May 



1922] 



NA TURE 



631 



Societies and Academies. 



Paris. 

 Academy of Sciences, April 10. — M. Emile Bertin 

 in the chair.— E. Borel : Arithmetical definition of 

 a distribution of masses extending to infinity and 

 quasi-periodic, with average density zero. — I. Fred- 

 holm : An application of the theory of integral 

 equations. — J. Andrade : The mechanical problems 

 of regulating springs. — P. Vuillemin : A new species 

 of Syncephalastrum : the affinities of this genus. — 

 E. Vessiot : The conformal geometry of systems of 

 circles. — M. Janet : The invariant canonical forms 

 of algebraical and differential systems. — T. Carleman : 

 Demonstration of a theorem of M. Borel. — A. Myller : 

 Remarks on M. Carleman's note. — A. Myller : Some 

 properties of ruled surfaces in connection with 

 the theory of paralleUsm of M. Levi-Civita. — H. 

 Chretien and P. Ditisheim : An electrochronograph 

 recording the time, in figures, to hundredths of a 

 second. — M. Sauger : A remarkable coincidence in 

 the theory of relativity.— MM. Berloty and Combier : 

 The eclipse of the sun of March 28, 1922, observed 

 at the Observatory of Ksara (Syria). — I. Tarazona : 

 Observation of the annular eclipse of the sun of 

 March 27-28, 1922, made at the astronomical Ob- 

 servatory of Valencia (Spain). — J. Guillaume : Ob- 

 servations of the sun made at the Lyons Observatory 

 during the fourth quarter of 1921. Observations 

 were possible on 76 days during the quarter. The 

 results are given in three tables showing the number 

 of spots, their distribution in latitude, and the dis- 

 tribution of the faculaj in latitude. — H. Chaumat : 

 An arrangement permitting the elimination and 

 determination of the correction factor of wattmeters. 

 — C. Deve : The noise caused by aeroplanes. The 

 pitch of the sound heard as an aeroplane is passing 

 overhead varies according to the distance of the 

 observer's ear from the ground, rising about two 

 octaves when the ear is lowered to about eight inches 

 from the soil. Possible causes of this phenomenon 

 are discussed. — J. Galibourg and F. Ryziger : A 

 method of recognising cultivated Japanese pearls. 

 The hole usually drilled in the pearl for attaching 

 to an ornament is utilised. A mirror is formed by 

 placing a minute drop of mercury in this hole, the 

 pearl is illuminated from the side and the structure 

 examined microscopically. Differences between the 

 natural and cultivated pearl are brought out in 

 this way, and reproductions of photographs illustrat- 

 ing the differences observed are given. — P. M. 

 Monval : The preparation of ammonium chloride. 

 Determinations of the solubilities in saturated solution 

 of sodium chloride, sodium carbonate, ammonium 

 chloride, and ammonium carbonate, singly and in 

 combination, the results being summarised on a Le 

 Chateher square diagram. — P. Riou : The velocity 

 of absorption of carbon dioxide by alkaline solutions. 

 A contribution to the experimental study of the 

 ammonia-soda process.— C. Cheneveau : An applica- 

 tion of the optical method of determination of the 

 solubility of one liquid in another. — R. Fosse and 

 A. Hieulle : The tendency of formaldehyde to form 

 liydrocyanic acid by oxidation in an ammoniacal 

 silver solution. Formaldehyde was oxidised in 

 strongly ammoniacal solutions containing ammonium 

 chloride and silver nitrate by a large excess of 

 potassium permanganate. Working with 10 milli- 

 grams of formaldehyde in each experiment, a yield 

 of 30-36 per cent, of hydrocyanic acid was obtained. 

