May 3, 1883] 



NA TURE 



2 3 



tabular conspectus of the present known species indicated. — A 

 paper was read on the joint and separate work of the authors 

 of Bentham and Hooker's "Genera Plantarum," by George 

 Bentham. 



Zoological Society, April 17. — Prof. W. H. Flower, 

 LL.D., F.R.S., president, in the chair. — The Secretary read a 

 report on the additions that had been made to the Society's 

 Menagerie during the month of March, and called special atten- 

 tion to three Sirens (Siren lacertina) from South Carolina, pre- 

 sented by Dr. G. E. Manigault, C.M.Z.S., and to an American 

 Teetee Monkey of the genus Callithtix, which it was difficult to 

 determine satisfactorily in its living state, but which was cer- 

 tainly new to the Society's Collection. — Prof. Flower, F.R.S., 

 gave an exposition of the systematic classification of the Mam- 

 malia which he had recently prepared for use in arranging the 

 specimens in the Museum of the College of Surgeons, and in a 

 treatise on the subject of Mammals in the " Encyclopaedia 

 Britannica." — A communication was read from Mr. W. L. 

 Distant, containing the first of a series of contributions to an 

 intended monograph of the Homopterous family Cicadidae. In 

 the present paper the author gave the results of an examination 

 of the Cicadida? contained in the Dresden Museum (including 

 the specimens collected in Celebes by Dr. A. IS. Meyer), and 

 added the descriptions of other species belonging to the collec- 

 tions of Dr. Signoret and the author. Eleven species were 

 described as new from various localities. — Mr. Sclater read a 

 second paper on the birds collected in the Timor Laut or 

 Tenimber group of islands by Mr. H. O. Forbes, based on 

 additional specimens lately received. The avifauna of the group, 

 as indicated by Mr. Forbes' s collection, contained 59 species, of 

 which 22 were pecu\ l ar to these islands. — A communication was 

 read from Mr. F. Moore, F.Z.S., containing the first part of a 

 monograph of the butterflies belonging to the groups Limnaina 

 and Euplaina. 



Physical Society, April 14. — Prof. G. Carey Foster in the 

 chair. — New Members : Mr. W. F. Smith, Mr. George Forbes, 

 M. A. — Mr. W. Lant Carpenter read a paper on science demonstra- 

 tion in Board schools, in which he showed the drawbacks of the 

 present system of leaving science to be taught by the other 

 masters, and pointed out the marked advantages of the system 

 followed in Birmingham and Liverpool, where skilled lecturers 

 are appointed to go from school to school, and provided with an 

 assistant demonstrator and proper apparatus. Mr. Carpenter 

 advocated the extension of this sy-tem to London and the country 

 in general. He also showed the evil of the present system of 

 cramming for examinations. Dr. W. Carpenter pointed out the 

 advantages of object lessons in training the minds of children. 

 Dr. J. H. Gladstone stated that much had been done in London 

 to introduce object lessons, and that under the Mundella code 

 science would be taught in all Board schools to all the children, 

 who, however, might have the opportunity of choosing between 

 science and literature. Mr. \V. Baily, I'rof. Foster, and Prof. 

 W. Chandler Roberts, also advocated the system of special 

 science teachers. — Prof. Roberts then took the chair, and Mr. 

 Glazebrook explained a new polarising prism which he had 

 devised to prevent displacement of the pencil of rays. He also 

 showed how the curved diffraction-gratings of Prof. Rowland do 

 not always give perfect definition, and calculated the aberration 

 of the rays. — The Secretary then read a paper by Mr. W, H. 

 Stokes and Mr. A. E. Wilson on experiments on the viscosity 

 of saponine. When a disk is rotated in water, the resistance to 

 its motion is greatest when the plate is immersed a little below 

 the surface; but with saponine the viscosity is greatest when 

 the disk is not wholly, but only partially, immersed below the 

 surface. 



Entomological Society, April 4. — Mr. J. W. Dunning, 

 M.A., F.L.S., &c, president, in the chair. — The death of Prof. 

