July 14, 1923] 



NA TURE 



75 



Paris. 



Academy of Sciences, June i8. — M. Guillaume 

 Bigourdan in the chair. — M. Mesnager : An indefinite 

 thin plate, uniformly loaded, supported by points 

 regularly spaced. — Marcel Brillouin : The possibility 

 of studying the phenomena of radiotelegraphy on 

 reduced models. A model constructed on the scale 

 of one-thousandth could be made to serve many 

 useful purposes. The modifications necessary to 

 secure similitude are discussed. — P. Sergesco : Sym- 

 metrisable nuclei. — Serge Bernstein : The extremal 

 properties of polynomials and of integral functions 

 on a real axis. — Bertrand Gambier : Minimal curves : 

 curves of constant torsion : Bertrand curves. The 

 deformation of the paraboloid and hyperboloid of 

 revolution. — A. Petot : The mode of working of 

 automobile brakes. — Etienne CEhmichen : The flights 

 carried out at Valentigney (Doubs), on April 28 and 

 ^lay I, 1923, on the helicopter " Othraichen-Peugeot, 

 No. 2." A detailed account of two flights with this 

 machine. — Max Morand : The electromagnetic radia- 

 tion of electrified particles. — L. Fraichet : The 

 magnetic testing of steels under traction. Elastic 

 limits. The variations in the magnetic state of a 

 steel under varying load show a permanent molecular 

 change at a point named by the author " the true 

 elastic limit." This point is lower than that corre- 

 sponding to a permanent extension of the bar ; the ratio 

 between the "true elastic limit," thus defined, and 

 the limit of proportionality is 0-7 to 0-95 for ordinary 

 steels after annealing, and 0-5 to 0-65 in ordinary 

 steels after tempering. — Paul Woog : Some phenomena 

 of the superficial alteration of glass, capable of 

 detection by high-tension currents. The phenomena 

 described depend upon the presence of a layer of 

 sodium carbonate on the glass and its absorption 

 of traces of water from oil, resulting in changes of 

 electrical conductivity. — Leon Guillet and Marcel 

 Ballay : The influence of cold hardening on the 

 resistance of metals and alloys. The changes in 

 the electrical resistance of metals produced by cold 

 hardening are less than 4 per cent. All the pure 

 metals examined (except lead and tin) showed 

 increased resistance. A brass (68/32) showed a 

 21 per cent, increase of resistance. In all cases, 

 annealing restores the original resistance. — A. Dau- 

 vjllier : Paramagnetism and the structure of the 

 atom. — P. Job : The complex ions formed by silver 

 salts and ammonia or the substituted ammonias. 

 The equilibrium constant of this reaction has been 

 studied by measuring the potential differences 

 between a silver electrode and two solutions con- 

 taining silver nitrate and silver nitrate plus amine 

 at varying temperatures. Results are given for 

 ammonia, diethylamine, ethylenediamine, and hexa- 

 methylcnctetramine. — Marcus Brutzkus : Contribu- 

 tion to the theory of internal combustion motors. — 

 T. Hackspill and A. Conder : In the ordinary method 

 of manufacturing liquid carbon dioxide, the gases 

 from the combustion of coke are absorbed by cold 

 potassium carbonate solution, and the pure carbon 

 dioxide required for compression recovered by 

 heating the potassium bicarbonate solution thus 

 obtained. Investigation of a case of rapid corrosion 

 oi the condenser of a compression plant showed that 

 ferric nitrate was being produced. This has been 

 traced to oxides of nitrogen produced during the 

 combustion of the coke. These are fixed by the 

 alkali, but small quantities of nitric oxide can arise 

 from the interaction of carbon dioxide and potassium 

 nitrite, and this is the source of the corrosion. — Max 

 and Michel Polonovski : Di-iodomethylates in the 

 eserine series. — Mile. Brepson : The formation of 



soils in the region of Saulieu (Morvan). In this 

 region the process of soil formation is simple, and is 

 due to the decomposition of the subjacent rock under 

 the influence of atmospheric agents : the action of 

 wind or streams plays only an insignificant role. — 

 J. Barthoux : Observations relating to the genesis 

 of certain manganiferous deposits. — C. E. Brazier : 

 The magnetic agitation at Pare Saint-Maur and at 

 Val-Joyeux, and its relation with solar activity. 

