not in Nature's way. He then goes on to consider animal shells, and concludes that they are not accidental ; for he says : " That Nature should form real shells, without any design of covering an Animal, is indeed so contrary to that innate Prolepsis we have of the Prudence of Nature, (that is, of the Author of Nature) that without doing some Violence to our Faculties, we can hardly prevail with ourselves to believe it." Nevertheless, he did not realise that fossil plants were real fossils ; for even after demonstrating Nature's abhorrence of wanton ornament he continues : " Yet I must not dis- semble, that there is a Phaenomenon in Nature, which doth somewhat puzzle me to reconcile with the prudence observable in all its works ; and seems strongly to prove, that Nature doth sometimes Itidere, and delineate Figures, for no other end but for the Ornamentation of some Stones, to enter- tain and gratifie our Curiosity, or exercise our Wits. That is, those elegant Impressions of the Leaves of Plants upon Cole-Slate." In 1695 Dr. John Woodward's famous "Essay toward a Natural History of the Earth " took the Deluge of Noah as a fact, and critically considered the time of its advent. The chief importance of Woodward's work is his firm and reasoned insistence that fossils were truly the remains of organic creatures, and not mere " natural fossils," as at that time crystals, minerals, and so on, were called. Woodward's general accoimt of what happened at the time of the Deluge is of as much interest to fossil botanists as to animal palaeontologists. One passage is worth quoting. He says : " That the whole Terrestrial Globe was taken all to pieces and dissolv'd at the Deluge ; the Particles of Stone, Marble, and all other solids dissever'd ... as also all Animal Bodies, and Parts of Animals, Bones, Teeth, Shells, \'egetablcs and Parts of V^egetables, Trees, Shrubs, Herbs, and to be short, all Bodies whatsoever that were upon the Earth, or that constituted the Mass of it ; if not quite down to the Abyss, yet at least to the greatest depth we ever dig : (that is, if not to the Depth of two thousand Miles, at least two hundred feet) ... 1 say, all these were assum'd up promiscuously into the Water, and sustained in it in such manner. that the Water and Bodies in it together made up one common confus'd Mass." Woodward goes on to explain that it all settled down according to gravity in layers which he called " strata." In 1697 " F.A.M.D." published a criticism of Woodward which is of interest to fossil botanists, for he makes particular use of the plants in his argument. He says : " Had this Earth been so dissolved only so far as the Roots of the greatest Plants reach, we must have lost most of the species of Plants which were before the Deluge. The Doctor (that is, John W'oodward) tells us, that after the Subsidence the plants, being lighter than stone, would be in strata near the surface, Trees, and the other more tender Vegetables shrubs and Herbs would rot and Decay ; but the Seeds of all kinds of Vegetables being by this means repos'd, and as it were planted near the Surface of the Earth, in a convenient and Natural Soil, amongst Matter proper for the Formation of Vegetables, would germinate, grow up and replenish the Earth." Till reading this I confess that it had never struck me that Noah's Ark only contained the animals which went in two by two, and that the existence of plant life at all after the Deluge had to be accounted for somehow by mediaeval naturalists. Woodward's critic gives an admirable picture of the mental attitude of those times toward the subject. He says, in reply to Woodward's easy solution for the continuation of vegetable life after the Flood : " The seeds of all kinds of \'egetables could not be preserved, for some Plants had not yet seeded at the time of the Deluge . . . the Deluge happening, according to the Doctor in the month of May, few Plants must have remain'd, but such as were seeded at the beginning of the month." He continues to develop his argument against \\'oodward's hypothesis that the strati- fication of the rocks depends simply on the settling of the sediment in layers according to gravity, and concludes that " tho' Dr. Woodward's Hypothesis seems to be liable to many just E.xceptions, the whole is not to be exploded." In 1699 I find the earliest reallj' good figures of fossil plants in the first edition of Edward Luidi or Lloyd's " Lithophylacii Britannici ^ Icheno- graphia." Calamite foliage is well drawn and described under the old name A parincac , or Lithophyton radiosum. It is worth noticing that the date of this plate is 1699 ; for Seward says that the oldest figures of fossil plants from English rocks drawn with any degree of accuracy are found in Lloyd's book, published in 1 760. The 1 760 volume is a second edition. So that in this connection I may notice that Scheuchzer's famous " Herbarium Diluvianum," published in 1709, contains beautiful figures of several English coal-measure fossils, which are additionally interesting because they were given to Schcuchzer by John Woodward himself. Janl'aRV, 1914. KNOWLEDGE. 17 The year before Schcuchzer's book was published, in 1708, some good figures of fossil plants appeared in the " Historia Lapidum Figuratorum Helvetiac," and Baier, also in the same year, figures Dicoty- ledonous leaf impressions, which he described as " Quercus et Fagi dido modo Peirifacta." In 1709 Scheuchzer's " Herbarium Diluvianum " appeared, and it may justly be considered the earliest text-book on fossil botany. The first edition consisted of forty-four pages and ten plates, and fourteen years later it was enlarged by the addition of a copious appendix, further plates, and an index. The illustrations of some of the specimens arc excellent. Figures 3 and 4 on Plate I and No. 3 on Plate X are among the good drawings of specimens given by Woodward and coming from the English coal measures. In 1720 we have a number of plates of fossil plants in Volkmann's " Silesia Subterranea " : they include W'hat seem to be the first good illustrations of Stigmaria and a number of fair illustrations of various plants, but his figures of Lepidodendron and Sigillaria are exceedingly poor. Beuth's extraordinarily beautiful figures of these plants were published in 1 776, and challenge com- parison with Volkmann's because Beuth refers to the earlier plates. Among pioneers of Palaeobotany it is surprising to discover a man so famous in another sphere as the great mystic, Swedenborg ; yet it is true that so early as 1 722 he published a plate in his " Miscel- lanea Observata " illustrating the first fossil plants described in Sweden, a country which counts among its honoured citizens to-day Professor Xathorst, who is perhaps the most distinguished, and certainly the most many-sided, palaeobotanist now living. From the time of Woodward onwards there has been httle backsliding into the morass of belief that fossil plants were accidental, and from his day the external impressions of plants were generally recognised as organic fossils. But internal petrifications, which are now so important to palaeobotanists, were, except for Hooke, not studied till much later, so that it is interesting to find that so early as 1732 one Silas Taylor, gentleman, in his " Historj' and Antiquities of Harwich," spends some time on the consideration of petrified woods. He elaborately examines the differences between fossil and li\4ng wood, which he notes are externally so alike, and formulates the points of distinction between them. He incorporates whole passages from Robert Hooke, as, for example, when he says that fossil differs from recent wood " in its Incom- bustibleness, in that it would not burn in the Fire ; nay, though I kept it a good while red-hot in the Flame of a Lamp, made very intense by the Blast of a very small Pipe, and a large Charcoal, yet it seemed not at all to have diminished in extension." He foUows this up with a curiously worded but acute account of his views of the entry of petrifying solutions and grains into all the pores of the wood. In 1781 W. Jones published an amusing book, which would perhaps be scarcely worth mentioning here except for the fact that he drew one or two surprisingly good conclusions from his mediaeval data. His book is called " Physiological Dis- quisitions, or Discourses on the Natural Philosophy of the Elements," and is divided into sections : the first on matter, the second on motion, the third on the elements, and so on, the sixth on sound and music, and the seventh on fossil bodies. He says, in the latter section, that " Fragments of wood are very often found in the strata of the earth. . . . The Armenians and Persians have a tradition that the ark of Noah rested on this or that mountain in their neighbourhood, because fragments of wood are found there turned into stone. That there may be petrified wood in their mountains is easy to be credited, because we have so much of it here : and it is all from the same original. It is all of the same age with Noah's ark, but never made a part of it, because the ark, when stranded after the settlement of the postdiluvian earth, must have been exposed to the air, and consequently must have perished in no great number of years." In another place he says : "It may be said that fossil plants are no more than accidental lineaments in the stone . . . but . . . we have a mass of fossil plants from a coal mine near Bristol in which it is e\ ident that the leaves were real ; for some are doubled backwards and folded over others of a different sort ; which could not have happened if they were no more than accidental figures on the stone." From these two quotations it will be seen that their author had in him the makings of a modern palaeobotanist. In 1755 and 1771 we have Knorr and Walch illustrating fossil plants with good drawings, and in 1767 a catalogue raisonne, published by M. Davila, shows some advance in classifying fossil plants under four headings, viz., the woods or Dendrolites, the plants themselves or Phytolites, the leaves or Biblioliles, and the fruits or Carpolites. Nevertheless, the end of the eighteenth century was a dull time for fossil botanists ; Palaeobotany was merely marking time awaiting the advent of Bron- gniart and his famous "Histoire." The " Histoire des Plantes Fossiles," however, did not appear on the horizon completed, like Aphrodite rising from the waves, as the bibliographies of some English palaeobotanists would lead us to suppose, but was published in fifteen separate parts from 1828 to 1838, and was never finished. Before entering the new epoch created by Brongniart, however, we must refer to one more eighteenth-century book, for it illustrates the fact that it was very long after fossil plants had been recog- nised and studied that coal itself was realised to be merely fossil plants in bulk. In 1 799, in Kirwan's " Geological Essays," we find the following amusing 18 KNOWLEDGE. January, 1914. paragraphs : "It appears to me highly probable that real mineral coal does not originate from vegetable substances of any sort ; the resemblance observed between bituminated carbonated wood and mineral coal arises from the similarity of their composition, both being formed of carbon and bitumen, but by no means e\'inces the filiation of the latter from the former." He goes on to explain that " carbonic substance and petrol . . . are derived from the primordial chaotic fluid." He says: " Natural carbon was originallj- contained in man}^ mountains of the granitic and porphyritic order ; . . . both petrol and carbon are often contained in trap, since horneblende very frequently enters into its composition. My opinion, therefore, is that coal mines or strata of coal, as well as the mountains or hills in which they are found, owe their origin to the disintegration and decomposition of primaeval mountains, either now totally destroyed or whose height and bulk, in consequence of such disin- tegration, are now considerably lessened . . . the seams of coals themselves and their attendant strata must have resulted from the equable diffusion of the disintegrated particles of the primi- tive mountains, successively carried down by the gentle trickling of the numerous rills that flowed from those mountains, and in many cases more widely diffused by more copious streams." But we must leave these fascinating hypotheses and turn to the early years of the eighteen hundreds. Schlotheim, Sternberg, and pre-eminently Bron- gniart, formed a constellation whose work ushered in a new epoch for our science. In their work, indeed, much, not only of the present investiga- tions, but of Palaeobotany of all time, finds its foundation. To take, for example, the nomenclature of fossil plants : there are remarkably few generic or specific names which go back earlier than the work of these writers, and at the same time, what is even more surprising, there are comparatively few main groups of fossil plants which they had not recog- nised. Indeed, one almost gets into the way of assuming that all such well-known names as Lepidodendron, Sigillaria, Splienopteris, and so on, were founded by one or other of these famous men between the years 1820 and 1832, so that I was much surprised when going through all the old books on which I could lay hands when preparing this lecture to find that so early as 1602 the name " Catamites" was in use. In aLatinbookof that date, entitled " De Metallicis Libri," we read : " Dicamus autcm primo deiis qui ex plantis, et animalibus ortum ducunt Syringites, Calamites, et Phycites, apud Plinium et Theophrastum, videtur fructices corallii modo in lapidem conversi." But this is by the way. The main fact to notice is that at the beginning of the nineteenth century Palaeobotany suddenly became scientific. In 1828 Sprcngel described silicified fern stems from their anatomical structure. In 1833 Witham published his book on " The Internal Structure of Fossil Vegetables," and this was shortlv followed by a large work giving beautiful drawings of the anatomy of Psaroniiis and other fossils by Corda, who never seems to me to have received proper appreciation in this country. The leading Continental workers I have mentioned were rapidly joined by many others, among whom may be noted Lindley and Hutton in our own country. As a forerunner of the newer type of work which crystallised round \Mlliamson one may here place Sir Joseph Hooker, who was much interested in and published several valuable papers on the structure of fossil plants, and who held from 1846 to 1848 the official post of Botanist to the Geological Survej'. The post has lapsed for all these years, and to-day, when the surveys of other civilised countries have their official palaeobotanists, it would be interesting to know why England, the first to originate the post and the premier coal-producing country in the world, should be minus so valuable a servant. Perhaps it may be a result of Hooker's early pessimism, for in his " Memoir " in 1848 he wrote : " Plants, whose tissues are so lax as to be convertible after death into a mass of such uniform structure as coal, evidently would not retain