Deuconid Calcisponge from the Middle Lias of Northamptonshire" (ibid., vol. iv., 1889, pp. 325-358, 1 pl.); "On Archocyathus, Billings, and on other Genera allied to it, from Cambrian Strata, &c." (Quart. Fourn. Geol. Soc., vol. xlv., 1889, pp. 125-148, 1 pl.); "Notes on Radiolaria from the Lower Paleozoic Rocks of the South of Scotland" (Ann. and Mag. Nat. Hist., ser. 6, vol. vi., 1890, pp. 40-59, 2 pl.); "On the Sponge Remains in the Tertiary Strata, near Oamaru, New Zealand (in conjunction with Mr. W. M. Holmes), (Linn. Soc. Journ. Zool., vol. xxiv., 1891, pp. 177-262, with 9 pl.); "Note on a Radiolarian Rock from Fanny Bay, Port Darwin, Australia" (Quart. Journ. Geol. Soc., vol. xlix., 1893, pp. 221-226, I pl.). Has paid special attention to the microscopic structure of Siliceous Deposits and Cherts, and has demonstrated the existence of Sponges, Radiolaria, and other organisms in them, and as largely composing such deposits, of all ages, and from the most distant parts of the world. HENRY ALEXANDER MIERS, 66 66 M.A. (Oxon), F.G.S., F.C.S., Assistant in the Department of Minerals, British Museum (Nat. Hist.). Has improved the Adams instrument for the measurement of optic axal angles; devised a form of goniometer for measuring the angles of growing crystals; and a stage-goniometer for use with the microscope. Distinguished as a mineralogist and crystallographer, and author of important investigations in crystallography and mineralogy, 1882-94, as under :-"Cerussit von La Croix' Zeitsch. für Krystall., vi.); "The Crystalline Form of Meneghinite (Mineral. Mag., v.); “Hemihedrism of Cuprite" (Phil. Mag., xviii.); Monagite from Cornwall and Connellite" (Mineral. Mag., vi.); "Crystallography of Bromostrychnine" Journ. Chem. Soc., xlvii.); "Crystallography of Tricupric Sulphate" (ibid.); "Orthoclase from Kilima-n-jaro and Adrelavia, Switzerland" (Mineral. Mag., vii.); "New Cornish Mineral” (Mineral. Mag., vii); "Zonenformal für Orthogonate Systeme" Zeitsch. für Krystall., xii.); Crystals for Baric Slag" (Journ. Chem. Soc., li.); “Use of Gnomonic Projection” (Mineral. Mag., vii.); "Calcites, Egremont, Cumberland" (ibid., viii.); "Pyrargyrite and Proustite" (ibid., viii.) ; Mineralogical Notes-Polybasite, Aikinite, Quartz, Cuprite, and Locality of Turnerite" (ibid.); "Stephanite and Kaolinite" (ibid., ix.); “Sanguinite (new mineral), Krennerite" (ibid.); Ullmannite Tetartohedrism" (ibid.); "Student's Goniometer" (ibid.); “Orpiment" (ibid., x.); “Cornwall Danalite' (with G. T. Prior, ibid.); (with W. J. Pope) "Mittheil. aus dem Krystall Laboratorium des City and Guilds of London Inst." (Zeitsch. für Krystall., xx.); "Spangolite from Cornwall (Neues Jahresbr. für Min., ii.); “Quartz from North Carolina (Amer. Journ. Sci., xlvi.); Xanthocanite," &c. (Mineral. Mag., x.); "Spangolite" (ibid., x.); "On a New Method of Measuring Crystals,' &c. (Rept. Brit. Assoc., NATURE, 1.). 66 FREDERICK WALKER MOTT, M.D. (Lond.), F.R.C.P. Lecturer on Physiology, Charing Cross Hospital. Distinguished as a physiologist. The following are his most important published papers:--" Bacteria, or their Antecedents, in Healthy Tissues" (with Prof. HorsleyJourn. of Physiol., 1883); "Myxofibroma of Spinal Cord" (Brain, 1888); "Cardio-vascular Nutrition and its relation to Sudden Death" (Practitioner, 1888); "Pathology of Pernicious Anæmia" (ibid., 1890); "Clarke's Column in Man, Monkey, and Dog" (Journ. of Anat. and Physiol., 1887); "On Eye Movements produced by Cortical Faradisation of the Monkey's Brain" (with Prof. Schäfer-Brain, 1890, and Internat. Med. Congress, Berlin); "On Movements resulting from Excitation of the Corpus Callosum in Monkeys' (with Prof. SchäferKrain, 1891); "Complete Sclerosis of Golt's Column " (Internat. Journ. of Med. Sci., 1891); "The Results of Hemisection of the Spinal Cord in Monkeys" (Phil. Trans., 1892). Supplementary Certificate.