336 



NA TURE 



[August 6, 1896 



of the disastrous effects upon the Museum produced by 

 this water-spout. — On some new experiments relating to the 

 preparation of the diamond, by M. H. Moissan.— Study of 

 the black diamond, by the same. Black diamond, reduced to 

 a very fine state of division, and heated in a stream of oxygen to 

 a temperature about 200° C. below the temperature of combustion 

 of the diamond, gives off a very small amount of carbon di- 

 oxide, and the diamond remaining is transparent. — A Spanish 

 truffle and three new truffles from Marocco, by M. Ad. Chatin. 

 The new specimens are described as Terfezia Mel/erioms, of 

 Laroche, Terfczia Leonis (var. helerospora), of Laroche, and 

 Terfezia Boiidicri, of Mazogan.— On the homogeneity of argon 

 and'helium, by Prof. W. Ramsay and J. Norman Collie. By frac- 

 tional diffusion through porous tubes, argon yields two portions, 

 of which the lighter has a density of 19-93, the heavier of 20-oi. 

 Similar experiments with helium gave densities of i 874 and 2 • 1 33 

 for the two extreme portions, results which were confirmed by 

 measurements of the refractive indices by Lord Rayleigh. Both 

 specimens gave spectra which were absolutely identical, and 

 hence the possibility is suggested of there being here a true 

 separation of light molecules from heavy molecules of the same 

 substance. — On the mononitrile of camphoric acid, its anhydride 

 and anilide, by MM. A. Haller and Minguin.— On a method 

 for giving the exact direction of a sound signal, by M. E. Hardy. 

 Two methods are given for effecting this at sea. — Note accom- 

 panying two memoirs on thermochemistry, by M. Langlois. — 

 On the error of refraction in geometric levelling, by M. Ch. 

 Lallemand. It is shown that the effect of the refraction of the 

 air, which can generally be neglected or eliminated in triangula- 

 tion, becomes quite appreciable in levelling, and a formula is 

 developed for introducing the necessary correction.— On the 

 distribution of the displacements in metals subjected to stresses, 

 by M. G. Charpy. The suggestion of M. Hartmann that 

 metals, in spite of their known heterogeneous structure, behave 

 as homogeneous bodies, has been submitted to further experi- 

 ments, with the result that the displacements vary from point 

 to point, and correspond in all respects with the structure 

 shown micrographically. — On the density and mean specific 

 heat between 0° and 100° of the alloys of iron and antimony, by 

 M. T- Laborde. The numbers found for the specific heats are 

 all greater than those calculated from the assumption of simple 

 mixture. — On the determination of the ratio of the specific 

 heats of gases, by MM. G. Maneuvrier and J. Fournier. 

 The final results are : for air i'392, for carbon di- 

 oxide I '299, for hydrogen i '384. — Researches on the re- 

 lations existing between the radiation of a body and the 

 nature of the surrounding medium, by M. Smoluchowski de 

 Smolan. An experimental study of the formula of Clausius, 

 according to which the emission should be proportional to the 

 square of the refractive index of the medium. The general 

 result is to confirm the law of Clausius.— Cranial endography 

 by means of the Ronlgen rays, by MM. Remy and Contre- 

 moulins.— Study of the nitrogren and argon of fire-damp, by 

 M. Th. Schlcesing, jun. Specimens of fire damp collected with 

 suitable precautions from many sources all contained nitrogen, 

 showing a notable amount of argon ; the ratio of argon to 

 nitrogen was, within the limits of experimental error, about the 

 same as in air. — On the preparation of selenic acid, by M. R. 

 Melzner. This acid is readily obtained by oxidising dilute 

 solutions of selenious acid with free permanganic acid. — On a 

 new coballite, by M. E. Dufau. By heating magnesia and 

 cobalt sesquioxide in the electric furnace a crystallised mag- 

 nesium cobaltite, MgCoOg is obtained. — On the solutions of 

 trichloracetic acid, by M. Paul Rivals. A thermochemical 

 study of the dissociation of trichloracetic acid in .solution. — 

 On vinyl-trimethylene and ethylidene-trimethylene, by M. G. 

 Gustavson.— On the constitution of pinacoline, by M. 

 Maurice Delacre. — Crystallographic properties of some 

 alkyl-camphors of the aromatic series, by M. J. Minguin. 

 — Formation and etherification of crotonylic alcohol, l)y 

 M. E. Charon.— On the electrolysis of the fatty acids, by 

 M. T- Hamonet. — On several modes of preparation of the blue 

 nitrosodisulphonic acid and its salts, by M. Paul Sabatier.— New 

 observations on Clythra quadripioKtata, by M. A. Lecaillon. 



Influence of the reaction of the medium upon the activity of 



the oxidising ferment of mushrooms, by M. E. Bourquelot. — 

 On a cellulose filter, by M. Henri Pottevin. A description of 

 a cellulose filter capable of taking the place of the biscuit porce- 

 lain filter. Owing to the cheapness of material, instead of the 

 cleaning process neces.sary for porcelain, a new disc can be used. 



