7 6 



NATURE 



[Nov. 20, 1879 



and the induction-balance showed that it was difficult to get 

 two pieces of the same metal exactly alike; hence the variation 

 of specific conductivity results. — Prof. Ayrton stated that at a 

 former meeting he had suggested that the electric inertia of the 

 different specimens of metal testtd might cause the difference 

 between the results obtained by the Wheatstone Bridge and the 

 induction-balance. Calculation had since led him to the conclu- 

 sion that the inductive effect is not proportional to the resistance 

 of the metal tested, but to an expression in which the resistance 

 is an exponential. Prof. Hughes replied that as the inductive 

 effect of the metal was destroyed by cutting it so as to interrupt 

 the circuit in it, it was reasonable to suppose that the said effect 

 was due to induced currents circulating in the metal, and there- 

 fore was proportional to the conductivity of the metal. — Capt. 

 Armstrong exhibited a standard Daniell cell formed of a porce- 

 lain vessel with a porous partition dividing it into two compart- 

 ments. In one the zinc plate was immersed in a solution of 

 sulphate of zinc, in the other the copper-plate in a solution of 

 sulphate of copper. To use the cell as a standard, it was only 

 necessary to connect the two liquids by a cotton string moistened 

 with water. This arrangement prevented mixing of the liquids, 

 as the string could be withdrawn after use. The resistance was 

 high, but it was a constant standard of electromotive force. — 

 Prof. Guthrie mentioned that Prof. Pirani, of Melbourne, in a 

 letter to him had pointed to the fact that when a dilute acid was 

 being electrolysed, the positive electrode, if made of iron, 

 became incandescent below the surface of the liquid. Prof. 

 Guthrie had found this to be true not only for iron but for other 

 metals, and that it could hardly be due to oxidation, because it 

 took place not only at the cathode or positive electrode, where 

 oxygen was evolved, but al-o at the anode where hydrogen was 

 evolved. The incandescence appeared to him to be due to 

 resistance. The .author .exhibited certain experimental results. 

 The positive electrode when immersed in the electrolyte was 

 seen to get red hot and to vibrate rapidly. As the liquid 

 heated the red glow became fainter. The negative electrode, on 

 the other hand, emitted a bright light, accompanied by a 

 noise. The light was tinged with the characteristic colour 

 of the flame of the metal of which it was composed ; in 

 the case of a copper electrode, for example, it was greenish. 

 These effects were shown by Prof. Guthrie with iron, copper, 

 and platinum electrodes, in dilute sulphuric and dilute nitric acid. 

 In reply to Prof. Adams, Prof. Guthrie said he had not yet 

 examined the flame by the spectroscope ; and in reply to Prof. 

 Foster he stated that the battery power used was fifty Grove's 

 cells. He asked for suggestions as to the cause of the pheno- 

 menon. 



Paris 

 Academy of Sciences, November 10. — M. Daubree in the 

 chair. — M. de Lesseps stated that a corps for boring operations 

 had been sent out to Panama, and he w as going out in a month 

 with a commission of selected engineers of various countries. He 

 applied for a committee to formulate a programme of observa- 

 tions that might be useful to science. — Climatological conditions 

 of the years 1869 to 1S79 in Normandy, and their influence on 

 ripening of the crops (first note), by M. Mangon. The observations 

 were made at Saint-Marie-du-Mont (Manche), a few kilometres 

 from the sea. The exceptional character of 1879 in temperature 

 and rainfall is shown by numerical data (the relation to the crops 

 being reserved for another paper). — On a new species of the genus 

 Anomaliirus, by M. Milne Edwards. The anioial was in a 

 collection formed at the Gaboon, by M. Leglaize. It is remark- 

 able for its beauty of colours, and the author calls it A. try- 

 thronotus. It is like A. Jraseri in general proportions, but is 

 easily distinguished. The discovery raises to six the number of 

 representatives of Anomaliirus ; all belong to the west of tropical 

 Africa. — On the presence, in surface layers of the ground, of 

 fecundated winter-eggs of phylloxera, by M. Boiteau. — On the 

 results of treatment of phylloxerised vines with sulpho-carbonate 

 of potash, and on the mode of use of this agent, by M. Mouillefert. 

 — The satellites of Mars in 1879, by Mr. Hall. — Determination 

 of the figure of apparent repose of an inextensible cord in motion 

 in space ; conditions necessary for its production, by M. Leaute. 

