552 



NATURE 



{Oct. 6, 1881 



aud on recent studies of M. Reue Thury on sounds of telephones 

 during thunderstorms, by M. Colladon. M. Thury stretched a 

 copper wire horizontally between two houses at the height of the 

 roofs, and connected it with the water pipes, and with tvio 

 telephones. The telephones gave a characteiistic sound cacli 

 time and at the same instant as a fla^h of lightning was seen, 

 near or far (and even when no ihunder was heard). It was like 

 the sound of a Swedish match rubbed on the box. M. Colladon, 

 in 1826, observed defleciions in a galvanometer in Paris during a 

 thunderstoim at a distance, while there was no cloud within 30° of 

 the zenith, and M. Peclet de^cribes like inductive effects in his 

 " Traite de Physique" {1832). M. Colladon thinks the sounds 

 will be best heard in the telephone when the air is surcharged 

 with humidity. The telephone affords an easy method of mea- 

 suring the velocity of transmission of those influences. — Meaure- 

 ment of rotation of the plane of polarisation of light under Ihe 

 magnetic influence of the earth, by M. H. Becquerel. Repeating 

 his experiments under more favourable conditions, he finds that 

 the yellow rays D, traversing horizontally a column of i metre of 

 sulphide of carbon at 0°, under the influence of ten-estrial mag- 

 netism at Paris, and in a direction parallel to the declination 

 needle, undergoes a simple magnetic rotation of o''8697 from 

 right to left for an observer supposed to lie with his head tow ards 

 the magnetic north. In the C.G.S. system of units this le.ads to 

 the number i '31 x 10-5 as expressing the magnetic rotation of 

 yellow rays through sulphide of carbon between two points of 

 unit distance in a magnetic field equal to unity. (Mr. Gordon's 

 figures, got by different methods, give l"24xio-S for sodium 

 light.) — On the passage of projectiles through resistant media, 

 on the flow of solids and the resistance of air to the motion of 

 projectiles, by M. Melsens. He arranged experiments n ith a 

 view to catching the air carried in front of a projectile. 

 Lead balls (about o'oi7m. in diameter) were shot into a 

 hollow cone in a block of iron, the apex being of steel, and 

 having an opening, smaller than the ball, into a gun-bai'rel 

 communicating with a bell-jar in a reservoir. The gun, the 

 reservoir, and the bell-jar were filled \\\\h. water, which was 

 prevented escaping through the cone by a light obstacle of paper 

 or thin brass. Detached fragments of the lead entered the gun- 

 barrel, the biilk of the ball stopping the hole of the cone, and 

 appearing pointed, or with an oblong drop. The effects of the 

 penetrating air are indicated in the cracks and rupture of the 

 gun-barrel, the bell-jar, and the bent tube between them. M. 

 Melsens considers the resistance of the air implies factors of 

 which artillery has not taken sufficient account. This resistance 

 is variable throughout the trajectory, in virtue of the mass of 

 the projectile, the form of the mass of adherent air, the velocity, 

 the thrust of the powder-gases, up to a certain distance from the 

 gun, and, lastly, from the very brief moment when the projectile 

 is equally pressed in all directions by air. — On new sulphurised 

 salts produced with sesquisulphide of phosphorus, by M. Lemoine. 

 — On tungstoboric acid and its s.alts, by M. Klein. — Determina- 

 tion of phosphoric acid by titrated liquors, by M. Perrot. — 

 On some of the scientific researches contained in the manuscripts 

 of Leonardo da Vinci, by M. Ravaisson. He calls attention to 

 a passage rec jmmending, as a method of hearing distant sounds 

 at sea or on land, inserting one end of a tube in the water or 

 in the earth, and putting one's ear to the other. M. Ravaisson 

 is preparing the manuscript B, one of twelve in the Bibliotheque 

 de ITnstitut, for publication (to follow MS. A, published in 

 December last). 



September 26. — M. Wurtz in the chair. — The following 

 papers were read : — Researches on the gymnotus in Venezuela, 

 by the late Dr. Sachs, by M. du Bois Reymond. At the instance 

 of Prof, du Bois Reymond, five years ago, Dr. Sachs went out 

 with modern electrophysiological apparatus, to study the gym- 

 irotus in the marshy waters of the Llanos of Calabozo. Re- 

 turning to Berlin in 1877, he set himself to composing a work on 

 his observations in general, and was about to write specially on 

 the gymnotus, when he lost his life by falling down a crevasse 

 in the Alps of the Tyrol. The monograph now presented gives 

 the re-ults of his studies of gymnotus, with further valuable 

 observations by Prof. Fritsch, who has worked out the anatomy 

 of the animal, numerous specimens of which Dr. Sachs had 

 brought home. M. Fritsch has been able to demonstrate in an 

 almost certain manner the development of the electric organs 

 through metamorphosis of striated muscles. — Results obtained 

 in treatment of phylloxerised vines by the use of sulphide of 

 carbon and suliiho-carbonate of potassium, by M. Henneguy. 

