NA TURE 



\_July 3, 1884 



the intervals Ebetween two stratifications the discharge is very 

 likely carried as through the dark space at the negative electrode, 

 while in the stratifications recombination of the decomposed 

 atoms takes place. 



An interesting law has been proved by Hittorf and E. Wiede- 

 minn in the case of the unstratified discharge Hittorf shows 

 that the fall of potential is the same in the positive part for the 

 same tube whatever the current. This means that the energy 

 dissipated is proportional to the current, and not to the square of 

 the current as in a liquid. In the latter form the proposition 

 had previously been proved by E. Wiedemann, who has shown 

 that the total quantity of heat generated is proportional to the 

 total < puntity of electricity which has passed through the tube, 

 whether in a few strong sparks or many weaker ones. 



These experiments seem to point to the fact that once t he 

 original velocity of the particles at the regular pole has been 

 reduced the velocity becomes independent of the strength of the 

 current, that is to say, that in the positive part of the current 

 greater intensity only means a greater number of particles 

 taking place in the discharge. 



The paper also contains spectroscopic evidence as to the state 

 of dissociation in a vacuum tube, especially in the negative 

 glow. 



The question as to how the electricity passes from the elec- 

 trode to the gas is not discussed, nor is it possible at present to 

 decide, should the theory prove true, whether the polarity of the 

 atoms in the molecule depends on the way in which these are 

 combined, or whether that atom takes positive polarity which 

 happens to be nearest the negative electrode as the molecule 

 approaches it. 



In conclusion some novel influence of the magnet on the 

 negative glow is described, and it is shown that two different 

 effects have to be clearly distinguished. The first is an effect of the 

 magnet on th :• discharge when that discharge is established, and 

 has been sufficiently well investigated. But the second effect de- 

 pends on the question from what part of the negative electrode 

 the discharge sets out. With respect to this question we meet 

 with many contradictory and inaccurate statements. If at any 

 place the magnet tends to throw the glow together the tem- 

 perature will be raised; and owing to this fact the current will 

 be strengthened, which again raises the temperature. It may 

 thus happen that a slight cause can induce the current to pass 

 almost exclusively from one part of the negative electrode. For 

 a detailed description the reader is referred to the paper itself 

 and the illustrations accompanying it. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 

 Mr. Andrew Gray, M. A., assistant to Sir William Thomson 

 in the Natural Philosophy department of the University of 

 Glasgow, has been appointed to the Chair of Physics in North 

 Wales University College. Dr. J. J. Dobbie, M.A., formerly 

 "Clark" Fellow in Natural Science, has been elected to the 

 Chair of Chemistry and Geology. 



The following is a list of prizes, scholarships, associateships, 

 eve, awarded at the Normal School of Science and Royal School 

 of Mines, South Kensington, June 1S84 : — First Year Scholar- 

 ships : Albert G. Hadcock ; Fred. Carrodus ; William C. 

 Rowden ; Thomas Rose. Second Year Scholarships : — George 

 Gibbens ; Isaac T. Walls. " Edward Forbes" Medal and prize of 

 books lor biology, Thomas Johnson ; " Murchison " Medal and 

 prize of books for geology, Martin F. Woodward ; "Tyndall" 

 prize ol books for physics, course I, Isaac T. Walls; "De la 

 Heche " Medal for mining,' Herbert W. Hughes; "Bessemer" 

 Medal, with prize of books from Prof. Chandler Roberts for metal- 

 lurgy, (1) Percy Bosworth- Smith, (2) William F. Grace; " Hodg- 

 kinson " prizes for chemistry, (1st, books, &c.) George T. Hollo- 

 way ; (2nd) StephenJ. Elliott and William P. Wynne. Associate- 

 ships in Normal School of Science : chemistry, 1st class, George 

 T. Holloway, William P. Wynne, and Elizabeth Healey ; 

 physics, ist class, Benjamin Illingworth and Alfred Howard ; 

 biology, 2nd class, and geology 2nd class, Joseph Lomas. 

 Associateships in Royal School of Mines : mining, ist class, 

 Herbert W. Hughes; mining, 2nd class, and metallurgy, Ist 

 class, George II. Schroder ; metallurgy, 1st class, Percy Bos- 

 worth- Smith, Alfred Sutton, Plenty G. Graves, ami Harry J. 

 Chancy ; metallurgy, 2nd class, William F. Fremersdorf and 

 Erskine H. B. Stephenson. 



