Apparatus for estimation of sulphur in spent oxide. GLASS BLOWING. All kinds of Scientific and Experimental Glass Blowing carried out on the Premises. Any form of Glass Apparatus repaired. Demonstrations given here, or at Colleges, &c. H. HELM, 66 HATTON GARDEN, LONDON, E.C. Actual Maker of all kinds of X-Ray and Vacuum Tubes, FREDK. JACKSON & Co. SECOND-HAND TOURIST TELESCOPES. (Late MOTTERSHEAD & CO.), 14 CROSS STREET, MANCHESTER Goods Entrance: 10 Half-Moon Street. LABORATORY FURNISHERS, Importers, Manufacturers, and Dealers in Of every Description. Fine Chemicals, Volumetric Solutions, AND EVERY LABORATORY REQUIREMENT. Telephone Number-2238. 56 CHARING SEVERAL SPECIAL BARGAINS. (1) Military Regulation Telescope, Power 20, £1 5s. (2) Military These Telescopes are by the leading London Makers. A. CLARKSON HARVEY & PEAK, BY APPOINTMENT TO THE ROYAL INSTITU- POST OFFICE BRIDGE SETS AND Newcastle-on-Tyne. CROSS ROAD, LONDON, W.c. MACMILLAN & CO.'S LIST. NEW AND REVISED EDITION, JUST READY. A TREATISE ON CHEMISTRY. By SIR H. E. ROSCOE, F.R.S., and C. SCHORLEMMER, F.R.S. Vol. I The Non-Metallic Elements. New Edition, completely revised by Sir H. E. ROSCOE, assisted by Dr. H. G. COLMAN and Dr. A. HARDEN. With 217 Illustrations. 8vo. 21S. net. SIXTH EDITION, REVISED AND ENLARGED. THE ADVANCED PART OF A TREATISE ON THE Being Part II. of a Treatise on the Whole Subject. With numerous Examples. ROCKS, MINERALS, FOSSILS. For Collectors, Students, Technical Schools, Colleges, &c. COLLECTIONS IN POLISHED DEAL BOXES. 15 Specimens, 5/6; 50 do., 10/6; Too 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. 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 Hall-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. 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, references 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.) ☛ New Catalogue (102 pp.) just issued, post free. TABLE OF RARE ELEMENTS. MARINE BIOLOGICAL ASSOCIATION Sycon; Clava, Obelia, Sertularia; Actinia, Tealia, Caryophyliia, Alcy. THE DIRECTOR. 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. GAIFFE-D'ARSONVAL MACHINE Replaces Coils, Interrupters, and Wimshurst Producing, perfectly regulating, and exactly measuring Silent in Working, Simple in Manipulation. This apparatus has been already installed by many of the chief workers in Electro-Therapeutics in France and England, and is giving the very best results (vide testimonials). Replaces large Induction Coils in Laboratory and Research Work requiring High Electric Tensions or Electric Oscillations of great power and uniformity. Descriptive Pamphlet gratis on application from the Sole Agents for Great Britain and its Colonies THE MEDICAL SUPPLY ASSOCIATION, 228 Gray's Inn Road, London, W.C., where the apparatus NEW MICROSCOPIC SLIDES From the New Issue of W. WATSON & SONS' No. 3 CATALOGUE, just published. Post Free on application. SEND FOR THE ABOVE NEWLY PUBLISHED CATALOGUE OF MICRO. OBJECTS. WATSON'S CATALOGUE OF MICROSCOPES (158 pages) is of special interest to all Microscopists. post free. W. WATSON & SONS, 313 High Holborn, London, W.C. Branches-16 FORREST ROAD, EDINBURGH, and 2 EASY ROW, BIRMINGHAM. CROSSLEY'S GAS ENGINES CROSSLEY BROS., LTD., GREAT REDUCTION IN CAS CONSUMED. Up to the end of 1904, over 51,000 gas and oil engines have been delivered, represent ing about threequarters of a million actual horse-power. OPENSHAW, MANCHESTER DALLMEYER'S IMPROVED PRISMATIC BINOCULARS. "THE SERVICE." Will not get out of Adjustment. Easy to Clean. Illustrated Pamphlet Post Free. J. H. DALLMEYER, LTD., 25 NEWMAN ST., LONDON, W. Makers of the Celebrated Dallmeyer Lenses. Printed by RICHARD CLAY AND SONS, LIMITED, at 7 & 8 Lread 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, June 22, 1905. |
