Feb. lo, 1876] 



NATURE 



299 



force to the same degree and with the same facility as in aerated 

 water, and (2) is this very feeble polarisation really a decomposition 

 of the electrolyte ? To test the first point experiments were made 

 with a voltameter containing dilute sulphuric acid which had 

 been previously boiled, the voltameter being connected with a 

 Sprengel pump. The platinum plates were acted on by a very 

 small external electromotive force for one minute, and the effect of 

 the polarisation current due to this action noticed on an extremely 

 delicate galvanometer, the effect of the direct current employed 

 being also noted. After a series of observations had been made, 

 using different amounts of electromotive force, the dilute acid was 

 removed, and, after being thoroughly aerated, replaced in the vol- 

 tameter. On repeating the experiments with this one change in 

 the conditions, the results obtained were almost identical, from 

 which fact the author concludes that the first question may be 

 answered in the affirmative. With regard to the second, Mr. 

 Fleming believes that the assertion that polarisation is decompo- 

 sition of the electrolyte has never been called in question, and in 

 proof of it, describes an experiment sho%ving that when acidu- 

 lated water flows rapidly past slightly polarised plates, the cur- 

 rent which they give is very much diminished, while by causing 

 the water to flow slowly but slight change is produced. This 

 seems to indicate that there is something on the plates which can 

 be 'viped off mechanically, and it can only be a product of elec- 

 trolysis. — Prof. Foster, while admitting the accuracy of Mr. 

 Fleming's experiments, doubted whether he was justified in 

 definitely ascribing polarisation to chemical action. He thinks 

 that, even though the effect be proved not to be due to dissolved 

 air, we must look for some cause other than chemical action. 

 For it has long been acknowledged that the decomposition of 

 water requires an electromotive force considerably in excess of 

 that employed in these experiments. — Prof. Gladstone then 

 made a brief communication on the photography of fluorescent 

 substances. He exhibited several photographs taken of white 

 paper on which devices had been previously drawn, with solu- 

 tions of sulphate of quinine, oesculine, &c. , and one was taken 

 in the room. He remarked that the leaves of trees come out 

 dark in a negative, as they contain the fluorescent substance 

 chlorophyll, and suggested that the irregularities of colour 

 observed in photographs of oil paintings are probably due to the 

 intermixture of fluorescent substances in the paints used. — Mr. 

 Meldola referred to Prof. Vogel's experiments on the effect pro- 

 duced on the resulting photograph by the addition of a fluor- 

 escent substance to tie collodion, thereby increasing the sensi- 

 tiveness of the plate to particular rays. — Air. S. P. Thompson, 

 B.A., B.Sc, then gave a summary of the recent experiments 

 made in America by Mr, T. E. Edison, Dr. Beard, Prof. 

 Houston, and others upon the new phase of electric manifesta- 

 tion, the so-called etheric force. Tlus force is characterised by a 

 j faint spark, the only evidence, in fact, yet known of its exist- 

 1 ence. It may be obtained from the iron core of any electro- 

 magnet, or from a metallic bar slipped into the coil in place of 

 the core, but only when the battery circuit is being interrupted, 

 ; as may be done by introducing into the circuit an automatic con- 

 j tact breaker. The sparks so produced are apparently without 

 j polarity, devoid of chemical or physiological effect, affect neither 

 electroscopes nor galvanometers, and are stated to be retroactive, 

 i being exhibited v/hen one end of a wire through which they are 

 passing is brought round to touch the wire. A detailed descrip- 

 tion was then given of experiments on this force conducted in 

 the Physical Laboratory at South Kensington, some of which 

 were confirmatory of the published researches of the discoverers, 

 Avhile others were at variance with them. Great pains had 

 been taken to avoid leakage and to distinguish the effects 

 from those of ordinary induced currents. The batteries and 

 coils employed were insulated from the earth as well as from the 

 other portions of the apparatus. A bar of zinc placed above 

 the poles of a powerful electro-magnet, or within its coils, was 

 found to give better results than one of cadmium, which is 

 recommended by the discoverers. The sparks, which resembled 

 those of dynamic electricity, were of inappreciable length and 

 far too faint to ignite gun-cotton or illuminate a delicate Geiss- 

 ler's tube. It was also foimd that when a bar of zinc was 

 placed within the coil of an electro-magnet in the place of its 

 core and joined by a wire to the gas fittings of the building, 

 faint but distinct sparks could be drawn from any portion of this 

 wire by a second wire proceeding from another part of the gas 

 pipes. Another peculiar effect was observed when the wire 

 attached to one end of the zinc bar, and armed at its extre- 

 mity vrith a thin iron wire, was rubbed lightly against the other 

 end of the zinc bar — sparks being thus obtained, apparently 



passing firom one pole of the zinc bar, through the wire, to the 

 other. — Dr. Stone believed he had detected a distinct galvanic 

 taste on applying to the tongue the wire through which the" force " 

 was passing. — ^Prof. Foster suggested the use of an electro- 

 dynamometer to ascertain the electromotive force of the current 

 exhibiting these sparks, as its indications would be independent 

 of direction of current. 



