November 12, iyo?<J 



/J A rURE 



59 



this temperature oscillation may exist even when the dis- 

 continuity is not pronounced. The attempts to measure 

 the ordinary seiche in Loch Garry were not very successful, 

 the seiches being irregular and diflficult to measure. The 

 periods indicated were 10-5-1 i-i minutes for the uninodal 

 and about 5-5 minutes for the binodal. — The discharge of 

 water from circular weirs and orifices : G. H. Gulliver. 

 The elliptic integral which gives the discharge was com- 

 puted graphically, and the results compared with experi- 

 ment. Curves were drawn showing the relation between 

 the discharge and the head. The observational and 

 theoretical curves were of the same form, and were prac- 

 tically straight for heads between the centre and top of 

 the circular aperture. This suggests that a circular weir, 

 if kept more than half full yet not completely drowned, 

 might be usefully employed in gauging streams. With the 

 orifice of 23 inches diameter used in the experiments, the 

 discharge in gallons per minute was given by the formula 

 1 1 H — 0-8, where H is the head in inches above the lowest 

 point of the orifice. — Dissymmetrical separations in the 

 Zeeman effect in tungsten and molybdenum : Dr. Robert 

 Jack. The relative intensities of the components of a 

 Zeeman triplet depend upon polarisation effects of the 

 grating in relation to the polarised state of the light. The 

 experiments showed that concurrently with the change in 

 the intensities of triplets for different parts of the spec- 

 trum there is a change in the type of dissymmetry. As 

 the middle component passes through its minimum value 

 there is a change from the normal dissymmetry (middle 

 component nearer the red side component) to the abnormal 

 dissymmetry (middle component nearer the violet side com- 

 ponent). The dissymmetry could not be entirely accounted 

 for by the angular position between the lines of the grating 

 and the planes of vibration of the components. Voigt's 

 theory based on the presence of couplings between elec- 

 trons of different vibration period seemed to explain the 

 phenomena sufficiently. — A question in absorption spectro- 

 scopy : Dr. R. A. Houstoun and A. S. Russell. The 

 question is as to th^ effect of mixing two coloured solu- 

 tions upon the absorption spectrum of each. Observations 

 by Melde, Bostwick, Kriiss, and Formdnek seemed to 

 indicate a shift of the absorption bands ; but Schuster 

 pointed out that a -hift of this nature would be observed 

 if, instead of mixing, the one solution was placed behind 

 the other. Any other change indicated by theory would 

 be too small to be appreciable. The experiments described 

 in this paper were made by a differential method, so that 

 the efTect with the solutions in line, but not mixed, could 

 be immediately compared with the effect when they were 

 mixed. The conclusion come to was that there is no 

 evidence for the existence of an effect of the kind described 

 by the experimenters named above. 



P.\RIS. 



Academy of Sciences, November 2. — M. Kmile Pic.ird in 

 the chair. — Spectroscopic researches on the Morehouse 

 comet, 19081; : H. Deslandres and A. Bernard. The 



observations were commenced on October 14, ten days 

 after those of La Baume-Pluvinel. Owing to the abnormal 

 proportion of the blue to the ultra-violet rays, this comet, 

 which w<as by eye observations of the sixth magnitude, 

 appeared photographically of a higher magnitude. No 

 trace of the hydrocarbon bands usual with comets could 

 be detected ; a continuous spectrum appeared on all the 

 plates from October 14 onwards, but its intensity is 

 relatively less than in the Daniel comet of last year. A 

 table is given showing the wave-lengths and intensities 

 of the principal condensations of the nucleus. Two ultra- 

 violet bands of the cyanogen group are present, together 

 with some lines of unknown origin, previously observed 

 in Daniel's comet. — The pumice of the volcanic massif 

 of Mont-Dore : A. Lacroix. — The value of the invariant 

 p for a class of .algebraic surfaces : L. Remy. — The 

 influence of pressure on the ionisation produced in gases 

 by the X-rays. The saturation current : E. Rothe. A 

 study of the influence of pressure on ionisation pheno- 

 mena in general. From pressures of O'l to 05 atmosphere 

 the intensity of the saturation current is proportional to 

 the pressure. The precautions found necessary for the 

 regular working of the Crookes's tube are detailed. — Com- 



N'O. 2037, VOL. 79] 



pensation electrometers and electroscopes : M. Hurmu- 

 zescu. The apparatus described, and of which a diagram 

 is given, is capable of measuring potentials down to- 

 0-0 1 volt. — An apparatus for receiving radio-telegraphic 

 time signals on board ship : C. Tissot and F^lix Pellin. 