-Physiologist and Neurologist. Secretary of the Neurological Society. Pathologist to the London County Council Asylums. Has published the following papers recently :—“ The Bipolar Cells of the Spinal Cord and their Connections" (Brain, 1891); "Ascending Degenerations of the Spinal Cord" (ibid., 1892); Article on "Pernicious Anæmia" ("Quain's Dict. of Med.," 2nd edit.); "A Case of Multiple Infective Neuritis" (Clin. Soc. Trans.); "A Case of | "Ex Amystrophic Lateral Sclerosis with Degeneration of the Motor Path from the Cortex to the Periphery" (Brain, 1895); perimental Enquiry upon the Afferent Tracts of the Central Nervous System” (ibid., 1895); "The Sensori-Motor Functions of the Central Convolutions of the Cerebral Cortex" (Journ. Physiol., 1894); "Experiments upon the Influence of Sensory Nerve upon Movement and Nutrition of the Limbs" (Preliminary Communication, with Prof. Sherrington, F.R.S.) (Proc. Roy. Soc., vol. lvii.). JOHN MURRAY, Ph.D. (Jena)., LL.D. (Edin.), D.Sc. (Camb.). One of the Naturalists on board the Challenger, 1872-76. First Assistant on the Challenger Editorial Staff, 1876-82. Editor and Director of the Challenger publications, 1882-95. Editor of the Reports on the Scientific Results of H.M.S. Challenger; joint Author of the Narrative of the Cruise of the Challenger, and of the Report on Deep-Sea Deposits; Author of a Summary of the Scientific Results of the Challenger Expedition; Author of numerous Papers dealing with Oceanography, Physical Geography, and Marine Biology. KARL PEARSON, M.A., LL.B., late Fellow of King's College, Cambridge. Professor of Mathematics and Mechanics at University College, London. Editor and joint Author of vol. i. of Todhunter's "History of Elasticity." Author of the following papers on Elasticity:-" On the Distortion of a Solid Elastic Sphere (Quart. Journ. Math., vol. xvi.); "On Twists in an Infinite Elastic Medium" (Mess. of Math., vol. xiii.); "On the Flexure of Heavy Beams (Quart. Journ Math., vol. xxiv.); “On the Generalised Equations of Elasticity, and their Application to the Wave Theory of Light" (Proc. Lond. Math. Soc., vol. xx.); "On Energy in an Elastic Solid" (Mess. of Math., 1889); "On Wöhler's Experiments on Alternating Stress" (ibid., 1890): also "Contributions to the Mathematical Theory of Evolution (Phil. Trans., 1894). THOMAS ROSCOE REDE STEBBING, Late (The M.A. (Oxon.), B. A. (Lond.). Clerk in Holy Orders. Fellow and Tutor of Worcester College. Author of Report on the Amphipoda collected by H.M.S. Challenger, a task which has occupied him almost exclusively for six years. It forms three large volumes (vol. xxix. of the Report), and consists of 1774 pages, and 212 plates, with a map, 4to, 1888. figures were all drawn by the author.) Also author of the following:-"Note on Calceola sandalina, Lmk." (Geol. Mag.. vol. x., pp. 57-61, pl. v., 1873); "A New Species of Sessileeyed Crustaceans (Ann. and Mag. Nat. Hist., ser. 4, vol. xvii., pp. 73-80, pl. iv.-v., 1876); Amphipodous Crustaceans (Hyale, Aronyx, &c.)" (ibid., pp. 337-346, pl. xviii.-xix., 1876); Some New and little-known Amphipodous Crustaceans (ibid., vol. xviii., pp. 443 449, pls. xix.-xx., 1876); “On Sessile-eyed Crustaceans" (ibid., ser. 5, vol. 1., pp. 31-37, pl. v., 1878); "On Species of Amphipodous Crustaceans" (ibid., vol. II., pp. 464-370, pl. xv., 1878); "The Sessile-eyed Crustaceans of Devonshire" (Trans. Devon. Assoc., vol. xi., pp. 516-524, 1879); "On Gastrosaccus spinifer" (Ann. and Mag. Nat. Hist., ser. 5, vol. vi., pp. 114-118, pl. iii., and P. 328. 1880); "A New English Amphipodous Crustacean" (ibid., vol. xv., pp. 58-62, pl. ii., 1885); "On the Crustacea Isopoda of the Lightning, Porcupine, and Valorous Expeditions" (joint paper with the Rev. A. M. Norman, Trans. Zool. Soc., 1886, vol. xii., pp. 77-142, pls. xvi.-xxvii.); "Exotic Amphipoda from Singapore and New Zealand" (ibid., vol. xii., pp. 199-220, pls. xxxviii.-ix.); Address as President of Devonshire Assoc. (Trans. Devon. Assoc., 1884). Supplementary Certificate.-Author of "The Naturalist of Cumbra; being the Life of David Robertson, F.L.S., F.G.S., by his Friend" (1891)” “The right Generic Names of some Amphipoda” (Ann, and Mag. Nat. Hist., 1890); “Sessile-eyed Crustaceans" (ibid., pl. xv.-xvi., 1891); "On the genus Urothe and a new genus Crothoides" (Trans. Zool. Soc., pl. i.