July 3, 1890] 



NATURE 



233 



of this torrent of negatively charged molecules which are 

 projected from the negative carbon. If we employ a soft 

 iron rod as our lateral pole, we find that, after enduring 

 for some time the projection of the arc against it, it is 

 converted at the extremity into steel. 



Into the fuller discussion as to the molecular actions 

 going on in the arc, the source and nature of that which 

 has been called the counter-electromotive force of the 

 arc, and the causes contributing to produce unsteadiness 

 and hissing in the arc, I fear that I shall not be able to 

 enter, but will content myself with the exhibition of one 

 last experiment, which will show you that a high vacuum, 

 or, indeed, any vacuum, is not necessary for the produc- 

 tion of the " Edison effect." Here is a carbon horseshoe- 

 shaped conductor, not inclosed in any receiver (see Fig. 

 17). Close to the negative leg or branch, yet not touching 

 it, we have adjusted a little metal plate. The sensitive 

 galvanometer is connected between this metal plate and 

 the base of the other or positive leg of this carbon arch. 



r\ 



Fig. 17. — " Edison effect " experiment shown with carbon in open air. 



On sending a current through the carbon sufficient to 

 bring it to bright incandescence, the galvanometer gives 

 indications of a current flowing through it, and as long as 

 the carbon endures, which is not, however, for many 

 seconds, there is a current of electricity through it equi- 

 valent to a flow of negative electricity from the plate 

 through the galvanometer to the positive electrode of the 

 carbon. The interposition of a thin sheet of mica be- 

 tween the metal plate and the negative leg of the carbon 

 loop entirely destroys the galvanometer current.^ 



These experiments and brief expositions cover a very 

 small portion of the ground which is properly included 

 within the limits of my subject. Such fragments of it as 

 we have been able to explore to-night will have made it 

 clear that it is a region abounding in interesting facts and 

 problems in molecular physics. The glow-lamp and the 

 electric arc have revolutionized our methods of artificial 

 lighting, but they present themselves also as subjects of 

 scientific study, by no means yet exhausted of all that 

 they have to teach. 



NOTES. 

 Prof. E. Ray Lankester, F.R.S., has been elected 

 Deputy Linacre Professor of Human and Comparative 

 Anatomy, Oxford. 



To- DAY a meeting will be held at the Mansion House in 

 support of the International Congress of Hygiene and Demo- 

 graphy, which is to be held in London in 1891. The Prince of 

 Wales has consented to act as President of the forthcoming 

 Congress ; and it is expected that the meetings will be "of great 

 magnitude and importance." Many delegates have already 

 been appointed, and other nominations are being received daily. 

 It is necessary, therefore, that a definite organization should be 

 formed, and that a fund should be raised for the defraying of 

 expenses. 



' This last experiment is due to my assistant, Mr. A. H. Bate. 



NO. TO79, VOL. 42] 



On Wednesday next, July 9, Prof. T. McKenny Hughes 

 F.R.S., will deliver a lecture in the saloon of the Mansion 

 House on the question, "Is there coal in the south-east of 

 England ? " The Lord Mayor will preside, and will be supported 

 by the "Coal Search Committee." This Committee has been 

 formed for the purpose of taking steps to discover whether there 

 really are good coal-fields in the south-east of England, and, 

 if so, to what extent. It consists of scientific and commercial 

 men, and their services are gratuituous. Among the members 

 are Prof. Boyd Dawkins, Colonel Godwin-Austen, Prof. A. H. 

 Green, Dr. Henry Hicks, Mr. W. H. Hudleston, Prof. Edward 

 Hull, Dr. A. Irving, Prof. J. W. Judd, Sir John Lubbock, 

 Prof. Meldola, Mr. F. W. Rudler, Prof. W. J. SoUas, Mr, 

 J. J. H. Teall, Mr. W. Topley, Mr. W. Whitaker, and Dr. 

 H. Woodward. 



A NEW scientific Society (Die Deutsche zoologische Gesell- 

 schaft, on the lines of the Anatomische Gesellschaft) has just 

 been founded. Early in May, nine representatives of zoology in 

 German Universities issued a circular inviting brother zoologists 

 to unite in forming a Zoological Society. On May 28 a 

 preliminary meeting was held at Frankfurt, and zoologists 

 from nearly a dozen German Universities were present. At 

 present there are fifty-four members, and the next meeting is to 

 be held on August I, when a President will be chosen. The 

 invitations to this meeting will be issued early in July. Appli- 

 cations for membership may be sent to Prof. Biitschli (Heidel- 

 berg), Prof. Victor Carus (Leipzig), or Prof. Spengel (Giessen). 

 The foundation of this Society is a step in the right direction, 

 and lit is to be hoped that the new Zoologische Gesellschaft will 

 speedily become as cosmopolitan as the sister anatomical one. 



The Norwegian Storthing, by 73 votes against 39, has voted 

 a grant of 200,000 kroner for Dr. Nansen's North Pole 

 Expedition. 



The third summer meeting of University Extension and other 

 students will be held at Oxford in August next. The meeting 

 will be divided into two parts. The first part of the meeting 

 will begin with an inaugural address by Prof. Max MUller at 

 8.30 p.m. on Friday, August i, and will end on Tuesday even- 

 ing, August 12. The second part of the meeting will begin on 

 Wednesday morning, August 13, and end on Tuesday evening, 

 September 2. This period will be devoted to quiet study. 

 The courses of lectures will be longer than those delivered 

 during the first part of the meeting, and will deal in greater 

 detail with the subjects then introduced. 



Sir Henry W. Acland has published a letter on " Oxford 

 and Modern Medicine." It is addressed to Dr. James Andrew, 

 and was printed originally for private circulation. In the 

 preface the author expresses an earnest hope that "the broad 

 and yet precise study of material science and of nature may 

 prosper at Oxford, as part of the whole range of University 

 thought, and that in the haste for technical education our 

 physicians may not be relegated as some now desire into a 

 professional class or clique by themselves, but be as formerly a 

 living part of the whole of the scientific and literary University." 



The third International Shorthand Congress will be held at 

 Munich from August 7 to 17. The centenary of F. X. Gabels- 

 berger, the originator of modern German shorthand, will be 

 celebrated by those who attend the meetings, and a bronze 

 statue of him will be unveiled. 



Accounts which have reached the Times from the Weatherby 

 district, in Yorkshire, agree as to the occurrence of distinct 

 earthquake shocks on Wednesday, June 25, about 10.30 p.m., 

 and again on Thursday morning about four o'clock. Mr. John 

 Emmet, of Boston Spa, sixteen miles from Leeds, states that 

 shocks werfe experienced, not only at Boston Spa, but at Wighill, 

 Clifford, Thorp Arch, Weatherby, and other places, and he 