their characters well during fossilisation, under whatever favourable circumstances that operation may be conducted." We know fo-day how much richer is our harvest than could then have been dreamed. Concerning the extreme value and originality of Professor Williamson's work I need say little. He may justly be described as the father of botanical Palaeobotany. Our present doyen, Dr. Scott, has recently written of his life in the volume entitled " Makers of British Botany " ; and then, too, fortunately we have Williamson's own auto- biography. In 1840 he was a student at University College, under Professor Lindley ; but he was an old man before he took up the science in which his researches opened up a new epoch. Like Hooker, Williamson was a man of exceptional calibre, eminent in other branches of learning. His study of the beautifully petrified plants in the now- famous " coal balls " gave results not only of palaeobotanical interest, but of vital importance for the science of modern botany. For instance, it was Williamson who, in face of the opposition of every living botanist of his day, propounded the fact that the lower vascular plants could develop secondary wood without, as the French school of palaeobotanists maintained, thereby qualifying for inclusion among the Angiosperms. Writing on \\'illianison's work on cambium, Solms Laubach said : " This is a general botanical result of the greatest importance and the widest bearing. In this con- clusion Palaeontology has, for the first time, spoken the decisive word in a purely botanical question." Williamson presented plant after plant from the lower coal measures of England, drawing the beautifully preserved structures with his own hand. lANUARY. ion. KNOWIJ-'.DGK. from a fhotO'^rath hv C. r. Kafr.!!. I'IGURE 24. The ■■ Maideu Hair Tree" yCiiiikgo bilohaK A native of China and Japan, now growing in the Royal Gardens. Kv 20 KNOWLI-.DCF,. January, lou. FiGVRE 25. Leaf of Baiera sracilis, belonging to a genus .illicd to Ginkgo, from the Inferior Oolite of Scarborough. Fir.ruK 26. -^ variety of Cnihiio dii^^itafn. from the Inferior Oolite of Yorkshire. Figures 27 and 28. Leaves of the living Ginkgo biloba. for comparison with the fossils. FlGlKE 29. Ginkgo leaf, from the Tertiary deposits of Mull. FOSSIL LF.WKS OF OINKGOS FiGlKi; 30. Another variety of Ginkgo digitatii. from the Inferior Oolite of Yorkshire. January, 1914. KNOWLEDGE. 21 How good both the drawings and the actual petri- factions were is evident on reference to any one of his famous series of monographs published by the Royal Society. The anatomical structure of plants was also receiving attention at the hands of other brilliant men about the same time, chief among whom were Renault and Solms Laubach. The more geological side of Palaeobotany was at that time growing rapidly as a result of the researches of Saporta, Heer, Ettingshausen, Lesque- reux, and others. Heer in particular was doing work of world-wide fame in describing the plants from the more recent deposits of the Cretaceous and Tertiary of Switzerland and elsewhere, and in particular really stirring geologists to an acute interest in his discoveries of arctic floras, which indicated a once warmer climate for those now frozen zones. It is interesting to find how much opposition Heer had to encounter, and how stead- fastly he continued in his intensely arduous and vexatious tasks ; the fact that to-day man}' of his determinations can be questioned does not diminish his importance as a pioneer in a much neglected subject. It is interesting to see how Hooker himself, who was always inclined to scorn leaf determinations, yielded ultimately a tribute to Heer. Nevertheless, to some of Heer's work, and to many monographs published at the end of the nineteenth century, one might apply the following words, which, curiously enough, were published a hundred years before such work appeared. In 1784 Francis-Xavier Burtin said: " Malheureuse- ment ceux qui decouvrent un fossile s'empressent trop de le nommer, et le mot je I'ignore paroit avoir ete de tout temps dur a prononcer. De la cette quantite de noms absurdes, dont la science oryctologique parvient si difticilement a se debarrasser." Now, in the course of this rapid survey, we have come to modern times, and of living palaeobotanists I can scarcely speak. Long ago Sir Joseph Hooker said : " The Science [of Palaeobotany] has of late made sure and steady progress and developed really grand results " ; and that is even more true to-day. Modern botany owes its chief advances in the branches of anatomy, morphology, and phylogeny to the study of fossil plants. To illustrate the magnitude of the recent contributions from fossils let me recall the coal-measure species Lyginodendron. The stems of this fossil described by Williamson showed cycadcan-\\]i.e wood, while the roots and foliage were fern-like. It was sus- pected by Williamson and Scott, Solms Laubach and others, that the fossil might belong to an intermediate group ; but it was left to Professor Oliver and Dr. Scott to demonstrate that this plant, externally fern-like, bore seeds. From this discovery the new and vitally important group of Pteridosperms was founded, and in addition many data of great value for the morphological study of the evolution of seeds became available for the botanist. Though the results of the anatomical study of plants are generally of much greater importance to the botanist than to the geologist, this is not always the case. For example, a certain specimen was discovered in the Cretaceous, and an enthusiastic Belgian restored a whole beast from this " bone " ; and christened the creature Aacheno- saurus. But, alas for this monster ! a palaeobotanist got hold of the one " bone " from which its super- structure had been raised, and, cutting a section of it, discovered that it was nothing more nor less than a piece of wood ! Geologists have thus been sav'cd by structural palaeobotany from one un- natural monster in their Thicrgarten. In my title I safeguard myself from the highly dangerous proceeding of speaking of the work of living colleagues. I have to consider only the past and the future of the palaeobotanist. But in order to show that my construction of the future is not entirely built on the dreams of my imagination, I must take some of the facts of the present for its foundation. Palaeobotany has three sides ; or, rather, the new science slowly reaching out from the shelter of its step-parents. Botany and Geology, is already a growth with three main branches, each of which bears fruits of value to three sections of the community. First to botanists. I have spoken of some of the recent work of Palaeobotany as being indispensable to the science of modern botany. This is now recog- nised by every leading botanist, and Sir Joseph Hooker, in a letter to Dr. Scott in 1906, wrote of our " knowledge of botany as it advances by strides under a study of its fossil representatives." From the student of the fossils one learns not only of whole genera, and even families of extinct plants which help us to comprehend the relationships of existing types, but often the fossils exhibit com- plexities and novelties of character which not the most vivid imagination could have foreseen. For instance, what modern botanist, even in a delirious dream, could have conceived of a cone for the lower Carboniferous Pteridophytes so complex as Cheirostrobus, the demonstration of whose actual structure w"e owe to Dr. Scott ? The modern botanist's conceptions of morphology, his definitions even of an organ like the seed, have undergone profound modification through the intro- duction of ideas based on fossil facts. But more than this : the botanist's ultima Thiile, his Nirvana, is the attainment of a complete knowledge of the Natural System of plants ; in other words, a complete knowledge of the lines of evolution of all existing species. From the study of modern plants we can obtain hints and make deductions, but onlv from a knowledge of titc fossils can 'die learn the actual facts of evolution. Only 22 KNOWLEDGE. January, 1914. the palaeobotanist can demonstrate what forms of plant Hfe actually did exist in all the succeeding epochs of the past. As Jeffrey said recently in America : " There can be no doubt whatever that, without the back- ground supplied b}' our increasing knowledge of fossil plants, the picture painted by the morphologist and ombryologist of the evolution of plants is without depth and entirely without perspective." And Professor Coulter, the leading American botanist, said : " No plant phylogeny is adequate until it has included the historical record, which, of course, is the province of palaeobotany ; and, furthermore, general conclusions based upon the study of the living flora alone are more apt to be false than true." Connecting botanists with geologists are the plant geographers. How do they stand in relation to Palaeobotany ? Let me illustrate by but one single well-known example, and in a few words tell the story of Ginkgo, the maiden-hair tree. This strange and beautiful tree, in the century just passed, was known to Europeans as occurring native only in the East of China and in Japan, and there always in temple grounds. Reports are current of finding it wild, but they have never been substantiated, and it is certain that in the livdng memory of man it is known only in culti- vation. How are we to account for a tree with so restricted a habitat ? Among modern plants it stands isolated ; it has no near relatives ; it is an enigma. But what has the palaeobotanist to say ? Its well-marked, easily recognisable leaves are found impressed on the rocks, and not only in the Far East, but widely spread over the whole world. This unique tree, a few decades ago living only in the retirement of Oriental temple grounds, once flourished in innumerable groves and forests all over the world before the advent of man. Even in our own country and in the north of Scotland it grew as long ago as the Inferior Oolite, and in the past it was one of a numerous family, with relatives like but slightly differing from itself. This isolated puzzle of to-day, extinct already in a wild state and only existing in semi-cultivation, is the remnant of an extremely ancient and prolific family. But the romance of Ginkgo is not yet finished. Aided by man it has come out of its old retirement, and once planted will grow almost anywhere. We have a splendid tree at Kew ; there is a still finer twin-tree in Vienna, and young trees are now- flourishing in many cities in Europe and America. Ginkgo has come to its own again, and has to-day nearly as wide a geographic distribution as it had millions of years ago. Yet who but the palaeo- botanist could have told us that it was no foreign intruder in England, but an ancient denizen of our country returning to its primaeval domains ? There are many similar cases in which the fossil history of a genus also affords evidence of departed land connections, gives indications of ancient climates, and in many other ways assists the palaeogeographer. Asa Gray said : " Fossil plants are the ther- mometers of the ages by which climatic extremes and climate in general through long periods are best measured"; and Charles Darwin, in 1881, wrote to Hooker : " The extreme importance of the Arctic fossil plants is self-evident." At this time Hooker was preparing a public lecture, and Darwin added : " Take the opportunity of groaning over our ignorance of the lignite plants of Kcrguelen Land or any Antarctic land. It might do good." Through the palaeogeographer we come to the geologist. To what extent is he indebted to Palaeobotany ? In this country it has been so arranged by Nature that there are no immense tracts of land composed of strata in which the only fossils are plants ; had there been, possibly that Survey post held by Hooker in 1 846 would not have lapsed. If our geologists think they can get along without palaeobotanists let us hear what the Americans have to say. There are twelve palaeontologists altogether in the United States Geological Survey, and of these four are palaeobotanists. Take the record of one of these geological palaeobotanists. Dr. Knowlton. He says : " For the past five years I have annually studied and reported on from five hundred to seven hundred collections, each of which embraced from one to hundreds of individuals, and with them have helped the geologists to fix perhaps fifty horizons in a dozen states." A leading geologist in this country was once frank enough to tell me that he despised fossil botany, and would not have anything to do with it. Had he been set to survey the American Continent he would have found it necessary to eat his words. Across the Atlantic it is not only in the Upper Mesozoic and Tertiary among which Dr. Knowlton works that plant fossils may afford the only criteria of the age of deposits. In a district I know myself. Eastern Canada, there is an important deposit in the Carboniferous, which is destitute of any save plant fossils. For many years the most misleading and conflicting statements hav-e been current about the age of these beds, some claiming them as Devonian, and some even as Silurian. Now that they have been studied in the light of modern Palaeobotany their Coal-Measure age is established beyond a doubt. But geologists still sometimes say to palaeo- botanists, as one said once to me : " No, no, you have let us down too often ; look at the wrong determinations in Heer's work and Lesquereux's. No, we'll have nothing more to do with you." Now in reply to such geologists I think I cannot improve on an illustration that appeared in The Times a year or two ago. We grant that deductions drawn from fossil plants have not always been perfectly reliable in the past. But this is because January, 1914. KNOWLEDGE. 