culture who pass a satisfactory examination, which shall consist of the preparation of a scientific thesis and a viva voce ordeal of not more than two hours. THE "Craggs" research prize will be awarded by the London School of Tropical Medicine in October next to a past or present student of the school who during the year (October, 1905, to October, 1906) has made the most valuable contribution to tropical medicine. The competing essays must reach the medical tutor of the school on or before October 1. Prof. G. S. BOULGER has accepted the post of honorary professor and external examiner for the diploma at the Royal Agricultural College, Cirencester, in succession to the late Dr. W. Fream, and Mr. W. Hunting has accepted the position of honorary professor and examiner for the diploma of the same institution in succession to the late Sir G. Brown, C.B. ACCORDING to Science, the General Education Board, endowed by Mr. J. D. Rockefeller with 2,000,000l., has made the following appropriations to nine institutions on condition that the sums in question be augmented three times in value from other sources:-Coe College, Cedar Rapids, Ia., 10,000l.; Washburn College, Topeka, Kan., goool. ; Tulane University, New Orleans, 15,000l. ; Wofford College, Spartanburg, S.C., 5000l.; Furman University, Greenville, S.C., 5000l.; Wake Forest College, N.C., 7500l.; Howard College, Birmingham, Ala., 5000l. ; South-western University, Jackson, Tenn., 5000l.; and Mississippi College, Clinton, Miss., 5000l. THE number of students attending the twenty-one German universities during the summer semester just ended is given as 45,630 matriculated students and 4566 nonmatriculated students, 665 of these being at Berlin University. Among the matriculated students there were in Freiburg, Heidelberg, Leipzig, Munich, and Tübingen taken together 182 women, whilst the number of nonmatriculated students included 1536 women. The number of science students (including mathematics) at these universities, that is, apart from the technical high schools, is given as 6323, as against 6125 in the corresponding semester of 1905; the number of pharmaceutical students is stated to have been 1767, against 1481 in 1905. PROF. RÖNTGEN having declined the offer of the physics chair at Berlin University in succession to the late Prof. Paul Drude, the direction of the physical institute has been temporarily placed in the hands of Prof. W. Nernst, the director of the neighbouring physical chemistry institute. The designation Physikalisch-Chemisches Institut was only recently granted to Prof. Nernst's institution, which had hitherto been known as the "II. Chemische Institut "; it may also be observed that the equipment of the institute has been extended on the electrical side by means of a grant of 10,000 marks, so that the various workplaces have easy access to direct current of voltages of 10, 110, and 220 volts, and a lowvoltage alternating current for electric furnace work. THE following appointments have recently been made :Dr. Wilhelm Deecke, professor of mineralogy in the University of Greifswald, as successor to Prof. Steinmann in the University of Freiburg i. B.; Dr. Johannes Walther as ordinary professor of mineralogy in the University of Halle; M. R. A. Raiss as extraordinary professor of scientific photography in the Lucerne University; Dipl.