I( 



NATUKE 



[August 4, 19 10 



H. Abraham : Explosive potentials. A study of the pheno- 

 mena of the spark discharge. In a previous paper a 

 description was given of the results obtained when the 

 changes of potential were slow ; the present note deals 

 with the effects of high-voltage alternating currents. — 

 D. Gernez : The colours arising in colourless solutions of 

 coloured bodies at the moment of the solidification of the 

 colourless solvent. Colourless solutions- of mercuric iodide 

 in various solvents (naphthalene, stearic acid, chloral 

 hydrate, phenol, &c.) become yellow on solidification, owing 

 ti the separation of the dissolved iodide in the unstable 

 yellow modification. — A. Lacroix : Some minerals formed 

 by the action of sea-water upon Roman metallic objects 

 found off the coast of Mahdia, Tunis. A sheet of lead 

 gave crystals of cotunnite (PbCI,) ; transparent brilliant 

 crystals of phosgenite (PbCO^.PbCI.) were also found. Two 

 copper minerals arc also described, covellite (CuS) and 

 chalcosite (Cu„S). — L. Mangin : New observations on 

 callose. This name is applied to a new substance obtained 

 from the membrane in fungi ; it is differentiated from 

 cellulose by several reactions, especially by its insolubility 

 in Schweitzer's reagent, and by its r.apid solution ,nnd 

 destruction by glycerol at 300°. — k. Ladenburg : Racemic 

 and liquid combinations. The results of experiments on 

 the melting points of mixtures of inactive pipecoline con- 

 taining variable quantities of d- or of Z-pipecoline are 

 shown in the form of a curve. The existence of the 

 racemic pipecoline in solution is clearly demonstrated. — 

 A. Calmette and L. Massol : The precipitation reactions 

 of serums from tuberculous subjects, and of the serums 

 from animals hyperimmunised against tuberculosis in 

 presence of the tulierculins. — J. Guillaume : Observations 

 of the sun made at the Observatory of Lyons during the 

 first quarter of 19 10. The results are collected in three 

 tables, giving the nvmiber of spots, their distribution in 

 latitude, and the distribution of the facula; in latitude. — 

 Jean Mascart : Photographs of Halley's comet. Repro- 

 duction of photographs taken from Mt. Guajura, Teneriffe, 

 at an altitude of 271s metres. — D. Eginitis : The physical 

 phenomena presented by Halley's comet. — R. Bricard ; 

 Concerning a claim for priority by E. Study. — Paul 

 Dienes : A problem of Abel. — .^tienne Mazurkiewicz : 

 The theory of cnscmhlcs. — A. Korn : The biharmonic 

 problem and the fundamental problem in the theory of 

 elasticity. — E. Pringrsheim : The emission of gases. A 

 reply to some remarks by M. Bauer on some experiments 

 by the author. — Gabriel Sizes and G. Massol : The 

 harmonics of wind instruments. — L. Hackspill : The 

 electrical resistance of the alkali metals. The metals 

 caesium, rubidium, potassium, and sodium were distilled 

 directly in a vacuum into the tubes used for the measure- 

 ments, and the electrical resistance determined at tempera- 

 tures ranging from 5^° C. to the boiling point of liquid 

 air. The figures are .somewhat lower than those given by 

 previous observers ; a trace of oxide appreciably raises the 

 resistance. — .A. de Gramont : The place of ultimate lines 

 in spectral scries. — G. Reboul : Chemical reactions and 

 ionisation. The experimental results are in general accord 

 with those given by MM. de Broglie and Brizard. — .Abel 

 Bugruet : The cryoscopy of the naphthylamines and addition 

 compounds. — E. Briner and A. Wroczynski : The action 

 of pressure and temperature upon cyanogen. Prolonged 

 heating at 220° C. under a pressure of 3/4 atmo- 

 sphere was without effect upon cyanogen ; at the same 

 temperature, under a pressure of 300 atmospheres, 10 per 

 , cent, of the gas was converted into paracyanogen in six 

 hours. At the ordinary pressure a temperature of 310° C. 

 is required to effect an appreciable change ; under high 

 pressures the change commences at lower temperatures, 

 and in the latter case, in addition to /ini-n-cyanogen, some 

 carbon and nitrogen are produced by the decomposition of 

 the gas. — Henri Bierry, Victor Henri, and Albert Ranc : 

 The action of the ultra-violet rays upon certain carbo- 

 hydrates. Under the influence of the ultra-violet rays the 

 molecule of d-fructose undergoes a profound degradation, 

 formaldehyde and carbon monoxide bring produced. — Daffy 

 Wolk : Aluminiimi nitride, its prepai\ntion and fusion. 

