[June io, 1909] 



NATURE 



449 



water seems to be the only satisfactory explanation to 

 account for the various details of the phenomenon. 

 Paris. 

 Academy of Sciences, May 24. — M. Bouchard in the 

 chair. — h hypothesis relating to the nature of the internal 

 pressure in fluids : E. H. Amasat. — The infinitely small 

 deformation of ruled surfaces : J. Haagf. — iVIi.xed linear 

 equations : G. Bratii. — The sum of the n first coefficients 

 of a Taylor's series : Carl Hansen. — General representa- 

 tions of functions : L. Desaint. — Certain singularities of 

 differential equations : Richard Birkeland. — Differential 

 equations of the second order with fixed critical points : 

 Jean Chazy, — -The preliminary map of the Chari region 

 (French Congo) : G. Bruel. — A self-recording compass : 

 M. Heit. An apparatus is described and illustrated capable 

 of recording automatically the deviations of a marine 

 compass, and hence the course of the ship. The instru- 

 ment is capable of furnishing valuable evidence as to the 

 responsibility in cases of collisions. — The theory of dis- 

 corttinuous discharges in Geissler tubes : H. A. Perkins. 

 Regarding the tube as a condenser in circuit with a high 

 resistance, a theory of the discharge through a Geissler 

 tube is developed which is in accord with some hitherto 

 unexplained experimental results. — Internal pressure in 

 gases : A. Leduc. From Amagat's results, the internal 

 pressure for any gas at constant temperature is inversely 

 as the square of the specific volume. From a discussion 

 of experiments made on gases at low pressures, 05 to 

 3 atmospheres, this law is confirmed, and the author 

 regards this as furnishing a proof of the accuracy of his 

 experimental work, especially that dealing with the 

 coefficients of expansion. — The solubility of lead sulphate : 

 J. Sehnal. The solubility of lead sulphate appears to be 

 the same at 20° C. and 100° C, 00824 gr. per 1000 c.c, 

 and this figure is reduced by the addition of very small 

 amounts of sulphuric acid. The experiments are in accord 

 with the hypothesis that lead sulphate is insoluble as 

 such, its apparent solubility being due to a slow inter- 

 action with water, lead hydroxide and sulphuric acid being 

 formed. — Revision of the atomic weight of phosphorus : 

 G. Ter Gazarian. The mean of six concordant experi- 

 ments on the density of carefully purified hydrogen phos- 

 phide gave 1-5293 grams as the weight of a litre under 

 normal .temperature and pressure. This gives 30906 as 

 the atomic weight of phosphorus (0=i6). It is worthy 

 of note that this is exactly the figure calculated by 

 Bernoulli, starting from certain hypotheses on the constitu- 

 tion of the elements. — Syntheses of some derivatives of 

 racemic fenone : L. Bouveault and M. Levallois. — Ring 

 formation of ketonic acids: E.. E. Blaise and A. 

 Kcehler. — The oxidation of the polyhydric alcohols by 

 a peroxydasic system : E. de Stoeckiin and E. 

 Vuiquin. The oxidising agent used is a saturated solu- 

 tion of quinhj-drone containing a trace of a ferr'C salt, 

 together with hydrogen peroxide. The application of the 

 reagent to the oxidation of glycerol, glycol, mannitol, 

 sorbitol, and dulcitol is described. — The phenomena of 

 fertilisation in the Zygnema : P. A. Dang-eard. — New 

 observation on the moth of the olive (Prays o\eae) : Th. 

 Dumont. This moth, in development, does not always 

 have three complete generations ; it may have two or 

 three, according as the eggs are deposited on the leaves 

 or fruit. If for any reason the flowers are lacking, only 

 a single generation can be observed. — The action of the 

 vibrations of the vowel siren on the ear in a pathological 

 state : M. Ranjard. — The relation between sleep and the 

 retention of interstitial water : M. Devaux, — The meta- 

 morphosis of the muscular system in the Muscida; : 

 Charles Perez. — The existence of gemmiform conjugation 

 in Ephclota gemmipara : B. Collin. — The function of . 

 external water in impregnation and first stage?; of develop- 

 ment of Rana fused : E. Bataillon.— The formation of 

 the body by the union of two independent halves in Svllis : 

 Aug. Michel. — Two different modes of regeneration in 



Linens ruber: Mieczyslaw Oxner The phenomenon of 



intcrmittence of the Gouffre de Poudak : E. A. 

