Oct. 1 6, 1879J 



NATURE 



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coveries." This motion, after some discussion, was 

 carried unanimously. 



Dr. Schroder (Hamburg) then finished the communica- 

 tion begun at the previous meeting. Herren Abbe (Jena), 

 Saffarik (Prague), Bruhns (Leipzig), Winnecke (Strass- 

 burg), took part in the discussion on it. Prof. Oudemans 

 (Utrecht) reported on the Gaussian object-glass of the 

 Utrecht Observatory. Dr. Huggins (London) gave an 

 account of his results in photographing star-spectra, and 

 showed some of them to the meeting. Prof. Bruhns 

 (Leipzig) exhibited drawings of nebula and neighbouring 

 stars made by students of the University with small tele- 

 scopes. Prof. Abbe (Jena) gave an elaborate account of 

 his important theoretical and experimental researches in 

 optics, followed by a discussion between him and Herren 

 P orster and Winnecke. Prof, van de Sande Bakhuyzen 

 (Ley den) explained his researches upon the dependance of 

 the personal error in transit observations from the magni- 

 tude of the stars. Prof. Schbnfeld (Bonn) reported on 

 the progress of his " Durchmusterung " of the southern 

 heavens. There is finished in observation at present 

 about two-thirds of the whole work. 



After a vote of thanks to the Prussian Government, the 

 Royal Academy of Sciences, and the Berlin astronomers, 

 the meeting of the International Astronomical Society 

 was closed late in the afternoon. A. Winnecke 



INFLUENCE OF ELECTRICITY ON 

 VEGETA TION 



SEVERAL months ago, it will be remembered, M. 

 Grandeau described to the Paris Academy experi- 

 ments made by himself and M. Leclerc at Nancy and 

 Mettray, whence it appeared that flowering and fructifica- 

 tion are retarded and impoverished if plants are excluded 

 from the inlluence of atmospheric electricity — as by being 

 inclosed in a metallic cage, or being near trees or other 

 objects which may carry off electricity of the air. 



Recently M. Naudin has repeated the experiments re- 

 ferred to, but with other plants and in a different climate, 

 and, without wishing to contradict the conclusions arrived 

 at for tobacco and maize (the plants that had been ex- 

 perimented with), he is led to regard the declarations 

 made as too general, inasmuch as his results are almost 

 exactly opposite to those obtained by MM. Grandeau and 

 Leclerc. 



It was at Antibes, in the large botanical garden formed 

 by the late Thuret (now Government property), that M. 

 Naudin made his experiments. He had an iron quad- 

 rangular cage made, covering a surface of fifty-one square 

 decimetres, and about one metre in height ; the frame 

 carried points above (like small lightning conductors), and 

 was covered with iron netting, the lozenge-meshes of this 

 being o'ogm. long by 0^054 m. broad (it intercepted more 

 light thanM. Grandeau's, but this is thought insignificant). 

 The cage was placed in a kitchen garden, and the plants 

 it was made to inclose were kidney beans, lettuce, tomato, 

 and herbaceous cotton (the last alone being sown as seed). 

 In the same garden, at 7 metres distance, plants as like 

 the others as possible were planted, and cotton seeds of 

 the same kind sown, but without a cage-cover. The soil 

 was perfectly homogeneous throughout, and all parts of 

 the plot were equally exposed to sunlight, dew, and rain. 

 The experiment began on May 25. 



-■ For a fortnight there appeared no sensible difference 

 beiween the two portions ; but about the middle of June 

 it was remarked that the plants of the cage were stronger 

 than those in the open air, and this difference became more 

 pronounced as time went on. The plants, indeed, pVo- 

 grcssed side by side in this sense, that the flowerings were 

 absolutely contemporaneous in the plants of the same 

 species ; and it was the same with fonnation and matura- 

 tion of fruits. But it was quite otherwise with the quantity 

 of vegetable matter produced in a given time and on the 



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same extent of soil, and this difference was entirely vcn 

 favour of the caged plants. 



We may take the figures tabulated by M, Naudin for 

 the tomato (examined August 14), as a good example o£ 

 this :— 



Tomato in Tomato under 



open air. the cage. 



Length of the principal stem ... 0"8om. ... I'om. 



Total weight of the plant cut 1 



at the level of the ground, V 2-072 kg. ... 3"7S4'^g- 



fruits included j 



Number of ripe fruits and i 



green fruits of all sizes 

 Weight of the whole of the 1 



fruit detached from the > I'Sokg. ... 2"i62kg, 



plant ) 



The other plants gave a similar testimony in favour of the 

 withdrawal of atmospheric electricity. Thus, the total 

 weights of the bean plants were respectively 142 gr. and 

 167 gr. ; and of the lettuce 337 gr. and 427 gr. The cotton 

 plants were weakly (as there had been no watering), but 

 their evidence was in the same line as that of the others. 



The injurious influence, which, according to M. 

 Grandeau's theory, trees exert on plants in their neigh- 

 bourhood, by withdrawing atmospheric electricity, is also- 

 considered by M. Naudin to be only a special case. 

 Besides, it is easy to ascribe to this withdrawal what iS' 

 merely the result of the shade cast by trees, and especially 

 of the exhaustion and desiccation of the ground by their 

 roots, which often extend to a great distance. On the 

 other hand there are many plants which seek the neigh- 

 bourhood of trees, and which even thrive only under their 

 shadow, and these, probably, must be adapted to a dimi- 

 nution of atmospheric electricity. At the Villa Thuret, 

 M. Naudin remarks, there are several lawns quite inclosed 

 1 by trees (pines, firs, cypresses, &c.), many of which are 

 ; adult and of pretty good size. These lawns contain, 

 besides their grass, thousands of anemones {A.pavoninay 

 i A. cyanea, A. sfcllati), some of pure race, others hybrid, 

 whose flowers present all shades of red, rose, purple, 

 white, and blue. The appearance is striking when the 

 flowers come out in March or April. The flowering is 

 not entirely contemporaneous throughout the lawn ; it 

 begins near the trees, and gradually extends to the middle 

 of the lawn ; the difference of time between these two 

 extremes being twelve to fifteen days. Moreover, th& 

 anemones nearest to the trees, in addition to their relative 

 precocity, are generally stronger and taller, and have 

 broader, perhaps more brightly coloured corollas, than 

 those in the middle of the lawn. 



From the observations described, M. Naudin is disposed 

 to think the question as to the influence of atmospheric 

 electricity on plants is complex, and far from being 

 decided as yet. This influence, in all probability, is^ 

 modified first by the very essence of the species, whiclv 

 must behave, in regard to atmospheric electricity, as to 

 other agents of vegetation, that is to say, in very diverse 

 manners ; then it is modified by climate, season, tem- 

 perature, degree of light, dry or wet weather, perhaps also 

 Ijy the geological structure or mincralogical composition o£ 

 the ground, the layers of which, superficial or deep, may 

 not be equally conductive of electricity. It is possible,, 

 lastly, that all tree species may not alike withdraw the 

 electric cffliivcs of the atmosphere, and this is a point 

 necessary to be determined. Until these numerous and 

 so obscure conditions of the problem before us are suffi- 

 ciently known, we should regard as premature any- 

 conclusion which is applied to the whole, or even only to- 

 the generality of the vegetable kingdom. 



THE DIFFUSION OF LIQUIDS 

 T is fortunate that various branches of the work with' 

 which Graham's name will always be connected 

 are now attracting the attention of physicists. At the 



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