SCIENTIFIC SERIALS 



American Journil of Science, June. — On the tendency of rivers 

 flowing to the north or to the south to encroach on their east or 

 west banks respectively, by G. K. Gilbert. The author, after 

 further study, here finally adopts the view that this tendency is 

 sufficiently accounted for by terrestrial rotation. — Examination 

 of Mr. Alfred R. Wallace's "Modification of the Physical 

 Theory of Secular Changes of Climate," part ii., geological 

 and paheontological facts in relation to Mr. Wallace's modifi- 

 cation of the theory, by Dr. James Croll. — Description of a 

 new fossil marsupial from the Miocene deposits of Chalk Bluffs, 

 Colorado, by W. B. Scott. This opossum, which the author 

 names Didclphys pygmaa, is intermediate in size between the 

 />. mii'ina and D. elegans of South America. It establishes 

 the fact that the small insectivorous opossums now characteristic 

 of South America existed in Miocene times in North America, 

 and is additional evidence that the latter continent is the source 

 from which the former received the greater part of its fauna. — 

 ( in a method of obtaining autographic records of the free vibra- 

 tions of a tuning-fork, and on the autographic recording of beats 

 (five illustrations), by Alfred G. Compton. — Notes on .the vol- 

 canic rocks of the Great Basin, stretching for over 400 miles 

 from the Sierra Nevada eastwards to the western base of the 

 Wahsatch Range, by Arnold Hague and Joseph P. Iddings. In 

 this region the association of andesites and trachytes, or trachytes 

 and rhyolites, is unknown, and the authors infer that trachytes 

 occupy a far more restricted position among volcanic rocks than 

 has hitherto been generally supposed. They also consider that 

 the geological independence of rhyolite and trachyte is now 

 clearly established. — Transition from the copper-bearing series 

 to the Potsdam in the St. Croix River Basin, Wisconsin, by L. 

 C. Wooster. — On the expression of electrical resistance in terms 

 of a velocity, by Francis E. Nipher. — Lateral astronomical re- 

 fraction, by J. M. Schaeberle. The author proposes a simple 

 remedy for the errors in astronomical observations arising from 

 the assumption that all atmospheric layers of the same density over 

 any given locality are parallel to the horizon. — Description of 

 a remarkable variety of kaolinite from the National Belle Mine, 

 Red Mountain, Ouray County, Colorado (three illustrations), by 

 Richard C. Hills. — The influence of convection on glaciation, 

 by Geo. F. Becker. — Description of anewDinichthys(ZJ. minor) 

 from the Portage Group of Western New York (two illustra- 

 tions), by Eugene K. S. Ringueberg. This specimen differs in 

 several important respects from the two Ohio species/?, fferzeri 

 and D. Terrelli, Newb. — Mineralogical notes on allanite, apa- 

 tite, ami tysonite (two illustrations), by Edward S. Dana. 



Revue a" Anthropologic, tome vii. fasc. 2, Paris, 1884. — On 

 the weight of the cerebellum and the hemispheres according 

 to Broca's mode of registration, by Dr. Philippe Rey. win, has 

 been commissioned by M. Topinard to continue the comparative 

 tables and determinations which had already served as the basis 

 of the memoir drawn up by the latter on the weight of the brain. 

 Bicetre, Saint-Antoine, La Pitie, and La Salpetriere are the 

 sources whence Dr. Rey has derived the requisite data for his 

 work, and his conclusions must therefore be regarded as having 

 more of a special than a general interest, since they are exclu- 

 sively based on observations of the particular classes of persons 

 confined in these institutions. — Study of primitive peoples, as 

 the Kaffirs, and more especially the Zulus, by Elie Reclus. This 

 paper presents little interest or novelty for English readers, a- it 

 consists almost entirely of extracts from English travellers and 

 missionaries, and neither opens up new sources of information 

 nor throws any novel light on the ethr. igraphy of the nation^ of 

 whom it principally treats. — On the Kalmuks, by M. Deniker. 

 In this second part of his memoir the author, after completing 

 his description of the anatomical and physiological characters of 

 the Kalmuk race, which he shows to be generally brachycephalic, 

 supplies much important information regarding their present social 

 and political condition under the influence of Russian domination. 

 1 1 would appear that the people have considerable mental capa- 

 city, various young Kalmuks having taken good places in the 

 examinations of the University of Astrakan, and officiating credit- 

 ably as medical practitioners, and as directors of the hospitals 

 which the Russians are establishing for the benefit of the tribes. 

 The change from a nomadic to a stationary life seems, however, 

 to have been productive of decided injury, the census of 1869 

 howing a diminution of 22 per cent, in the population since 

 1862. According to the author, this diminution principally 

 affects females, while this census presents, moreover, the singular 



