NA TURE 



\_A71g11st 12, 1880 



electric candle point downwards cannot be claimed as anything 

 new for the candles of Mr. Wilde have been successfully used 

 in this position and without any directing frame. This latter, 

 beinij of fine wire, must offer a considerable resistance to the 

 current and cannot be overlooked. It is claimed as an advantage 

 in this system that the leading wires used are of the smallest 

 description even for considerable distances, but the same may be 

 said of any other system where the current-producing machine 

 has a very high electromotive force. The size of wire for the 

 circuit is not dependent upon any particular form of candle or 

 regulator, but upon the current-producing strength of tlie 

 machine employed for working the system. 



The automatic lighting and re-lighting of the Jamin candle 

 shows no advance over the means employed by others, nor does 

 the insertion of a resistance in the place of an extinguished lamp 

 constitute anything new. In any construction of candle where 

 the two carbons are separated by the action of magnetism (one 

 carbon being movable and attached to an armature influenced liy 

 an electro-magnet) it is impossible to keep the distances of the 

 carbons apart always constant. Any vai-iation in the current 

 produces a corresponding variation in the magnetism which 

 affects the movable carbon, this being especially the case in using 

 alternating currents where the carbon must necessarily be in a 

 continual state of vibration from the rapid changes of polai'ity. 



Those candles of the Jablochkoff type are free from such a 

 fault, owing to both carbons being made quite rigid by the 

 insulating material between them, and the distance apart, tliere- 

 fore, being invariable throughout the whole length, ^^ hich conduces 

 greatly to the steadiness of the arc. 



It is probable that the brilliancy of the light may be increased 

 by burning the candle point downwards, but it must consume 

 more rapidly than when in the reverse position, as the arc 

 would tend to warm the carbon rods throughout their length. 

 It is however certain that improvements will be made, and 

 that probably this system will eventually compete favourably 

 with others ah-eady established, althougli at present it is diflicult 

 to see much advantage over such candles as Wilde's, Rapieff 's, iS;c. 



T. E. G. 



SOCIETIES AND ACADEMIES 

 Paris 

 Academy of Sciences, August 2. — M. Edm. Becquerel in the 

 chair. — The following papers were read : — On the preparation 

 of chlorine, by M. Berthelot. The formation of the brown 

 soluble compound (preceding the liberation of chlorine) requires 

 not only chlorine and manganese, but a considerable excess of 

 hydrochloric acid ; it is a perchlorised chlorhydrate of man- 

 ganese. — On heats of combustion, by M. Berthelot. This re- 

 lates to the agreement between Thomsen's results and his own. — 

 Synthesis of hexamethyl benzine and of mellic acid, by MM. 

 Friedel and Crafts.— On human walking, by M. Marey. With 

 liis odograph he proves that the step is longer in mounting than 

 in descending for an unburdened man than for one carrying a 

 load, for one with very low-heeled, than for one with high- 

 heeled shoes, for one with a thick sole prolonged slightly beyond 

 the foot than when the sole is short and flexible. It seems as 

 though the heel might be lowered indefinitely with advantage, 

 but soles must not be elongated beyond a certain limit, 

 nor made quite rigid. Sometimes (as in ascending) the length of 

 the step is increased, and the rhythm retarded ; at other times (as in 

 more rapid walking) the step both lengthens and is accelerated. — 

 i'v.eport on the Interoceanic canal project. (Second Part.) M. 

 de Lesseps' documents are approved. — On the gallicolar phyl- 

 loxera and Phylloxera vastatrix, by M. Laliman. — M. Zazareff 

 described a battery in which electricity is produced by pas- 

 sage of a solution of glycerine, under pressure, through a 

 mixture of coke and anthracite. — On the theory of sines of 

 superior orders, by M. Farkas.' — Researches on the electric 

 efiluvium (silent discharge), by MM. Ilautefeuille and Chappuis. 

 M. Thenard's apparatus (with alternative discharges) is weU 

 fitted to show the rain of electric fire in various gases. Fluoride 

 of silicium gives the best effects ; nitrogen comes next ; hydrogen 

 and chlorine also present the phenomenon. — Researches on 

 batteries, by M. D'Arsonval. He indicates two methods of 

 obviating the chemical action which goes on in batteries with 

 two liquids when the circuit is open. The first consists in use 

 of animal charcoal, substituted e.g. for the sand in a Minotto 

 l)attei-y ; the second, in using, as a depokariser, a liquid which 

 gives a precipitate by its mixture with the liquid which attacks 

 the zinc (there are many ways of doing this; and the autlior 



mentions some). In the latter case the diaphragm is rendered 

 impermeable by means of a conducting and electrolysable preci- 

 pitate. — On the optical properties of mixtures of isomorphous 

 salts, by i\I. Dufet. Let ^V be the index of the raLxei salt, n 

 and 11' those of the components, p and /' the numbers of 



equivalents of the two salts ; then N - /" + /"'_ xhis 



p + p' 

 law is demonstrated, at least, for sulphates of the magnesian 

 series.— -Influence of temperature on the distribution of salts in 

 their solutions, by M. Soret. The concentration of the heated 

 part diminishes, that of the cold increases. The difference 

 grows with the original concentration, and nearly in proportion. 

