288 



NATURE 



[Jan. 22, 1880 



which is connected an insulated wire. At or near the top of the 

 vessel, and immersed in the solution, is placed a second copper 

 plate or one of hard carbon, or metal unchanged by contact w ith 

 zinc sulphate solution and less positive than metallic zinc ; this is 

 also connected with a wire. A current from a dynamo-electric 

 machine is sent in the direction from the lower to the upper 

 plate, the result being deposition of metallic zinc on the upper 

 plate and the formation of a dense solution of copper sulphate 

 overlying the under plate. The cell, after charging, constitutes 

 a gravity cell, and continues a source of electrical current till re- 

 conversion of all the copper sulphate into zinc sulphate, with 

 deposition of copper on the lower plate and removal of zinc from 

 the upper. The cells, in charging, may be arranged in multiple 

 arc or in series, and differently from that in discharging, according 

 to the object. The authors believe it possible to store and recover 

 50 per cent, or more of the 50 or 60 per cent, which good 

 dynamo-electric machines realise in external work of the power 

 used in driving them. Thus 25 per cent, of the original power 

 may be given out secondarily as electric current. Assuming that 

 in the best steam engines 20 per cent, of the heat energy of the 

 coal may be utilised, then about 5 per cent, of the heat energy, it 

 is thought, may be recovered after storage as current ; but even 

 with this small percentage the economy would be much superior 

 to the use of zinc and other materials in the ordinary battery in 

 production of current. 



In a recent paper to the Vienna Academy, by Prof. Exner, on 

 the theory of inconstant galvanic elements, proof is offered that 

 there is no so-called galvanic polarisation in elements, but that 

 the phenomena referred thereto are attributable to the oxygen 

 dissolved in water. The electromotive force of an element « ith 

 only one liquid appears accordingly as a constant which is in no 

 way affected by any polarisation of the negative pole. It is 

 further shown that the force of a Smee element is not altered 

 when its platinum is .replaced by some other metal, provided 

 only this do not itself give rise to chemical processes. 



GEOGRAPHICAL NOTES 

 Dr. Emil Holub will read a paper before the Royal Geo- 

 graphical Society next Monday evening on his journey from the 

 Diamond Fields through South Central Africa to the upper 

 waters of the Zambesi. Dr. Holub, we understand, has for 

 some time been exhibiting at Prague a small museum of zoo- 

 logical and ethnographical curiosities collected during his various 

 journeys in Southern Africa, which has attracted much attention, 

 and he is coming to England to attend this meeting at the special 

 invitation of the Council of the Geographical Society. 



The Colonies and India reports the return of Mr. Alexander 

 Mitchinson after some years spent in Africa. He appears to 

 have arrived on the Gambia in 1876, and to have journeyed with 

 a small number of followers into various parts of Africa. Fol- 

 lowing the course of the Niger, he visited the waterfalls, and 

 returning to the west coast, made excursions into the country in 

 various directions. After a brief rest his travels were again 

 resumed, and from the Gaboon country Mr. Mitchinson made 

 his way into Angola, and from Benguela proceeded viA Bihe to 

 Lake Ngami, returning to the coast at Walfisch Bay at the end 

 of 1879. The notes which he made in the course of his travels, 

 are said to contain much interesting matter. 



- In the current number of the Tour du Monde M. Desire 

 Charnay, the well-known archaeological explorer of Southern 

 Mexico, Yucatan, and Madagascar, has commenced an account 

 of what he saw during the six months he recently spent in Aus- 

 tralia. His observations on the aborigines, their legends, cus- 

 toms, and traditions will no doubt be interesting, and his story 

 will certainly be well illustrated. M. Charnay, who returned to 

 Europe not long since, had, previously to his visit to Australia, 

 spent some time in the East Indian Archipelago. 



Dr. Benjamin Bradshaw, who was met by Major Serpa 

 Pinto, during his famous journey near the Zambesi, and who 

 was also with the late Mr. Frank Oates when he died near the 

 Tati settlement on his way from the Victoria Falls, arrived in 

 Capetown a short time ago, presumably to make another trial of 

 the ways of civilisation. Dr. Bradshaw has spent a long time 

 in the Matabele country and other parts of the Zambesi basin, 

 living the life of the natives and making zoological collections 

 for his own amusement and benefit. During his wanderings he 

 has acquired a considerable amount of information respecting 

 the less-known parts of the Zambesi and some of its tributaries, 



which, we have reason to hope, may be made public before 

 long. 



