4o8 



NATURE 



\_AiigiLst 25, 1887 



point the meteor burst out with a great accession to its brilliancy, 

 and there was a vivid flash, though the moon was near. The 

 radiant of this fine meteor was probably near Delphinus at 

 304° + 11°. 



On August 10, before midnight, the Perseids were by no 

 means numerous. Only 22 were seen during ijh., and after 

 the moon rose the display was not critically watched, as observa- 

 tions made during moonlight are not comparable with those 

 obtained under more favourable conditions. There were fine 

 meteors now and then, but the phenomenon never developed 

 into an imposing shower. On August 1 1 the sky was much 

 overcast, and not many shooting-stars were discerned. In i hour 

 before ilh. 30m., when the firmament was fairly clear, I 

 counted 21 meteors, of which 16 were Perseids. On August 14 

 the weather became very fine, and I enumerated 45 meteors in a 

 44 hours' watch. There were only 8 Perseids, and amongst the 

 meteors I registered were about 5 Aquariads from the same 

 radiant as at the end of July. I also noticed the Aquariad 

 shower at the middle of August in 1877, and in 1879 on August 

 21, 14 meteors were traced from 339° - 10°, so that it would 

 appear this system is prolonged until the end of the third week in 

 August, and without any apparent displacement of the radiant 

 point. The members of the latter stream are widely dissimilar 

 in their visible aspect to the Perseids, and move slowly, often 

 covering considerable arcs before extinction. In its chief rich- 

 ness the shower belongs to the July meteoric epoch, though 

 sometimes, as in the present year, remaining conspicuous until 

 the middle of August or even later than that, as in 1879. 



Bristol. W. F. Denning. 



SOCIETIES AND ACADEMIES. 

 Paris. 

 Academy of Sciences, August 16. — M. Janssen in the chair. 

 — Note on the work recently carried out at the Observatory of 

 Meudon, by M. J. Janssen. Special reference is made to the many 

 successful solar photographs already obtained, representing the 

 history of the solar disk for the last ten years. The processes 

 are now so perfected that on the same plate the details are taken 

 both of the brighter and less luminous parts, such as the edge of 

 the disk and the penumbra: of the spots. Photographs ten 

 times enlarged were exhibited of the extremely interesting spots 

 taken on June 22, 1885, and last June. The striae of the 

 penumbra and the faculse surrounding the former consist of 

 granulations, in form and size resembling those constituting the 

 entire solar surface. The same phenomenon reappears on the 

 large round spot photographed last July, so that it seems all but 

 demonstrated that the whole solar disk has a uniform constitution, 

 and that the so-called granulations are in fact the constituent 

 elements of every part of the surface of the sun. — Fresh re- 

 searches on the relations existing between the chemical and 

 mechanical work of the muscular tissue (continued), by M. A. 

 Chauveau, with the co-operation of M. Kaufmann. Plere a 

 determination is made of the coefficient of the quantity of 

 mechanical work produced by the muscles performing useful 

 work in the physiological conditions of the normal state. By trans- 

 lating into absolute measurements the indications furnished by the 

 dynamograph already referred to, it is shown that the muscular 

 work performed may be estimated at about 31 to 35 millionths of 

 calorie. — Some further remarks on the radicular nature of the 

 stolons in Nephrolepis, by M. A. Trecul. In reply to M. 

 Lachmann's recent note, the author again shows that these 

 stolons are not stems or stalks, but true roots. No matter what 

 their length, they never produce leaves, have always the structure 

 of roots, and as they alone represent the primary roots of 

 Nephrolepis, the expression "radicular stolons," applied to 

 them by the author, is fully justified.— New fluorescences with 

 well-defined spectral rays (continued), by M. Lecoq de Bois- 

 baudran. The author here treats fully the combination of 

 alumina and the earth Z/S^Oj, which, without being pure, is 

 very rich in ZjS and poor in Z«. Alumina with 1/50 of this 

 earth heated with sulphuric acid and moderately calcined shows 

 a somewhat yellowish-green fluorescence, much more vivid than 

 that of alumina containing the same quantity of ZooOj impure. 