-iv., 1891); "A History of Crustacea and "Recent Malacostrace" (1893); "A New Pedunculated Cirripede” (Ann. and Mag. Nat. Hist., pl. xv., 1894); "The Amphipoda collected during the Voyages of the Willem Barents in the Arctic Seas in the Years 1880-84" (Soc. Nat. Art. Mag., Amsterdam, 1894, pl. i.vii.); "On the Amphipoda of the Buccaneer (Zool. Soc. Trans., 1895, pls. i.-iv.); Notes on Crustacea " (Ann. and Mag. Nat. Hist., pl. ii., 1895); “On Four New British Amphipoda (Stebbing and Robertson, Zool. Soc. Trans., vol. xiii., pl. v.-vi., 1891). CHARLES STEWART, Geol. Soc. (1879, 1880); of eleven other papers published by 66 WILLIAM PALMER WYNNE, M.R.C.S., President of the Linnean Society. Conservator Supplementary Certificate.-Since the above certificate was of the Museum of the Royal College of Surgeons, and Hunsent in, Mr. Woodward has been President of the Geologists' terian Professor of Human and Comparative Anatomy. Late Association and of the Norfolk Naturalists' Society. He has decturer on Comparative Anatomy, and joint lecturer on Physio- also published various papers and memoirs, including the followlogy at St. Thomas's Hospital. Distinguished as a Biologist.ing: Formation of Landscape Marble" (Geol. Mag., 1892); Author of the following papers :-" On the Structure and Cause Geological Zones" (Proc. Geol. Assoc., 1892); "Oolitic Iron of Colour in the Nacreous Layer of Shells" (Devon. Assoc. Ore in Raasay" (Geol. Mag., 1893); Memoir on the Lias of Trans., 1864); “On the Spicula of the Regular Echinoidea England" (Geological Survey, 1893). (Trans. Linn. Soc., 1865); "On a New Sponge, Tethyopsis columnifer" (Quart. Journ. Micros. Sci., 1870); "On the Minute Structure of certain Hard Parts of the genus Cidaris" (ibid., 1871): "Note on the Scalp of a Negro (Monthly Micros. Journ., 1873); "Note on the Calcareous Parts of the Sucking Feet of an Echinus, Podophora atrata" (ibid., 1873); "Notes on Bucephalus polymorphus" (ibid., 1875); "On the Lachrymal Gland of the Common Turtle (ibid., 1877); “On a New Coral, Stylaster stellulatus, and Note on Tubipora musica" (ibid., 1878); Note on an Abnormal Amblypneustes griseus Journ. Linn. Soc., 1880); 'On certain Organs of the Cidarida" (Linn. Soc. Trans., 1877); "On Some Structural Features of Echinostrephus molare, Parasalenia gratiosa, and Stomopneustes variolaris" Journ. Roy. Micros. Soc., 1880); "On a Supposed New Boring Annelid" (ibid., 1881); “On a Hermaphrodite Trout, Salmo fario" (Journ. Linn. Soc., 1891); "On a Hermaphrodite Mackerel, Scomber scomber" (ibid., 1891); "On Some Points in the Anatomy of Heloderma" (Proc. Zool. Soc., 1891); “On a Specimen of the True Teeth of Ornithorhynchus” (Quart. Journ. Micros. Sci., 1891). Supplementary Certificate.-Fullerian Professor of Physiology in the Royal Institution. WILLIAM E. WILSON, A gentleman who has devoted himself to astronomical research. Supplementary Certificate.—In addition to the qualifications already set forth the following may be mentioned:-(1) Mr. Wilson has undertaken to carry out Experiments on Solar Radiation for the Committee of the British Association; (2) he has written a paper entitled "The Thermal Radiation from Sun Spots" (Monthly Notices R.A.S., vol. lv., No. 8); (3) he has also written on "The Effect of Pressure of the surrounding Gas on the Temperature of the Crater of the Electric Arc" (Proc. Roy. Soc., vol. Iviii.). HORACE BOLINGBROKE WOODWARD, Country around Norwich" (1881); "Geology of the Country around Fakenham, &c." (1884); and of parts of five other memoirs; also of parts of sixteen sheets of the map, and of nine sheets of sections. Author of The Geology of England and Wales" (1876 and 1887); of two papers in Quart. Journ. Geol. Soc. (1876, 1886); nine papers, &c., in Proc. Geol. Assoc. (1875-1889); of two Presidential Addresses to the Norwich D.Sc. (Lond.), Assistant Professor of Chemistry in the Royal College of Science, South Kensington. Distinguished for his zeal and ability as an organic chemist. Author of "Action o. Sulphuryl Chloride on Acetorthotoluidide and Acetoparatoluidide, Mono-, Di-, and Tri-chlorotoluenesulphonic Acids," and "Note on the Constitution of Nevile and Winther's Orthotoluidenesulphonic Acid and of the Sulphonic Acids of Orthochlorotoluene and Orthobromotoluene (Trans. Chem. Soc., 1892). Joint Author with Prof. Japp of "Action of Aldehydes and Ammonia on Benzil" (Trans. Chem. Soc., 1886). Joint Author with Prof. Armstrong of twenty-four papers in the Proc. Chem. Soc. from 1886-93 on Naphthalene and its Derivatives. Supplementary Certificate.