 A thermoelectric detector is employed, capable of respond- 

 ing to waves of one determined wave-length only. — A new 

 determination of the mechanical equivalent of heat: V. 

 Cremieu and L. Rispait. The heat produced was 

 measured at constant temperature in a Bunsen ice calori- 

 meter, the recent determinations of M. Leduc on the 

 densities of the ice and water being used. The mean value 

 obtained for J was 4-1851X10' ergs, with an experimental 

 error of less than 1/1500. — The separation of tungstic acid, 

 and silica : Paul Nicolardot. The method is based on 

 the volatilisation of the tungsten by heating the mixture 

 of tungstic acid and silica to 440° C. in a current of 

 partially dried air and chloroform vapour. — The determina- 

 tion of the atomic weight of the simple ponderable sub- 

 stance, pantogen : G. D. Hinrichs. A fundamental 

 material, pantogen, of atomic weight 1/128, or 0-007813, is 

 assumed, and a theory developed of the weight and 

 geometrical form of the atoms of hydrogen, helium, 

 nitrogen, oxygen, and fluorine. — The phosphides of zinc : 

 Pierre Jolibols. Zinc and red phosphorus were heated 

 to a red heat in a crucible until phosphorus vapours ceased 

 to be evolved. The resulting phosphide was separated 

 from the excess of zinc by three methods :— the volatilisa- 

 tion of the zinc in a vacuum at 600° C, the solution oi 

 the zinc in mercury, and the action of fuming nitric acid. 

 The same phosphide is left by all three methods of separa- 

 tion, and its composition corresponds to the formula 

 ZnjP,. This phosphide with dilute hydrochloric acid gives 

 a verv pure phosphoretted hydrogen. The preparation and 

 properties of ZnP, are also' described. — The hydrolysis of 

 perchloride of iron ; the influence of neutral salts : G. 

 Malfitano and L. Michel. Solutions of ferric chloride to 

 which potassium chloride has been added present the 

 phenomena of the colloidal state more rapidly and to a 

 greater degree than solutions of pure ferric chloride. 

 Other chlorides (sodium, barium, ammonium, magnesium) 

 behave in a similar manner. — Aloesol, a complex phenol 

 prepared with the aid of certain aloes : E. Legrer. The 

 tetrachloro-derivative of a new phenol is obtained by the 

 action of hydrochloric acid and potassium chlorate on Cape 

 aloes. — The fixation of different derivatives of the same 

 colouring matter, and an explanaJ:ion of dyeing : L. Pelet- 

 Jolivet and N. Andersen. The' experiments cited confirm 

 the theory of dyeing of Freundlich and Loser. — Glycocholic 

 acid : Maurice Picttre. The method described is capable 

 of giving a yield of 60 per cent, to 75 per cent, of the 

 bile as glycocholic acid, and the product is not con- 

 taminated with taurocholic acid, an advantage over the 

 usual methods of separation. The chemical and physical 

 properties of the purified acid are given, together with 

 the results of some experiments on the toxic power of 

 sodium glycocholate. — The colloidal properties of starch 

 and the unitv of its constitution : Eugfene Fouard. — The 

 oidium of the oak : Paul Hariot. This disease of the oak 

 has become widelv distributed in France during the last 

 vear, and the dry north-east winds appear to have 

 contributed to the spreading. All the native trees may 

 be attacked, but the American oak appears to be 

 immune.— The discovery of coal in Madagascar by 

 Caotpin Colcanap : Marcellin Boule. Layers of coal, of 

 a thickness of 0-3 to 0-5 metre, have been discovered in the 

 neighbourhood of B^n^nitra.— Report of the wireless 

 telegraphy committee of the .Academy of Sciences : 

 Bouquet de la Grye. 



DIARY OF SOCIETIES. 



THURSDAY, Novembek 12. 

 {OYAt. SociETV, at4.30.— The Charae^ on Ions in Gases, and ll 

 of Water Vapour on the Molion of Negaiive Ions : Prof. J. S^ T^ 

 F.R.S.—The Charges on Ions pr-'duced by Radium : C. E. Haselfoot, 

 —The Occlusion of the Residual Gas and the Fhiorescence of the Glas- 

 Walls of Crookess Tubes : A. A. Campbell S«-inton.— .\n Investlganor 

 on the .\naIomical Structure and Relationships of ihe Labyrinth in th< 

 Reptile, the Bird and the Mammal : Dr. .\. A. Gray. -The Natura 

 Mechanism for Evoking ihe Chemical Secretion o( the Stomach (Prelim 

 inary Communication! : Dr. J. S. Edkins and Miss M. Tweedy.- Furthei 



Effect 