 P. C. Zeller of Stettin, one of the Honorary Members of the 

 Society, was announced and commented u; on. — Two new Mem- 

 bers were elected. — Mr. W. F. Kirby exhibited specimens of 

 Acridium succinctum, Linn., one of the most destructive species 

 of migratory locusts in India. — Prof. Westwood mentioned that 

 a Myriopod, Polydesmus co?nplanatns, Linn., had lately been 

 erroneously announced to be the cause of the potato disease. — 

 Rev. A. E. Eaton exhibited a patent revolving object-holder 

 used by mineralogists, which seemed likely to be useful to ento- 

 mologists also. — Mr. E. A. Fitch exhibited galls of Cecidomyia 

 1/iola, Loew., and of Aploneiira lentisci, Licht. — Sir S. S. Saun- 

 ders read a short paper on the classification of the germ-feeding 



races of fig-insects.— Mr. H. Goss exhibited specimens of 

 Pimeha augulata, Fabr., from the temple of the Sphinx at 

 Ghizeh.— Papers read :— On a small collection of Clavicorn 

 Coleoptera from North Borneo, by Mr. A. S. Olliff; Descriptions 

 of new genera and species of Hymen op! era, by Mr. P. Cameron ; 

 and notes on new or little-known species of Hymtnoptcra, chieflv 

 from New Zealand, by Mr. W. F. Kirby. 



Edinburgh 

 Royal Society, April 16. — Mr. Murray in the chair.— Mr. 

 Sang read a paper on some properties of the curve of simple 

 flexure, of which he gave neat geometrical demonstrations. A 

 simple construction was given for finding the radius of curvature 

 at any point and so affording a ready means for tracing the 

 curve. The related theorems in pendulum motion were also 

 given. — Dr. Knott communicated the results of electrometer 

 measurements of the resistance of electrolytes, which had been 

 carried out lately in the Edinburgh University Laboratory. The 

 method seemed capable of giving fairly accurate values. — In a 

 note on the electrical resistance of hydrogenised palladium, Dr. 

 Knott gave 1*51 as theratio of the resistances of the fully-charged 

 and pure palladium, the increase of resistance being very nearly 

 proportional to the charge for smaller charges. It was also 

 noted that the electromotive force bttween palladium and 

 platinum dipping in dilute sulphuric acid was greatly increased 

 for a slight charge of hydrogen, falling off again very markedly as 

 the charge reached its maximum. — Dr. Macfarlane, in a note on 

 plane algebra, or double algebra, as De Morgan named it, de- 

 monstrated with facility certain theorems that ordinarily require 

 considerable algebraic manipulation. — Prof. Tait presented a 

 continuation of his theoretical investigations on heat conduction 

 in heterogeneous bodies, as modified liy the Peltier and Thomson 

 effects, and gave the result of his investigation of the thermo- 

 electric position of pure ruthenium. On the diagram this metal 

 lies below iridium, to which it is in other thermoelectric respects 

 very similar. 



Berlin 



Physical Society, April 6. — Dr. Aron reported on the 

 accumulators, on which he has been making experiments for 

 several years past. Even before M. Faure's discovery, at the 

 time when M. Planle announced his first essays with the secondary 

 batteries, Dr. Aron was endeavouring to determine a convertible 

 electric element which, being theoretically possible, might also be 

 available for practical purposes. Ke fir-tof all tried to make the 

 Daniell chain convertible by using, instead of the two amalga- 

 mating fluids, hydrate of soda and sulphate of copper which do 

 not amalgamate, but without success. Like many others he 

 repeatedly tested Plante's already published statements regarding 

 convertible cells Vf plates of lead immersed in diluted sulphuric 

 acid, and which had to be charged in a very definitely prescribed 

 way, but without any certain results. The cell sometimes 

 became charged and discharged alternately, at other times not. 

 He accordingly tried plates of lead which had been previously 

 crystallised by corrosion, and these he found far more reliable. 

 He therefore constructed accumulators of plates of lead in sul- 

 phuric acid to which some nitric acid had been : dded. Although 

 more certain in their application, these were by no means equal 

 to the practical requirements. The favourable results of the 

 corrosion, as regarded the crystalline surface, a point also con- 

 firmed by Plante himself, was explained by Dr. Aron, who 

 attributed it to the disintegration of the metal. He there- 

 fore tried to increase the effect by using lead-sponge, but with- 

 out result. At that time he also thought of red lead, but made 

 no experiments with it, because he knew of no means of fixing 

 this powder to the lead plate conductor. It is now known that 

 M. Faure simply spread the red lead on the plates, and thus 

 produced his powerful accumulators possessing great storage 

 capacity. When this became known, Dr. Aron carried out an 

 extensive series of similar experiments in order to test its prac- 

 tical value, and even increase it. For the latter purpose he 

 introduced a substantial improvement by attaching the red lead 

 with collodium, which in the practical application of the chains 

 is of course out of the question. But as regards their practical 

 utility the accumulators have fallen far short of the hopes generally 

 entertained of them. The main difficulty lies in the thin plates 

 of lead which, when thickly covered with red lead, although 

 very effective, become corroded and useless afier being once 

 used, while thick plates, by the formation of sulphate of lead, 

 are rendered ineffective. As to the theory of accumulators, to 

 rightly understand it, it is very important to bear in mind the 