-Ing. Johannes Galli, technical director of the Annen Steel Works, Ltd., in Westphalia, as successor to the late Prof. A. Ledebur in the professorship of metallurgy in the Mining School, Freiburg, Saxony; and Dr. Karl Hintze, professor of mineralogy in the University of Breslau, has been offered an appointment in the University of Bonn, in succession to Prof. Dr. Laspeyres, retired. THE calendar of the Merchant Venturers' Technical College, Bristol, for the session 1906-7, contains an interesting section dealing with the attempts being made in Bristol to secure the cooperation of employers in the work of educating apprentices and artisans suitably. The plans which certain firms adopt to secure this object are enumerated. Some firms pay the fees of students attending classes relating to the industry in which they are engaged; they also in some instances provide the necessary books and instruments, or they offer prizes for the best student in their employ. Other employers increase the wages of those of their servants who attend specified classes and pass the examination held at the end of the course. The time spent at evening classes is allowed to count in reduction of the working hours of apprentices by a third class of employer. Every plan which tends to bring home the importance of technical training to the manufacturers and their workmen deserves commendation, and it is to be hoped that the Bristol experiments will be tried in other large centres of industry. : SOCIETIES AND ACADEMIES. PARIS. Academy of Sciences, August 6.-M. H. Poincaré in the chair. The iodomercurates of sodium and barium: A. Duboin. The author has isolated crystals of the double iodide of sodium and mercury, having the composition 2Nal, HgI,,4H,O, and of the corresponding barium compound, Bal,,HgI,,5H,O. The latter crystals were remarkable for their length, approaching 2 cm.-The borostannates of the alkaline earths: the reproduction of nordenskiöldine: L. Ouvrard. Calcium borostannate, possessing crystallographic characters identical with those of the natural mineral, was obtained by heating precipitated calcium borate with tin dioxide to a white heat in a slow current of hydrogen chloride.-The influence of the temperature of dehydration of alabaster on the setting of the plaster obtained E. Leduc and Maurice Pellet. The causes of the appearance of so-called anomalous forms in plants. P. Vuillemin.-Researches on the gaseous exchanges of a green plant developed in the light in the absence of carbonic acid, in a soil to which amides have been added: Jules Lefèvre. Under the above conditions it has been found that a green plant can develop, increasing its dry weight three times, without any oxygen being given offThe action of the X-rays on the ovary of the dog M. Roulier. Contrary to the results obtained with rabbits atrophy of the ovary is very difficult to obtain, in spite of the production of serious lesions of the skin.-Experimental nagana. The variations in the number of the trypanosomes in the blood of the dog. The intravascular trypanolysis and trypanolytic power of the serum: A. Rodet and G. Vallet. Section G.-Engineering (Illustrated).-Opening University and Educational Intelligence 419 CANTERBURY. W. WILSON. LIQUID AIR AND LIQUID HYDROGEN. Dr. HAMPSON'S AIR-LIQUEFIER is now made to a standard pattern, and numbers are in use in University Laboratories and elsewhere in various countries. The whole apparatus is neat and compact and its parts very easily moved; the Liquefier, without stand, being a cylinder 17 inches high and 8 inches in diameter. It begins to liquefy air in from 6 to 10 minutes after the admission of air at from 150 to 200 atmospheres pressure, making over a litre of liquid per hour. It requires no auxiliary refrigerant and produces a perfectly clear liquid which requires no filtering. The operator has only one gauge to watch and one valve to control. HYDROGEN LIQUEFIER