604 



NATURE 



{April 22, 1880 



evernic acid; by distillation it furnishes carbonic acid and 

 betorcinol (or Borcin). Betorcinol melts at 163 C, giving a bright 

 crimson colour with hypochlorites : its ammoniacal solution is 

 rapidly coloured by exposure to air. Chlorine, bromine, and 

 nitroso compounds were prepared and examined. — Note on 

 chemical equilibrium, by M. M. P. Muir. The object of this 

 paper is to describe a few measurements of the variations caused 

 in chemical changes by modifications in the conditions of these 

 changes, and to attempt to generalise some of the conditions of 

 chemical equilibrium, looking at the phenomena from a dynamical 

 point of view. — Preliminary note on the action of the new diasta-e 

 Eurotin on starch, by R. W. Atkinson, Professor of Chemistry 

 at Tokio. The author has studied in detail the interesting 

 manufacture of "saki," the fermented liquor from rice; he 

 comes to the conclusion that the ferment solution " koji " con- 

 verts the starch of rice not into maltose and dextrin, but into 

 glucose and dextrin. Analyses of the "mash" are given at 

 various stages from the first to the twenty-eighth day. — Note on 

 the products of the combustion of coal-gas, by L. T. Wright. In 

 opposition to the paper recently read before the Society by Mr. 

 Ridout, the author concludes that ozone is not formed by the 

 combustion of coal-gas, and that the substance which gives the 

 blue colour with iodide of potassium and starch is probably nitrous 

 acid, as when the coal-gas and air are carefully freed from am- 

 monia no blue colour is produced. — On polysulphides of sodium, 

 by H. C. Jones. The author establishes the existence of the 

 pentasulphide, which is probably a tetrathiosulphate ; this is 

 probably the highest sulphide. On heating it is converted into 

 a tetrasulphide. The precipitate produced by the addition of 

 the pentasulphide to cadmium salts contains cadmium sulphide 

 and sulphur. — On the reflection from copper and on the calori- 

 metric estimation of copper by means of the reflection cuprimeter, 

 by T. Bayley. The author has shown that the light reflected 

 from metallic copper contains all the elements of white light, but 

 that the region of the spectrum to the red side of the D line is 

 more intense than in the spectrum of the reflection from a white 

 surface of equal illumination ; the light transmitted by dilute 

 solutions of cupric salts is deficient in those rays which the spec- 

 trum of reflection has in excess. It follows that if we look at a 

 copper surface through a sufficient thickness of cupric sulphate 

 solution the metal appears silver white. Upon these facts the 

 construction of the reflection cuprimeter is based. — On pyrene, 

 by Watson Smith and G. W. Davies. Crude material from Dr. 

 Schuchardt was purified by crystallisation from petroleum spirit. 

 Light yellow monoclinic crystals were obtained melting at 149°, 

 having a vapour density of 6'QI2, calculated 6 - QQQ. — Analyses 

 of the ash of the wood of Eucalyptus rostrata a.nd £, globulus, by 

 Watson Smith. — On the action of organo-zinc compounds on 

 quinones (second notice), by F. R. Japp. The author has suc- 

 ceeded in isolating the substance Ci H 14 O a , and has studied its 

 more important reactions. From various considerations he con- 

 cludes that Graebe's views, giving to phenanthrene quinone the 

 formula of a peroxide, are correct. 



Paris 

 Academy of Sciences, April 12. — M. Edm. Becquerel in the 

 chair. — The following papers were read : — Nebulae discovered 

 and observed at Marseilles observatory, by M. Stephan. — On the 

 explanation of MM. Lontin and de Fonvielle's experiment, by M. 

 Jamin. He traces the effect to the magnetisation of the direct cur- 

 rent being greater than that by the inverse. — On some compounds 

 of halogen substances, by M. Berthelot. A thermo-chemical 

 Study.— The plague in modern times : its prophylaxy defective or 

 nil: its limitation spontaneous, by M. Tholozan. Like other 

 evil, whose secret is unknown, it appears at one or several points, 

 extend-, reaches its acme, then diminishes, and ceases; and this 

 independently, to a great extent, of sanitary measures. — Disin- 

 fection of vehicles by means of anhydrous sulphurous acid, by 

 M. Fatio. This relates to the effects of a spray of the acid in 

 waggons containing phylloxerised roots and plants. — On eyclo- 

 tomic functions, by M. Lucas. — Reply to a note of M. Bonssinesq, 

 by M. Bresse. — Studies on chronometry ; compensation, by M. 

 Roze. — On a new dynamometric indicator, by M. Deprez. 

 He sought a mechanism giving a diagram from motion of the 

 pencil only, the paper being at rest ; the problem was to impart 

 to a point C a motion proportional and parallel each instant to 

 the resultant of the motions of two other points A and B. The 

 pantograph meets this want (where the three points are in a line). 