23 the science was young ; the work until the last decade or two was all in the nature of pioneer work ; and even to-day much of it is still fundamentally pioneering. But because the pioneers cannot give one a detailed map of the whole country, is it sensible to reply we will have nothing more to do with anyone who goes into that country again ? "It would have been just as sane in the old days to object to the Admiralty charts, and to stop all work on them, because the}' did not register all the rocks at sea, and some ships went down. The remed}^ for that was accurate study and correction of detail at the expense of enormous labour ; and now the charts guide the ships quite safely. The remedy for the uncertainties regarding the rocks of the past is accurate study and correction of detail at the expense of enormous labour — labour greater than that of the making of Admiralty charts — for the rocks of to-day are in place, and, in the main, stay there, while the rocks of the past represent a series of world structures, continents, and seas fluctuating and merging in the long millions of years." Now let us turn to the third branch of my science. This is the practical side, and deals specially with coal-mining because it happens that our main fuel is coal, and that coal is entirely composed of fossil plants. In their rough-and-ready way miners have " muddled along " without much help from palaeo- botanists ; but with a collaboration between the two, great advantages to both would accrue, and are to be looked for in the future. Palaeobotanical information to be of any value to the miner must be very detailed and accurate. It represents the ultimate refinement of the stratigraphical work I have just mentioned as being the province of geological Palaeobotany. Fine and accurate zoning lay plants has already been successfully carried on, however, particularly in France, where Professor Zeiller of Paris, or M. Grand' Eury, is called in consultation before most mining operations of importance are undertaken. Let me illustrate this by an actual example of what happened on one occasion. In the Grand'Combe A'alley there are many coal seams, and among them two in particular called the Sainte Barbe and the Grand'Combe. From a study of the fossil plants Professor Zeiller determined that the Sainte Barbe was the older of the two. As a result of this knowledge M. Zeiller advised the company to sink a shaft at a place called Richard, which would, he foresaw, take them into the Sainte Barbs seam. They sanK the shaft for four hundred \'ards through barren beds, but did not finish it. Then M. Grand'Eury, studying the same horizons elsewhere, found that in his locality the same series cropped up with six hundred yards of barren strata between the two seams. He therefore pointed out that at Grand'Combe the miners should have continued the shaft Professor Zeiller advised a little further through the strata, and that they would find the coal where he had predicted. This the company did, and coal of the age foretold by Professor Zeiller was found where he had promised it. Thus Palaeo- botany was vindicated. Such achievements as Professor Zeiller's, however, are attained only as a result of detailed study based on a wide foundation. At his service M. Zeiller has magnificent collections filling many galleries in the Paris ;\Iuseum, and the Department of ]\Iines has published handsomely his extensive memoirs with their numerous magnificent plates. Now this leads me back to my main pronounce- ment. Palaeobotany is an intricate and independent science. Not even Professor Zeiller in Paris, nor the Survey in Washington, nor Professor Nathorst in Stockholm has all the equipment and the staff necessary. In Palaeobotany isolated individuals are struggling against the inchoate condition of the science, which is now so much vaster than is realised by more than a few people. To illustrate the enormous mass of detail with which a conscientious palaeobotanist has to cope turn to Dr. Jongmans' resume of the publications for the year on the subject. It is 569 pages long, and on each page are on an average twenty-one entries. But this invaluable work has only been published for the last three years. For everything before that we have no centralisation of results, and the consequence is that everyone doing original work is hampered by being unable to find out what is previously known on the subject without himself wading through reams of print in a dozen languages, with the likelihood that he will miss many important things after all. What do I think the palaeobotanist of the future will demand ? That in at least one institution in each civilised country there shall be a recognition of his science and adequate accommodation for it. This institution would form the headquarters, the centralising bureau, for all the branches of work in which the individual palaeobotanists may be specialising, whether as geological palaeobotanists, botanical palaeobotanists, or practical miners. In this central department should be kept standardised collections of fossil plants, consisting, not only of handsome show-case or valuable type specimens, but also, so far as possible, of completely zoned collections of fossils of all ages, which should be referred to as the standards in any practical question of strati- graphy or mining. In this central department also should be available herbaria and immense series of sections of modern plants, with which to compare the fossils while working on the botanical elucidation of their structure. As things are to-day in any new branch of Palaeobotany the modern botanists do not provide exactly the kind of data wanted for comparison by the palaeobotanist. This is notice- ably the case, for instance, in the study of early fossil Angiosperms. No modern botanist can show us the preparations of living Angiosperms that it is essential for us to see. Then, too, in this central department of the science would be collected together, not only all 24 KNOWLEDGE. January, 1914. the literature on Palaeobotany, but this literature would all be indexed, analysed, and made available on several series of card catalogues. The work done by Dr. Jongmans for the last three years must be done for the last one hundred and fifty years, and put in the handiest form for reference, which is, of course, a card catalogue. Then there must be a complete card index of all the names ever given to fossil plants. Toward this great headway has been made in Washington, but their tens of thousands of slips are not yet complete, nor can European palaeobotanists go to Washington every time they need to use them. At present most palaeobotanists — all, indeed, save a few — tend to despise questions of nomenclature ; but our science is in a very bad way owing to the immense numbers of names given on insufhcient or wrong grounds. In a recent number of the American journal. Science, Mr. Casey, writing on zo> logical nomenclature, says : " The subject is really serious, and should be given the attention of the ablest natural historians now, and without further delay, so that a secure foundation may be laid for future generations. Other work should be laid aside until this foundation is secure." Without going so far as that, it is well to emphasise stronglj' the urgent necessity for palaeobotanists to reduce order from the chaos of their present nomenclature, and this can only be done by some centralising institution or com- mittee who are sufficiently grounded in the science to realise the special needs of Palaeobotany. Beyond all this it must not be forgotten that the collections of fossil plants at present made are trivial in comparison with those which will have to be made from all parts of the earth before we can completely unravel the histories of the ancient continents, solve questions of past climates, restore the details of innumerable extinct floras, and reconstruct the tree of plant evolution through the ages. In spite of all the service rendered to science by Palaeobotany in the time of her humiliation and neglect, immense problems still lie unsolved. Darwin said in a letter to Hooker : " The rapid development, so far as we can judge, of all the higher plants within recent geological times is an abominable mystery." To-day it is an abom- inable mystery still, and it is my belief that an abominable mystery it will remain until Palaeo- botany' is recognised as an independent science and housed, endowed, and equipped so that she has the tools she needs for her work. Nevertheless, until they are given spades or steam ploughs, palaeobotanists will continue to dig with their hands and to yield up gladly the fruits of their labours to any other science that needs them. CORRESPONDENCE. " THE ORIGIN OF LIFE." To the Editors of" Knowledge." Sirs, — My apologies are due both to Mr. Soddy and Mr. W. A. Douglas Rudge, for having, in a contribution to " Knowledge," attributed the work of the latter on Mr. Burke's so-called " radiobes " to the former. The original papers were not by me at the time of writing, and I can only attribute my error to some freak of the memory. Accounts of Mr. Rudge's experiments will be found in Nature (Vol. LXXII, page 631, and Vol. LXXIIl, page 78) and were also presented to the Cambridge Philosophical Society. As to the apphcability of the expression " nine-day's wonder " to Mr. Burke's experiments : the question is hardly worth debating. In using it, I was thinking of the attitude of the general press and pubhc. They seemed, at the time, to beheve that Mr. i'.urke had solved the problem of life and accomplished spontaneous generation. Of course, no one believes that now. In fact, the experiments, I think, have little significance so far as this problem is concerned ; and I merely referred to them in my article in the function of historian. H. STANLEY REDGROVE. The Polytechnic, Regent Street, W. THE CHEMISTRY OF THE RADIO-ELEMENTS. To the Editors of " Knowledge." Sirs, — I notice that in the November number of " Know- ledge " a note appears regarding my contribution to a discussion in the Chemistr^' Section of the British Association meeting at Birmingham, in which it is stated : " That of the . . . radio-active elements studied, all with the exception of Uranium — X, are chemically identical with common elements already known, such as lead, thallium, and thorium." I trust that you will allow me to correct two errors that appear in this paragraph. In the first place the exception to the general rule is that Uranium —X.^, not Uranium — X, has a chemical nature peculiar to itself alone. The body which was formerly called tJranium— X is now known to consist of two sub- stances, Uranium — Xi and Uranium — X.,. It is the first of these bodies that was known as Uranium— X, and for some considerable time now it has been recognised that that substance has chemical properties absolutely identical with those of thorium. The second substance, Uranium — X.,, was only discovered some eight months ago, and has chemical properties which no other substance possesses. It is some- what analogous to tantalum, but can be separated from that element, as, e.g., by volatilisation. In the second place there are a number of other radio- elements wliich are not chemically identical with any common element, but the chief point to notice is that these elements have not chemical properties peculiar to themselves alone. For instance, mesothorium — 2 and actinium can be separated from any common element, but they cannot be separated from one another. There are one or two other examples of the same kind. It is of interest to note that in examining the chemical nature of the radio-elements the quantity used was of the order of only a million millionth part of a gram, and yet their chemical properties are definitely known. Physical Department, ALEXANDER FLECK. The University, Glasgow. THE FACP: of the sky for FEBRUARY. By A. C. D. CROMMELIN, B.A., D.Sc, F.R.A.S. Table 1. Sun. K.A. Dec. Mo R..^. De. Mercury. R.A. Dec. Venus. R.A. De> M.irs. R.A. De. Nep.une. K.A. Dec. Feb. 5 , 1I3-3S.I6-I I 33'3 I4"5 1 52'9 I2'9 4 26'7 N.27*o 9 23'9 N.i7'8 13 50-9 S. 15-5 iS 42 "6 .S. 27 "9 4S0 S 15-1 8-6S.I7-7 33'7 i5'9 SS-S ■3'9 6 25*6 26'9 6 26*9 26'7 6 29*4 N.26'6 4 39-7 N.2 4 39 '5 2 4 396 2 4 39-S 2 Table 2. Date. Sun. P B L Moon. P Mars. P B L T Greenwich Noon. Feb. 5 -13-8 -6'4 I27'8 15-7 6'6 61-9 17-4 6-9 356-1 19-1 7-1 2903 -206 —7-2 224-4 - 8-9 + .6-7 + 19-6 - 3-6 -20-9 0 0 0 h. m. -22-3 +1-2 231 3 8 40f 22-5 i-i 188-0 II 46 itreak.s. Swift, streaks. Swift, bright. Swift, streaks. Double St.^rs and Clusters. — The tables of these given two years ago are again available, and readers are referred to the corresponding month of two years ago. VARL'kBLE Stars. — The list will be restricted to two hours of Right .\scension each month. The stars given in recent months continue to be observable. Table 4. Non-.^lgol Stars. .Slar. Right Ascension. Declination. M.-ignil-uaes. Peiiod. Date ol Maximum. T Lvncis Z Cincri R V Hydrac S Ilydrae ... ... X Cancri \V Cancri RS Cancri V Dr.iconis U Leonis Min. ... R I.eonis Z Leonis V Ilydrae h. ni. f '7 S 17 f 35 8 49 S 50 9 5 9 5 9 33 9 40 9 43 9 47 9 47 + 33 'S + 15 -2 -9-3 + 3 '4 -fi7-6 4-25 -6 + 31 -3 -F78-2 + 34 -9 •f 1 1 -8 + 27 -3 -22 -6 8-5 to II- 2 8-5 to 9-2 7SI0 90 7-5 to 12-5 6-0 to 79 7 4 I" 1.3- 0 5-4 10 6 6 8-2 to 11-5 62 to 130 50 10 102 7-9 to 9-6 6-5 lo lo- I d. 91-3 74 irregular 256 irregular 3S5 unk.K.wn 3i<> 371 -5 3128 59 irregular Mar. 25. Jan. 19. Dec. 13. Jan. 10. Jan. 24. Jan. 8 Dec. 20. Jan. 15. Principal Minima of /i Lyrae Feb. 7'' 3'';«, 20" 1^ ni. Period 12" 21'' -8. Algol minima Feb. 1'' ll"- 25"e, 4" 8'' W'e, 7" 5'' 3'^, 22" l''8'"m, 24'' 9'' 57""c, 27" 6" 46" Mira Ceti will reach maximum in March. NOTES. ASTRONOMY. Bv A. C. D. Crommelin, B.A., D.Sc, F.R.A.S. USE OF GALACTIC COORDINATES FOR STAR- PLACES. — Mi. R. T. a. Innes read a suggestive paper last July advocating the use of the Galaxy as the prime circle of reference for the stars, instead of the terrestrial Equator, which is continually shifting, necessitating an enormous amount of labour in bringing places up to the current date. If referred to a circle that was fixed among the stars, the only reduction to date would be that arising from proper motion, which is in most cases very small. The drawback of choosing the Galactic Circle is that the Galaxy is some- what irregular and broken, and different estimates have been made of the great circle that represents itbest. The choice must be to some extent arbitrary, and the starting- point for Cralactic longitudes is also arbitrary. Mr. Innes suggests using the longitude of the Sun's apex, which he takes as K.A. 18", N. Dec. 30". But obviously there is room for much difference of judgment, and it is exceedingly difficult to get the astronomers of all nations to agree on points of this kind. Further, it is likely that, for a long time to come, meridian instruments will be the chief means of obtaining the places of at least the brighter stars. Hence their K.A. and Dec. must still be found ; and a tedious calculation, with seven-figure logarithms, would be required to reduce these to Galactic coordinates, whereas a four-figure calculation suffices for the present " star-corrections." For these and other reasons I do not expect the immediate adoption of Mr. Innes' proposals. The late Dr. Kistenpart's plan seems to me more practicable, viz., to publish all ANUARY, 1914. KNOWLEDGE. .-•Car-places referred to one of a series ol standard equinoxes twenty-five years apart (in this century 1900, 1925, 1950, 1975) : the labour of " bringing up " stars would thus be minimised, though not entirely removed. THE OCTOBER /OL'i?A'.lL OF THE ASTROSOMICAL SOCIETY OF THE PACIFIC contains an interesting paper by Professor Campbell on the astronomical congiosscs that were held in Germany last summer. I cull a lew points. iM. Donitch, of St. Petersburg, invites astronomers going to Kussia for the eclipse of ne.xt August to communicate with him, so that they may be distributed as uniformly as possible along the line, and the risk of failure tlirough cloud minimised. Attention is called to Ur. Abbot's con- clusion that the output of solar energy increases at sunspot maximum, but that temperatures at the Earth's surface diminish then. These may be reconciled on the hypothesis that the cloudiness of our air increases with an increase of sunspots. It is not long since Professor Joel Stebbins introduced the selenium photometer for recording star-variations. A further development has been made by Herr Rosenberg, of Tubingen, with a photo-electric cell. " When it was attached to a 5-inch refracting telescope he was able to determine the brightness of a fifth-magnitude star in two minutes within 0-002 magnitude. Stebbins commented in a generous spirit, saying that he liimself took an hour to get the magnitude of a second-magnitude star within 0-01 magnitude." Professor Campbell considers the new instru- ment as important for stellar investigation as the spectro- scope and photographic plate. GREAT -UIERICAN REFLECTORS.