to the designs of Dr. MORRIS W. TRAVERS for use in conjunction with Air-Liquefier. For Prices and Particulars apply to the Sole Makers :BRIN'S OXYGEN COMPANY, L MITED, ELVERTON STREET, WESTMINSTER, S. W. RADIUM ON HIRE. (Activity 1,800,000 units.) Fluorescent Screen, Electroscope, &'c., and Radium Pendant Microscope with Radium, 2/6 Self-Luminous Radium Screen, 5/ Certificates of Radio-activity, 5/- each sample. Post free within United Kingdom. F. HARRISON GLEW, Patentee, 156 Clapham Road, London, S.W. CHEMICALS RARE METALS MINERALS For Laboratory, Scientific, and all other purposes. COCOA NUT CHARCOAL SPECIALLY PREPARED. HARRINGTON BROS., Chemical Manufacturers and Dealers, MACMILLAN & CO.'S BOOKS FOR STUDENTS OF PHYSICS. AnINTRODUCTION to PRACTICAL PHYSICS, for use in Schools. By D. RINTOUL, M. A. PHYSICS for STUDENTS of MEDICINE. BY ALFRED DANIELL, M.A., LL.B., D.Sc., F. R.S. E. Fcap. 8vo. 4s. 6d. A PRIMER OF PHYSICS. By B. THE STEAM ENGINE AND GAS PHYSICS. By B. STEWART, LL.D., F.R.S. 8vo. 4s. 6d. QUESTIONS. By T. H. CORE. 8vo. 25. Fcap. Pott CHEMISTRY. By Prof. R. A. GREGORY and A. T. SIMMONS, B.Sc. In three stages. Globe 8vo. 1s. 6d. each. EXERCISES IN PRACTICAL PHYSICS. By Prof. R. A. GREGORY and A. T. SIMMONS, B.Sc. Gl. 8vo. Parts I. and II. 25. each. ELEMENTARY GENERAL SCIENCE. By A. T. SIMMONS, B.Sc., and LIONEL AND OIL ENGINES. By Prof. JOHN PERRY, D.Sc., F.R.S. 8vo. 75. 6d. net. EXAMPLES IN PHYSICS. With For Matriculation Students. By D. E. JONES, B.Sc. Gl. 8vo. 35. 6d. PRACTICAL EXERCISES in HEAT. By E. S. A. ROBSON, M.Sc. Gl. 8vo. 25. 6d. HEAT, for ADVANCED STUDENTS. By E. EDSER, A.R.C.Sc. Gl. 8vo. 45. 61. HEAT. By Prof. P. G. TAIT. Cr. 8vo. 65. The THEORY of HEAT. By Prof. T. PRESTON, M.A. (Dub.), F.R.S. Second Edition. Revised by J. ROGERSON COTTER, M.A. Svo. 18s. net. A MANUAL OF ELEMENTARY The THEORY of SOUND. By LORD SCIENCE. By Prof. R. A. GREGORY and A. T. AN ELEMENTARY COURSE OF PHYSICS. Edited by Rev. J. C. P. 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LABORATORY MANUAL of PHYSICS AND APPLIED ELECTRICITY. Edited by E. L. NICHOLS. In 2 Vols. 8vo. 12s. 6d. net each. THE OUTLINES OF PHYSICS. By E. L. NICHOLS. Crown 8vo. 7s. 6d. net. ELEMENTS OF PHYSICS. By Three Vols. E. L. NICHOLS and W. S. FRANKLIN. EDSER, A. R.C.Sc. Gl. 8vo. 6s. LIGHT VISIBLE and INVISIBLE. By Prof. SILVANUS THOMPSON, F. R.S. Illustrated. 8vo. 6s. net. ELEMENTARY LESSONS IN ELECTRICITY AND MAGNETISM. By Prof. S. THOMPSON, F.R.S. Fcap. 8vo. 45. 6d. MAGNETISM AND ELECTRICITY FOR BEGINNERS. By H. E. HADLEY, B.Sc. Gl. 8vo. 2s. 6d. PRACTICAL EXERCISES in MAG- A COURSE OF SIMPLE EXPERIMENTS IN MAGNETISM AND ELECTRICITY. By A. E. MUNBY, M.A. Gl. 8vo. 15. óð. A TEXT-BOOK of the PRINCIPLES of PHYSICS. D.Sc., F.R.S. E. CRYSTALLOGRAPHY. WATKINS & DONCASTER, Naturalists and Manufacturers of Our New Catalogue, XIX., with many illustrations, CABINETS AND APPARATUS has just come out (post free on application). The following are included: 442 1. New Collection of 416 Crystal-models of wood, containing all the crystal forms and combinations represented by illustrations in the 4th ed. of the Physikalische Kristallographie," by Prof. P. Groth (1905) at Munich £27 10 0 2. Large Collection of 916 Crystal-models of wood to illustrate the crystal forms of the minerals, by Prof. C. Hintze at Breslau. £90 0 0 3. New Collection of 8 Trigonal-Glass-models of Calcite, with the crystallographic axes according to Bravais (Weiss) and with the axes according to Miller, constructed by Prof. J. Beckenkamp at Würzburg ... £1 15 O 4. New Collection of 450 Crystal-models of pasteboard, systematically arranged