Feb. 28, 1884] 



NA TURE 



423 



ever, capable of throwing additional light on the value of this 

 electrolytic n elhod. It is well known that water forms with 

 CuSOj a definite hydrate, CuS0j5H„0. Now, if in the elec- 

 trolytic process the water of hydration suffers decomposition 

 along with the CuSOj, the primary chemical changes might be 

 expected to be — 



Positive pole Negative pole 



(A.) CuSOjSHoO = SO3 + Og Cu + sHjj. 

 But, if the water of hydration takes no more part in the elec- 

 trolysis than the water of solution does, then the chemical 

 changes would manifestly be- 



Posi 



i pole 



-f o 



Negative pale 



Cu. 



(B.) CUSO4 = SO; 



Of course the collateral action — 



Positive pole Negative pole 



HjO =0 H„ 



might also take place, but this would occur only with currents of 

 considerable density. The method is obviously capable of 

 discriminating between these two actions, even supposing a 

 con-iderable quantity of the electrolyte travelled unchanged 

 from one compartment of the apparatus to the other. For, in 

 the first case, either free hydrogen would be liljerated at the 

 negative pole, or free acid formed in the negative compartment, 

 equal to five-sixths of the total copper deposited ; the free acid, 

 and the five-sixths of the total capper, to which it is equivalent, 

 being produced by the chemical action 5H2 -f 5CUSO4 = Ctij 

 + 5H.,SOj ; equation A becoming — 



Positive pole Negative pole 



CuSOj, 5H,,0 -f 5CUSO4 = So7+"o7 'Cu6--f SH2SO4. 



On the other hand, if the action was in accordance with B there 

 would be only a deposition of copper on the negative electrode, 

 and no formation of free acid in the negative compartment. In 

 the annexed table the results and particulars of the authors' 

 experiments are set out : — 



Free sulphuric acid 



In none of these experiments was there any trace of hydrogen 

 visibly e-caping from the negative electrorte, while, as will be 

 seen from the table, there was no free acid formed in the 

 negative compartment till two hours or more had elapsed. By 

 that time some admixture in the horizontal part of the apparatus 

 might reasonably be expected, but even in the greatest instance 

 it is small as compared with the amount of salt decomposed. 



Similar experiments were made with the sulphate of zinc, 

 with similar results, no hydrogen being evulved, and little or no 

 sulphuric acid appearing in the negative compartment. 



\Ve conclude, therefore, that it is not possible to determine 

 the composition, or even to show the presence of a hydrated salt 

 in aqueous sohition by means of this electrolytic method. 



Zoological Society, February 5. — Prof. W. H. Flower, 

 F.R.S., president, in the chair. — Mr. F. Day, F.Z.S., exhibited 

 and made remarks on a specimen of a Dog-fish, of which the 

 entire interior had been eaten out by Isopod Crustaceans of the 

 genus Conilera. — Mr. G. F. Butt, F.Z.S., exhibited two speci- 

 mens of a singular variety of the Red Grouse, shot in West- 

 moreland. — A communication was read from Mr. W. Leche, of 

 the University of Stockholm, in which he gave an account of a 

 collection of bats from Australia. Two new species were 

 described and named respectively Nyctinomus petersi and N. 

 albidus. — Mr. Sclater read some notes on the Lesser Koodoo 

 (Strepsiceros imberbis of Blyth), with a view of confirming the 

 distinctness of this Antelope from its larger relative, Strepsiceyos 

 kudu. — A communication was read from Mr. R. Bowdler 

 S harpe, containing the description of a new species of Bush- 

 Shrike of the geims Laniarius, based on a specimen obtained in 

 Ashantee by Mr. Godfrey Lagden, which he proposed to call L. 

 lagdeni, after its discoverer. — Prof. Flower made some remarks 

 on the chief points of interest exhibited by the Burmese Elephant 

 now in the Society's Gardens. 