— it is good news that work on the 100-inch reflector and its mounting is advancing satisfactorily. It will need a dome one hundred feet in diameter and one hundred and five feet high. The telescope tube will be partly balanced by floating in mercun,-. Another great reflector, of 72-inch aperture, has been ordered by the Canadian Astronomical Society, and will be placed on a mountain site. It will be possible to use it either as a Cassegrain or a Newtonian, or for observation or photography at the principal focus. The 60-inch at Mount Wilson is being put to good use in stellar spectroscopy'. It has been possible to obtain the spectra of nineteen stars in the Hercules cluster : of these seven are of the Sirian type, ten of the Procyon type, and two of solar type. Thus early spectral types predominate, wliich is in favour of the idea that the clusters are nurseries of stars at their earher stages which have been formed from a single nebula, rather than that they have been collected together by gravitation after their formation as isolated stars. However, this must not be pressed too far, for the stars of late type are generally faint, and might be invisible at the great distance of the cluster. Three faint stars in different parts of the sky are found to have high velocities of approach. Lalande 15290 tR.A. 7'' 48°') approaches us 242"''" per second, its total motion being 316°™. It is of solar type, magnitude 8-2. Lalande 5761 (R.A. 3^ 3"", magnitude 8-0) approaches at the rate of 144'^"', and Lalande 28607 {R.A. 15" 38"\ magnitude 7-3) at 170'"". Both stars are of the Sirian type. THE GEGENSCHEIN. — Professor Moulton and others suggested that the Gegenschein might be caused by the Earth gathering together a cluster of meteors at a distance of nine hundred thousand miles from it, on the side opposite the Sun. Professor H. D. Curtis took t\vo photographs of the region with exposures of an hour each, in the hope that some meteors might be large enough to photograph ; tlie result was negative. He considered that a meteor one hundred feet in diameter would have been registered : tliis is probably far above the usual size of meteors, though a few verj' large ones have been recorded. Hence the experiment in no way dispro\es the suggestion as to the cause of the phenomenon. SIK UAVII) GILLS HISTORY OF THE CAPE OBSEK\'.\TORV. — The work pays a well-deserved tribute to Lacaille, who went out in 1750 under the auspices of the Paris Academy of Sciences, and laid the foundation of Southern astronomy. He made a catalogue of ten thousand stars, besides determining the parallax of the Moon and fixing 10" as a rough appro.ximation to that of the Sun. The amount of work that he accomplished in under two years was marvellous. The present establishment dates from 1821, when Fallows was sent out to found an observatorj'. The early conditions were anything but pleasant. The spot was known as " Snake Hill " ; there were jackals and hippopotami in the neighbourhood, and on one occasion a leopard was found sitting on a shutter of the mural circle. Fallows died in 1831, after ten years of strenuous work under difiiculties. His successor, Henderson, soon resigned his post, but not till he had done good work, including the finding of the paraUa.x of alpha Centauri. His was really the first reliable stellar parallax, though it was not generally accepted till after the results of Struvo and Bessel on Vega and 61 Cygni respectively. Henderson found 1"-16, which is only 0'-4 above the modern value, a very good appro.ximation considering the instrument and method that he used. Maclear, the next astronomer at the Cape, had the advantage of association with Sir J. Herschel, who spent four years (1834-1838) at Feldhausen, tliree miles distant. Maclear had a splendid record of work, which he continued till his retirement in 1870. .\mong other items may be mentioned observation of Halleys Comet vvhen it ran south in 1835 and the commencement of the geodetic survey of South .\frica, which was so energetically continued by Sir David c;ill. An interesting personal reminiscence is the visit of Livingstone to the observatory before his famous explorations in Central .\frica, to learn the best methods of obtaining geographical positions. I shall resume these notes on the book in a future number. OBITU.\RY.— Sir Robert Ball was probably the best known to the general pubhc of all British astronomers. His books and lectures appealed to a ver}' wide circle, from the ingenuity displayed in presenting facts in a quite untechnical way, with much grace of language and with many anecdotes and illustrations of a kind likely to come within the experience of his audience. I have vivid recollections of a visit to Dunsink when a 3-oung schoolboy, and of Sir Robert's kindness in showing and explaining everything of interest. I saw much of him during the echpse expedition to Norway in 1896. He contributed greatly to the public entertainment by his lectures and some humorous personifications of Irish characters — these were particularlj' acceptable when the ship ran aground at Tromso and the party was in low spirits, fearing considerable delay. He will be missed and long remembered among a large circle of friends. .Vnother well-known astronomer is dead, Professor L. Weinek, of Prague. His chief study was the Moon, and he published a series of enlargements of the principal craters from the earlier photographs taken at the Lick Observatory. BOTANY. By Professor F. Cavers, D.Sc, F.L.S. THE WILD W^HEAT OF P.ALESTINE.— The discovery a few years ago of wild wheat in Palestine by Aaronsohn has attracted much attention, chiefly because of the possible practical importance of a hardy race of wheat. In Bulletin 274 of the I'nited States Bureau of Plant Industry, O. F. Cook gives a full account of the culture of this wild wheat, which has been under observation for some time in .\merica. The plant was first discovered on Mount Hermon, and later in the Jordan \'alley, and is especially abundant on lime- stone. Its flowers show variable arrangements for pol- lination, being not only adapted for cross-pollination by 28 KNOWLEDGE. January, 1914. extruding its stamens, but in sonic cases being protogynous (stignia matures in advance of stamens) or protandrous (stamens mature before stigma), though sometimes it is adapted for self-polhnation like the domesticated races of wheat. The great indi\-idiial variation shown by this wild wheat is attributed to the great freedom in its adaptations for pollination, and it is further concluded that the self- pollination of the domesticated races is not a primitive condition, but that the adaptations for cross-polhnation have been lost, and that as a result there has been a decline in %igour, fertility, and disease resistance. While there is apparently no reason for doubting that this Palestine plant is a genuine wild wheat, it is not certain that it is the protobi'pe of our domesticated races ; it is, in fact, suggested that it be named as a distinct species, Triticum hermonis. Whether or not it is the prototype of tlie domesticated wheat does not, of course, affect its practical value ; for it is a hardy plant in the sense of being able to live under a wide range of natural conditions, and it suggests the possibility of obtaining from it races of wheat adapted to the arid regions of the world, and also of breeding its power of resisting rust disease into the domesticated races. SOIL FUNGI. — The mere fact of the abundance of different species of fungi which appear above the surface of the soil in tlie form of spore-producing bodies indicates the existence in the soil of the thread-like vege- tative organs of an enormous number of fungi. Indeed, rich soil like that of woods is penneated with fungus threads, and is practicall)- the " spawn " of these fungi. Besides tliose fungi which hve in the soil and send up large con- spicuous spore-bodies — mushrooms, toadstools, and so on — there are numerous forms with small and inconspicuous fructifications, includmg the common moulds of various kinds. A close: investigation of the matter shows that many species of fungi live habitually in the soil, carrying out their hfe-history there, either wholly or in part, and that a con- siderable number of these have only been found, so far, in the soil. Several recent workers have isolated soil fungi by culti\-ating samples of soil in various nutrient media, and their results show that not only is the fungus flora of the soil an extraordinarily rich one, but that many of the species have a remarkably wide range, and are apparently world-wide in distribution. Identical species have been found in England, Holland, and in different parts of North America. One of the latest papers on tliis subject is by Goddard (Hot. Gazette, October, 1913), who finds that these forms are to a large extent uniform in different soils, and that, unlike the bacteria, they are also uniformly distributed at different depths down to about fourteen centimetres. Moreover, it would appear that tillage and manuring produce but little change in the number or kind of these fungi, though further investigation is required on this point. One may infer in a general way that these soil fungi probably play an important part in connection with soil fertility, since they convert organic matter into other forms of which some are suitable for the nutrition of higher plants. Some of the soil fungi enter into a symbiotic asso- ciation with the roots of plants, and help to supply these with food in a suitable form for absorption : these are the well-known " mycorrhiza " fungi. There is a certain amount of evidence that the mycorrhiza fungi are, hke some bacteria, capable of fixing free atmospheric nitrogen ; that is, con- verting the free nitrogen into nitrates which are absorbed by roots. Goddard has carefully investigated this matter in the case of a number of soil fungi, but his results were in everj^ case negative : none of the forms studied showed any power of assimilating free nitrogen. The fungi showed a certain amount of growth in nitrogen-free media, but in such cases the nitrogen content was found by analysis to fall within the limit of error of the method employed, and the growth was starved and shrivelled as if deficient in a necessary element. The question is a rather difficult one to decide, as it involves very delicate methods of analysis, and the capability of fungi for fixing free nitrogen has been alternately denied and affirmed by different investigators. ACTION OF FOR-MALDEHYDE ON LIVING PLANTS. — Many kinds of evidence point to formaldehyde (CH.jO) being the first, or one of the first, organic compounds pro- duced in photosynthesis — that complex and still very imper- fectly understood chain of processes by which green plants build up organic substance out of carbon dioxide and water. Miss S. M. Baker has recently [Ann. Bot., 1913) made quanti- tative experiments on tlic effects of formaldeliyde on green plants, in which seeds were grown in an atmosphere containing known quantities of formaldehyde, some of the cultures being grown in darkness and some in light. .-\ comparison of the change in dry weight with that of control cultures, with and without carbon dioxide, showed that formaldehyde could be used for the synthesis of food materials to some extent in light. The gain in dry weight was about half the loss due to respiration ; and an increase in the percentage of formaldehyde in the air did not produce a correspontling increase in dry weight after a certain concentration. An excess of formaldehyde was, of course, poisonous. In the dark formaldehyde was not assimilated, but appeared to stimulate respiration : its to.xic effect was more marked than in light. Acetic aldehyde could not be taken up by the plants ; hence the assimilation of formaldehyde in light is not due merely to the aldeliyde group. These results are capable of two interpretations : (1) Formaldehj'de is a step in respiration, and is converted by the plant into carbon dioxide before it can be assimilated ; or (2) it is the first step in photosynthesis, and its further elaboration by the plant requires light energy. To decide between these two possibilities quantitative experiments were made, in which the change in dry weight of the cultures could be directly compared with the carbon dio.xidc evolv-ed during respiration. It was found that this ratio agreed closely with that calculated for the complete oxidation of a carbohydrate. When formaldehyde was passed over the cultures in the dark there was no change in the quantitative relations between the loss in dry weight of the cultures and the carbon dioxide of respiration. Hence formaldehyde was not converted into carbon dio.xide by the plants, nor used as a source of food material in the dark. Probably, therefore, formaldehyde may function as a stage in photo- synthesis, but the production from it of sugars and other food materials requires light energy. USE OF LIQUID AIR IN PLANT PHYSIOLOGY.— In a series of interesting papers Dixon and Atkins [Sci. Proc. Royal Dublin Soc, 1913) have shown that liquid air may be applied with great advantage in the extraction of plant juices. Many conflicting determinations have been made of the osmotic strength of the sap in plants by investigators who had obtained the sap by pressure from the plant organs — leaves and so on. The sap obtained by pressure has been regarded as a fairly average sample of the sap of the organ pressed ; but it was found that when leaves were exposed to chloroform vapour and then pi'essed the sap was obtained with much greater ease, and its freezing- point was much lower than that of sap from untreated leaves. The greater concentration of the sap froin chloro- formed leaves is evidently due to the fact that the chloro- form makes the protoplasmic membrane of the cell more permeable, and thus allows the sap to escape more readily under pressure ; but it was found that prolonged treatment was necessary to make all the cells permeable, and so allow the sap obtained to be a fair sample of that of the uninjured leaf, and such prolonged exposure has the objection that, during the process, enzymes in the cells may considerably alter the nature of the dissolved substances and so lead to a change in the concentration and constitution of the sap. Much better results were obtained by exposing the leaves and other parts to the extremely low temperature of liquid air, which made tlie membranes permeable, and at the same January, 1914. KNOWLEDGE. 