356 



NA TURE 



[Feb. 12, 1885 



and G. Bemont. — On vincetoxine, by M. Ch. Tauret. This term, 

 " vincetoxine " (from Vincetoxicum, the common name of the 

 Asclepias), is applied by the author to a new glucoside, to which 

 is due the remarkable property possessed by the aqueous solution 

 of the hydro-alcoholic extract of the Asclepias root of clouding 

 when the temperature is raised, and becoming limpid when 

 lowered. Vincetoxine has the same centesimal composition as 

 glycyrrhizine, C 48 H 3B 18 . — On the signification of the polari- 

 metric experiments executed with the solution of cotton in the 

 ammonicupric reagent ; polarimetric researches on this reagent, 

 by M. A. Kechamp. — On a particular case of catalytic action. — 

 On the composition of the ashes of the Equisetacea: ; its appli- 

 cation to the formation of coal, by M. Dieulafait. The author 

 finds that the Equisetacea; and other typical plants of the Car- 

 boniferous epoch contain a much larger proportion of sulphuric 

 acid than those of the present epoch. In this fact we have the 

 natural explanation of the large quantities of sulphur and of 

 sulphate of lime present in all kinds of coal. The sulphur 

 and sulphate entered into the original composition of those 

 plants to whose decomposition are due the carboniferous forma- 

 tions. — On the various cetaceans cast up on the French sea- 

 board during recent years, by M. Georges Pouchet. — Note on 

 the influence of sudden barometric pressure on earthquakes and 

 volcanic activity, by M. F. Laur. Arguing from the fire-damp 

 explosions in mines and other analogous phenomena, the 

 author concludes that all underground disturbances are due to 

 abrupt atmospheric changes communicated even through the 

 medium of the ocean to the crust of the earth. Volcanic erup- 

 tions are relatively superficial phenomena due to the expansion 

 of the internal gases when a rupture of equilibrium takes place. 

 Hence they are all the more violent the nearer they are to the 

 surface, and the more closely connected with previously existing 

 terrestrial vacuums. 



Berlin 



Physical Society, January 23. — Dr. Kayser laid before the 

 Society a photograph of lightning taken in France and probably 

 under the same minimal atmospheric pressure as that under 

 which he had himself taken his recently-published photograph, 

 the lightnings in France having been photographed three days 

 earlier than those in Berlin. On the small gelatinous membrane 

 sent to Dr. Kayser, still better than on that, on an enlargement of 

 the original prepared by the speaker, there was presented very 

 beautifully to view the extraordinarily manifold ramifications of 

 the lightning. From the lowest part of a dark cloud a broad 

 flash of light was seen to dart forth and throw off" many fine 

 branches, which again united multifariously, the junction at one 

 place between one branch and another showing a broader line, 

 while at other places the flashes appeared double. — Dr. Lumner 

 spoke on the interference phenomena produced by two plain 

 parallel glass plates. He briefly adduced the experimental 

 results, already published by him, of an investigation of his own, 

 according to which, at small angles of the glass plates, namely, 

 up to as far as 60°, the interference phenomena represented a 

 circle passing, with increasing angles, into an ellipse, the axis 

 of which at 90° were as 1:2, until, on still further enlargement 

 of the angle, the ellipse became transformed into a straight line, 

 which soon in turn, and till the angle of the plates approximated 

 to 180°, changed into a hyperbola. The speaker developed at 

 large the theory of the phenomenon, and deduced the formula", 

 which, on inserting the numerical data, were found to coincide 

 remarkably with the experimental results. — A communication 

 from Dr. Muller-Erzbach, designed for the Verhandlungen, had 

 been given in and was read. Dr. Midler had sought to deter- 

 mine the sphere of action of the molecular forces by the thick- 

 ness of the layers arising from the adhesion on solid surfaces of 

 gases and vapours. He chose for his experiments pulverised oxide 

 of iron and carbon disulphide. The latter became, at first very 

 strongly, and then with abating intensity, condensed by the oxide. 