according to the 32 classes of symmetry, by Prof. K. Viba at Prague £48 0 0 5. The Planes of Symmetry, 5 models constructed by Prof. K. Vrba at Prague ... £5 15 0 6. The Optical Wave Surfaces, 4 wire-models constructed by Prof. K. Vrba at Prague... £6 8 0 7. The Optical Indicatrix, 3 wire-models by Prof. K. Vrba at Prague £2 5 0 8. The Sclodromes, 5 coloured plaster-mode's constructed by Prof. F. Becke at Vienna £5 0 0 9. Stands for Crystal models, various constructions and in various ... Dr. F. KRANTZ, *** 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, &e., 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.) CATALOGUE (102 pp.) POST FREE. CLARKE & PAGE, Specialists in Microscopy, 104 LEADENHALL STREET, LONDON. MICROSCOPIC SLIDES. Marine. Exquisite Mounts. Curious and rare forms of extended zoophites, corals, wing-footed pteropods, siphon-bearing animals, young sea-horses, &c., &c. A stock of over 20,000 slides to select from, including all branches. Full catalogue free. See "NATURE," Jan. 4, '06, page 231. SECOND-HAND MICROSCOPES, &c. Large and varied stock of stands and accessories-leading makers. List free. Great Reduction in Prices of CLASS-CAPPED BOXES, CARD TRAYS, WOOD TABLET & SPECIMEN TUBES. Collections or Single Specimens of Minerals, Rocks or Fossils, ROCK SECTIONS PREPARED TO ORDER. THOMAS D. RUSSELL, 78 Newgate Street, London, E.C. THE MICROSCOPE. Volvox, Spirogyra, Desmids, Diatoms, Amoeba, Arcella, Actinosphærium, Vorticella, Stentor, Hydra, Floscularia, Stephanoceros, Melicerta, and many other specimens of Pond Life. Price 1s. per Tube, Post Free. Helix pomatia, Astacus, Amphioxus, Rana, Anodon, &c., for Dissection purposes. THOMAS BOLTON, 25 BALSALL HEATH ROAD, BIRMINGHAM. MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM. THE LABORATORY, PLYMOUTH. The following animals can always be supplied, either living or preserved by the best methods: Sycon; Clava, Obelia, Sertularia; Actinia, Tealia, Caryophyllia, Alcy. onium; 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. 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. THE ROYAL DENTAL HOSPITAL OF OF DENTAL SURGERY, The WINTER SESSION, 1906, will commence on MONDAY, OCTOBER 1. DENTAL AND MEDICAL OFFICERS. Hon. Treasurer of the School-H. Lloyd Williams. House Anesthetists-John MacCormac, L.R.C. P. and S. Edin., L.F.P. and S. Glas.; T. Graham Scott, L.R.C.P., M.R.C.S. LECTURERS. Dental Anatomy-A. Hopewell-Smith, L.R.C.P., M.R.C.S., L.D.S. Mechanical Dentistry-W. J. May, L R.C.P., M.R.C.S., L.D.S. Five House Surgeons are appointed every six months. Six Operative and three Mechanical Demonstrators assist Students in their practical work. The Royal Dental Hospital was founded in 1858 in Soho Square, and in March, 1874, was removed to Leicester Square. The increased demands made on it by the public and the rapid growth of the Medical School necessitated the erection of an entirely new building. The new Hospital was opened in March, 1901, and is complete in every detail with modern appliances, and the School portion of the building thoroughly equipped for teaching purposes. The clinic of the Hospital is unrivalled. In 1995, 98,588 operations were performed. SCHOLARSHIPS AND PRIZES. The ENTRANCE SCHOLARSHIP, of the value of £20, awarded in October. Subjects: Chemistry and Dental Mechanics. The SAUNDERS SCHOLARSHIP, of the value of £20, awarded to the Students obtaining the highest aggregate number of marks in the various class examinations. The STORER-BENNETT RESEARCH SCHOLARSHIP, of the value of £50, awarded once in three years, and open to students who have obtained their qualification within six