Royal Microscopical Society, Feb. 2. — Anniversary Meet- 

 ing. — H. C. Sorby, president, in the chair. — The Report of the 

 Council and the Treasurer's Annual Statement of Accounts were 

 submitted to the Fellows, and showed that the Society was, at 

 the present time, in a satisfactory and prosperous condition. 

 Votes of thanks to the President and Cotmcil for their services 

 during the past year were proposed by Mr. J. Glaisher and car- 

 ried unanimously. The President then delivered the address, 

 the subject of which was the probable limit of the powers of the 

 microscope with reference to the ultimate size of the molecules 

 of matter, and the general bearing of the conclusions arrived at 

 upon the various germ theories. The following gentlemen were 

 elected as Officers and Council for the ensuing year : — President, 

 Henry Clifton Sorby, F.R.S. Vice-presidents: Charles Brooke, 

 F.R.S., William B. Carpenter, F.R.S., Rev. W. H. Dallinger, 

 Hugh Powell. Treasurer, John Ware Stephenson, F.R.A.S. 

 Secretaries : Henry J. Slack, F.G.S., Charles Stewart, F. L.S. 

 Coimcil : Robert Braithwaite, F.L.S., Frank Crisp, LL.B., 

 John E. Ingpen, Emanuel Wilkins Jones, F.R.A.S., William 

 T. Loy, Henry Lawson, M.D., John Millar, F.L. S., John 

 Rigden Mummery, F.L.S., John Matthews, M.D., Frederic H. 

 Ward, M.R.C.S., Francis H. Wenham, C.E., Charles F. White. 

 Assistant Secretary, W^alter W. Reeves. 



Institution of Civil Engineers, Feb. i. — Mr. Geo. 

 Rob. Stephenson, president, in the chair. — The paper read was 

 on the " Holyhead New Harbour," by Mr. Harrison Hayter, 

 M. Inst, C.E. 



Victoria (Philosophical) Institute, Feb, 7, Mr. C. Brooke, 

 F.R.S., in the chair. — After the election of new members it was 

 stated that during the past year thirty-three town, sixty-four 

 coimtry, and eighteen foreign and colonial members had joined. 

 A paper on " Heathen Cosmogonies compared with the Hebrew " 

 was read by the Rev. B. W. Savile. 



Philadelphia 

 Academy of Natural Sciences. — During 1875 a large 

 number of interesting papers and communications were read. — 

 Prof. Cope, in describing some vertebrate fossils from the Sas- 

 katchewan district, said that they gave indications of the future 

 discovery of a complete transition from Cretaceous to Eocene 

 life. The collection was chiefly remarkable for the great number 

 and variety of DLnosaurian remains. In another paper Prof. 

 Cope attempted to trace the evolution of the sectorial tooth of 

 Camivora from the simple quadri-tuberculate molar. He regards 

 the process as having consisted first in an addition of an anterior 

 cusp, and subsequently in the loss of internal and posterior cusps. 

 There had been a progressive extinction of genera with numerous 

 sectorial teeth, with an increasing specialisation of the sectorial 

 tooth in the surviving genera. Parallel with this change was 

 another, in the character of the tibio-astragalar articulation, which 

 he believed to indicate that the American Eocene Camivora were 

 plantigrade. In describing a new Mastodon from Santa Fe, 

 Prof. Cope divided the North American Mastodons into two 

 groups, the first having teeth with continuous cross-crests divided 

 by a fissure only, the other having transverse series of two or 

 more deeply-separated tubercles. Comparatively recently Prof. 

 Cope announced the discovery of vertebrae and pother remains 

 from Illinois, which appear to give the first definite indication 

 of the existence of FJiynchocephalous hzards in the western 

 hemisphere. — Prof. Eddy's contributions have referred chiefly 

 to Rhizopods and Vermes, and to Vertebrate Palasontology. He 

 described a remarkable Rhizopod, which he compared to the 

 reticular pseudopods of a Gromia separated from the body. At 

 one time it appeared as an extremely thin disc with a multitude 

 of minutely ramified and anastomosing pseudopods proceeding 

 from its edge. At other times it divided up into branches from 

 a trunk like a tree. Again it would assume the form of a cord, 

 and the jelly accumulating at some portion of it would run along 

 it like a drop of water on a piece of twine. A granular circula- 

 tion was observable as in Gromia. — Mr. T. G, Gentry presented 

 an important paper on the phylogeny of the Lepidoptera, sug- 

 gested by an anomalous development of certain larvae olAcronycta 

 oblinita, without the slightest attempt at cocoon-making. 



II 