- Has submitted to the Chemical Society since 1893 papers on the Disulphonic Acids of Toluene and of Ortho- and Para-chlorotoluene (in conjunction with Mr. James Bruce); on the Six Dichlorotoluenes and their Sulphonic Acids (in conjunction with Mr. Alfred Greeves); and eleven communications on Naphthalene Derivatives (in conjunction with Dr. Armstrong). In their communications on Naphthalene (thirty-nine in all) made to the Chemical Society during the past ten years, Drs. Armstrong and Wynne have revised practically the whole of the Chemistry of Naphthalene in so far as relates to the formation of its Chlorinated and Sulphonated Derivatives, and, besides describing many new Derivatives, have placed beyond question the structure of the ten Di- and fourteen TriChloronaphthalenes to which respectively all other Di- and TriDerivatives may be referred. ON LIPPMANN'S COLOUR PHOTOGRAPHY IN the discussion which followed Prof. Lippmann's splendidly interesting communication to the Royal Society (April 23), on colour photography, I suggested the possibility of applying his method to the Röntgen X-light; but at the same time remarked that it might be found impracticable on account of the smallness of the specular reflection of the X-light from polished surfaces, unless at obliquities little short of 90°. Lord Blythswood's experiments, communicated to the Royal Society on March 19, seemed to prove decisively something of true specular reflection of X-light, incident on a plane mirror of speculum metal at 45°. Experiments, which he has since made by means of a concave mirror of speculum metal, have demonstrated beyond all doubt that there is regular reflection at nearly normal incidence; but they have also proved that the amount of regularly reflected light is exceedingly small in proportion to diffuse light caused to emanate from the mirror, by the incidence of X-light upon it. Experiments by Joly, of Dublin, have, I believe, proved somewhat abundant specular reflection of the X-light, at incidences little short of 90, on surfaces of bodies transparent to ordinary light. And the extremely small refractivity of the photographic gelatine film for X-light, will allow incidences little short of 90° upon the metal mirror, to be used instead of the normal incidences which Prof. Lippmann has hitherto used. But for very oblique incidences the mercury mirror, with its surface fitted to the not rigorously plane surface of the photographic film, would be unsuitable; and the plan, which Lord Rayleigh described in the discussion, of forming the film on a solid metallic mirror, might be substituted for it. All things considered, it seems not improbable that Lippmann's process may be applied successfully to X-rays at nearly grazing incidences on metallic mirrors, and possibly even on non-metallic mirrors. Suppose now, for instance, the directions of the incident and reflected rays to be inclined to the mirror at angles of I of a radian (57). The distance between the planes of stratification in the photograph would be ten times that which would be produced by the same light at normal incidence. Thus if, for example, the wave-length of the particular X-light used is 5 × 10 6 cms. (or one-tenth of that of green light), the photograph would show tints of from green to violet when viewed normally, or at less or more oblique angles, by Lippmann's ordinary arrangements. It is quite possible, however, that when we know something of the composition of Röntgen light, we may find such great differences of wave-lengths in it, and so much difficulty to obtain approximately homogeneous X-light by sifting through metal plates (as we sift ordinary visible light by coloured glasses), or by other