29 l-me arrested changes taking place in the tissues. On being immersed in liquid air the tissues immediately become frozen hard, and then they are at once transferred to, and enclosed in, a stoppered vessel to prevent the condensation of moisture on them from the air owing to their extreme cold ; such condensation would, of course, cause ddution of the sap. When the tissues have assumed the temperature of the surroundings they are pressed in the usual way, and com- paratively small pressure is required to obtain the sap, which flows easily from them without requiring the dis- ruption of the cells, while at the same tune the sap is much freer from the debris of broken cells than that from an untreated leaf. Sap thus obtained always gives a greater lowering of freezing-point, and usually a higher electrical conductivity, than that from the same tissues untreated. The estimates obtained in previous work on osmotic pressure of cell-sap must be raised, and in some cases considerably, as the result of the apphcation of this new method. The fact that exposure to intense cold makes the proto- plasm permeable, so that the sap can be obtained by pressure in an unaltered condition, suggested the possibility that similar exposure of the yeast-cell would render its protoplasm penneable, and that the zymase and other enzymes in the cell would be free to escape. Experiment has confirmed this surmise. The liquid-air method for extracting yeast ferments is not only extremely efficient, but also very rapid : it requires only about half an hour to prepare the zymase-containing liquid from the solid yeast, and the time for changes taking place in the enzyme is reduced to a minimum. The authors are now investigat- ing the possibihty of appljang the method to the extraction of endo-cellular substances from bacteria. Another use of the method is suggested by the authors. It is generally held that sterilised foodstuffs are less assimilable owing to the destruction of the enzymes of the tissues. The experi- ments here noted have shown that by means of liquid air sap-containing enzymes may be extracted from cells without serious alteration. The sap, frozen immediately after e.xtraction, might be evaporated to dryness as ice under reduced pressure, and the resulting powder stored and added to the food as desired to replace the enzymes lost by sterilisation. CHEMISTRY. By C. AiNswoRTH Mitchell, B.-A. (Oxo.n), F.l.C. BEES\YAX OF THE VIKING PERIOD.— Some eight years ago a ship of the early \'iking period was discovered at Oseberg, near Tonsberg, in Norway. It was completely buried in the earth, and when disinterred was found to belong to the grave of a Viking queen, who died about A.D. 800. Horses, carriages, and sledges were also discovered in the grave, together with all kinds of household furniture and utensils and personal ornaments, the whole forming a picture of the state of northern civiUsation ten centuries ago. Among the other articles found were two dark rect- angular masses, which proved to be wax that had apparently been used for the waxing of sewing thread. This wax has recently been chemically examined by Dr. J. Sebehen, who has published the results of his analyses in the Zeii. angewandle Chem. (1913, XXVI, 689). It melted at 63= C, and had a specific gravity of 0-963 at 15° C, and thus in both respects agreed with the values given by normal beeswax. Its chemical constants were also well witliin the limits of those given by genuine beeswax, although in some respects they were a little high as compared with the values of modem Scandinavian beeswax. For example, the ratio between the acid value and the ester value of modem Norwegian beeswax ranges from 4-0 to 4-3, whereas the ratio in the case of the Oseberg wax was 4-74. The iodine value {i.e., the percentage of iodine absorbed) was 6-0, and in this respect the wax agreed more nearly with ordinary beeswax than with humble bees' wax, which has an iodine value of about 16. The microscopic examination of the vegetable debris in the wax proved particularly interesting. The wax was dissolved in warm .xylene, and the solution whirled in a centrifugal machine to separate the insoluble matter. The deposit consisted of a few pollen grains, including one which appeared to have been deri%'ed from Vaccinimn vitis idaea, since cuticle hairs, similar to those occurring on the stamina of that plant, were also present. Other pollen grains were identified as belonging to cruciferous plants, while another appeared to have been derived from a member of the Caryophyllaceae. In addition to pollen the deposit contained fragments of wood charcoal, hairs from the bodies or legs of bees, the epidermis of a barley corn, granules of barley starch, a single oat-starch granule, and particles of conifer wood. NEW SALTS OF PHOSPHORUS.— Among the com- pounds of phosphorus and hydrogen is a solid body, P-H.,, which has been found by MM. Bossuet and Hackspill to act as an acid and form salts with metals [Comptes liendtis, 1913, CLVII, 720). If the rubidium salt, P. Rb„ be exposed to gaseous ammonia it is unaffected, but when liquid ammonia is used a yellow solution is obtained, and this, on evaporation at — 18" C, leaves crystals of a double salt with the composition, P-Rbj.SNHj. By treating solutions of this compound in hquid ammonia with a solution of a heavy metal in the same solvent double decomposition takes place, with the precipitation of the corresponding insoluble compound. For example, lead has in this way been made to combine directly with phosphorus to form a lead phosphide with the composition P.Pb. This compound is an amorphous black substance, which will ignite spontaneously in the air. It is slowlj' attacked by water and by dilute sulphuric and hydrochloric acids, which decompose it into solid hydrogen phosphide and lead sulphate or chloride. Similar compounds may be obtained with silver, copper, strontium, barium, and so on, the precipitates being yeUow in the case of metals of the alkaline earths, brown with silver, and black with other metals. The difficulty of separating these phosphides in a pure state is increased by the fact that they have to be washed with hquid ammonia in closed Hasks, and that they readily undergo oxidation. THE FORilS OF ARSENIC— Several crystalline forms of arsenic have been described, but doubts have been expressed as to whether these are all allotropic modifications of the element. Dr. Kohlschiitter and two collaborators have recently studied the question, and have come to the conclusion that the only definite allotropic modifications of arsenic are black or metalhc arsenic and yellow arsenic (Annalen, 1913, CCCC, 268). This opinion is based upon the great difference in the specific gravity of the two modifications. \Mien black arsenic (specific gra\-ity 4-7) is distilled at 450^ C, in a vacuum in a dark room, with only a red light, and the vapours condensed by means of liquid air, the yellow crj'stalUne modification with a specific gravity of 1-97 is obtained. By subhming this yellow form, or by crystallising it from carbon bisulphide, a grey arsenic, of coarser character, is obtained which has the same specific gravity (4-7) as metallic arsenic, and must be regarded as being merely in a different ultra-microscopic state of division. Again, when solutions of arsenic compounds are treated with certain reducing agents a very fine crystalline brown arsenic is obtained. This has the same specific gravity as the metallic or grey forms of arsenic, and apparentlj' differs from them only in the state of its cr^staUine division. ENGINEERING AND METALLURGICAL. By T. Stenhouse, B.Sc, A.R.S.M., F.l.C. THE FIXATION OF NITROGEN.— Calcium carbide is formed by heating together lime and carbon, and when calcium carbide is maintained at a temperature of 1650" F. for about t\venty-four hours, in an atmosphere of nitrogen, the carbide becomes converted into calcium cyanamide. The resulting product is known as nitrolim, and contains 30 KNOWLEDGE. January, 1914. twenty per cent, of nitrogen, twelve per cent, of free carbon, sixtj' per cent, of lime (free and chemically combined), and eight per cent, of inert substances. The wonderful com- mercial development of these processes is described in an article in The Times Engineering Supplement for October 15th. Electric furnaces, having a capacity of sixteen to eighteen tons a day, are charged automatically and almost continuously with powdered anthracite and burnt lime, the temperature being maintained at 5720 " F. The calcium carbide formed is tapped in the molten state at intcr\'als of forty-five minutes, allowed to solidify, and crushed to sizes suitable for packing or for further treatment. The annual output of carbide at Odda, on the west coast of Nonvay, is now eighty thousand tons. The electric power for the furnaces is, of course, obtained by the utilisation of waterfalls. Most of the carbide formed is converted into cyanamide. Entirely new works are now in process of construction at Aura capable of making two hundred thousand tons of cyanamide annually. To obtain the requisite nitrogen, air is liquefied by the Linde process, and the nitrogen and oxygen are then separated by fractional distillation. No less than one himdred tons of atmospheric air are liquefied daily at the Odda factor}', seventy-seven tons of nitrogen being obtained. Calcium cyanamide, as such, is being increasingly used throughout the world as a fertiliser, and its utilisation for the production of ammonia on the commercial scale has recently been developed. As from ammonia and nitric acid the road is clear to countless products required by modern peoples, the manufacture of calcium cyanamide must further increase, and already the production of nearly two million tons a year is contemplated. EXPOSURE TESTS OF COPPER, COMMERCIAL ALUMINIUM, rVND DURALUMIN.— In Section G of the British Association j\Ir. Ernest Wilson communicates the continued effect of exposure in London on the electrical resistance of wires of copper, aluminium, and duralumin. Since 1911 the percentage increase of electrical resistance, taken on the value in 1911 at 1.5° C, is 2-0 for high-con- ductivity copper, 4-4 for commercial aluminium, and S'2 for duralumin. The specimens have a length of seventy feet and a diameter of 0T26 inch. Duralumin is a copper- manganese-magnesium alloy of high tensile strength, and exposure has apparently made it more brittle. COPPER STEEL.— The view has been widely held that the presence of even small amounts of copper in steel has a prejudicial effect, and red-shortness has been attributed to copper in cases where the harmful element was un- doubtedly sulphur. As copper occurs chiefly as sulphide when present in iron ores, the presence of copper in steel made from such ores might also necessarily mean the presence of sulphur. It has been frequently found, on the other hand, that in cases of specimens of steel showing unusual strength, hardness, and resistance to corrosion these improved qualities were due to copper present accident- ally. In an investigation designed to ascertain the effect of adding pure copper to steel of good quality. Professor C. Howell Clevenger and Mr. Bhupendranath Ray succeeded in preparing a series of sound ingots containing up to 4-5 per cent, of copper. {Trans. Amer. Inst. Min. Eiig., 1913, 2437, through /. Soc. Chem. Ind., 1913, 1071.) Structurally the copper, which alloyed with the ferrite, was found to produce a more even distribution of the fibrous cementitc, giving rise to a finer structure. .All the ingots forged well, except the one richest in copper, and strength and hard- ness both increased with increasing copper content. The results obtained indicate, in fact, that the addition of small amounts of pure copper to the extent, say, of one to two per cent, has only a beneficial effect on the quality of the steel so treated. THE INTERCRVSTALLINI-: COHESION OF METALS.- — Considerable interest has been aroused by the " amorphous cement " theory put forward by Dr. W. Kosenhain, with others, in several papers, one of which, by Dr. Roscnhain and Mr. D. Ewcn, was read before tlie August meeting of the Institute of Metals. The theory is that the crystals of which metals are built up are held or " cemented " together by an extremely thin layer of amorphous, or non-crystalline, material chemically identical with the substance of the metal, or alloy, in question, but in a widely different physical state. Tiie amorphous con- dition of this intercrystalline layer is regarded as being identical with, or at least closely analogous to, the condition of a very greatlj- undercooled Uquid, which has remained in that condition in the minute interstices which occur where adjacent crystals meet one another in various orientations. The curve connecting temperature and strength of such a material would naturally be continuous, while that of crystallising material would show a discon- tinuity at the crystallising point, and the two curves would intersect at a point corresponding to some temperature below the crystallising temperature. This indicates that at the temperature corresponding to the point of inter- section the cement and the crystals have the same strength, but that at other temperatures one or other would be more considerably affected under strain. If the intersection temperature and the solidifying temperature of a metal or alloy are wide apart, then at temperatures just below the solidifying point one should find the cement considerably weaker than the crystals, and under fracture, at least for slow straining, the fracture should not only be of the inter- crystalline type, but should occur without any material deformation of the crystals themselves, even if the crystals are those of extremely ductile metals. To test the truth of this reasoning the authors made e.xperiments with the metals lead, tin, aluminium, and bismuth, using metals of a liigh degree of purity, liars of the metals were cast, and while suspended in a vertical position were-heated to a temperature about 50' C. below the melting-point of the metal in question. This temper- ature was held for one hour, and then a small weight was attached to the lower end in order to produce a slight and constant load. The weight chosen gave a stress of about seventy-two pounds per square inch. The temperature of the bars was then slowly raised until fracture took place. The results were in all cases completely as anticipated, fracture of the heated bars taking place without appreciable elongation or reduction of area, and with the jagged edges in keeping with its intercrystalline character. It is pointed out that the general fact that all metals become extremely weak and brittle at temperatures near their melting-points is thus explainable by the amorphous cement theory. The authors discuss the question as to whether the intercrystalline material may not consist of films of eutectic alloys formed with traces of impurities in the metals, hut consider the evidence to be much more favourable to the theory they advance. GEOGRAPHY. By A. Stevens, M.A., B.Sc. TRAVEL IN THE CAUCASUS.