& CO.'S LIST. MACMILLAN 1905 ISSUE READY NEXT TUESDAY. THE STATESMAN'S YEAR-BOOK. Statistical and Historical Annual of the States of the World for the Year 1905. Edited by J. SCOTT KELTIE, LL.D., Secretary to the Royal Geographical Society. CROWN 8vo. 10s. 6d. NET. LANDSCAPE IN HISTORY & OTHER ESSAYS. By Sir ARCHIBALD GEIKIE, D.C.L., F.R.S. 8vo. 8s. 6d, net. A MANUAL OF QUATERNIONS. By CHARLES JASPER JOLY, M.A., D.Sc., F.R.S., Sec. R.I.A.; Fellow of Trinity College, Dublin; Andrews' Professor of Astronomy in the University of Dublin, and Royal Astronomer of Ireland. 8vo. 10s. net. By H. S. HALL, M.A., and F. H. STEVENS, M.A. LESSONS IN EXPERIMENTAL AND PRACTICAL GEOMETRY. By H. S. HALL, M.A., and F. H. STEVENS, M.A. Crown 8vo. 1s. 6d. NATURE.—“The subject is treated in the masterly way that is found in the mathematical text-books of these writers. Young pupils are fortunate who obtain their first notions of geometry from a course such as the one outlined in its pages." AN INTRODUCTION TO THE CALCULUS. BASED ON GRAPHICAL METHODS. By GEORGE A. GIBSON, M.A., F.R.S.E., Professor of Mathematics in the Glasgow and West of Scotland Technical College. ELECTROMAGNETIC THEORY OF LIGHT. By CHARLES EMERSON CURRY, Ph.D. THIRD EDITION. Entirely Re-written and Enlarged. CHEMICAL TECHNOLOGY AND ANALYSIS OF OILS, FATS, AND WAXES. By Dr. J. LEWKOWITSCH, M.A., F.I.C., &c. With 88 Illustrations and Numerous Tables. In 2 Vols. Medium 8vo, gilt tops, 36s. net. NATURE.-"The standard English book of reference on the subject." THE LABORATORY COMPANION TO FATS AND OILS INDUSTRIES. NEW EDITION REVISED IN ACCORDANCE WITH THE FOURTH GERMAN EDITION. By THEORETICAL CHEMISTRY FROM THE STANDPOINT OF AVOGADRO'S RULE AND THERMODYNAMICS. By Professor WALTER NERNST, Ph.D., of the University of Göttingen. Svo. 15s. net. The revision of this standard treatise has been executed by Dr. R. A. LEHFELDT. JOURNAL OF THE SOCIETY OF DYERS AND COLOURISTS.-"To the student of chemistry this treatise forms an inexhaustible mine of information, from which may be extracted the arguments and evidence bearing upon all phases of chemical theory." THE SPIRIT OF ORGANIC CHEMISTRY. Literature of the Subject. An Introduction to the Current By ARTHUR LACHMAN (B.S. Calif.; Ph.D. Munich), Professor of Chemistry in the University of Oregon. With an Introduction by PAUL C. FREER, M.D., Ph.D., Professor of General Chemistry in the University of Michigan. Extra Crown Svo. 6s. 6d. net. MICROLOGICAL LABORATORY AND SCHOOL OF NATURAL SCIENCE. GRATIS AND POST FREE. THE NEW COLLECTION OF Scientifically arranged Catalogue of Megascopic and Microscopic 336 SPECIMENS AND SLIDES OF ROCKS, now prepared. Gentlemen are invited to send in their applications without delay, as only 5000 copies will be issued. Sample Slide of expertly prepared ROCK SECTION, 1/-, post free. Metals, Minerals and Rocks expertly mounted for Microscope, 1/- each, from material supplied. LESSONS IN PRACTICAL LITHOLOGY BY CORRESPONDence. A vacancy for one Geological Student, desirous of passing with high distinction in University or Civil Service. Small premium. Pocket-money allowed. Apply:- THE DIRECTOR, MICROLOGICAL LABORATORY, 11 ASPENLEA ROAD, HAMMERSMITH, LONDON, W. MINERALS, ROCKS, FOSSILS. A large stock of BRITISH ANd foreign MINERALS always on view. CORNISH MINERALS A SPECIALITY. Special display for Teachers and Students on Saturdays. Open till 7 p.m. RICHARDS' SHOW ROOMS, 3 Beauchamp Place, Brompton Road, South Kensington, London, S. W. MICROSCOPICAL PETROGRAPHY. Gentlemen