January 4, 1894] 



NA TURE 



239 



Wiedema>in' ^ Ainmlen dei Physik tmd Chcmie, No. 12.— 

 On the change of in-ensity of light polarised parallel to the 

 plane of incidence by reflection on glass, by Paul Glan. The 

 light reflected from a glass prism was compared with that of a 

 petroleum flime by means of a polarisint; arrangement consist- 

 ing of a doubly-refracting prism and a Nicoll, between which a 

 Hofmann prism was placed in order to obtain a spectrum of 

 the reflected light. For crown glass, the ratio of the intensity 

 of the reflected to that of the incident light polarised in the 

 plane of incidence ranged from 0^055 at 30° to 0293 at 70", the 

 corresponding values for flint glass being 0070 and 0-327. — 

 Hydrodynamico acoustical investigations, by W. Konig. The 

 turning moment exerted by a moving column of a fluid upon a 

 disc suspended in it was subjected to experimenialinvestigation, 

 the torsion being balanced by a magnet. For very small velo- 

 cities of the column of air employed the form of flow was 

 uniform, but it was found impossible to keep it so in the case of 

 any considerable velocities. The contemplated determination 

 of all the dynamical conditions of Rayleigh's disc swinging in 

 an organ pipe, and its application to the absolute measurement 

 of sound intensities has not yet succeeded. — Experimental in- 

 vestigations concerning elastic longitudinal and torsional fatigue 

 in metals, by Louis Austin. The wires experimented upon were 

 23 m. long, and were suspended in the tower of the Strassburg 

 Physical Institute. It was found that longitudinal and torsional 

 fatigue phenomena are subject to similar laws. The fatigue 

 effects in copper, silver, and brass were, for torsion, as 7 : 3 : 2, 

 and for tension, as 4 : 3 : 2 approximately.— On the properties 

 of various modifications of silver, by H. Liidtke. — On thermo- 

 piles made of electrolytes and unpolarisable electrodes, by A. 

 Gockel. — On the magnetism of iron cylinders, by O. Groirian. — 

 On the pissage of electric waves through layers of electrolyte, 

 by G. Udny Yule. — On some modifications of the Thomson 

 quadrant electrometer, by F. Himstedt.— A calibrated electro- 

 dynamometer, by J. \V. Giltay. — A new method of measuring 

 self-potentials and induction coefficients of induction, by L. 

 Gr£Etz. 



SOCIETIES AND ACADEMIES. 



London. 



Chemical Society, December 7, 1893. — Dr. Armstrong, 

 President, in the chair. — The following papers were read : — An 

 apparatus for the extraction and estimation of the gases 

 dissolved in water, by E. B. Traman. — The magnetic rotation 

 of hydrogen chloride in different solvents, and also of sodium 

 chloride and of chlorine, by VV. H. Perkin. The author con- 

 firms his previous observations on this subject, and also shows 

 that isoamylic oxide and hydrogen chloride do not appreciably 

 interact. The magnetic rotation of hydrogen chloride in 

 isoamylic oxide solution is 2'245, in alcoholic solution 3'324, and 

 in aqueous solution 4 300. The magnetic rotations of sodium 

 chloride and of chlorine were also determined. — Analysis of 

 water from the Zem-Zem well in Mecca, by C. A. Mitchell. The 

 author gives analyses of waterolitained by the late Sir R. Button 

 from the holy «ell in Mecca. — The preparation and properties 

 of bromolapachol, by S. C. Hooker. Bromolapachol is 

 obtained by reducing dibromolapachone ; when dissolved in 

 sulphuric acid it yields bromo-/3-.apachone. The latter is con- 

 verted into bromo-a-lapachone by the action of hydrobromic 

 acid, whilst the reverse change occurs on dissolving the a-iso- 

 meride in sulphuric acid. — Studies on citrazinic acid (Part 

 ii.), by T. H. Easterfield and W. J. Sell. — The oxides of the 

 elements and the periodic law, by R. M. Deeley. The author 

 obtains a new periodic diagram by plotting the atomic weights 

 of the elements against the numbers obtained on dividing the 

 densities of the oxides by the atomic weights of the corre- 

 sponding elements. — The freezing p >ints of alloys in which 

 the solvent is thallium, by C. T. Heycock and F. \\. Neville. 

 The uiean depression of the freezing point by the addiiion of 

 one atomic proportion of gold, sdver, or platinum to one 

 hundred atomic proportions of thallium is 6 '31 ; the addition of 

 lead to thallium, however, raises the freezing point. 



Geological Society, December 20, 1893. — W. H. Hudle- 

 ston, F. R.S., President, in the chair. — The following com- 

 munications were read : — On the stratigraphical, lilhological, 

 and palaeontological features of the Gosau beds of the Gosau 

 district, in the Austrian Salzkammergut, by Herbert Kynasion. 