 After four days the quantity of carbon disulphide absorbed 

 in twenty-four hours had sunk to less than I mg., without, 

 however, entirely disappearing. By microscopic measurements 

 of the grains of oxide of iron, the author approximately calcu- 

 lated the magnitude of the absorbing surface, and from the 

 quantity of the absorbed carburet of sulphur the thickness of 

 the layer ofvapiur held fast by adhesion. From the circum- 

 stance that the absorption of the vapour very rapidly diminished 

 and after a few days became quite inconsiderable, Dr. Muller- 

 Erzbach concluded that it was not the quantities of vapour at 

 flrst condensed which drew in those later absorbed, but that the 



whole absorbed layer of vapour got to be held fast through ad- 

 hesion by the surface of the iron, and in this way he arrived at 

 values bearing on the sphere of action of molecular forces which 

 far surpassed all that had been hitherto obtained. — Finally, 

 Prof. Neesen directed attention to the disadvantage of having 

 but one term for two different meanings, such, for example, as 

 the word " Gewicht " (gravity, weight), which was employed to 

 signify bodi a force and a mass, a confusion which often led to 

 inconveniences. Scientifically either the force or the mass 

 should be called Gewicht, the other being denominated by 

 another name. The debate which this question gave rise to 

 was to be continued at a future silting. 



Vienna 



Imperial Academy of Sciences, January 8. — On the 

 fossil flora of Sagor (Carniola), by C. von Ettingshausen. — On 

 pendulum experiments, by P. Czermak and R. Iliecke. — On a 

 new construction of electromagnets for dynamo-machines (sealed 

 packet), by A. von Waltenhofen. 



January 15. — On the difference between crystalline and other 

 anisotropic substances, by V. von Ebner. — On a new S) 

 cable-telegraphy for long cable-lines, called the differential 

 recorder (sealed packet), by E. von Taund-Szyll. — On a new 

 method for determining manganese in specular iron ore, ferro- 

 manganates, and in the most important ores, by \V. Kalmann 

 and A. Smolka. 



Stockholm 



Society of Natural Sciences, November 15, 1SS4. — The 

 President, M. Warn, in the chair.— Prof. Lecke gave an ac- 

 count of a certain fish larva; which he hail studied during a 

 sojourn at Messina. At times the sea was so full of animals, 

 that a vessel immersed in the same would contain as much of 

 the latter as water. He further exhibited a number of rare 

 fish from the Mediterranean, comprising Trachypterus, Peloria, 

 and Ki-ohnius. — Dr. Lindberg explainer! the working of the 

 Siemens apparatus for registering the quantity and alcoholic 

 contents of spirits. They are now compulsory in all Swedish 

 distilleries, and work very satisfactorily. 



CONTENTS Page 



Iron and Steel 333 



Phillips's " Manual of Geology." By A. H. Green 334 

 Our Book Shelf:— 



Clark's " Transit Tables for 1 88$ " ....... 336 



Poljakow's " Reise nach der Insel Sachalin in den 



Jahren 1881-1882" . 337 



Letters to the Editor : — 



Gardiner's Researches on the Continuity of Vegetable 

 Protoplasm.- Prof. W. T. Thiselton Dyer, 



C.M.G., F.R.S 337 



A Plea for the Experimental Investigation of some 

 Geological Problems.— Dr. H. j. Johnston- 



Lavis ' ■ 338 



Iridescent Clouds.— Prof. C. Michie Smith ... 338 



Science Teaching in Schools. — G. H. Bailey . . . 338 



Barrenness of the Pampas. — Edwin Clark .... 339 

 Recent Earthquakes. — Dr. M. Eschenhagen : 



Edward Parfitt 339 



Loligopsis ellipsoptera. — Wm. E. Hoyle 339 



Civilisation and Eyesight. By Lord Rayleigh, 



F.R.S 340 



The International Inventions Exhibition 340 



The Retina of Insects, By Sydney J. Hickson. 



{Illustrated) 341 



Roraima 34 2 



Benjamin Silliman 343 



Masai Land. (Illustrated) 343 



Notes 347 



Geographical Notes 350 



Astronomical Phenomena for the Week 1885, 



February 15-21 35 ' 



Catalogue of Earthquakes 351 



Japanese Learned Societies 352 



The Proposed Teaching University for London . 352 



University and Educational Intelligence 353 



Scientific Serials 353 



Societies and Academies 354 