may be normally, according to Prof. Lippmann's ordinary procedure, will be seen as a complete spectrum in concentric circles, with violet in the centre, and red, of wavelength 715 x 10", at the circle of 56° incidence; but, if viewed by an eye placed at the position of the source of the violet light which photographed it, it will, according to the principles explained by Dr. Lippmann in his paper, be seen of uniform violet light throughout its whole area. KELVIN. TH THE OBSERVATORY AT MONT MOUNIER. HERE is no end to the generosity of M. Bischoffsheim. Not so very many years ago he endowed science with an observatory at Nice, and now again he has presented another, and this one is at the high altitude of over 8900 feet The observatory is situated on the summit of Mont Mounier, one of the peaks in the Maritime Alps. The advisability of having it at this spot was suggested by M. Bischoffsheim himself. It was not till early in 1893 that the plans were worked out, but the observatory was sufficiently finished in August of the same year, to allow observations of Venus to be made before the planet passed into its inferior conjunction. means if other means can be found, that the experiment which I have suggested may fail on account of want of homogeneousness of the incident light. But here, suggested to me by thinking of oblique incidence for the photographic light, is an illustrative experiment which (with variations of detail to facilitate realisation) cannot fail if Prof. Lippmann will think it worth while to try it. Place a point source of homogeneous violet light (wave-length 4 x 105 cms.) so near to the centre of the mirror and sensitive film that rays shall be received at all angles of incidence from zero up to 56° (being the angle of which the secant is 1788). The thickness of each stratum will vary in different parts of the photograph in simple proportion to the secant of the angle of incidence, and in the centre it will be equal to the half wave-length. It will therefore vary from 2 x 105 in the centre to 36 x 105 at the circle of 56° incidence. This photograph, viewed or thrown on a screen as nearly as It is to be hoped however that, very soon, we shall have definite knowledge of wave-lengths of Röntgen X-light by diffraction fringes actually seen instead of estimates of their smallness from diffraction fringes not seen. I should explain that I am writing on the supposition which seems to me, after much correspondence with Sir George Stokes, to be exceedingly probable that Röntgen light is merely ordinary transverse-vibrational light of very short period. That its period is less than one-fifth that of green light seems well proved by the skilful experiments described by Perrin in Comptes rendus, January 27, 1896, p. 187; and by Sagnac, Comptes rendus, March 30, p. 783. The buildings consist of a house for the astronomer and his assistant, the actual observatory, which has a revolving metallic dome (26 feet in diameter), and a wooden hut, used as workshop or depôt. The house and actual observatory are united by a passage, which is indeed a necessary arrangement, on account of the very severe weather, and the snow, which sometimes lies thickly on the ground. The observatory is a branch of the one at Nice, and at the time that important observations were being made at Nice, for the purpose of verifying M. Schiaparelli's discoveries on the rotation of the planet Venus, they were simultaneously being carried on at Mont Mounier by M. Perrotin, and with most successful results. M. Bischoffsheim suggested that the observatory should be a meteorological station; it has therefore been furnished with Richard's recorders, and instruments for ascertaining the temperature, pressure, and other conditions of the air. Nor is the observatory now isolated. For some weeks the house has been connected by telephone to Beuil, the nearest village with a telegraph office, a distance of five miles. This was also done at the expense of M. Bischoffsheim. It will therefore be possible to send daily reports to the central meteorological office of the observations made on Mont Mounier. |