— In the National Geographic Magazine for October Mr. George Kennan has an interesting and well-illustrated article on a journey which he made over the eastern Caucasus in company with a magnate of the country, to whose train he managed to add himself. In such difficult and unknown country, where guides could not be got, he was fortunate to secure such an escort. These mountain tracts have been from distant times a refuge for the exile, the wanderer, and the outcast of a score of different nations, and are inhabited by an assortment of the descendants of peoples ranging from wandering Jews to derelict Crusaders, who preserve, as a dress for gala days, the armour and trappings of their chivalrous forebears ; and the types remain almost as distinct and characteristic as their ancestors. There has been no blending into any sort of nationahty, and there jANl'ARV. 1014. KNOWLKDGE. 31 are no common characters bcvond fuch as the precarious life in the inhospitable mountains, where every man's hand is against his neighbour's, impressed on one and all. The scenery of this " Russian Switzerland " is of the wildest and grandest, and the mountain barrier is passable at two places only. The descent on the southern side is interesting. On the summit of the pass the wind that meets one climbing over from the ea.st chills to the core. One breakfasts amid Arctic snows, lunches in the cool air of a temperate region, and in the evening dines in the open fanned by the soft air of an Italian summer ! Most interest- in ; are the dwellings of the natives, built reckle.ssly, tier on tier, in the manner of the Puebla Indians, on an inaccessible mountain-steep, reached bv a dizzy track with eternal zigzags. On the topmost eminence stands the watch-tower to testify to the troublous nature of bygone times. But past these relics of mediaevalism runs the telegraph wire, and gradually civilisation is penetrating the formerly impiegnabl? ?'nd lawless stronghold of one of the most primitive populations of Europe. THE ALLEGHANY DIVIDE.— The study of the fauna of rivers, from the point of view of the histor\^ of drainage systems-, i-- particularly fascinating, and Mr. A. F. Ortman, whf, has done a considerable amount of faunistic work in the region, has in the Proceedings of the American Philo- sophical Socieiv, No. 210, an interesting study of the relations of the Alleghany system from this point of view. He has worked mainly on evidence obtained from the Najades, but remarks that Gastropods, Cra^-fishes, and Fishes should pro\'ide almost equally interesting and v.iluable testimony. His main conclusions may be men- tioned. The Alleghany system forms an old and effective faunistic barrier, whose efficiency may have been reduced as the country assumed the aspect of a peneplane, but which was emphasised by post-Cretaceous elevation of the countr\' and consequent rejuvenation of the drainage. West of the divide is a uniform and distinct fauna which exhibits remnants of an older one ; but the unit^' of the I'pper Ohio fauna has been acquired since Glacial times, and it demonstrates the connection of certain rivers assigned to other basins with the Ohio system. The Atlantic fauna of the eastern slope of the .Vlleghany is distinct from, but a derivative of, the western fauna, and includes trwo distinct elements, a northern and a southern, the latter containing some ancient forms, the former not being very old, but pre- Glacial. Along the Atlantic slope there is a north and south dispersal line, available for both land and water forms, which probably lies along the coastal plain, where the rivers are at base-level ; and there has doubtless been dispersion of forms by stream-capture also. GEOLOGY. By G. W. Tyrrell, A.R.C.Sc, F.G.S. VESICULAR SEDIMENTS AND SEDIMENTARY INFILLINGS IN LAVAS.— The curious infiUings and intercalations of sediment in the Old Red Sandstone volcanic rocks of Scotland, first noticed and described by Sir Archi- bald Geikie, are described in detail by Dr. A. Jowett in a paper on " The Volcanic Rocks of the Forfarshire Coast " {Quarterly Journal of the Geological Society, October, 1913). The same subject has also been dealt with recently by Mr. John Smith in his book, " The Semi-precious Stones of Carrick " ; and by the author in a paper on the Old Red Sandstone Volcanic Rocks of Carrick, AjTshire, now in the press. The sediments in question are red and green mudstones and fine-grained, compact, mica-spangled red and green sandstones. They frequently enclose lumps of slaggy volcanic material, and are themselves occasionally vesicular. They are found as small inconstant lenticles wedged in between the flows, and also filling cracks and cavities in the solid lava. The fine layers of sediment have frequently been broken and distorted. Dr. Jowett ascribes the singular occurrence of vesicular sediments, as well as the buckling and distortion of the layers, to the flow of hot lava over unconsolidated material containing much water. The water in the rock was boiled, but the steam generated was prevented from escaping owing to the outlets being sealed by the molten rock. Hence spheroidal cavities were produced, which later were usually filled with calcite and chlorite, forming amygdales. The movement of the molten magma over the moist sediment crumpled the superficial layers, and gave rise to the crumpling and breaking of the bedding planes. Dr. Jowett concludes that the lavais were outpoured into water in which fine sediments were accumulating, but does not say whether the water was that of the sea or of inland lakes. Mr. John Smith believes that the similarOld Red Sandstone lavas of the Carrick Hills, Ayrshire, were poured out on land, and that the intercalated sediments were accumulated in temporary pools on the surfaces of the lava-flows. He has found what he believes to be trailing marks, tracks, and other traces of land animals in the sediments, which form conclusive evidence of terrestrial conditions. The present writer supports Jlr. John Smith's view as to the accumulation of the lavas and sediments on land surfaces, and believes the sediments to represent the fine muddy wash from the lava-flows into temporarj^ pools. This material was supplemented by wind-carried grains, especially mica-flakes, gathered from the arid surface of the Old Red Sandstone continent. .A conglomerate indicating terrestrial deposition was found, similar to those described by Dr. Jowett from Forfarshire. In the Carrick coast section certain dark, highly polished knobs of lava-rock stand out, having resisted marine erosion better than the surrounding rock. Under the microscope it is found that this rock is thoroughly permeated with red iron oxide (haematite). These areas are believed to represent the sites of temporaiy pools into which ferriferous solutions drained from the surrounding rocks. THE R.\TE OF EROSION AND THE AGE OF THE EARTH. — In a recently published paper H. S. Shelton makes it clear that the present stage of the contro\-ersy as to the age of the Earth is marked by the revolt of the geologists against the physicists. (" Some Aspects of Geological Time. " Science Progress, October, 1913.) He goes so far as to say that no single one of the methods which up to a few years ago were regarded as valid is of any value whatever. Recent criticism and discovery have shattered the theories of Lord Kelvin, and the collateral methods of Joly and SoUas have also been subjected to destructive criticism. The trend of present-day opinion is to demand a vastly greater duration of geological time than even geologists had hitherto thought probable. These views are supported by several considerations. For example, the data concerning the rate of erosion of the surface of the Earth, on which is based an estimate of the age of the Earth, are extremely variable. Rivers provide the chief index of the rate of erosion in the amount of material they carry with them, and which they must have obtained from their drainage areas. The rivers of which reliable measurements have been made are the ^Mississippi, the Ganges, the Hoang- Ho, the Rhone, the Danube, and the Po. It is a remarkable fact that all the rivers with a large discharge of sediment, such as the Ganges, the Irrawaddy, the Hoang-Ho, the Rhone, the Danube, and the Po, are situated in densely populated and highly cultivated areas. The high rate of erosion indicated by these rivers may be regarded as due to the exceptionally great denudation to which alluvial and cultivated land is liable. Rivers which have a low rate of discharge of sediment are the Uruguay, Rio Grande, and the Nile. With the exception of the Nile, these are situated in districts of sparse and low cultivation. The Nile is exceptional owing to the absence of rainfall in the lower part of its basin and the discharge of its sediment over the rcunless areas dunng its annual overflow. These facts suggest that the normal rate of di=charge of sediment from a river is low% and that high rates are abnormal and due to 32 KNOWLEDGE January, 1914. the influence of man as a geological agent. Hence estimates of geological time should be based on a rate of denudation calculated from rivers whose basins are as yet undisturbed, or little disturbed, by man. In general tliis will result in a large increase of the estimate of geological time arrived at by this method. METEOROLOGY. By William Marriott, F.R.Met.Soc. TORRENTIAL RAINFALL AT MONTELL, TEXAS. — In the United States Monthly Weather Review for June it is reported that on the 2Sth a Gulf disturbance of moderate intensity moved inland near Corpus Christi, w-here a wind velocity of fifty miles per hour from the south-east was recorded. The storm apparently broke up over the upper Nueces watershed, after giving copious rains in that .section. The centre of heaviest precipitation was at Montell, Uvalde County-, where from 2.30 p.m., June 28th, to 9 a.m., June 29th, the fall amounted to 20-60 inches, being equivalent to an average rate of 1-11 inches per hour for eighteen and a half consecutive hours. Uvalde, in the same county, and less than thirty miles south-east of Montell, reported a rainfall of 8-50 inches from 1 p.m., June 28th, to 6 a.m., June 29th. These rains caused considerable damage in that section, flooding the lowlands, washing away houses and stock, and interrupting traffic and communication by telegraph and telephone for several days. One person was drowned in the vicinity of MonteU. The rainfall at Montell is the heaviest twenty-four-hours precipitation record in Texas, and the next heaviest is eighteen inches, occurring at Fort Clark on June 14th and 15th, 1899. It is remarkable that these torrential rains should have occurred in the same section of the State and in corresponding months. DAILY TEMPERATURE CHANGE AT GREAT HEIGHTS. — When observations by means of registering balloons were first started in England in 1907, it w'as soon found that the effect of solar radiation upon the thermo- graph was a matter that must be reckoned with. To avoid the trouble balloons were mostly sent up a little before sunset, and this custom was continued till the meeting of the International Committee for Scientific Aeronautics at Monaco, in the spring of 1909. At that meeting the time of 7 a.m. was fixed for the international ascents, that being the time for which the morning weatlier chart is drawn. Since then ascents have been made in England at the specified time, viz., 7 a.m., on the twenty-three specified days per annum. But other ascents have also been made on the international days, and on days of special meteoro- logical interest, such as the occurrence of thunder, or of a very high or very low barometer ; and such ascents are mostly made in the evening. Some two hundred good observations have been made in the British Isles, reaching to about sixteen kilometres, concentrated into two nearly equal groups, one with its centre two hours after sunrise and the other about a quarter of an hour after sunset. Mr. W. H. Dines, F.R.S., has carefully discussed these records, and he gave the results in a paper which he read at the November meeting of the Royal Meteorological Society. He found that above two kilometres and up to the isothermal column the daily range of temperature, if it exists at all, does not exceed 2^ C, and that the maximum is in the afternoon or evening. AWARD OF THE SYMONS GOLD MEDAL.— The Council of the Royal Meteorological Society have awarded the Symons Gold Medal for 1914 to Mr. W. H. Dines, F.R.S., in recognition of the distinguished work which he has done in connection with meteorological science. The medal, which is awarded biennially, was founded in 1901 in memory of the late Mr. G. J. Symons, F.R.S., the originator of the British Rainfall Organisation. The former recipients of the medal have been : Dr. Alexander Buchan, F.R.S., in 1902 ; Dr. Julius Hann, of Vienna, in 1904 ; Lieut. -General Sir Richard Strachey, F.R.S., in 1906 ; M. L. Teisserenc de Bort. of Paris, in 1908 ; Dr. W. N. Shaw, F.R.S., in 1910 ; and Professor Cleveland Abbe, of Washington, in 1912. The medal will be presented at the annual meeting of the Royal Meteorological Society on January 21st. GREAT RAINSTORM AT DONCASTER.— On Septem- ber 17th, 1913, during a period of disturbed weather, a remarKably heavy and local fall of rain occurred in the vicinity of Doncaster. Mr. R. C. Mossman and Mr. C. Salter, of the British Rainfall Organisation, have investigated the matter, and have found that the storm lasted fourteen hours, from about 7 a.m. to 9 p.m., and in that time more than four inches of rain fell at six ob.serving stations, of which four had more than five inches. The greatest amount measured was 6-43 inches at the Doncaster Sewage Pumping Station, while 5-67 inches fell in Avenue Road and 5-50 inches at Brodsworth and Wyndthorpe. The small area embraced by the heavy rain is shown by the circumstance that more than four inches of rain fell over only sixty-one square miles, and more than five inches over only twenty- seven square miles, while more than half an inch fell over 2,336 square miles. Over the latter area it is calculated that 47,330 million gallons of water were precipitated. No adequate explanation of the storm has been offered, but the phenomenon affords an opportunity for special investigation. MICROSCOPY. By F.R.M.S. GROUND-GLASS LABELS.