 The author, after referring to the previous literature of the 



subject, treated of the situation and physical aspects of the 

 Go-au valley, the distribution of the Gosau beds, their 

 stratigraphy, palaeontology, and geological horizon, and the 

 physical conditions under which they were deposited, and 

 a comparison was instituted between the Gosau beds and 

 the equivalent beds of other areas. He showed that 

 Hippurites occur at two horizons in the Gosau beds — 

 a hippurite-limeslone immediately above the basement- 

 conglomerate being characterised essentially by Hippurites 

 cornuvacciiiuin, which is overlain by Acl^roiidla- and Nerin,,:a- 

 limestones and an estuarine series, and above these was a second 

 hippurite-limestone characterised essentially by Hippurites 

 organisans. It was p linted out that Toucas similarly dis- 

 tinguishes two hippurite zones in Southern France, the lower, 

 characterised essentially by H. corniruacciniim, being placed by 

 him at the top of the Turonian system, whilst the second, with 

 H. orgatiisans, is refeired to the summit of the Scnonian ; and 

 the auihor gave reasons for regarding the Gosau zones as the 

 equivalents of those of the South of France, in which case the 

 Gosau beds will represent the uppermost Turonian and the 

 whole of the Senonian, i.e. the zones of Holaster planus, 

 Micraster, Marsupites, and Bdemnitella nnuronata in Eng- 

 land, whilst the upper unfossiliferous beds may be the equiva- 

 lents of the Danian beds. The strata are, on the whole, of 

 shallow-water origin, and were deposited in shallow bays in the 

 L^pper Cretaceous sea of Southern and Central Europe, on 

 the northern flanks of the Eastern Alp.=. Probably towards the 

 close of Upper Cretaceous times the southern area of the Gosau 

 district was cut off from the sea to form a lake-basin in which the 

 upper unfossiliferous series was deposited. Mr. W. Whitaker, Sir 

 John Evans, and Prof. J. F. Blake spoke on the subject of the 

 paper, and the author briefly replied. — Artesian boring; at New 

 Lodge, near Windsor Forest, Berks, by Prof. Edward Hull, 

 F.R. S. The boring described in this paper was carried down 

 from a level of about 220 feet above Ordnance datum through the 

 following beds : — London Clay and Lower London Tertiaries, 

 214 feet ; Chalk, 725 feet ; Upper Greensand, 31 feet ; Gault, 

 264 feet ; Lower Greensand, 7 feet. The chalk was hard, and 

 contained very little water ; but on reaching the Lower Green- 

 sand the water rose in the borehole to a height of 7 feet from 

 the surface. The author discussed the probability f the Lower 

 Greensand yielding a plentiful water supply in the Windsor 

 district. In the discussion that followed, the President said it 

 was satisfactory to learn that there was an area near West 

 London in which the Lower Greensand was full of water. He 

 thought that the section exhibited by the author explained 

 why It was full in that particular locality, for the rainfall about 

 the extensive area of Hindbead, which lay nearly due south, 

 must be considerable. Mr. W. J. Lewis Abbott and Mr. W. 

 Whitaker also spoke, and the author replied. — Boring on the 

 Booysen Estate, Witwatersrand, by D. Telford Edwards. An 

 account was given of a boring on the Booysen estate, situated 

 about two miles from Johannesburg, and about 5000 feet south 

 of the nearest point of outcrop of the "Main Reef" of the 

 Witwatersrand. The "Bird-Reefs" crop out generally at a 

 distance of 4000 feet south of the Main Reef The borehole, 

 1020 feet deep, passed through sandstones (often micaceous), 

 quartzites, and conglomerates, the last-named having a col- 

 lective thickness ot 91 feet 7 inches, the two thickest reefs 

 being respectively 26 and 22 feet thick. The dip of the beds 

 was 35'. Traces of gold were obtained. All the reefs were 

 highly mineralised, principally with iron pyrites, and belonged 

 to the " Bird- Reef " series which overlies the Main Reef. 



Paris. 

 Academy of Sciences, December 26. — M. de Lacaze- 

 Duthiersin the chair. — On the motion of Jupiter's fifth satellite, 

 by M. F. Tisserand. A calculation of the displacement of the 

 "perijove" of the fifth satellite due to the polar depression of 

 Jupiter shows that it would amount to 882' per annum, or one 

 revolution in nearly five months. It is hoped that powerful 

 instruments will enable observers to verify this. — On the pro- 

 paga'ion of electricity, by M. H. Poincarc. Starting from the 

 " telegraphists' equation," the author shows that when an elec- 

 trical disturbance proceeds along a wire, the head of the dis- 

 turbance moves with a velocity such that, in front of this head, 

 the disturbance is nil, as in the case of light and of plane sound 

 waves, with the difference, however, that the electric disturbance 

 leaves behind a residue of finite magnitude. — Numerical verifi- 

 cations relating to the focal properties of plane diffraction 



NO. 1262, VOL. 49] 