NO. 1397, VOL. 54] 



— The mechanism of the extension of the bla.stoderm, and its 

 relation to the eye of the fish, by M. E. Bataillon.— On the 

 presence in the superior laryngeal nerve of .secretory and vasculo- 

 molor fibres for the mucous memV)rane of the larynx, by M. E. 

 lledon.— On the physiological significance of direct cellular 

 division, by MM. E. G. Balbiani and F. Hcnneguy.— Study of 

 thegizzard in some htaltidie and GryllidiC, by M. Bordas. — 

 The constitution of the phosphates of lime from Tunis, by 

 M. L. Cayeux. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Books.— The Student's Handbook of British Mo 



H. N. Dixon and 



H. G. Jameson (Eastbourne, Sumfield).— The G. E. R. Co.'s Tourist Guide 

 Conlinent(London).— A Text-Book of Physical K.xercises : Dr. A. H. 



Carter and S. Bott (Macmillan).— La Distillation des Bois : E. Barillot 

 (Paris, G.iuthier-Villars).— Monthly Current Charts of the Indian Ocean 

 (London).— Catalogue of the Described Diplera from South Asia: F. van 

 der Wulp (Nijhoff, Hague). 



Pamphlets. —Peabody Institute 29th Annual Report (Baltimore). Sym- 

 bolism in American Art : F. W. Putnam and C. C. Willoughby (Salem, 

 U.S.A.). 



Serials.— Astronomical Observations and Researches m.ide at Dunsink, 

 7th Part (Dublin, Hodges).— Longman's Magazine, August (Longmans).— 

 Chambers's Journal, August (Chambers).— Proceedings of the Aristotelian 

 Society, Vol. 3, No. 2 (Williams).— Proceedings of the Edinburgh Mathe- 

 matical Society, Vol. xiv.(Wimams).— L'Anlhropologie, tome vii. No.3(Paris, 

 Masson).- Good Words, August (Isbisler).— Sunday Mag.Tzine, August 

 (Isbister).— Humanitarian, August (Hutchinson).— Contemporary Review, 

 August (Isbister).— National Review, August (Arnold). — Physical Re\iew, 

 Vol. 4, No. I. (Macmillan).— Bulletin de I'Acadimie Royale des Sciences de 

 Belgique, 1896, No. 6 (Bruxelles).— Journal of the Institution of Electrical 

 Engineers (Spon).— Journal of the Chemical Society, (Gurney).— Century, 

 August (Macmillan). — Scribner's Magazine, August (Low). — Notes from the 

 Leyden Museum, Vol. xviii. No. t (Leyden, Brill).- Fortnightly Review, 

 August (Chapman and Hall), — Westminster Review, .-August (Warne). — 

 Ornithologist, August (Bale).— Gazetta Chimica Italiana (Rome).— Revue 

 GdnSrale des Sciences, July (Paris).— Memoire della Spettroscopisti Italian!, 

 July (Rome).— Bulletin de la Socie'td d'Encouragement, July (Paris). 



CONTENTS. PAGE 



Travels in Eastern Africa. By Dr. J. W. Gregory . 513 



Apollonius of Perga. By G. B. M 314 



The Hare, from the Field to the Table. By R. L. . 315 

 Our Book Shelf:— 



Dannemann : " Grundriss einer Geschichte der Natur- 



wissenschaften " 3'^ 



Hertwig : " The Biological Problem of To-day " . 316 



Thornton: "TheX-Rays" 316 



Letters to the Editor: — 



Sun-spots and Facula-. {With Diagram.)— '^z.m.e.s 



Renton 3'7 



Sailing Flight. ( ;K/MZ)/a^-aw.t.)— S. E. Peal . . 317 

 The Position of Science at Oxford.— The Writer of 



the Article 3'^ 



The Salaries of Science Demonstrators. — " An 



Aggrieved Tadpole " 3'9 



The Date of the Glacial Period.— Percy F. Kendall 319 



Taxidermy and Modelling. (Illustrated.) 319 



Progress in Stereochemistry. (IVitA Diagrams.) By 



Dr. Arnold Eiloart 321 



Notes 324 



Our Astronomical Column: — 



The Planet Saturn 3^7 



New Nebulosity in the Pleiades 327 



New \'ariable in Hercules 327 



The Institution of Mechanical Engineers 327 



Old 'World Meteorology 3^9 



Prizes offered by the Socitte d'Encouragement . . 331 



Science in the Magazines i3i 



The Reproduction of Diffraction Gratings. P.y 



Lord Rayleigh, F.R.S 33^ 



University and Educational Intelligence 333 



Scientific Serials 334 



Societies and Academies 334 



Books, Pamphlets, and Serials Received 336 