 In the series of the alkaline chlorides the difference is greater 

 (for the same concentration), tlie higher the molecular weight of 

 the salt. The phenomenon seems to have no relation to solu- 

 bility of the salt. — On the rise of the zero point in mercury ther- 

 mometers, by M. Crafts. This rise (through heating) is quicker 

 and greater in crystal thermometers than in those of glass without 

 oxide of lead ; it is quicker at fu'st, and tends to a limit (with 

 heating at fixed temperature). The zero point becomes fixed 

 at the new height, when tlie instrument is kept at ordinary 

 temperature and tlie thermometer becomes more stable. — Deve- 

 lopment, by pressure, of polar electricity, in hemlhedral crystals 

 with inclined faces, by MM. Jacques and Curie. — On the pyridic 

 bases, by M. de Coninck. — On the heats of combustion of some 

 substances of the fat -series, by M. Louguinine. — Identity of acute 

 experimental septicaemia with the cholera of fowls, by M. Tous- 

 saint. — Formation of new races ; researches in comparative 

 osteology, on a race of domestic oxen observed in Senegambia, 

 by M. de Rochebrune. The animal — a zebu — is specially dis- 

 tinguished by a conical nasal horn. — Action of poison on cepha- 

 lopoda, by M. Yung. The effects of curare, strychnine, nicotine, 

 &c., are described. — On a hailstorm at Paris on July 30, iSSo, 

 by M. Ferriere. — On determination of crystallisable sugar in 

 presence of glucose and dextrine, by M. Pellet. 

 Vienna 

 Imperial Academy of Sciences, July i. — The following, 

 among other papers, were read : — Development and formation 

 of the glands of the stomach, by Prof. Toldt. — Tuberculosis, by 

 Prof. Heschl. — On the absorption of radiant heat in gases and 

 vapours, by Herr Leclier and Herr Pernter. — On an optical 

 property of the cornea, by Prof. Fleischl. 



CONTENTS Pagb 



Ancient Geography 333 



The Menhaden 335 



Our Book Shelf ; — 



Ross's " Alphabetical Manu.il of Blowpipe Analysis " 336 



Dall's " U.S. Coast and Geodetic Survey " 336 



Wood's "Tree Planter " and "Tree Pruner" 336 



Vinter's " Tables for the Analysis of a Simple Salt " 337 



Letters to the Editor: — 



The late Count L. F. de Pourtales.— Prof. P. Martin Duncan, 



F.R.S 337 



The Recent Gas E.-iplosicn.— Dr. Herbert McLeod, F.R.S. . . 337 



He.1t of the Comstock Lode.— J. Arthur Phillips 337 



BrilishMuseum Attendants.— \Vm. Flinders Petrie .... 338 



Quassia .ind Mosquitos.— J. E. Dancer 33S 



Fascination. — Thomas R. R. Stebbing 338 



Strange Method of Crossing a Torrent.— Surgeon-Major W. 



CURKAN 339 



Intellect in Brutes.— Surgeon-Major W. Curran 339 



Anchor-Ice.— R. J. Farquharson 339 



Depraved Taste in Animals.— Arthur Nicols 339 



Thunderstorms. "By 'Proi.TA.ir {With Illustration) 339 



Observations on Arctic Fossil Floras With Regard to Tem- 

 perature. By J. S. Gardner 34* 



Meteorology in Japan 342 



Mineral Statistics of Victoria 343 



Physics without Apparatus, II. (With lllustratioi:s) 320 



Notes 345 



Our Astronomical Column ; — 



Comets of Short Period 347 



Is n Cygni a Variable Star ! 348 



Geological Notes : — 



Geology of Belgium and the North of France 348 



The Right of Priority in Palaiontological Nomenclature . . . . 34S 



Geological Survey of New Jersey 348 



Geological Survey of Alabama 4S 



Central Asian Geology 34^ 



Geology of Geneva 348 



Jurassic Rocks of the Altai Mountains 349 



Miocene Flora ?43 



Chemical Notes 349 



Physical Notes 35o 



Geographical Notes , • • • • ■ 35" 



The Structure and Origin of Coral Reefs and Islands. By 



John Murray 35> 



The Jamin Candle 355 



Societies and Academies 35° 



