4o8 



NA TURE 



\_Pcb. 25, 1886 



length of the organ stripe. This ineciprocity of conduction ex- 

 plained in a most highly interesting manner the powerful effect 

 of the strokes directed outwards of electrical fish. Let us sup- 

 pose a column of the electrical organ reaching from the back to 

 the belly, then would the electrical currents of the organ diffuse 

 themselves at the positive pole surface of the back, and in accord- 

 ance with well-known laws respecting the distribution of electrical 

 currents in an endless conductor, betake themselves to the negative 

 pole surface of the belly. Were the organ a good conductor of its 

 currents, then would the most intense threads of currents balance 

 themselves in the organ, and only very faint ramifications of cur- 

 rent penetrate into the water. These current"^, however, had a 

 heterodromous direction in the organ, and were therefore ill-con- 

 ducted. The most intense threads of current were forced tlicrefore 

 to penetrate into the water, and were accordingly able to produce 

 vigorous effects outwardly. The speaker had finally examined 

 a phenomenon in the powerful electric nerves of the tor- 

 pedo, which he had earlier had occasion to observe in other 

 nerves. If a piece of nerve were cut off and the electromotory 

 energy of the two transverse sections determined, then did 'he 

 electric nerves show that the peripherical cross-section acted in 

 an electromotory sense more powerfully than did the central. If 

 both cross-sections were derived, then was an ascending current 

 received in consequence thereof. This occurred witii such 

 regularity that the peripheral and the central nerve could be 

 recognised on any piece whatsoever by the direction of the axial 

 nerve current, which was opposed to the direction of the physio- 

 logical action. In the sensory nerves Prof, du Bois-Reymond 

 had found a reverse axial current directed from the centre to 

 the periphery. He had the phenomenon then further investi- 

 gated by Dr. Mendelssohn, and it was quite generally established 

 that centripetal active nerves, such as the nerves of the senses 

 and the posterior roots of the spinal nerves, always showed a 

 descending axial nerve current, whereas centrifugal active nerves, 

 such as the motory and the electric nerves, possessed an ascend- 

 ing axial nerve current. In the case of mixed nerves an axial 

 nerve current could not be decidedly demonstrated. 



Meteorological Society, January 12. — Dr. Hellniann laid 

 before the Society in the form of a table, the results of the 

 rain registration at the eleven stations to the west of Berlin for 

 the six months from July to December, and drew attention to the 

 fact that in the winter months the values yielded by the dif- 

 ferent rain-gauges coincided very closely, whereas in summer 

 differences reaching as much as 50 per cent, occurred. — Herr 

 Opel spoke of the quantities of water discharged by rivers, .and in 

 particular by the Elbe. In view of the great difference pre- 

 vailing in the registrations of the amounts discharged at high 

 water, it deserved to be noted as an indication of impnrtant 

 progress that Herr Sasse, on the basis of a careful special 

 investigation of the subject, had formulated the proposition that 

 the curve of the quantities of water discharged formed a parabola 

 to the high-water marks as abscissas, but that the zero-point of 

 the parabola lay deeper than the zero-point of the water-mark. 

 From a long series of examples the author demonstrated the 

 correctness of the formula, and directed attention to several singu- 

 larities in the quantities of water discharged by the Elbe at 

 various stations of its course through Germany, singularities 

 which, while in part explicable by the tributaries, demanded 

 further investigation. The speaker then discussed the question 

 of the volumes of water in rivers, on which in quite recent times 

 several scientific investigators had expressed an opinion to the 

 effect that they had diminished in comparison with the volumes 

 of water in the rivers last century. This diminutioir of volume 

 was in larje part attributed to the progress of the denudation 

 of forests in the river districts. Herr Opel was, however, of 

 opinion that these registrations of the rivers were rather related 

 to the present well-ascertained lower state of the rivers at low 

 water. Since at many places the beds of the rivers had, .alto- 

 gether irrespective of their profile, been enormously narrowed, 

 the rivers at high water had, in consequence, dug themselves 

 out a deeper channel, and in this way depressed the mass of 

 waters. Rain returns did not, at all events, testify to any 

 diminution in recent times in the supply of water. The ob- 

 servations on the amounts discharged by the rivers of Prussia 

 have hitherto rested on very unsatisfactory bases. At a num- 

 ber of stations daily observations of water-marks were made. 

