May 6, 1880] 



NA TURE 



21 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, April 22.— " Effects of Electric Currents on 

 the Surfaces of Mutual Contact of Aqueous Solutions. Jiy <-r. 

 Gore, LL.D., F.R.S. . , , „„ 



In the year 1859 I made the following experiments, for the 

 purpose of ascertaining whether visible movements, similar to 

 those obtained by passing an electric current through mercury 

 and an aqueous solution, could be obtained by passing a current 

 through the surface of mutual contact of two aqueous liquids 

 alone°-" I. A definite layer of oil of vitriol \yas placed beneath 

 a layer of distilled water weahly acidulated with sulphuric acid, 

 and the terminal wires of a voltaic battery immersed in the upper 

 liquid ; no visible movements occurred at the boundary line of 

 the two liquids. , . i j • 



" -7 A dense solution of cyanide of potas'ium was placed in 

 a small ''lass beaker, a few particles of charcoal sifted upon its 

 surface and a layer of aqueous ammonia, half an inch deep, 

 carefully poured upon it. A vertical diaphragm of thin sheet 

 gutta-percha «as then fixed so as completely to divide tne upper 

 liquid into two equal parts ; the vessel %vas placed m a strong 

 li4t and two horizontal platinum wire electrodes, from sixty-six 

 freshly-char'Ted Smee's cells, were immersed one-eighth of an 

 inch deep in the liquid ammonia on each side of the diaphragm. 

 A copious current of electricity circulated, but no movement of 

 the liquids at their mutual boundary line could be detected 

 (^-ee Five. Roy. Soc, vol. x., 1S60, p. 235, par. 9). 



Recently, also, I have made similar experiments, but in a 

 much more searching manner, in order to ascertain whether an 

 electric current, passing between two aqueous liquids, affects 

 their diffusion into each other. The essential difference in the 

 form of these experiments from that of the above-mentioned 

 ones w as to concentrate the action of the current upon a very 

 much smaller surface of contact of the liquids, and thus render 

 any visible effect upon their diffusion more manifest. 



After making several forms of apparatus, in order to obviate 

 certain difficulties of manipulation which arose and were fatal 

 to success, I found that, when an electric cuixent was passed 

 between the surfaces of mutual contact of certain aqueous solu- 

 tions of different specific gravities, the boundary line of contact 

 of the two liquids became indefinite at the surface where the 

 current passed from the lighter into the heavier solution, and 

 became sharply defined where the current left the heavier liquid 

 and re-entered the lighter one ; and that on reversing the direc- 

 tion of the current several times in succe>sion after suitable 

 intervals of time, the?e effects were reversed with each such 

 change. Also, in various cases in which the contiguous boun- 

 darylayers of the two liquids had become mixed, the line of 

 separation of the two solutions became, by the influence of the 

 electric current, as perfect as that between strata of oil and 

 water lying upon each other. In rarer cases two such distinct 

 lines of stratification appeared. Other new phenomena were 

 also observed. ^ . . 



As I have sought, without success, for any record of previous 

 discovery of essentially similar effects, and as it is evident that 

 those I have observed belong to a large class of simUar pheno- 

 mena, I beg leave to take the earliest opportunity of submitting 

 tills brief statement to the Royal Society. , , ,^ 



" Revision of the Atomic Weight and Valence of Aluminium,' 

 by |. W. Mallet, F.R.S. 



The general mean from all the experiments, if all be included, 

 is Al = 27'032, with a probable error for this mean of ± -0045. 

 If Series I, B, be excluded, the mean of all the remainmg 

 twenty-five experiments is Al - 27-019, with a probable error 

 of i -0030. , . . ,1 



The general result adds, the author hopes, aluminium to the, 

 unfortunately still limited, list of those elementary substances 

 whoie atomic weights have been determined within the limits of 

 ijrecision attainable with our present means of experiment. 



This result also adds one to the cases already on record of the 

 numbers representing carefully determined atomic weights 

 approaching closely to integers, and leads the author to say a 

 word on the reconsideration of "Front's Law." Taking the 

 following eighteen elements as the only ones of which the atomic 

 weif'hts may be fairly considered as determined, with reference 

 to hydrogen, with the greatest attainable precision, or a near 

 approach°thereto, namely, oxygen, nitrogen, chlorine, bromine, 

 iodine, sulphur, potassium, sodium, lithium, silver, thallium, 

 aluminium, carbon, phosphorus, barium, calcium, magnesium, 

 and lead, and making a reasonable allowance for the errors of 



the determinations, he calculates the probability that nine of 

 those numbers should lie, as they are found to do, within o'l of 

 mtegers, supi osing the value of the true numbers to be deter- 

 mined by chance, and finds it only as I to 235-2. The exact 

 figure for the chance will of course depend upon the limit of 

 en-or taken ; but the above example seems sufficient to show- 

 that not only is Prout's law not as yet absolutely overturned, but 

 that a heavy and apparently increasing weight of probability in 

 its favour, or in favour of some modification of it, exists, and 

 demands consideration. 