 — A. Lanquine : The direction and dislocations of 

 the Cheiron strata to the south of the upper Est^ron, 

 up to the high valley of Loup (Maritime Alps). — 

 A. Guebbard : Remarks on the last Proven9al earth- 



NO. 2741, VOL. 109] 



quake. — P. Garrigou-Lagrange : Great movements 

 of the atmosphere and weather prediction. — E. Gain : 

 The ultra-maximum temperature supported by the 

 embryos of Helianihus annuus. If the seeds are 

 gradually dried and heated by stages, with interposed 

 periods of cooling, the seed can survive exposure to 

 much higher temperatures than has been hitherto 

 supposed. One lot of seeds submitted to this treat- 

 ment gave 80 per cent, germination after a final 

 exposure to 145° C, but this result was exceptional ; 

 another lot of seeds gave only 2-5 per cent, of 

 germinations after the same exposure. — A. Petit : 

 Concerning the " awakening " of arable earth. In 

 a recent paper A. Lumi^re has pointed out the 

 favourable effect on soil of a thorough washing with 

 water. This washing acts as though it removed 

 products opposed to the germination of seeds. The 

 author directs attention to the fact that he published 

 similar observations in 1909. — W. Kopaczewski : The 

 differentiation of phenomena of shock by contact. — 

 R. Bayeux : Maximum respiration at very high 

 altitudes. An account of experiments on two 

 subjects at Chamonix (1050 metres), the Vallot 

 Observatory on Mont Blanc (4370 metres), and at 

 intermediate heights. — W. Koskowski : Nicotine and 

 the inhibitory nerves of the heart. Nicotine does 

 not act on the heart by the intermediary of the 

 pneumogastric nerve, but directly on the intracardiac 

 ganglia. — J. Mawas : The lymphoid tissue of the 

 spiral valve of the middle intestine of Ammocoetes 

 branchialis and its morphological significance. — 

 A. Dehorne : The muscular histolysis and phago- 

 cytosis in the coelom of the Nereids at sexual maturity. 

 — K. Abrest : The toxic index of illuminating 

 apparatus, of heating apparatus, and of explosion 

 motors. The ratio of carbon monoxide to carbon 

 dioxide produced in any form of lighting or heating 

 apparatus is termed the toxic index. This magnitude 

 has been estimated for various forms of lighting 

 burners and radiators, and in the exhaust of explosion 

 motors. 



Academy of Sciences, April 18. — M. Emile Bertin 

 in the chair. — E. Goursat : The problem of the 

 thrust of earth. It is shown that the partial differ- 

 ential equations of M. Boussinesq, modified by M. 

 Remoundos, can be reduced to an integrable form. — 

 E. Borel : Physical hypotheses and geometrical hypo- 

 theses. — E. Aries : The maximum of the latent heat 

 of evaporation. — G. Valiron : Integral functions. — 

 E. Belot : The role of nebular media in the dynamics 

 of stellar and planetary systems.— L. Bull : An 

 apparatus for the rapid dissociation of images in 

 kinematography by the "electric spark. The film is 

 stationary and the images, illuminated by electric 

 sparks (at the rate of 50,000 per second), are received 

 on a rotating total-reflection prism. The one dis- 

 advantage of the method is that the images are not 

 parallel to each other from one end of the film to the 

 other. — A. Nodon : The photogenic action of ultra- 

 radiations. — E. Darmois : The action of acids on 

 ammonium molybdo-malate. The polarimeter shows 

 that this ammonium salt is very sensitive to the 

 action of acids, and the diminution ' of the rotation 

 appears to be proportional to the concentration of the 

 hydrogen ions. The use of this method readily 

 detects traces of sulphuric acid in vinegar. — A. 

 Braly : A new method for the detection of gold and 

 silver in minerals by means of the blowpipe. — 

 A. Schoep : Soddite, a new radioactive mineral. This 

 is a yellow crystalUne mineral found associated with 

 curite from Kasolo (Belgian Congo). It is a uranium 

 silicate of the composition 12UO3 . sSiOg . i4Hj,0, 

 and its radioactivity is in proportion to its high 

 uranium content (86 per cent. UO3). The name 