 — On the thermal absorbent and emissive power of flames, and on 

 the temperature of the voltaic arc, by M. Kossetti. For o'ot m. 

 of any flame traversed by radiation from a flame of the same nature, 

 the coefficients of transparence and of absorption are represented, 

 respectively, by o'S65 and OM35 m. A thickness of I in. renders 

 a flame almost completely athermanous for rays from another like 

 flame. The absolute thermal emissive power of white gas flames 



(or the intensity of radiation of such flames of indefinite thickness, 

 compared with that of soot at a temperature equal to the mean 

 temperature of the flame), is equal to unity ; that of a Bunsen flame 

 0*3219. A large number of experiments gives about 3900 C. 

 as the maximum temperature of the positive polar carbon 

 extremity, and 3150° for the negative; for the voltaic arc, 

 between these, a temperature of about 4800 (with any intensity of 

 current or thickness of arc). — Researches on the passivity of iron, 

 by M. Varenne. Fuming nitric acid does not act on iron and 

 render it passive, so that it is not attacked by dilute nitric acid. 

 The author describes various experiments throwing light on the 

 case. It appears that any agitation in the neighbourhood of the 

 passive metal, whether by a shock or a vibration, or by a current 

 of gas (very weak it may be) as from spongy platinum placed at 

 the bottom of the vessel of dilate acid, in which the passive iron 

 is hung, abolishes the passivity. The gaseous sheath formed on 

 the iron seems to be the obstacle to attack. It is more adherent 

 on a smooth surface, and on a specimen of great molecular 

 condensation than on one rugous and less compact. In vacuo 

 the sheath, and with it the passivity, disappear. — On alcoholic 

 fermentation, by M. Cochin. He concludes from experiment 

 that yeast does not produce a soluble alcoholic ferment. — Com- 

 plementary note on calcination of the vinasses (or spent-wash) of 

 beetroot, by M. C. Vincent. A reply to MM. Duvillier and 

 Buisine. — On the organisation and the cellular form in 

 certain kinds of mosses (Dkraniim and DicraneUa), by M. 

 Heckel. — On the resistance of sheep of Barbarine race to inocu- 

 lation with chorion, by M. Ollive. He affirms the generality of 

 this character. During the eight years he has lived in Mogador 

 he has never met with any case of the disease. — On the rhythmic 

 excitability of the muscles and their comparison with the heart, 

 by M. Richet. For the heart, as for the muscle of a claw of 

 the cray-fish, contraction (systole) exhausts the muscular element, 

 which then ceases to contract ; but it is restored very quickly, 

 and it is during the period of exhaustion (diastole) that the 

 reparation takes place. The cause of rhythm is the same in 

 both heart and muscle — rapid exhaustion and rapid reparation. — 

 Comparison of the action of various curares on the smooth and 

 striated muscles, by M. De Lacerda. They differ in intensity 

 of action on these muscles, not in the nature of the action. — On 

 medullary osseous abscesses, by Dr. Chassargnac. — M. Larrey 

 presented Dr. Bateman's work on Darwinism demonstrated by 

 language, and gave an apcrcu of it. — M. Chasles presented (from 

 Prince Boncompagni) a photolithographed copy of a long letter 

 from Gauss to Mdlle. Sophie Germain, a student of the Ecole 

 Polytechnique. 



CONTENTS Pagb 



The Double Stars 53 



Our Book Shelf: — 



Benson's " Saidapet Experimental Farm Manual and Guide." — 



R. W • 54 



Post's " Grundriss der chemischen Technologic " 55 



Letters to the Editor : — 



The November Meteors.— Rev. S. J. Perry, F.R.S 55 



The Platysomid Fishes.— R. H. Tkaquair 55 



Voice in Fish.— S. E. Peal 55 



Silurian Fossils in the " Lower Old Red Sandstone" of the Curlew 



Mountain District. — G. Henry Kinahan 55 



The Paces of the Horse.— Sir W. G. Simpson, Bart 53 



A Curious Rainbow.— J. B. Hannay (Irith Illustration) . . . . 5 S 



How Snakes shed the Skin. —Samuel LOCKWOOD 56 



The " Hexameter," Ilu.ra.Wff.caVW, ...—J.J.Walker ... 57 



The Swedish North-East Passage Expedition 57 



Galileo anu the Application of Mathematics to Physics, II. By 



William Jack, M.A., LL.D., F.R.S.E 58 



Who was Prince AlumayO? By A. H. Keane 61 



Colour-Vision and Colour-Blindness. By Prof. J. D. Everett, 



F.R.S 62 



Some Observations on Fleuss's New Process of Diving and 01 

 Remaining under Water. By Dr. Benjamin Wakd Richardson, 



F.R.S. (With Diagrams) 62 



New Guinea (With Illustrations) 64 



Vertical Shafts i.\ the Chalk i.n Kent. By F. C. Spurrell . . 67 



Prof. Geikie on the Geology of the Far West 67 



Notes . 6) 



Our Astronomical Column: — 



The Biela Comet Meteors 7 1 



A New Nebula 71 



The Satellites of Mars 72 



Physical Notes 7 s 



G™u.« f ». t AL Notes 73 



IUivkkmty and Educational Intelligence 73 



Scientific Sekials 7-» 



Societies and Academies 75 