interested in the above study are invited to send to JAMES R. GREGORY & CO., 1 Kelso Place, Kensington Court, London, W., for a Prospectus of THE TWENTIETH CENTURY ATLAS OF MICROSCOPICAL PETROGRAPHY, now being issued in Twelve Monthly Parts, each Part containing Four Fine Half-Tone Plates, and also Four actual Rock Sections. Subscription in advance, either Monthly, 7/-; Quarterly, 21/-; or for the whole Series of 12 Monthly Parts & 48 Sections, £4 4s. ALBERT EDWARD JAMRACH (Late CHARLES JAMRACH), 180 ST. GEORGE STREET EAST. Implements of Savage Warfare, Idols, Sacred Masks, Peruvian Pottery, Netsukis China, Lacquers, Gongs, Shells, and other Curios. LIVING SPECIMENS FOR THE MICROSCOPE. Volvox, Spirogyra, Desmids, Diatoms, Amoeba, Arcella, Actinosphærium, Vorticella, Stentor, Hydra, Floscularia, Stephanoceros, Melicerta, and many other specimens of Pond Life. Price is. per Tube, Post Free. Helix pomatia, Astacus, Amphioxus, Rana, Anodon, &c., for Dissection purposes. THOMAS BOLTON, 25 BALSALL HEATH ROAD, BIRMINGHAM. MARINE BIOLOGICAL ASSOCIATION The following animals can always be supplied, either living or preserved by the best methods : Sycon; Clava, Obelia, Sertularia; Actinia, Tealia, Caryophyllia, Alcyonium; Hormiphora (preserved); Leptoplana; Lineus, Amphiporus, Nereis, Aphrodite, Arenicola, Lanice, Terebella; Lepas, Balanus, Gammarus, Ligia Mysis, Nebalia, Carcinus; Patella, Buccinum, Eledone, Pectens Bugula, Crisia, Pedicellina, Holothuria, Asterias, Echinus. Ascidia, Salpa (preserved), Scyllium, Raia, &c., &c. For prices and more detailed lists apply to Biological Laboratory, Plymouth. THE DIRECTOR. according to H. ROSENBUSCH: "Elemente der Gesteinslehre, 2d ed. 1901." Accompanied by a text-book: "Practical Petrography," giving a short description of the polarizing microscope and its application, and also of the macroscopical and microscopical features of every specimen of this collec tion, by Professor Dr. K. Busz of the University of Münster. This collection is intended for the practical use of students, and contains typical representatives of all important types of rocks; it is composed of 277 massive rocks (94 deep-seated rocks, 50 dike rocks, 133 volcanic rocks), 28 sedimentary, and 31 crystalline schists. Out of it two smaller collections of 250 and 165 specimens have been selected. The prices are as follows:Collection I. 336 Specimens of Rocks 380 Marks. 420 270 99 99 Ia. 336 Slides ... II. 250 Specimens of Rocks RHENISH MINERAL OFFICE, BONN-ON-RHINE, GERMANY. ESTABLISHED 1833. WATKINS & DONCASTER, Naturalists and Manufacturers of CABINETS AND APPARATUS FOR ENTOMOLOGY, BIRDS' EGGS AND SKINS, AND ALL SPECIAL SHOW-ROOM FOR CABINETS. N. B. For Excellence and Superiority of Cabinets and Apparatus, refer ences are permitted to distinguished patrons, Museums, Colleges, &c. A LARGE STOCK OF INSECTS, BIRDS' EGGS AND SKINS. SPECIALITY.-Objects for Nature Study, Drawing Classes, &c. Birds, Mammals, &c., Preserved and Mounted by First-class Workmen true to Nature. All Books and Publications on Natural History supplied. 36 STRAND, LONDON, W.C. (Five Doors from Charing Cross.) Our Catalogue (96 pp.) Post free on application. ROCKS, MINERALS, FOSSILS. For Collectors, Students, Technical Schools, Colleges, &c. COLLECTIONS IN POLISHED DEAL BOXES. 