 Point A is attached to the piston of the indicator, point B (which 

 must be guided in a straight line) to the cord commanded by the 



piston of the engine, and the crayon is at C. The arrangement 

 has several advantages. — On the deformation of glass tubes under 

 strong pressures, by M. Amagat. He shows by an experi- 

 ment (with mercury) that the glass or crystal tubes, nearly 

 I mm. internal diameter, and 10 to 12 mm. external, which 

 he has used in experiments on the compressibility of gases, do 

 not sensibly increase in volume under pressures up to 400 atm.— 

 On some new experiments of magnetic attractions, by M. Ader. 

 Of various substances tried (wood, paper, &c), elder-pith was 

 most attracted by a magnet. With a Jamin magnet capable of 

 holding 100 kg., and having two small polar armatures 0'0O2 m. 

 apart, he attracted at 003 m. distance a suspended pith ball 

 0005 m. diameter. He could raise it at a distance of o.'OD4 m. , 

 and, once attracted, it was held, spite of shocks given to the 

 magnet. — On the freezing-point of alcoholic liquors, by M. 

 Raoult. For solutions containing o gr. to 10 gr. alcohol in 

 100 gr. water, the retardation of the freezing-point resulting 

 from addition of I gr. of alcohol is constant and equal to O'yj"]'. 

 The lowering of the freezing-point below zero is proportional to 

 the total weight of alcohol dissolved in a constant weight of 

 water (whence, probably, the alcohol here exists in the anhy- 

 drous state). For solutions with 24 to 51 gr. alcohol in 100 gr. 

 water, the retardation of the freezing-point, on adding each 

 gramme of alcohol, is constant and equal to o - 528°. The total 

 lowering below zero is not proportional to the total weight of 

 alcohol (so that the dissolved body is probably a hydrate of 

 alcohol, at least between - 10° and -24°). M. Raoult gives a 

 table of freezing-points of various fermented liquors ; these are 

 always lower than for equivalent mixtures of alcohol and water. 

 The freezing-point descends as the freezing progresses. — On two 

 new silico-titanites of soda, by M. Hautefeuille. — On the ex- 

 amination of pyrites by the gravivolumetric method, by M. 

 Houzeau. The sulphur in pyrites can be determined much more 

 quickly by this method.- — On the formation of tetramethylam- 

 monium, by MM. Duvillier and Buisine. — On the natural and 

 mydriatic alkaloids of Belladonna, Datura, Hyoscyamus, and 

 Duboisia, by M. Ladenburg. — On the exi-tence of ammonia in 

 plants, by M. Pellet. Operating with the normal plant, he 

 found in beet-leaves (dry) C155 gr. ammonia per cent. ; 

 beet-seed, 0"i68 and 0'2i6 gr. ; beet-root (dry), o'iu6 and 

 0*147 g r - y corn, 0*16 gr. ; ordinary linseed meal, 01SS gr. 

 The regular existence of ammonia in plants is important, suggest- 

 ing that magnesia and phosphoric acid penetrate them in the 

 form of ammoniaco-magnesian phosphate. — On some facts rela- 

 tive to the gastric digestion of fishes, by MM. Richet and 

 Mourrut. Experiments [with fishes of the genus Scyllum and 

 with Loplria piscatorius seem to show that there are very great 

 differences in the stomachic mucus as to richness in pepsine. 

 The acidity of liquids in the stomach is extreme. (The authors 

 give results of a number of comparative artificial digestions. 1 — 

 Analyses of chlorophyll, by M. Rogalski. His resu 

 with those of M. Gautier and M. Hoppe-Seyler. — On the 

 formation of the shell in Helix, by MM. Longe and Mer. 



CONTENTS p 



The St. Gothard Tunnel. By Adolfhe Gautier (With 



Illustrations) 



Colloids 



Our Book Shelf: — 



Hoskiser's "Guide for the Electric Testing of Telegraph Cables " 

 Letters to the Editor : — 



The Antiquity of Oceanic Basins. — Prof. Alexander Agassjz 



On the Alum Bay Flora.— J. Starkte Gardner 



Negritoes in Borneo. — A. Hart Everett 



Seeing by Electricity. — John Perry : W. E. Avrton .... 



Musical Sounds within the Ear. —Dr. A. Ernst 



Ice Filaments.— Wm. LeRoy Broun {With Diagram) . . . . 



lepis mirabilis.— Prof. P. Martin Duncan, F.R.S. . . . 



The Stone in the Nest of the Swallow.— J. E. HaRTING .... 



The Easter Excursion of the Geologists' Association to the 



Ham ps hike Coast 



Deep-Sea Dredging and Life in the Deep Sea, III. By H. N. 



Moseley, F.R.S. (.With Illustrations) 



A Magneto-Electric Gyroscope (With Illustrations) 



Notes 1 



Our Astronomical Column: — 



The Southern Comet 



A New Comet 



Geographical Notes 



On the Employment of the Pendulum for Determining the 



Figure of the Earth. By Major J. Herschel, R E 



Note on some Effects Produced by the Immersion of Steel 

 and Iron Wires in Acidulated Water. By Prof. D. E. 



HUGHBS 



University and Educational Intelligbnch 



Societies and Academies 