 The temperature of formation of aluminium nitride from 

 aluminium and .ammonia is 820° C. to .S5o° C- — Miroslaw 

 Kernbaum : The decomposition of steam by the brush 

 ilischntge. Working at the ordinary temperature, the brush 



NO. 2127, VOL. 84] 



discharge converts water vapour into hydrogen and 

 hydrogen peroxide. At higher temperatures the latter sub- 

 stance is decomposed, and a mixture of hydrogen and 

 oxygen is observed. — V. Grig^nard : The decomposition of 

 phenol ether-oxides by mixed organo-magnesium derivatives. 

 — Gabriel Bertrand and G. Weisweilier : Researches on 

 the constitution of vicianose. The products of the diastatic 

 hydrolysis of vicianose have been found to be d-glucose and 

 i-arabinose. — G. Friedel and F. Grandjean : The 

 anisotropic liquids of Lehmann. — Leclerc du Sablon : The 

 theory of periodic mutations. — M. Hue : 'IK variation of 

 the gonidia in the genus Solorina. — J. Virieux: The 

 sheaths and mucilages of the fresh-water alga:;. — .\udebeau 

 Bey : Experiments carried out in Egypt with the view of 

 determining the influence of the level of the underground 

 water of the Delta on the growth of cotton. — M.M. 

 de Drouin de Bouville and L. IMercier : The appearance 

 of the fiironciilosc in France. This formidable disease of 

 the trout has appeared at Bellefontaine, near Nancy. — 

 O. Duboscq ancl B. Collin : The sexual reproduction of 

 a parasite of Cyllarocyclis Ehrenhergii. — J. E. Abelous 

 and F. Bardier : An attempt at the immunisation of 

 animals against urohypotensine : the antitoxic action of the 

 serum of immunised animals. — E. Tassilly and R. 

 Cambier : The abiotic action of ultra-violet rays of 

 chemical origin. The light from a carbon bisulphide flame 

 burning in nitric oxide possesses a distinct, though feeble, 

 sterilising action. — E. Gley : The modes of extraction of 

 secretine. A new stimulant for the pancreatic secretion. — 

 A. Briquet : The genesis of relief forms in the Gallo- 

 Belgian region. 



CONTENTS. PAGE 



Christian Topography 133 



Trophoblast and the Early Development of Mam- 

 mals. By B 134 



Plant-life in the Balkans. By A. B. R 135 



Mathematical Text-books. By T. J. I'a. B. ... 136 



Schlich's Manual of Forestry. ByJ. F. A 137 



General Biology. By A. D 137 



Our Book Shelf 138 



Letters to the Editor: — 



XRay Spectra— Prof. C. G. Barkla and J. Nicol 139 



Pwdre Ser.— Geo. H. Pethybridge 139 



The Pressure of Light. (Illustiated.) 139 



A New Trypanosome Parasitic in Human Beings. 



(Illinlra/cil.) By Prof. E. A. Minchin 142 



Tidal Researches. By Sir G. H. Darwin, K.C.B , 



F.R.S 144 



The Leaning Tower of Pisa. {Illustrated.) By Prof. 



A. Battelli 145 



Recent Books on Botany. (Tlliislrated.) 146 



Notes 148 



Our Astronomical Column: — 



A Centr.Tl Bureau for Meteor Observatior.s .... 1 52 



The Rotation of Sun-spots 152 



Halley's Comet 152 



Large Meteorites 152 



The United Slates Naval Observatory 152 



Measures of Double Stars 153 



The British Medical Association in London . . 153 



The Institution of Mechanical Engineers .... 154 



The British Pharmaceutical Conference 156 



Association of Economic Biologists. By W. G. F. 156 

 The First International Agro-geological Confer- 

 ence. By Dr. E. J. Russell 157 



Science in South Africa 158 



Indian Palaeontology 159 



Dutch Meteorological Work in the East .... 159 



Practical Spectroscopy '59 



Plant Distribution 160 



The Maintenance and Administration of Roads . 160 



University and Educational Intelligence 163 



Societies and Academies 163 



