August 31, 1893] 



NATURE 



431 



ledge may be arrived at from the readings of the dry and wet 

 bulb thermometers under different atmospheric pressures. Ben 

 Nevis, with its two observatories, one at the top, the other at 

 the foot of the mountain, would, with a third half-way up the 

 hill, afford unique facilities for the prosecution of this all- 

 important hygrometric inquiry, which would, however, require 

 considerable additions, for the time it is carried on, to the 

 observ^tpries' present appliances and staff." 



St. Elmo's Fire and Thiimitrstorms. 



" Cases of Sf. Elmo's Fire are not infrequent occurrences on 

 Ben Nevis. The cases observed have mostly occurred during 

 the night, and during the winter monihs from September to 

 February. A careful discussion of these cases shows that the 

 weather which precedes, accom.panies, and follows has quite 

 peculiar characteristics not only on Ben Nevis but also over the 

 West of Europe generally ; indeed, so well marked is the type 

 of weather, and so notorious is it for its stormy character, that it 

 is familiarly known at the observatory as 'St. Elmo's 

 weather.' It is further observed that in almost every case 

 another cyclone, with its spell of bad weather, follows the par- 

 I icular cyclone on the south-eastern side of which St. Elmo's 

 Fire is observed. 



" The winter thunderstorms are observed under the identical 

 weather conditions under which St. Elmo'.s Fire occurs ; that is, 

 ihey invariably occur on the south-east side of the cyclone's 

 centre, with the easterly passage of which they appear to be in- 

 timately connected. The thunderstorms and cases of sheet- 

 lightning of Ben Nevis are essentially autumn and winter occur- 

 rences, 70 per cent, of the whole having occurred from 

 .Sept?jaber to February." 



Electric Currents. 

 "Prof. C. Michie Smith has shown that on the edge of a dis- 

 I solving mist the potential is lower than the normal, but higher 

 Ion the edge of a condensing mist. Now, almost always when 

 the top of Ben Nevis becomes clear for a short time, a strong 

 ■ current comes up the telegraph cable, while as soon as the 

 ; summit is again enveloped the current is reversed. The connec- 

 ilion between the moisture of the atmosphere and the earth cur- 

 I rents is still further shown by the rainfall. Daring a fall of rain 

 or snow the current nearly always passes down the cable ; and 

 in the case of a sudden shower the current has sometimes driven 

 the mirror of the galvanometer violently off the scile. A cessa- 

 tion of the rain or snow generally has an exactly opposite effect. 

 Ifit be assumed th.tt the summit of Ben Nevis takes the potential 

 of the masses of vapour covering it, and if we consider the earth- 

 ! plate at the base as the earth, or zero of potential, it is obvious 

 ihat the results confirm the theory advanced by Prof. Michie 

 {Smith, a conclusive proof of which would be of the greatest 

 jimportance in investigations connected with thunderstorms." 



;| Dust Particles in the Atmosphere. 



Observations of the numbers of dust particles in the atmo- 



re have been made by means of the dust-counting appara- 



icvised by Mr. John Aitken in 1889. The results show a 



defined diurnal period, the number of particles being above 



iverage in the afternoon, and below it in the morning. 



'From the whole of the observations on Ben Nevis, the 



11 :;m is 696 per cubic centimetre, the maximum being 14,400, 



le on several occasions the minimuti fell to o. In a large 



i.l)er of observations made by Mr. Aitken at Kingairloch, on 



west shore of Loch Linnh;?, the average number was 1600 



icles per cubic centimetre; in London he found, on one 



a^ion, 100,000, and this nu uber was exceeded in Paris." 



'any other investigations of a high scientific value have been 



!e by the Ben Nevis observers, and the observations have 



.ished matter for discussion to a number of meteorologists. 



■ though much has already been done, it is evident from the 



I :jrts issued by the directors of the observatory from time to 



iine that still more important results can confidently be 



jiccted. 



UNIVERSITY AND EDUCATIONAL 



INTELLIGENCE. 



! HE seventh session of the Edinburgh summer meeting ended 



Saturday. As regards number of students and scope of 



iies this meeting is still on the increase. Among the scien- 



courses may be noticed contemporary social evolution, by 



NO. 1244, VOL, 48] 



Prof. Patrick Geddes, co>.iparative psychology by Prof. Lloyd 

 Morgan, bionomics by Messrs. J. Arthur Thomson and Nor- 

 man Wyld, history and principles of the sciences by Prof. Car- 

 gill Knott, Prof. Geddes, Mr. Bosanquet, and others, physio- 

 logy of nutrition by Dr. Louis Irvine, a regional survey of 

 Edinburgh and neighbourhood by Mr. J. G. Gjodchild, Dr. 