— The late Dr. Dallinger advocated the use of ground-glass labels for all specimens (Carpenter, Edition VHI, page 524). He used a special i)lock of wood, a lead buft", and emery powder ; when the writing was completed it was covered with a drop of balsam and a coverglass. For many purposes the method may be simplified. The edge of any table may be used as a support protected with a piece of brown paper. Two slides may be prepared at a time, by using the second to do the grinding. Put a drop of water on the end of Slide A, which is held close to the edge of the table, not overlapping it. Add to the water about a cubic millimetre of fine emery powder (not knife-powder), and stir up gently and evenly with the flat end of Slide B. When the powder is seen to be evenly distributed on the part of the slide to be converted into a label one applies a little more friction, combined with pressure, with the thumb of the other hand. The powder is then washed off in a stream of running water. The whole process is quite br'ef and easy, if care be taken to use only a little powder and to distribute it well before rubbing hard. One can then write on the prepared suface with an ordinary' lead pencil, the marks of which may be removed by friction, but not by any ordinary handling, nor by the reagents used to stain the slide. If necessary, they could be after- wards removed and the necessary inscription written in Indian ink, which could be covered in balsam after drying ; but for many purposes the pencil marks ma.ce a satisfactory label. This plan is especially useful when films of blood are to be taken from a number of patients : being marked at the time of taking, they cannot be afterwards miixed up. An ordinary label, or a grease pencil, would not serve the purpose, as the film must be stained in a neutral methyl- alcohol solution. E. W. B. NOTES ON BLOOD FILMS.— In making the film the usual mistake is to take too large a drop of blood. A drop two millimetres in diameter is large enough for normal blood ; in cases of anaemia make it a very little larger. This drop of blood being near one end of a clean .slide, bring up to it the rounded surface of a glass rod one inch long, which is held lightly at the sides of the slide by two fingers. Let the blood flow along the side of the rod distal to that part of the slide on which the film is to be. Then, without delay, steadily draw the rod backwards along the slide, not rolling it, nor brushing the blood along in front ot January, 1914. KNOWLEDGE. it, but merely drawing out the column into which the drop has been converted. Practically no pressure is required. The film, when complete, .should be quite uniform, without lines — of only the faintest orange colour — exhibiting diffraction colours when viewed at an angle by transmitted light. It is, of course, necessary to wash the little glass rod after use. Staining is usually carried out by means of the double salt of eosin and methylene blue in methyl-alcohol solution. Various distinguished persons have introduced modifications of the process, the most interesting being that of Dr. S. G. Scott, who has found that the best staining effects are obtained by mi.\tures of various eosinates. It is advisable, for instance, to have some of the thionin salt present, in addition to the eosinate of methylene blue. I have myself obtained good results from a number of dif- ferent compounds, especially when combined as Dr. Scott recommends (" Fotia Haematologica," Band XIII, 1911, page 302). I find it is best to keep the solution in plain- stoppered bottles of the first quality, which have been care- fully washed and neutralised. Pour about four drops of the stain into a clean watch-glass and pour this straight on the slide in one sweep, so as to cover all the parts to be stained simultaneously. Now put into the watch-glass the same quantity of distilled water. WTien the undiluted stain has acted for half a minute (tliirty seconds) pour it back into the watch-glass and mix it with the water. Then quicldy return the mixture to the slide, and allow it to act for three minutes — not longer. Finally wash away the excess of stain with distilled water until the corpuscles are seen under the microscope to be duly differentiated. If the stain is allowed to act for longer times than these (according to the usual directions) the eosin will tend to extract the methylene blue ; and unless you wash for a long time the red cells will be lilac in tone, while, if washing be prolonged, you may lose the blue stain more or less completely. Some writers speak of the methyl alcohol as having a fixative effect on the film. If one tests the fixation by trying other stains, it is found to be of an extremely mild order. I prefer to say that the methyl alcohol has a slight hardening effect, but does not harden to such an extent as to prevent the methylene blue and its compound acting as an intra vitam stain. I.e., exercising an independent and selective fixing action. The stain is also soluble in ethyl alcohol ; but in this medium the solution is much more dilute, so that about t\venty-four liours are needed to stain the film. Evidently the staining process is in this case delayed by the hardening action of the ethyl alcohol, which ultimately inhibits it altogether, so that even after a day's exposure one does not get a well-coloured film. The little clay tripods which are used to support inverted incandescent mantles form most excellent supports, on which the slide may be placed for the operation of staining, so as to avoid that extra staining of surrounding objects which is at once inartistic and unnecessary. In spite of the durabihty of these mantles disused clay tripods are not rare. Undoubtedly blood films are best examined by the aid of an immersion lens, and it is all but essential that it should be an oil immersion. When the film has thoroughly dried the colour will be fairly permanent under a layer of oil, but quite the reverse under balsam and glass. As one must rapidlv examine a great many cells, it would be an advantage to use an objective of lower power than the ^,", and for this special purpose the i", formerlj' made by Reichert, is exceedingly convenient ; indeed, it may be doubted whether for general purposes an eighth (3 mm.) is not preferable to a twelfth (2 mm.), if the numerical aperture be the same. At the same time, if no abnormalities or doublrful forms be present, a differential count can be quite well made with a B (half-inch) objective and a high-power orthoscopic ocular. Strain of the eyes is then the chief disadvantage, g "w B DARK-GROUND ILLUMINATION FOR THE HAEMOCYTOMETER.— It is a frequent complaint that the lines in ruled counting chambers are difficult to see. This is probably often due to the iUurnination being bad, either because in the circumstances proper light cannot be obtained, or because the usual form of substage condenser will not focus through .so thick a slip. The back of the Zeiss Abbe condenser will do this admirably, and with a suitable-sized stop it will give excellent dark-ground illumination to an objective of medium aperture, such as the Zeiss B ; and this, with a medium or high ocular, gives all the magnification that can be required for such a purpose. With such an arrangement the lines are distinct enough. But, in any case, the lines are more ob\aous with a half-inch and a high ocular than with a sixth and a low ocular. As it is only a question of seeing the lines the worse definition does not matter ; it is still good. -Vt Professor Sahli's suggestion, Messrs. Leitz have recently brought out a form of haemocytometer, in which the reticulum is in the eyepiece. (\ similar reticulum to fit micrometer oculars has been made for some time past by Messrs. Winkel : it has a different arrangement lor identify- ing the individual squares : evaluation must in this case be performed by the user, but this is not difficult.) In this arrangement there can be no difficulty in seeing the lines. It may occasionally be desirable to ensure special accuracy in the count by roughly sketching each corpuscle visible in the field. The size of the field in squares is then found, and the corpuscles counted on the sketch. If due regard is paid to its proper adjustment the Abbe camera permits this process to be carried through quite quickly. ' E. W. B. QUEKETT MICROSCOPICAL CLUB.— At the meeting held on November 25th, 1913, the President, Professor A. Dendy, F.R.S., dealt with " A Red Water Phenomenon due to Euglena." The water of a pond near Manchester was observed to be of a brilliant red colour. Examination showed this to be due to Eugletia, which formed quite a thick scum of the red colour. The red colour was due to the replacement of the chlorophvU by haematochrome. Mr. Jas. Burton (Honorary Secretary) read a paper on " The Disc-like Termination of the Flagellum of some Eiiglenae." Some two years ago a member (Mr. N. EUis) had observed that Euglena, after prolonged confinement in the life-slide, threw off the flagellum, which then, in the majority of cases, appeared to be terminated by a small disc or bulb. Reference was made to similar observ-ations recorded in Science Gossip, 1879. Mr. Burton had come to the conclusion that the disc is purely an optical effect due to the " kinking," or coihng upon itself, of the thin thread of protoplasm. Mr. Burton also described a method of marking a given object on a mounted shde for future refer- ence. In the case of objects large enough to be recognised under a hand-lens a dot of water-colour is placed over the object with a fine camel-hair or sable brush. The slide is placed on a turntable, and the dot carefully centred. A small ring of some dark cement is run round the dot, and, when dry, the dot cleaned off. In higher-power work find and centre the object in the field with a suitable power. Then substitute a water-immersion one-tenth ; put on the front lens as small a drop of water as possible, and focus. When the object is recognised and centred raise the tube rather sharply, leaving a dot of water on the shde. Charge this with colour — -carmine was suggested — and, when dry, ring as before and clean off the colour. An oU-immersion used \vith water may be employed, or any close-working objective available if a water-immersion be not in the outfit. Dr. Spitta said that, after having centred an object, he replaced the objective with a dummy carrying on its lower end a rubber letter O. This was inked and carefully lowered on to the shde. Mr. J. Grundy read a paper, by Mr. E. M. Nelson, F.R. M.S.. on " The Measurement of the Initial Magnifj'ing Powers of Objectives." The apparatus required is a stage micro- meter, and a screw micrometer with positive eyepiece. With a tube of a length as described below the interval of two ijr\;3 inch divisions of the stage micrometer is read 34 KNOWLEDGE. January, 101-t. on the drum of the eyepiece. This reading will be the initial magnifying power of the objective. The formula for the determination of tiibe-length is 15a/ — |- . 335, where f> is V p the nominal initial power. All powers of a quarter of an inch and less, and all apochromats, require a nine-inch tube. This is measured from the nosepiece to the web of the micrometer. PHOTOGRAPHY. By Edgar Senior. FURTHER TEST FOR THE PRESENCE OF " HYPO." — In addition to the methods given in our Notes for the December issue of " Knowledge " that in which a solution of mercuric chloride is employed is strongly to be recommended, as it is capable of detecting the presence of a very small quantity' of " hypo " in the washing water from negatives or prints. Tlie test solution is prepared according to the following formula : — Mercuric chloride Ammonium chloride Water Strong hydrochloric acid 300 grains 109-5 „ 5 ounces 40 minims The ammonium chloride is for the purpose of forming the double chloride HgCl._. . (NH, Cl),>, which affords a more delicate test, and the hydrochloric acid prevents anv pre- cipitate of carbonate of mercury when hard water containing carbonates is employed, but in no way interferes with the reaction due to " hypo." Having prepared the above solution its usefulness may be shown in the following manner : Take an ordinary test tube and fill it three-parts with water, and then add a single drop of the ordinary " hypo " fixing solution, and well shake. The contents of the tube are then to be emptied out and fresh water intro- duced, when, on the addition of one or two drops of the mercury solution, a bluish opalescence will be produced, caused by the small quantity of " hypo " which still remains. .\s the amount of " hypo " will be very small the test must be carried out with nicety, using a clear solution and a glass vessel that is perfectly clean. It is also advisable to have a second tube filled with clean water for comparison. If, in testing the washing water of prints, the washing is carried to such a point that " hypo " cannot be detected in it, heating the water in which some strips of the prints are soaking will, in nearly all cases, cause " h3rpo " again to show itself to the test. This, of course, shows that the salt is never completely removed by washing ; but the less of it that remains the longer the prints are likely to last. " HYPO " ELIMINATORS.— On account of the pro- longed washing that is neccssarj' very completely to remove " hypo " from prints and negatives various methods have been recommended to be applied after a short washing in order to decompose the remaining ",hypo " into an inert substance, and thus gain a saving in time. The first " hypo " eliminator suggested appears to have been alum, which was recommended as far back as 1855 by Sir W. J. Newton ; and, while this substance does react with " hypo," the products appear to be undesirable, although it is sometimes employed after a prolonged washing for removing the remaining trace of " hypo " previous to intensification with silver in the case of negatives. Now thiosulphates (" hypo "), like sulphites, -are readily o.xidised ; thus free chlorine, sodium hypochlorite, and ferric chloride completely oxidise them to sulphates, even when cold, and d vantage has been taken of this by using sodium hypochlorite as a " hypo " eliminator, the late Mr. F. W. Hart havinc; been the first to employ it for this purpose in 1866. The method " which was applied to paper prints " consisted of treating them with a very dilute solution of the salt until the prints no longer discharged the blue colour cf iodide of starch, which is bleached if " hypo " is present. .\ftervvards the prints were washed in a very weak solution of ammonia to decompose any silver chloride formed during the reaction. The method is effective owing to the " hypo " being completely oxidised to sulphate, as shown by the equation Na, Sj 0„ + 4Na CIO + H2 0=2Na HSO^ -j- 4Na CI. Of the various methods that have been introduced for the elimination of " hypo " this one appears to be the most satisfactory, o\ving to the complete oxidation of the " hypo " ; and, although sulphates are, generally speaking, inert, they are liable to undergo decomposition in tlie presence of moisture and organic matter such as paper. .A.bout the year 1866 Dr. Angus Smith and Mr. J. Spiller suggested the use of hydrogen peroxide for the purpose of eliminating " hypo." Tliis body, however, produces a mixture of sulphate and trithionate of so:lium as follows : — 2Nij S, O,, + 4H2 O, ^ 4H2 O + Naj SO, + Na, S, O,, and the latter decomposes into other substances. After the expiration of some days the solution will give a pre- cipitate with the mercuric chloride test, showing that the whole his not been converted to sulphate ; and on this account a solution of hydrogen peroxide is not to be recom- mended for the purpose. In 1872 the late Dr. Vogel recommended employing tincture of iodine, this being added to water until a straw- coloured solution was produced, when the prints were immersed in repeated baths of the same until the paper assumed a bluish tint, indicating excess of iodine ; and, although the method appears to increase the permanency of the prints, it is open to the same objection as the la.st one in giving a precipitate with the mercury test solution. Moreover, the action of iodine upon " hypo " is to produce a tetrathionate 2Na, S, O, -I- 21 = Na-, S, O, -f- 2Na I and while both of these salts are soluble in water they are less so than " hvpo," while the tetrathionate is itself unstable. .