NA TURE 



{Nov. 4, i! 



the taxonomic importance of the petiole, by M. Louis Petit. — 

 On the reproductive organs of vegetable hybrids, by M. Leon 

 Guignard. — On the relations of geodesy and geology : a reply to 

 the observations of M. Faye, by M. A. de Lapparent. 



Berlin 

 Meteorological Society, Octobers. — Dr. Brix, in the name 

 of the Telegraph Administration, handed over to the Society a 

 paper containing the results of observations respecting earth- 

 currents instituted through the medium of German telegraph 

 lines, and giving a brief history of these investigations. — Dr. 

 Assmann spol<e of the thunderstorms of the summer of 1886. 



Physical Society, October 22. — Prof, von Helmholtz in the 

 chair. — Prof Bornstein communicated the results of his investi- 

 gations into the thunderstorms of July 18S4. The days from 

 July 13 to 17 were very prolific in thunderstorms, and respecting 

 them the spealier had collected and elaborated observations from 

 more than 200 stations in Germany. For twenty-four separate 

 thunderstorms, drawings were made of the "isobronts, " isobars, 

 and isothermals, from which it appeared that a fall in the baro- 

 meter always preceded the outburst of the storm ; that with the 

 occurrence of the sinking of the barometer the atmospheric 

 pressure ; rose very steeply and then relapsed gradually to its 

 former level ; and that the temperature, which was very high 

 before the storm, declined rapidly with the outbreak of the 

 storm. Local observations had formerly led to the same result. 

 The ' ' isobronts, " or the lines uniting the places where the first peal 

 of thunder was simultaneously heard, had in general a north- 

 south direction. The " isobronts "made the passage from west to 

 east with an average swiftness of from 38 to 39 kilometres an 

 hour. The "isobronts " were attracted by the mountains, so that 

 the part in whose west-e.ast direction a mountain was situ- 

 ated approached it sooner, and, after the passage of the "iso- 

 bront," delayed there longer than did the remaining part. Rivers 

 retarded the progress of thunderstorms, and small thunder- 

 storms often terminated at large rivers without crossing them. 

 This relation of thunderstorms to mountains and rivers might be 

 explained on the assumption that the storms were caused by 

 ascending air-currents. When such an ascending air-current 

 approached a mountain, then the mountain hindered the hori- 

 zontal air from flowing in at the anterior side of the ascending 

 current. The air flowing in at the posterior side, on the other 

 hand, thereby obtained tlie preponderance, and urged the phe- 

 nomenon with all the greater force to the mountain. The 

 reverse occurred after the thunderstorm had surmounted the 

 mountain. The horizontal currents in front then obtained the 

 preponderance, and delayed the progress of the storm. The 

 influence of the rivers found its explanation in the fact that the 

 air above the water was considerably cooler than the air above 

 the land, whereby a descending air-current was continuously 

 maintained, operating in opposition to the ascending current of 

 the thunderstorm, to the possible degree even of annulling it. 

 The speaker had been able artificially to produce an imitation 

 of all these processes by causing, in accordance with the direc- 

 tions of Dr. Vettin, visible currents to ascend in a glass box 

 filled with tobacco smoke, by means of local depressions of 

 temperature, by setting these currents in constant motion, and 

 making them strike against obstructions (corresponding with the 

 mountains), as also on descending currents which were likewise 

 artificially created. In the discussion which followed the above 

 address. Dr. Vettin laid stress on the fact that precisely at the 

 moment when the barometer mounted steeply from its lowest 

 position, the thunder followed the lightning most rapidly, and 

 discussed how, in accordance with his conception of the nature 

 of thunderstorms, by the curving round of the ascending air- 

 current, a whirling movement round a horizontal axis came into 

 shape, whereby, .is determined by its situation and its extent, 

 were produced thunderstorms, sleet, and hail. — Prof, von Helm- 

 holtz described the formation of a thunderstorm observed by him 

 in Rigi-Kaltbad. From a free point of prospect, allowing 

 a survey of the plain as far as the Jura, he observed how the 

 lower warm and moist layer of air was distinguished by a sharp 

 horizontal boundary of somewhat long strips of cloud from the 

 upper dry and cooler air. The cloud-masses resembling the 

 stripe-shaped cirri diffused themselves and formed a coherent level 

 boundary-layer between the two air-masses. He next noticed, 

 at ditTerent spots, balls of cloud arise above the boundary-layer, 

 evidently as the effects of ascending air-currents. The different 

 cloud-heaps then rose higher and grew into larger cloud-masses 



within which different electric sparks leapt from one spot to 

 another. It was only subsequently that he saw the lightning fly 

 downward to the earth. At last a heavy rain rendered the lower 

 air-mass, bounded by the horizontal cloud-basis occupying a 

 position nearly at a level with the height of the stand-point, 

 which had hitherto been clear, opaque. The phenomenon had 

 developed itself under weather in which the wind was at rest, 

 and could be followed very precisely into its details. — Prof. 