Geological Society, February 6.— J. W. Hulke, F.R.S., 

 president, in the chair. — Edward John Dunn was elected a 



Fellow, and Dr. Joseph Szabo, of Buda-Pest, a Foreign Member 

 of the Society. — A delta in miniature — twenty-seven years' 

 work, by T. Mellard Reade, F.G.S. The author described a 

 delta deposit, which, during a period of twenty-seven years, 

 had formed in the Rake reservoir (Kivington Waterworks) from 

 materials brought down by a stream of that name. The reser- 

 voir at this part was divided by a road, water communication 

 being maintained by a culvert, once eight feet high, now almost 

 silted up. The author described the stratification of these deltas : 

 that near the influx of the Rake consisted of peaty matter, gritty 

 sand, gravel, shingle, and boulders of Millstone-grit up to about 

 one foot diameter ; the other chiefly of fii.e sand with some 

 peaty matter. The former covered an area of 2508 yards, with 

 an average thickness of 2 yards ; the latter, an area of 430 yards, 

 with an average thickness of 3 yards. These materials had 

 come from the drainage-area of the Rake. This is estimated as 

 1 •176 square mile, and the delta being estimated at 6306 cubic 

 yards, and the time being 27 years, gives, as the annual rate of 

 denudation over the whole area, 1/432 inch per annum, or i foot 

 in 5184 years. The mean rainfall of the Rake Brook watershed 

 for the last ten years was 49'57 inches per annum. In this cal- 

 culation no account is taken of the finer materials which have 

 doubtless been distributed over the rest of the bed of the 

 reservoir. The author pointed out that this rate of deimda- 

 tion was rather more rapid than that of the Mississippi (i foot in 

 6000 years), and that the arrangement of the materials under the 

 varying condition of the stream illustrated the phenomena of 

 larger deltas. — On the nature and relations of the Jurassic de- 

 posits which underlie London, by Prof. John W. Judd, F. R.S., 

 Sec. G.S., with an introductory note on a deep boring at Rich- 

 mond, Surrey, l)y CoUett Homersham, A.M.Inst.C.E., F.G.S. 

 An account of this appeared in Nature, vol. xxix. p. 329. 



Sydney 



Linnean Society of New South Wales, December 27, 

 1S83.— C. S. Wilkinson, F.G.S., F.L.S., president, in the 

 chair. — The following papers were read : — On the localities of 

 some plants from the southern parts of New South Wales, by 

 Baron von Miiller, K.C.M.G., F.R.S., &c.— Descriptions of 

 Australian Microlepidoptera, No. 10, by E. Meyrick, B.A. 

 This is a continuatior of the CEccophoridte of Australia, and 

 deals with the genera Philobota, Leistomorpha, Compsotropha, 

 and Eriodyta. About seventy new species are described. — Notes 

 on the geology of the southern portion of the Clarence River 

 basin, by Prof. Stephens. This was an account of the sugar 

 lands of the Clarence, explaining the mode of their formation, 

 and their relation to the Coal-measures which underlie them un- 

 conformably. The period of deposition of these latter rocks was 

 also considered, and their immediate superposition upon the 

 vertical Siluro-Devonian slates and quartzites described. The 

 existence of a great north and south fault at the present outcrop 

 of these rocks was demonstrated, and the probable existence of 

 others near the present coast-line supported by various con- 

 siderations. 



Paris 



Academy of Sciences, February ii. — M. RoUand in the 

 chair. — Note on Faraday's law (continued), by M. Ad. Wurtz. 

 — Remarks on the slight horizontal and vertical vibrations of the 

 ground observed at Abbadia, near Hendaye, for several years 

 past, by M. d'Alibadie. — Note on the meteorite which fell at 

 Grossliebenthal, near Odessa, on November 7/19, 1881, by M. 

 Daubree. In its outward appearance and microscopic structure 

 it presents all the characters of the typical meteorite which fell 

 at Luce, Sarthe, on September 13, 1768, and which is already 

 represented in the collection of the Natural History Museum, 

 Paris, by fifty-four other identical specimens. — Description of an 

 absolute calculating actinometer invented by M. G. A. Him. 

 This delicate instrument is based on the principle of steam con- 

 densers, that a saturated vapour contained in a closed vessel 

 acquires a tension corresponding with the minimum temperature 

 of the walls of the receptacle. So far it acts with perfect satis- 

 faction, and the inventor will report the numerical results as soon 

 as he feels that they are absolutely trustworthy. — Report on the 

 thunderstorms oliserved in France during the first six months of 

 the year 1883, with complete and detailed tables of all the 

 I accidents caused by lightning in every part of the country during 

 that period, communicated by the Minister of the Postal and 

 Telegraph Department. The fatalities amounted altogether to 

 nine persons and seventy-eight animals killed, and about fifty 