\nother " hypo " eliminator, under the name of " anthion," was introduced by Messrs. Schering in 1895. This substance, which is potassium persulphate, was to be employed at a strength of about seventy-seven grains, dissolved in thirty-five ounces of water ; and the plate, after having been washed for five minutes, was to be im- mersed in this solution for five minutes, again washed for five minutes, when the treatment was repeated once more and the plate again washed. As the persulphates dissolve metallic silver, the action cannot be prolonged without risk of damage to the negatives ; and so far as tests with the mercury solution are concerned the action appears to be no more effective than the treatment with iodine or peroxide of hydrogen, as a precipitate is formed even after an excess of the persulphate has acted upon " hvpo " for several days. PHYSICS. By Alfred C. Egerton, B.Sc. MOLECULAR WEIGHT OF ACTINIUM EMANA- TION.— The radio-active elements — radium, thorium, and actinium — give rise to radio-active gases, or " eman- ations," when their atoms disintegrate. They disintegrate with the expulsion of an a-particle — an electrically charged helium atom ; as the helium atom weighs 4 (compared to the atom of hydrogen), it is evident the atomic weight of the atom of the emanation should be a number less by 4 or a multiple of 4 than the atom of the parent element. Radium has an atomic weight about 226, so that the atomic weight of niton (the emanation) should be 222. This number was about the mean of the determinations which Ramsay and Gray succeeded in carrying out by their delicate method of weighing gases, which has already been described in these columns. The case of actinium is interesting. There is dmilit January, 1914. KNOWLEDGE. 35 what IS lis position lu Uie series of radio-active elements. If it could be obtained in sullicient purity and quantity its atomic weight might be determined, and this would act as a means of telling whether it was a direct ancestor of the radium atom coming after the uranium products, or whether it was the progeny of one of lliose products on a side issue ; or, again, it might be the member of a radio-active series which had no relation to the Uranium-radium series — a different family of radio-active substances. Now the atomic weight has not yet been established ; but if the weight of the emanation could be found, that of the actinium atom would be known. Actinium emanation has a period of only a few seconds, and the quantity of it which can be obtained is ver^- small ; consequently a direct determination of its density by weight is practically out of the question. The density of gases can, however, be determined by their diffusion, the rate of diffusion being inversely proportional to the square root of the density. The method which has been devised by Messrs. Marsden and Wood is on these lines. Two vessels of known volume are separated from each other by a small hole (one square mm. area) : one of the vessels contains a small branch tube containing actinium. The actinium will give rise to emanation, which will etfuse into the empty chamber ; the number of molecules passing through the hole depends on its area, on the mean molecular path of the molecule, and on their number on either side of the hole. A steady state would be reached when the number disintegrating in the second vessel equalled the number entering through the hole. The ratios of the number of molecules passing through the hole could be determined by measuring the activity of the deposit on the walls of the vessel after a certain time (about three hours). The mean molecular path could then be calculated, and hence the weight of the molecule, because U =14546/W^ -v— • where e is the temperature. In this way the above-mentioned authors have obtained the number 232 as a preliminary' measurement of the molecular weight of actiiuum emanation, .\ctinium gives rise to two products of the same atomic weight, radio- actinium and actinium X ; and this disintegrates into the emanation, so that the atomic weight of actinium should be 232+8 =240. This would place it outside the uranium family of radio-active elements. Some have considered that actinium is the product of Uranium Y ; others that it is a branch product from Radium C ; but the above result would make these ideas improbable. It will be interesting to hear if the value is confirmed. INTERMITTENT VISION.— The wheels of a motor-car are often seen so that the spokes appear stationary for a moment, although the wheels are rapidly rotating. This has been traced by Mr. MaLIock, F.R.S., to a shght shock received by the observer, such as is given by a motion of the jaw or the jerk of a stride or a bUnk of the eye. The same effect can be observed if a top is covered by a diagram representing the spokes of a wheel and is rotated ; when the observer's head is tapped the spokes appear stationary for the moment. SPECIFIC GRAVITY LEVER.— Dr. Butler Savory has introduced an instrument for measuring the specific gravities of all Uquids from the hghtest to the hea\dest, with only a small amount of the hquid. It has also the advantage of portabihtj'. The instrument consists of a vessel, at one end of a lever, which is balanced level by means of a shding weight. The instrument is set by filling the vessel with water and adjust mg the slides until the spirit-level on the beam shows that the latter is level. Another hquid being substituted for water, the adjustment is made by means of another smaller shde which moves along a graduated beam. The instrument appears eminently practical, and should be very useful, jis the determinations would be very quick and easy to carry out. ZOOLOGY. By Professor J. Arthur Thomson, M.A., LL.D. SPELLING DOGS. — Everyone has heard during the last two years of the " thinking horses " of Elberfeld, wliich stamp out answers to arithmetical questions written on the board, and in many cases gi\'e the correct answer the very first time. When ^ 15876— \ 12769 was written on the board one of them stamped out tliirteen before any person present, so far as is known, had been able to work the sum. That they understand what an arithmetical process is remains unproved ; that they compute in some fashion of their own like " calculating boys " is possible ; that they simply stamp out an answer somehow communicated to them is also possible ; but, telepathy apart, no suggestion of the mechanism of signalling has been offered that fits the facts. Another chapter in animal education has been opened by the careful training of a dog at ^lannheim, wliich has learned to spell and to recognise drawings of common things. The speUing lessons were on " Morse" lines, as used with the Elberfeld horses. Each letter is denoted by two figures ; thus « by 11, which involves two stamps — one with the right paw and one with the left — and n by 12, which involves two stamps with the right paw and one with the left. Now the other day Professor H. E. Ziegler, a well-known zoologist and student of instinct, called on the dog and drew a mouse on a piece of paper, whereupon the dog spelled out " Maus." The Professor then drew a flower, and the dog spelled " Bliml," which is a dialect form of the German for flower, Blume. What happened the third time, when Professor Ziegler drew an elephant, may be suppressed just at present. REMARKA.BLE RESPIRATION.— Professor O. Fuhr- mann describes the respiration of an interesting Caecihan genus, Typhlonectes, from Colombia. In Caecilians the left lung is usually rudimentarj', but in this type both lungs are long and very narrow. Both are supported by rings of cartilage, as if they were tracheae. The long trachea gives off ventrally in front of the heart a curious spindle-shaped body, which turns out to be an accessor^' third lung. More- over, the animal breathes through its skin. Finally, it probably has buccal respiration. The creatures often swim energetically in pursuit of fishes, and then: elongated, very narrow lungs seem to require assistance, and they have got it ! HOW CUTTLEFISHES DEAL WITH CRABS AND BIV.\LVES. — It used to be supposed that cuttlefishes suffocated crabs with their suckers and then tore them open with their beaks. But the method is more subtle. In 1895 Krause showed that the secretion of the posterior salivarj' glands of the octopus was very toxic, and it was supposed that the octopus gave a poisonous bite. But Pieron has recently shown that the octopus at least does not bite the crab until after death. The paralysing secretion is probably wafted into the crab with the respiratory current. Similarly, in regard to bivalves it was thought that the cuttlefish forced the valves asunder by fLxing suckers to each valve and then pulling in opposite directions. But Pieron has shown with cockles, mussels, scallops, and the like that the to.xic juice first paralyses the adductor muscles. In the case of the cockle the octopus breaks some of the teeth on the posterior margin of the shell, so that the salivary juice may get in more readily. .A.fter paralysis has set in force is employed, but it does not require much. The secretion from the stomach of the starfish has apparently the same paralysing action on bivalves. TROPISM OF HORNED BEE.— A tropism is an obligatory reaction of an organism to some persistent external stimulus, the organism seeking to adjust itself 36 KNOWLEDGE. Jantary, 1914. symmetrically in reference to the stimulus. A. Popovici- Baznosanu has experimented with the homed bee (Osmia biconiis), which often develops inside reeds. The cocoons made by the lar\-ae have the conical pointed end upwards. If lar\'ae that have eaten all their provisions be placed in boxes they make cocoons at right angles to the floor ; if the reed be inverted they make their cocoons pointed upwards as usual ; if a larva is put in a sloping box the cocoon is still made vertically in relation to the earth ; if the larsae are placed in a horizontal glass tube the cocoons are all disposed \-ertically. There is a strong tropism to dispose the cocoon symmetrically in relation to gravity. COLORATION OF A SEA-URCHIN.— Dr. J. Stuart Thomson has done an interesting piece of w-ork in analysing the possible interpretations of the variable coloration of Echinus angulosiis, a sea-urchin common on South African coasts and elsewhere. Many colours occur on different specimens — purple, red, green, grey, intermediate between purple and grey, intermediate between green and purple, pink, lilac, and so on. It is shown that the coloration has nothing to do with sex, and that it cannot be grouped under the headings " protective " resemblance, " aggressive " coloration, " warning " indication, except by excessive exercise of imagination and ingenuity'. The meaning of the coloration of E. aiigiilosKs is to be sought for in the internal phj-siological processes (probably respirator^' or excretory) of the animals themselves. The \ariable tegumentar^' colouring of E. angulosiis is probably due to by-products or waste-products produced during the metabolic processes. The author's view, that it is not necessary to hold that eveiy characteristic of an animal is adaptive, seems to us very sound sense. CHINESE FLEA-TRAP.— Dr. Edward Hindle describes a flea-trap much used in Sze-Chwan. It consists of two pieces of bamboo, one inside the other. The outer is about a foot in length and trwo and a half inches in diameter ; it is longitudinally fenestrated. The inner bamboo is of equal length, but only about an inch in diameter. It is kept in position by means of a short wooden plug. The inner bamboo is coated with birdlime or the like ; the outer bamboo is protective. The trap can be placed under bedclothes, among rugs, and so forth ; any fleas that go through get caught on the birdlime. Dr. Hindle suggests that the trap might be of great value in connection with plague epidemics. POISON OF HORNETS.— Professor E. Bettarelli and Dr. A. Tedeschi have made an experimental study of the poison of hornets. It behaves on the whole like that of bees and wasps, and has also distinct resemblances to snake poison. It tends to dissolve blood-corpuscles and to produce convulsions. The investigators have not been able to decide as yet whether the hornet's poison produces an antitoxin or not. SOLAR DISTURBANCES DURING NOVEMBER, 191, By FRANK C. DENNETT. As compared with October, November proved a veiy quiet month to the solar observer. The Sun was under observation every day, but on three only (24th to 26th) were dark spots visible. Faculae, or bright markings, were recorded on twelve days (3rd to 6th, Uth, 14th, 15th, 20th to 23rd, and 27th) ; but on all other days the disc appeared free from disturbance. The longitude of the central meridian at noon on November 1st was 312^ 30'. No. 16. — Two larger spots, with pores, in the midst of bright faculae were first seen on the 24th approaching the south-western limb, the leader being much the smaller, and the following spot at first appeared double. The umbrae of both appeared more conspicuous next day, whilst the eastern spot was still visible near the south- western limb on the 26th. The eastern spot was at least eight thousand miles across, and the length of the group appears to have been over ninety thousand miles. As will be seen, it was situated in high southern latitude. On the 24th the area of the group was found by the spectroscope to be strewn with flocculi of hydrogen, which caused deflections of the C-line on the red side, the same line also showing brilliant reversals. On the 3rd, 4th, and 5th a fine group of faculae — marking the position of spot group No. 15 — was approaching the north-western limb. On the two later days dark hydrogen flocculi widened the C-line, and the helium D,, was visible as a dark line. Traces of the same group were also seen within the north-eastern limb on November 20th to 23rd. On the 6th a tiny bright granule was visible within about 15' of the North Pole, near the eastern limb. On the 11th a tiny bright facula was situated a few degrees from the South Pole well to the east of the central meridian. On the 14th an elliptical faculic ring, somewhat pale, was seen in longitude 200' to 211=, approaching the south-western limb, some of the rear portion being observed on the 15th, when some small faculic loiots were seen about the same longitude only 8' south of the Equator. Faculae were also visible within the south-eastern limb on November 27th. Our chart is constructed from the combined observations of Messrs. John McHarg, A. A. Buss,C. Frooms, and F. C. Dennett. DAY OF NOVEMBER, 191, 'A li ?£ 2 20 ? 18 I •s ♦ l5 12 1 10 9 ^ 7 a ^■ i 30 t 25 I 28 r ' 24 2S 10 7i 16 i> * :g3 20 ID " 2C a H 10 !0 M ifi r.?' rco 0 a n u to so u 90 iU in la) so M ISO 160 i70 lao fu £0o iio m im z