424 



NATURE 



[August 24, 1905 



OUR ASTRO.NOMICAL COLUMN. 

 Observation of Jupiter's Seventh Satellite. — A 

 telegram from Prof. Pickering to the Kiel Centralsfelle 

 announces that Prof. Albrccht has observed Jupiter's 

 seventh satellite with the Crossley reflector. Observations 

 were made on August 7, 8, and q, and on the first named 

 day the satellite's position in reference to Jupiter was as 

 follows :— 



' G.M.T. Positi'jn .ingle Di5t. 



1905 Aug. 7 96 ... 289° 7 ... 54' -6 



(Circular No. 78 Kiel Centralstelle). 



Cos.Mic Dust of .Solar Origin. — The hypothesis that 

 certain terrestrial phenomena, e.g. magnetic storms and 

 aurora;, are caused by the earth passing through denser 

 portions of streams of finely divided gravitating matter 

 ejected by the sun is discussed by Prof. Schaeberle in 

 No. 4041 of the .■Istronomiscltc Nachriclilcn. One of the 

 greatest objections to this hypothesis appears to be that 

 no regularity of period has been discovered for the ejections 

 which would fit in with the observed data of the terrestrial 

 phenomena. Prof. .Schaeberle shows, however, that a 

 largely irregular period affords fundamental evidence in 

 favour of the hypothesis. 



Both theory and observation lead to the conclusion that 

 the cjective forces on the sun are very variable, and this 

 would certainly mean that the initial velocities of the 

 particles ejected would vary considerably. In a table ht 

 has prepared the author shows that particles ejected with 

 an initial velocity of 376-76 miles per second would just 

 reach the earth's orbit, the time taken being 64-6 days. 

 An initial velocity of 381-78 miles per second would carry 

 the particles to four times the earth's distance; their 

 velocity on passing the earth's orbit would be 224 miles 

 per second, w-hilst the time taken to reach the earth on 

 the outward journey would be 29.7 days; 1003 days would 

 elapse before they crossed the earth's orbit on the return 

 journey. Particles ejected with a velocity of 382 miles 

 per second would cross the earth's orbit with a velocity 

 of 25-9 miles per second in 27-4 days, and would be carried 

 10 an infinite distance. Thus a very small change in the 

 initial velocity at which the particles are ejected causes 

 a very large change in the time taken to reach the earth, 

 and therefore Prof. Schaeberle maintains that the 

 irregularity of such phenomena is evidence in favour of 

 the existence of such streams. He also discusses some 

 comctarv phenomena which, he considers, furnish the 

 strongest evidence in favour of the hypothesis. 



The Orbit of 7 Coron.e Borealis. — The following 

 elements for the binary system of y Coronae Borealis have 

 been deduced by Mr. Doberck, of the Hong Kong Observ- 

 atory, from all the available observations recorded since 

 1826:^ 



a =113' 20' I 7 = So° 8' I P=79-63 years 

 A =254° 55' (f =0-3589 T= 1839-60 



I (7 = o"-59S I 



Mr. Doberck gives a table containing the results 

 obtained by each observer, omitting those which are in 

 any way doubtful {Astrononiische Nachrichtcn, No. 4041). 



SOCIETIES AND ACADEMIES. 

 Paris. 

 Academy of Scienres, August 14. — M. Bouquet de la 



Orye in the chair. — The study of the solar atmosphere 

 round the spots ; H. Deslandres. The author explains 

 in detail the method adopted by him for the study 

 of the spectra of the sun-spots, the special lines 

 selected being the K, and K, lines of calcium. 

 — On the gases produced by actinium : A. Debierne. 