25 Specimens, 5/6; 50 do., 10/6; 100 do., 21/-; 200 do., 42/20 Coal Measure Rocks and Fossils, 12/6; do., larger, 15/-. Adapted for the Board of Education Examinations in Geology, Physiography, and Mineralogy. A large stock of Minerals, Rocks, Fossils and Microscopic Objects for selection. Specimens sent on approval. Cabinets, Geologists' Hammers, Chisels, Card Trays, Glass-capped Boxes, Models of Crystals, &c., &c. NEW CATALOGUE POST FREE. THOMAS D. RUSSELL, 78 Newgate St., London, E. C. NOTICE.-Advertisements and business letters for NATURE should be addressed to the Publishers; Editorial Communications to the Editor. The telegraphic address of NATURE is 'PHUSIS," LONDON. SUBSCRIPTIONS TO "NATURE." 66 CHARGES FOR ADVERTISEMENTS. A RECENT COMMENT UPON The SYTAM SYSTEM TOWNSON & MERCER. "Your System will assuredly revolutionize the present method-or want of methodin fitting up Laboratories, Libraries and Offices." The Sytam Bottle Element. Patent No. 7433. This Bottle Element is sub. stantially a Drawer, and is operated as such. It can be placed in a cupboard or underneath a bench or table, or several can be supplied in a suitable outer casing to form a complete cabinet. One hundred 4 oz. bottles Single Element, without The Sytam System is also applied to the storing and classifying of Books, Pamphlets, Manuscripts, and all other Documents, Specimens, &c. ESTABLISHED 1798 (OVER A CENTURY). RETAIL-89 BISHOPSCATE STREET WITHIN, E.C. WHOLESALE-34 CAMOMILE STREET. E.C. NEW INCLINED PLANE, designed by W. J. WOODHOUSE. 25/ This Plane is made of polished mahogany, with brass supports and pegs to vary the angle of inclination. The centre is cut away so that the force can be applied parallel either to the base or plane. The roller runs on glass tube, thus reducing the friction to a minimum, and the plane can be raised at right angles and used as an ordinary pulley, if desired. TOWNSON & MERCER, 34 CAMOMILE STREET, E.C. THE STEREOSCOPIC COMPANY'S DOUBLE-SURFACE ARTIST'S REFLEX Patent applied for. CONDENSER. Overcomes the many disadvantages of Answers equally well for distillations with direct steam, ordinary distillations, or under reduced pressure. Easily cleansed by removing inner condensing tube. In case of breakage (chances of which are reduced to a minimum), any part may be readily renewed at very small cost, or, in fact, replaced from the stores of any ordinary laboratory. May be used in any position, with or without vacuum. Takes less than one-third the bench room of an ordinary Liebig type condenser. For distillations under reduced pressure, where - fractions have to be separated, the fractionating end (as shown in Fig.) will be found extremely useful and convenient. TO Condenser, 5/6; Fractionating End, 10/6; SOLE MAKERS C. E. MÜLLER, ORME & CO., Ltd., 148 HIGH HOLBORN, LONDON. The Ideal Camera for BIRD PHOTOGRAPHY, NATURAL HISTORY 106 & 108 REGENT STREET, W., Printed by RICHARD CLAY AND SONS, LIMITED, at 7 & 8 Bread Street Hill, Queen Victoria Street, in the City of London, and published by MACMILLAN AND CO., LIMITED, at St. Martin's Street, London, W. C., and THE MACMILLAN COMPANY, 66 Fifth Avenue, New York.-THURSDAY, April 6, 1905. THE VERY LATEST "TYPE" OF EXTENSIMETER IS. THE "O'TOOLE." A Simple, Convenient, Accurate, and Reliable Instrument, designed by the Rev. Father O'Toole, College, Dublin, for Students' use in determining the coefficients of expansion of metal rods, at a moderate price. The Apparatus may be adapted for lecture demonstrations, by the simple expedient of using an optical lever. Price, with steamjacket, graduated spirit level and micrometer gauge, complete, £22:0 SOLE MAKERS PHILIP HARRIS & CO., LTD.. 144 EDMUND ST., BIRMINGHAM, AND 179 GT. BRUNSWICK ST., DUBLIN. |