A correspondent in the G/asgcKu Herald advocates the 

 formation of a geographical society in that great commercial 

 centre, the second most populous city in the kingdom. We 

 have on several occasions pointed out the advantages of the 

 formation of such societies in our chief ports, by means of which 

 much useful information might be tapped that otherwise would 

 not see the light. No better field could be found for such a 

 society than Glasgow. 



Prof. Nordenskjold and his staff evidently do not consider 

 that their work was finished when they got outside Behring's 

 Strait in the Vega. During the brief stay of the ship at Galle 

 they made excursions into the island to examine its mineralogy 

 and natural history. Great preparations have been made for the 

 reception of the Vega at Naples. The King of Sweden desires 

 that the professor and the captain should visit Rome, Brussels, 

 Paris, and London, and join the vessel again at Copenhagen, to 

 be ultimately received at Stockholm. 



Dr. Otto Finsch left Honolulu on July 30 last,;on board 

 the barque Hawaii, and arrived at Dsbaloot, on the island of 

 Bonham (the principal island of the Marshall group) on August 

 21. He intended to investigate this island thoroughly, as it 

 appears that this has never before been done in a scientific 

 manner. From Bonham Dr. Finsch will proceed to the islands 

 of the Radak group. 



News from Dr. Stecker, the well-known companion of Dr. 

 Gerhard Rohlfs, stated that he was going to leave Benghasi at 

 the beginning of the present month, in order to proceed to Bornu 

 by way of Fezan. 



A French Company intends to cut a canal through the 

 Isthmus of Corinth. Steps have already been taken to obtain 

 the permission of the Greek Government. 



The German residents of Sydney have founded a branch of 

 the Berlin Central Union for Commercial Geography. 



Mr. IM Thurn, of the Georgetown Museum, whose labours 

 in British Guiana have been referred to in Nature, arrived in 

 England last week. 



THE SIXTH CONGRESS OF RUSSIAN 

 NATURALISTS 

 ""THE Sixth Congress of Russian naturalists began at St. 

 Petersburg on January I, by a public meeting in the great 

 hall of the University. The number of members present was 

 very large — 1,200 — of whom 500 were from the provinces, and 

 thirty-eight were ladies. Prof. Kessler was unanimously elected 

 President, but the bad state of his health not allowing him to 

 fulfil this function, he was made honorary president, Prof. 

 Beketoff being elected as the active one. 



At the first public meeting, Prof. Wagner gave an interesting 

 address on the " Means of Solution of the complicated Problems 

 of Natural Science," and after a brilliant sketch of the methods 

 of science, he drew the attention of naturalists to the necessity 

 of the study of physiological chemistry, and especially of the 

 problems connected with albuminous matters. 



Two proposals were then discussed : — On the scientific explo- 

 ration of Bulgaria, and on the necessity of making complete 

 botanical collections of Russian plants. 



The second public meeting of the Congress, held on January 7, 

 was opened by an address by Prof. Timiriazeff, on the physio- 

 logical significance of chlorophyll in the life of plants, on the 

 absorption by it of solar rays, and on the limits of the produc- 

 tivity of the soil. After this the president proposed that the 

 several projects of scientific inquiries approved by the Congress 

 be transmitted to a special committee, which would remain as a 

 permanent institution after the Congress, and see to the carrying 

 out of these projects ; the proposal was unanimously accepted by 

 the Congress and will be accomplished, if the Ministry of Public 

 Instruction does not oppose, as it has done hitherto, the creation 

 of a permanent scientific association of all Russian naturalists. 

 Prof. Mendeleef proposed the publication of a popular descrip- 

 tion of Russian colonies, being a sketch of their climate, soil, 

 flora, fauna, and economical conditions ; the proposal was 

 approved. Prof. Dobroslavine gave an address on the relations 

 between natural sciences and hygiene. The latter has only one 

 point in common with medicine — general pathology — whilst any 

 progress in the department would be impossible if it were not for 