 It has been shown by Ramsay and Soddy that solu- 

 tions of radium salts give off detonating gas con- 

 taining a very minute quantity of helium. The author 

 has examined actinium salts from the same point of view-, 

 and has found that in this case also a mixture of hydrogen 

 and oxygen is continuously evolved. Helium was found 

 to be present in this gas, and in quantity comparable to 

 lh:it given by radium. By way of control, the experi- 



ments with a solution of radium bromide were repeated 

 and the results of Ramsay and Soddy confirmed. — On the 

 production of heavy liquids with the alkaline iodo- 

 mercurates : M. Duboin. The compounds of mercuric 

 iodide with potassium, sodium, lithium, and ammonium 

 iodides have been prepared, and the densities of the 

 heaviest solutions obtainable measured. Whilst Thoulet's 

 liquid (solution of potassium iodomercurate) has a 

 density of 3-196, the solution of the corresponding sodium 

 salt has a density of 346, of lithium 328, and of 

 ammonium 2-98. The sodium and lithium salts are there- 

 fore superior to the original solution proposed by Thoulet. 

 They are soluble without decomposition in alcohol, and 

 are suitable for the separation and determination of the 

 density of minerals. — The pure culture of green plants 

 in a confined atmosphere in presence of organic sub- 

 stances : M. Molliard. The results of the experiments 

 show- the possibility of the absorption and utilisation of 

 glucose in sunlight by the plant, this absorption being 

 increased when asparaginc was also present in the solution. 

 — The physiology of the placenta: .MM. Charrin and 

 Goupil. — On a toxic product extracted from the cerebral 

 substance : A. Marie. The brain substance was brought 

 into an emulsion with five times its weight of water, 

 centrifugalised, and filtered, first through paper and finally 

 through a Berkefeld filter. The liquid thus obtained 

 showed distinctly toxic properties, the nervous system 

 being especially affected. — On infectious anremia in Ihr 

 horse : H. Carre and H. Vallee. ."Xttention is directed 

 to the state of latent infection exhibited by certain horses, 

 apparently cured, and means given of detecting such cases. 

 The results of the research are summarised in the form 

 of practical instructions as to the best mode of dealing 

 with an outbreak. — On the preparation of cholera toxin : 

 MM. Brau and Denier. 



CONTENTS. p.\GE 



School Mathematics 393 



Panama Canal 394 



Our Book Shelf :— 



Trevathan : "The American Thoroughbred." — R. L. 395 



Pycraft : " The Story of Reptile Life" 395 



" Dige.^t of the Evidence given before the Royal 



Commission on Coal Supplies (1901-1905)" . . 395 

 Peckham and Peckham : " Wasps, Social and 

 Solitary."— W. F. K. . . . ..'.... 395 



Cowen : " X-Rays : their Employment in Cancer and 



ether Diseases" . 395 



v. Leibniz : " Neue Abhandlungen iiber den mensch- 

 lichen Verstand " ; Jasche : " Immanuel Kant's 

 Logik " : Leicht : "Lazarus der Begiilnder der 



Volkerpsychologie " 396 



Letters to the Editor:— 



British Fruit Growing. — Spencer Pickering, F.R.S. 396 

 Artificial Diamonds. {//h/s/raUd.)—'Dr. C. V. Burton 397 

 The Spre.id of Injurious Insects. — Prof. T. D. A. 



Cockerell 397 



A Parasite of the House-fly. — M. D. Hill . . . - 397 

 More Light on Ancient Britain. (Ilhislra'ed.) . . 398 



The Forthcoming Total Solar Eclipse 399 



First International Congress of Anatomists .... 4C0 



Prof. T. R. Thalen 403 



The South African Meeting of the British Association 403 

 Section C. — Geology— Opening Address by Prof. 

 H. A, Miers, M.A., D.Sc, F.R.S., President 



of the Section 405 



Section D. — Zoology. — Opening Address by G. A. 

 Boulenger, F.R.S., V.P.Z.S., President of the 



Section 413 



Notes. {Illusiralecl.) 421 



Our Astronomical Column : — 



Observation of Jupiter's Seventh Satellite 424 



Cosmic Dust of Solar Origin 424 



The Orbit of 7 Corona- Borealis 424 



Societies and Academies 424 



NO. 1869, VOL. 72] 