 The vines treated with sulphide of carbon retain their greenness 



longer than those treated with sulpho-carbonate of potassium, but' 

 their branches are shorter and bear fewer grapes. — Observations 

 relative to accidents to vines treated iniSSi with sulphide of carbon, 

 by M. Pastre. These accidents have lieen mostly due to excess 

 oi" humidity in a compact clayey soil. The sulphide either remains 

 liquid, or evaporates in too little space ; and in both cases (the 

 former especially) it destroys the roots. A less frequent cause 

 is too lov/ temperature Among rules M. Pastre lays down 

 are these : To treat only well-dried ground, and vines not too 

 much affected ; to multiply the holes and diminish the doses ; to 

 manure well ; to leave off treatment when the tempeiature is 

 too low. — On trilinear forms, by M. le Paige. — Pliotometric 

 comparison of luminous sources of different colours, by M. 

 Crova. He uses a spectrophotometer. With two sources (say 

 an electric light and a standard Carcel lamp), so placed that the 

 mean luminosity of the two contiguous spectra is the same, the 

 ratio the intensities of simple radiations of one light to those 

 of the other (corresponding) is represented by a fraction greater 

 than unity in violet, and less in red, and there is one simple 

 radiation for which the ratio is equal to unity. If this radiation 

 be exactly known, the measure of the ratio of its intensities in 

 the two spectra will give exactly the natio of the total intensities. 

 M. Crova realises this with the aid of two Nicol prisms having 

 a quartz plate between them. The apparatus gives very exact 

 results. — Studies on the chemical action of light, by M. I.emoine. 

 He has compared experimentally, from various points of view, 

 the influence of light with that of heat in chemical reactions ; 

 considering, more especially, isomeric transformations, and 

 the influence of dissolution, temperature, organic matters, 

 and colour. Inter alia, chloride of silver, so sensitive 

 to light, is unaltered by it when dissolved in ammonia. 

 The rate of chemical transformations often varies extremely 

 with the temperature, for light as well as for heat. Presence 

 of organic matters often accelerates a reaction in light and 

 allows of its commencing at a lower temperature. For various 

 substances which heat alone would decompose at hiw tempera- 

 tures, the red end of the spectrum seems much less eflicacious 

 than the violet end ; but in time both lights seem to produce the 

 same effect. — Researches on tropine, by M. Ladenburg. — On a 

 ureometer, by M. de Thierry. This ajiparatus, fo'- determining 

 the urea in urine of men and animals, is ba-ed on the process of 

 decomposition of urine by hypobromite of soda. It is in two 

 parts, one comprising a tube, with ampulla and stop cock, adapted 

 to a reservoir which communicates through a lateral tube of 

 caoutchouc with the second part. This includes a te.-ttube, a 

 gr.aduated bell-jar, and a thermometer. — M. Larroque described 

 an instrument for observation of meteors ; it is a mirror having 

 the form of a double pyramid. 



CONTENTS p„< 



Australian Aborigines. Ey Edward B. Tvlor, F.R.S s 



OiiR Book Shelk:— 



Watts' "Dictionary cfChemistrv and Allied Sc'.ences" .... 5 



Letters to the Editor :— 



The Madeira Earth-Electric Cloud again.— Prof Piazzi Smyth . 5 



American Cretaceous Flora.— J. S. Gakdner ........ 5 



Gradations between Hermaphroditism and Gyn jdicecism. — Dr. 



Hermann Muller 5 



Red Stars. -J. Birmingham 5 



Bombay K.ainfall and Nile Floods. — Morgan Brierlrv .... 5 

 Tn.^ International Exhibition and Congress of Electmcitv 



AT Paris, II 533 , 



Illustrations of New or Rare Ani.mals in the Zoological 

 Society's Living Collection, IV. (;F;« ///7«/r/7/M>/s) . . . .534 



Shipbuilding A Thousand Years Ago 536 



Learned Societies in Japan 533 



Notes 539 



Our Astronomical Column : — 



Comet v.. 18S3 541 



The New Comet %\i 



Minima of Algol 5-|2 



A Probably Variable Star 542 



Ccraski's Variable, U Cephei 542 



Chemical Notes 542 



The German Association S43 



Biology as an Academical Study, I. By Prof. T. Jeffery 



P.IRKER 543 



The Electrical Discharge, its Forms and its Functions, I. 



By Dr. William Spottiswoode, P.R.S. (With Diagrams) ... 546 



Societies AND Academies . . . 55i ' 