years of the award. The ROBERT WOODHOUSE PRIZE, of the value of £10, for Practical Dental Surgery. CLASS PRIZES are awarded by the various Lecturers. INSTRUCTION IN MECHANICAL DENTISTRY. The instruction in Mechanical Dentistry as required for the Dental Curriculum can be obtained at this Hospital. After passing through a Preliminary Course, students are required to make and adapt dentures to the mouth, under the guidance of the Medical Staff. THE LIBRARY AND MUSEUM. The Library is always open for reading, and books can be obtained from the Sub-librarian for purposes of study. The Museum has been carefully arranged with a view of illustrating in detail the various text-books recommended by the authorities. FEES. For the two years' Hospital Practice and Lectures as required by the Royal College of Surgeons of England the fee is £53 35. in one instalment, or £55 135 in two yearly instalments. Students are required to join the Students' Club, the fee for which is £3 3s. For a Single Course of Lectures in any subject the fee is £5.5$. The fee for the complete curriculum, namely the Instruction in Mechanical Dentistry and two years' Hospital Practice and Lectures, is £150 if paid in one instalment, or 150 guineas if paid in three yearly instalments of 50 guineas. For one year's instruction in Mechanical Dentistry the fee is 50 guineas. For one year's Hospital Practice, £21. The necessary course of two years at a General Hospital can be taken simultaneously with that at the Royal Dental Hospital. The fees for the former vary at the different hospitals, being usually about £60. Further particulars can be obtained on application to A Prospectus containing full particulars of the Lecture and Laboratory Courses in Inorganic and Organic Chemistry qualifying for the Degrees in Chemistry, and for the Certificate in Applied Chemistry, will be forwarded Physics... Botany ... (ALEX. MCKENZIE, Ph.D., D.Sc., M.A. H. WREN, Ph.D., B A.. B.Sc. ALBERT Griffiths, D.Sc D. OWEN, B.A., B.Sc. B. W. CLACK, B.Sc. JE. H. SMArt, M.A. C. V. COATES, M.A. V. H. BLACKMAN, M.A. H. W. UNTHANK, B.A., B.Sc. J. W. EVANS, D.Sc. Geology & Mineralogy Calendar 3d. (post free 5d.), on application to the SECRETARY. CITY OF LONDON COLLEGE. ACTING IN CONJUNCTION WITH THE LONDON CHAMBER OF COMMERCE. WHITE ST., and ROPEMAKER ST., MOORFIELDS, E.C. (Near Moorgate and Liverpool Street Stations.) PRINCIPAL: SIDNEY HUMPHRIES, B.A., LL.B. (Cantab.) Michaelmas Term begins Monday, October 11t. EVENING CLASSES in ALL BRANCHES of SCIENCE. Well-equipped LABORATORIES for Practical Work in CHEMISTRY, BIOLOGY, BOTANY, GEOLOGY, and all branches of PHYSICS. Special Courses for London University Matric., Inter., and Final B.A., B.Sc., Conjoint Board, Pharmaceutical and other examinations. Clace are also held in all Commercial Subjects, in Languages, Literature and Art. All Classes are open to both sexes. SATURDAY COURSES for Matric.. Inter., and Final B.A., B.Sc. DAY COMMERCIAL and HIGHER COMMERCIAL SCHOOLS Prospectuses, and all other information, gratis on application. DAVID SAVAGE, Setary. UNIVERSITY OF DURHAM. ARMSTRONG COLLEGE, NEWCASTLE-UPON-TYNE. Principal: Sir ISAMBARD OWEN, D.C.L., M.D. Matriculation and Exhibition Examinations, Sept. 24-29, Particulars of curricula for University Degrees and College Diplo in Engineering, Electrical Engineering, Naval Architecture, M Metallurgy, Agriculture, Pure Science and Letters; as well as of Fel.. ships, Scholarships and Exhibitions, and of facilities for residence application toF. H. PRUEN, Secretary Armstrong College, Newcastle-upon-Tyne. For other Scholastic Advertisements, see page clix, ala |