 Beard, -Mr. Robert TurnbuU, and Mr. S. 11. Capper. A healthy 

 sign is the attention given to practical wor'K ; thus the afternoon 

 classes of botany, zoology, and geology were wholly practical. 

 The less strictly scientific part of the month's miniature curri- 

 culum shows an almost equal development, indeed, so many 

 excellent subjects were offered to the students that it must have 

 been difficult to choo.se a course of study. Whatever the course 

 selected, however, there is n:) doabt that the students derived 

 considerable benefit from it. 



The following list of successful candidates for Royal exhibi- 

 tions, national scholarships, and free studentships, has been 

 issued by the Department of Science and Art : — National 

 Scholarship; for Mechanics— William Buchan (Glasgow), 

 Frederick C. Lea (Crewe), James Eagles (Bury, Lancashire), 

 Richard II. Cabena (Glasgow) ; N.itional Scholarships for 

 Chemistry and Physics — .\lbert Howard, (Much Wenlock, 

 Salop), Francis R. Penn (Noithampton), Andrew N. Meldrum 

 (Aberdeen), William A. Bradley (Lee, Kem), Robert H. 

 Jones (Manchester) ; National Sc'iolarships for Biological 

 subjects — Arthur O. Allen, (Walthamstow), Robert Sowter, 

 (Brighouse, Yorks) ; National .Scholarships —Charles F. Smith 

 (Glasgow), John B. Chambers (London), John W. Hinchley 

 (Lincoln), Henry J. Loveridge (Southsea, Portsmouth), 

 Bernard C. Laws (Sjuthsaa, Portsmouth), Henry T. 

 Davidge (London), Joseph B. Butters (Urighton), Henry 

 H. Clements (Anahilt, Co. Djwn), Christopher Outhett 

 (Burnley), William Micdoaald (Manchester), Wdliam N. 

 Piatt (Chester) ; Royal Exhibiiions — George S. Blake (.Man- 

 chester), Wdliam H. Atherton, (Newcastle-on-Tyne), Ernest 

 H. Bagnall (Manchester), Frank H. Newman (London), 

 William A. Taylor (Crewe), Joseph H. Ivcy (Camborne), 

 Joe Crowther (Brighouse, Yorks) ; Free Studentships— John 

 Schofield (Huddersfield), Joseph Jeffery (Birmingham), 

 George A. Robertson (Oldham), Charles Kelly (Bilfast), John 

 Robinson (I3elfast), Edmund F. W. Mondy (London). 



SCIENTIFIC SERIALS. 



American Journal of Science. — August. — We notice the 

 following papers : — The use of cupric nitrate in the voltameter, 

 and the electro-chemical equivalent of copper, by Frederick E. 

 Beach. Copper nitrate solution of density I '53 possesses certain 

 advantages over the sulphate in voltameters. It is best to add 

 one drop of saturated NHjCI solution. The dependence of the 

 amount of copper deposited up m the current density does not 

 appear until a density of o'2j amperes per sq. cm. of electrode 

 is reached, and then it is counteracted by adding more NH4CI. 

 With the nitrate, the weight of c ipper deposited is practically 

 independent of the temperature between 10° and 35°. The 

 solution may be used a number of times. The equivalent of 

 copper as determined from the nitrate voltameter agrees to fear 

 figures with that calculated from the best chemical determina- 

 tions. But it is essential that the solution should be pure, and 

 especially free from traces of nitrite. — On M;ickintoshite, a new 

 thoiium and uranium mineral, by Wm. Earl Hidden ; with 

 analysis by W. F. Hillebrand. This is the original mineral of 

 which thorogummite, discovered in 1891, is the alteration pro- 

 duct. It is an opaque black mineral of hardness 5 '5, and re- 

 sembles zircon and thorite in form. It differs from thoro- 

 gummite by the further oxidation of the uranium and the 

 assumption of one molecule of water. It contains three mole- 

 cules of silica, one of urania, three of thoria, and three of water. 

 — On the reduction of nitric acid by ferrous salts, by Charlotte 

 F. Robeits. The volume of nitric oxide disengaged, swept along 

 by carbon dioxide and collected over caustic soda, was measured 

 for the estimation of nitrates. The best results were, obtained 

 by passing the gas through KI solution l>efore collecting, and 

 estimating from the total volume of gas collected. Nitric oxide, 

 being slightly soluble in caustic soda solution, must not be left 

 long in contact with it. When the reaction takes place at high 

 temperatures, some higher oxides of nitrogen may be formed, 

 but this is corrected by the KI solution. — Concerning the struc- 