 The fluorescences have also been examined of calcined alumina 

 containing the oxides of Ce, La, Er, Tu, Dy, Yb, Gd, Yt, 

 and U. During these researches several rays were noticed ap- 

 parently belonging to none of the already determined elementary 

 bodies. Some of these rays may perhaps correspond to the sub- 



stances announced by Mr. Crookes ; but each case will have to 

 be determined for itself. — Determination of the longitude of 

 the Observatory of Tacubaya, Mexico, by MM. Anguiano 

 and Pritchett. Continuous observations spread over six months 

 show a definite longitude of 6h. 36m. 46'56s. west of Green- 

 wich, which will require a correction of close upon 5s. for the 

 accepted longitude of the capital of Mexico. — Electric excite- 

 ment of the liver, by MM. Grehant and Mislawsky. The 

 question is discu'^sed, whether the excitement of the liver by 

 electricity increases the quantity of urea contained in the blood. 

 In opposition to the views of M. Stolnikow the experiments 

 here described show that variations in quantity occur only in 

 the arterial blood, and that the blood of the supra-hepatic veins 

 presents no change in the weight of the urea after electric 

 excitement of the liver. — Dissemination of the Bacillus of tuber- 

 culosis by flies, by MM. Spilmann and Haushalter. Observa- 

 tions recently made in consumptive-hospitals seem to show that 

 the virus (Koch"s Bacillus) may easily be disseminated by the 

 house-fly. — Note on Haematocytes, by M. Fokker. The author 

 recently showed that the protoplasm taken from a healthy 

 animal and protected from microbes survives and may produce 

 fermentations. Here he continues his researches, showing that 

 this protoplasm is capable of generating a vegetable form differ- 

 ent from that under which it existed in the animal organism. 

 But the Hrematocytes thus produced do not multiply themselves 

 in a cultivating medium, and their development should perhaps 

 be described as a case of heterogeny. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Dijmphna— TogtetsZooIogisck— BotaniskeUdbytte : Dr. Chr. Fr. Liitken 

 (Kjobenhavn).— Seven, the Sacred Number : R. Samuell (K. Paul).— Uni- 

 versity College, Dundee, Calendar 1887-88 (Leng, Dundee).— Qualitative 

 Chemical Analysis : Dr. C. R. Fresinius, loth edition, translated by C. E. 

 Groves (Churchill). — Notes to accompany a Geological Map of the Northern 

 Portion of the Dominion of Canada : G. M. Dawson (Montreal).— Die 

 Geoiddeformationen der Eisjeit : E. von Drygalski (Berlin) —Proceedings of 

 the Linnean Societyof New South Wales, 2nd series, vol. ii. Part i (Cunning- 

 hame, Sydney). — Verhandlungen der Naturhistorischen Vereines, Funfte 

 Folge. 4 Jahrgang, Erste Hiilfte (Max Cohen, Bmn). 



CONTENTS. PAGE 



The Health of Nations 3^5 



The Forestry of West Africa 3^7 



Our Book Shelf :— 



" Annals of the Astronomical Observatory of Harvard 



College" •, • 



Symons : " The Distribution of Rain over the British 



Isles during the Year 1886 " • 



Letters to the Editor : — 



Slate Ripples on Skiddaw High Man.— J. Edmund 



V. Clark 388 



Dr. Klein and "Photography of Bacteria."— Dr. 



Edgar Crookshank 



The Landslip at Zug. By Prof. T. G. Bonney, 



F.R.S. (Illustrated) 389 



The Norwegian North Atlantic Expedition .... 390 

 The Colours of Thin Plates. By Lord Rayleigh, 



F.R.S 391; 



Fifty Years' Progress in Clocks and Watches. I. 



By Henry Dent Gardner. {Illustrated) 



The Recent Drought. By Fredk J. Brodie. {llhis- 



trated) 



Thunderstorm in London. By Chas. Harding . . . 



Spencer F. Baird . 



Notes 



Our Astronomical Column j — 



Magnitudes of Nautical Almanac Stars 



Comet 1887 f (Barnard, May 12) 



Astronomical Phenomena for the Week 1887 



August 28 — September 3 



The Factors of Organic Evolution. By Dr. George 



J. Romanes, F.R.S 



The August Meteors of 1887. By W. F. Denning . 



Societies and Academies 



Books, Pamphlets, and Serials Received 



39 



395 

 397 

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398, 



401 

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40 



401 

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