 The variations of the solar activity show no relation 

 with the position of the earth in its orbit, while the 

 magnetic agitation has a clear seasonal variation. 

 For this reason the amplitude of the annual variation 

 of the magnetic agitation is compared with the solar 

 activities, lo-year periods corresponding with definite 

 solar conditions being chosen. This annual variation 

 of amplitude follows fairly well the changes in the 

 solar activity. — Femand Obaton : Experimental 

 researches on the reddening of cherries. The 

 reddening of cherries depends on the temperature, 

 and light has no direct action on the phenomenon : 

 a study of the respiratory coefficient showed that 

 an absorption of oxygen accompanies the reddening 

 process. — A. Goris : The chemical composition of 

 Monotvopa Hypopitys. — Ch. Kilian : Coefficients of 

 utilisation and velocity of growth in fungi. — Emile 

 Haas : The undulation of fatigue in different regions 

 of the spectrum. — A. Desgrez, H. Bierry, and F. 

 Rathery : The action of insulin on glycaemia and 

 acidosis. — P. Benoit : Ovogenesis and segmentation 

 of Myrioihela Coksi. — L. Mercier and R. Poisson : 

 A case of accidental parasitism of a Nepa by infusoria. 

 — A. Policard and G. Mangenot : Cytological researches 

 on the condition of the oil in oleaginous seeds. The 

 ripe seed. — Maxime Menard : Ten cases of pregnancy 

 after treatment of fibroma of the uterus by X-rays. 

 — J. Chevalier and Femand Mercier : The pharmaco- 

 dynamic action of the insecticidal principle of 

 pyrethrum flowers. 



Perth (W.A.). 



Royal Society of Western Australia, December 12. — 

 Mr. E. de C. Clarke in the chair. — L. Glauert : 

 (i) Contributions to the fauna of Western Australia, 

 No. 3. A new species of burrowing crab is described. 

 (2) Cidaris comptoni, sp. nov., a cretaceous echinid 

 from Gingin. This is the first fossil sea-urchin to 

 be described from Australian cretaceous formations. 

 Affinities are noted with echinids from the white chalk 

 of England and lower cretaceous beds of N. Africa, 

 Sinai, and India. — R. J. Tillyard : The Embioptera or 

 web-spinners of Western Australia. The history of 

 the insects as revealed by Palaeozoic fossils is described. 

 The previously recorded Oligostoma hardyi and a new 

 species, O. glauerti, are discussed. — L. Glauert : An 

 annotated list of lizards from Wallal. The list 

 includes one new species. — C. A. Gardner : Second 

 contribution to the flora of Western Australia. 

 Eight new species are described, one establishing 

 a new genus and introducing the family Ericaceae 

 into the West Australian flora. 



March 13. — Mr. E. de C. Clarke in the chair. — 

 E. S. Simpson : Secondary sulphates and chert 

 in the Nullagine series. In the softer beds of the 

 Nullagine (Keweenawan ?) series, which covers large 

 areas in the north-west of Western Australia, gypsum, 

 epsomite, tamarugite, pickeringite, copiapite, alunite, 

 and jarosite occur as vein fillings, efflorescences or 

 imbedded crystals. Chert is widespread as hill- 

 cappings and waste therefrom. The paragenesis of 

 the minerals is detailed and their origin traced to 

 weathering of pyrite and marcasite concretions 

 which are abundant in the series. New analyses of 

 the minerals are given, also the striking chemical 



NO. 2802, VOL. I I 2] 