 The average of these was then taken, and the monthly and 

 yearly averages of these water-rnarks were used as a basis for 

 the calculation of the monthly and yearly discharges. Seeing, 

 however, that the amount of water discharged represented a 



parabola, it was impossible to calculate it from the height of the 

 state of the water alone. The amounts of water corresponding 

 with the average water-marks deviated, as was shown in a 

 number of instances, very considerably from the average of the 

 water volumes corresponding with the several high-water marks. 

 Another source of error lay in the circumstance that the obser- 

 vations of water-marks were made only once a day, from which 

 observations the monthly and yearly averages were deduced. 

 In view, however, of the repeated and often important variations 

 in the states of the water, once-a-day observations were really of 

 little value. Hourly observations even would not suffice. Wh.at is 

 required are self-registering gauges of the states of the water, 

 as being the only means whereby to obtain trustworthy values 

 for the amount of the river-discharges. Over and above this, 

 in the case of the larger rivers, measurements of their respective 

 quantities at low, mean, and high water should, every few years, 

 be very carefully made and the parabola determined, from which 

 the quantities discharged could then be calculated from the 

 registered high-w ater marks with some degree of certainty. 



BOOKS AND PAMPHLETS RECEIVED 



" Class-Book of Geology ■■ : Dr. .\. Geikie (M.icnillan and Co.) — 

 "Trigonometry for Beginners"; Rev J. B. Lock (.Macmillan and Co.).— 

 " Fourth Annual Report of the Board of Control of the New York Agri- 

 cultural Experiment Station for the Year 1885" (Andrew.s, Roctiester). — 

 "The Co-operative Index to Periodicals," vol. i. No. 4 (New York). — 

 " Hints for Land Transfer and a State Land-Bank" : Nemo. — " Revista 

 di .\rtigheria e Genio," vol. i. (Roma).— "The Star-Guide": Latimer 

 Clark and Herbert Sadler (Macmillan and Co.(.— "The Artist's Manual 

 of Pigments"; H. C. Standage (Locknood and Co.).— " Observaciones 

 Magneticas y Meteorolugicas del Real Colegio de Belen de la Compania 

 de Jesus," January to March, April to June. 1885 (El Iris, Habana). — 

 "Scientific Results of the Second Varkand Mission — Araneiida"; Rev. 

 O. P. Cambridge (Government Printing-Office, Calcutt.i) — " The Corapar.a- 

 tive Anatomy of the Pyramid Tract " ; E. C. Spitzka (Jenkins, New York). 

 — "Science for Nobleness, for Knowledge, and for Use"; Sir H. W. 

 Acland (K. Paul and Co.). 



CONTENTS Page 



Prestwich's "Geology" 385 



The Pictorial Arts of Japan. By F. V. Dickins . . 386 

 The Evolution of the Phanerogams. By J. Starkie 



Gardner 388 



Our Book Shelf:— 



Carroll's " Tangled Tale."— Dr. A. R. Willis . . 389 

 Lancaster's " Tableaux-Resumes des Observations 

 Meteorologiques faites a Bruxelles pendant une 



periode de cinquanle annees (1S33-1882) " . . . . 390 



" Notes from the Leyden Mu-eum " 390 



Milne's " Solutions of Weekly Problem Papers" . . 391 

 Letters to the Editor : — 



Heat Quantities. — Harry M. Elder 391 



Permanent Polarity of Quartz. — Dr. Arthur Schuster, 



F.R.S ^ 391 



Variegated Iridescent Halo. — G. H. Stone . . . • 391 



White Rainbows. — A. Ramsay 391 



A Nocturnal Ilymenoptera of the Genus Boinbus. — 



Marquis G. Doria 392 



Phylloxera at the Cape 392 



Oscar Schmidt 392 



The Story of Bielas Comet. By Prof. H. A. 



Newton. {Ilhislrated) 392 



On the Coagulation of Blood. By Ernst Freund , 395 



Inoculation as a Preservative against Consumption 39!; 



Notes , 396 



Our Astronomical Column : — 



The New Star in the Great Nebula in Andromeda . 397 



Present State of the Solar .•\ctivity 39S 



Astronomical Phenomena for the Week 1886 



February 28 — March 6 398 



Biological Notes : — 



Continuity of Protoplasm 398 



New Edible Fungus 399 



Worms in Ice 399 



Star-Fishes from South Georgia 399 



Geographical Notes 399 



The Sun and Stars. By J. Norman Lockyer, F.R.S. 



(Illustrated) 399 



Scientific Serials 403 



Societies and Academies 403 



Books and Pamphlets Received 408 