 Schwalbe reported on an investigation of Herr Meissner, who, 

 in the Strasburg Laboratory, had determined the warmth effect 

 on the wetting of powdery bodies. In the way of powder were 

 used amorphous silicic acid, glass, emery, carbon ; as fluids, 

 distilled water, benzol, and arnyl alcohol. In all cases an 

 increase of temperature was observed. 



BOOKS AND PAMPHLETS RECEIVED 



La France en Indo-Chine: Bouinais and Paulus (Challamel, Paris).— 

 Zeitschrift tiir Wissenscdafdiche Zoologie, October 1886 (Engclmann, Leip- 

 zig).— Huddersficld Technical Sch.ol Calendar for 1886-87 (Broadbent, 

 Huddersfield).— Student's Hand-Book of Historical Geology : A. J. Jukes- 

 Browne (Bell and Sons).— Units and Physical Constants, and edition : J. D. 

 Everett (Macmillan and Co.).— Principles and Practice of Canal and River 

 Engineering, 3rd edition : D. Stevenson (Black. Edinburgh).— Monthly- 

 Weather Report, June 1886. — Quarterly Weather Report, January to 

 March 1886. — Report of the United States Commission of Fish and Fisheries, 

 Part II, for 1S83 (Washington). — Phantasms of the Living, 2 vo's. : Gurney, 

 Myers, and Podmore (Triibner and Co.) —Den Norske Nordhaus Expedi- 

 tion, 1876-78, XV. Zoologi : Crustacea. IL : G. O. Sars (Grondahl, 

 Chrisliania).— Bulletin of the U.S. National Museum, No. 30: J. B. 

 Marcou (Washington). — Proceedings of the Society for Psychical Research, 

 October (Triibner and Co.).— Scientific Prevention of Consumption : C!. W. 

 Hambleton (Churchill). 



CONTENTS p.\GE 



Explosions in Coal-Mines. lly Prof. T. E. Thorpe, 



F.R.S I 



McLennan's "Studies in Ancient History." By 



Dr. W. Robertson Smith 3 



British Hymenomycetes 4 



The Ocean 6 



Letters to the Editor : — 



On the Connection between Cheinical Constitution and 



Physiological Action. — Dr. James Blake .... 6 



Disinfection by Heat. — R. Strachan 7 



The Beetle in Motion. — Prof. C. Lloyd Morgan. 



(Illustrated) 7 



The Astronomical Theory of the Great Ice Age. — 



W. H. S. Monck 7 



The Enormous Loss from 0.k- Warble. — John Walker 7 



Aurora.— Prof. F. Hahn S 



Earthquakes.— Dr. F. A. Forel ; H. du Bois . . 8 



Meteor. — ^Joseph John Murphy S 



Frederick Guthrie S 



The Longevity of Great Men. By Joseph Jastrow . 10 

 The Geology of the Lebanon. By Prof. Edward 



Hull, F.R.S 10 



Autumnal Flowering. By Dr. Maxwell T. Masters 11 



Arrow-Release. {Illustrated) 12 



Climatology of the Croydon District 14 



Notes on the Recent Swarming of Aphides. By G. B. 



Buckton, F.R.S 15 



Notes 15 



Our Astronomical Column : — 



The Binary Star 7 Coronas Australis 17 



Oppolzer's Astronomical Refractions 17 



Comets Finlay and Barnard 17 



Astronomical Phenomena for the Week 1886 



November 7-13 18 



The High Temperature in October. By Chas. 



Harding iS 



Volcanoes of Japan. By Prof. Milne. {Illustrated) . 19 



Solution 21 



University and Educational Intelligence 22 



Scientific Serials 22 



Societies and Academies 23 



Books and Pamphlets Received 24 