Chemical Society, April 15.— Prof. H. E. Roscoe, presi- 

 dent, in the chair. — The following papers were read, — On the 

 lecture illustration of chemical curves, by E. J. Mills.^ The 

 author has contrived an apparatus for exhibiting the variations m 

 the actions of sulphuric acid on zinc and sodic hydrate on 

 aluminium, produced by alterations (i) in the strength of the 

 solution, (2) in the time during which the action is allowed to 

 proceed. The gas evolved is collected in a series of inverted 

 glass cylinders filled with water, arranged at equal distances. 

 The surfaces of the water levels after the gas has been collected 

 form a curve.— On the analysis of organic bodies containing 

 nitrcen, by W. H. Perkin (continued). The author finds that 

 a mixture of precipitated manganic oxide and potassium chromate 

 (containing 10 per cent, of bichromate) in about equal parts kept 

 at a temperature of 200^-250° C. is preferable to the chromate 

 alone for absorbing the oxides of nitrogen.— On the volatilisation 

 of solids in vacuo, by W. D. Herman. The author has obtained 

 adamantine colourless transparent crystals of phosphorus by volati- 

 lising ordinary phosphorus in vacuous glass tubes in the dark. 

 The crystals may be as long as 8 mm. ; they turn red in sun- 

 li-rht. Similar experiments have also been made with sulphur, 

 selenium, &c.— On the determination of nitric acid as nitric 

 oxide by means of its reaction wdth ferrous chloride, by R. 

 Warincton. The author describes an apparatus for the above 

 purpose. The air is expelled by carbon dioxide, the nitrate 

 heated by a calcium chloride bath to 1350 C, and the mtric oxide 

 measured as gas ; organic matter does not affect the results.— On 

 the six possible isomeric dibromtoluols and other of the bromo- 

 and bromonitro derivatives of toluol related thereto, by R. INevile 

 and A Winther. The authors criticise the results of \V robleosky, 

 7fl/H- 1870, 52S, and 1871, 450. and establish the conclusion 

 that in such bodies the bromine never occupies a position which 

 is "meta" to the amido group. 



Zoological Society, April 20. —Prof . W . H. Flower, F.R.S., 

 president, in the chair.— Prof. Owen, C.B., read descriptions 

 of some new and rare Cephalopoda, to which were added notes 

 on the occurrence of gigantic species of this group.— A second 

 paper was read by Prof. Owen on the external and structural 

 characters of the male of Spinda aus/rahS.-Di: M. Watson 

 read a paper on some points in the anatomy of the Proboscidea, 

 in which he described the structure of the female organs of the 

 Indian elephant, as observed in a specimen recently dissected.— 

 Lieut -Col H H. Godwin-Austen read a paper on the land- 

 moUuscan genus Cinrsia of Gray, and made remarks on its 

 anatomy and on the form of the "capr.Wus" of Lister or the 

 spermatophore, as developed in species of this genus of Indian 

 HelicidK — A communication was read from Dr. Jlax Schmidt 

 on the duration of life of the animals in the Zoological Garden 

 of Frankfort-on-the-Main.- A communication was read from 

 the Rev O P Cambridge, C.M.Z.S., contaimng descriptions 

 of new or little-known spiders of the genus^;;^'»-^a'c-^.-A com- 

 municition was read from Mr. Edgar A. Smith con aimng an 

 ac ount of a collection of the sheUs of Lake Tanganyika andof 

 the neighbourhood of Ujiii, Central Africa, made by Mi. E. C. 

 Hore Sf the London Missionary Society. Twentyone species 

 were represented in this collection, amongst which were tw^o new 

 genericto-ms proposed to be called T:pMia horet and Ncodauma 

 tauganyiccnsis. ^ T^ c 



Geological Society, April 14. -Robert Ethendge, F R.S., 

 Di-elident, in the chair. ColviUe Brown, John N. Dufty, and 

 Seo-ge Benjamin Nichols were elected Fellow-s of *« So^^ j 

 —The following communication was read '.—On a new Ihei 

 dont Reptik (CliorhhoJon orenburgensis, Twelveti'.) from the 

 Unoer Pe mian S.andstone of Kargalinsk, near Orenburg in 

 Somh Eas mr Russia, by W. H. Twelvetrees, F.L.S. The 

 nWe measu es are cupriferous, and rest on limestone %Mth 

 Zechstern fos its. Associated with the remains of Saurians and 

 Labyrinthodonts are Calamites, Lepidodmdron, Aroides crass,. 

 sPta, Conifers, and a Unio. The specimen noticed m this 