 Martel. This basin is situated at a height of :;40 metres, 

 at Poudak (Hautes-Pyrdn^es), and has a depth varying 

 from 3 to 14-5 metres. The water-level rises 4 metre's in 

 fifteen minutes, remains steady for three minutes, and 



NO. 2067, VOL. So] 



descends to the original level in forty minutes, each com- 

 plete pulsation thus taking fifty-eight minutes. A complete 

 explanation is wanting for this curious phenomenon. — 

 The roots of the higher strata of the western Alps : Emile 

 Haug. — The extension of the chalk marl in the neigh- 

 bourhood of Foucarmont (Soine-Inf^rieure) : Paul 

 Lemoine. 



June I. — M. Bouchard in the chair. — The relations 

 between the permeability of soils and their aptitude for 

 irrigation : A. Muntz and L. Faure. Alluvial deposits, 

 contrary to the generally received idea, differ greatly in 

 their permeability to water. Thus one of two supposed 

 identical soils proved to be 600 times more permeable than 

 the other, and the results of cultivation obtained were in 

 close relation to the permeability. A method of measuring 

 the permeability of a soil is described, and also a mode 

 of establishing a scale by means of which different 

 soils can be compared. Details of the results obtained 

 with seventeen soils are given, showing permeabilities 

 ranging from o to 141, and these figures are discussed 

 from the point of view of the suitability of these soils for 

 irrigation. The first results obtained by the commission 

 for studying the water-power of the Alps and Pyrenees : 

 Michel Levy. The mean altitude of the greater part of 

 the hydrographic basins of the French Alps has been 

 calculated. The yields are considerably below the figures 

 accepted before the survey. — The granite, gneiss, and 

 porphyry of the island of Elba : Pierre Termier. — The ■ 

 perpetual secretary announced the death of T. \V. Engel- 

 mann, correspondant of the academy for the section of 

 medicine and surgery. — The theory of functions : Paul 

 Koebe. — The evolution of heat by radio-active bodies : 

 William Duane. Two evacuated glass bulbs containing 

 ether, and connected by a capillary, form a differential 

 calorimeter of great sensitiveness, the whole being enclosed 

 in a massive block of lead. Any heat evolved in one bulb 

 results in an increase in the vapour pressure of the ether 

 and the motion of an air bubble in the connecting capillary. 

 This bubble is brought back to the original position by 

 utilising the Peltier effect in an iron-nickel couple. The 

 instrument has been applied to the measurement of the 

 heat evolved from radio-thorium, 0-025 calories per hour, 

 a quantity of the same order as that disengaged by radium. 

 — The radium and uranium contained in radio-active 

 minerals : Mile. Ellen Gleditsch. A new method for 

 determining the radium in radio-active minerals ^ is 

 described. The minerals examined were a French autunite, 

 a Joachimsthal pitchblende, and a Ceylon thorianite ; the 

 ratio of radium to uranium was not found to be constant 

 in these minerals. — The composition of atmospheric air : 

 Georges Claude. A description of further results obtained 

 by the fractional distillation of liquid air by the apparatus 

 described in an earlier paper. The conclusion is drawn 

 that 1,000,000 volumes of air contain 15 of neon, 5 of 

 helium, and i of hydrogen. — The conditions of electric 

 charge of particles in suspension in a gas : the charges 

 of chemical fumes : MM. de Broglie and Brizard. The 

 fumes were examined by the ultramicroscopo in an electric 

 field. Any fumes produced by chemical action without 

 rise of temperature are not charged electrically, and this 

 also holds for sulphur distilled in a current of nitrogen. 

 Fumes produced in vigorous chemical reactions, with 

 marked rise of temperature, are charged. — The_ physico- 

 chemical studv of some pharmaceutical incompatibles : E. 

 Caille. Certiin mixtures, such as salol and camphor, 

 form eutectics fusible at ordinary temperatures. Curves 

 are given for salol-camphor and resorcinol-camphor 

 mixtures. — Observations on the oxides of uranium : 

 Oechsner de Coninck. — A chromyl subchloride : P. 

 Pascal. Chromyl chloride, CrOXU, is reduced by nitric 

 oxide, a chloride, (CrO,),,,Clt, being formed. Details of 

 the chemical properties "of this substance are given.-— A 

 new medicinal bark from the Ivory Coast and its alkaloid : 

 Em. Perrot. — The catalase of the blood : C. Gessard. 

 Ha;moglobin and fibrin, carefully freed from catalase, are 

 without action on hydrogen peroxide solutions. — The 

 determination of the temperature of Pasteurisation of 

 milk with respect to its industrial applications. The 

 influence of the heating on the conservation of the physio- 

 logical properties of milk : P. Maze, P. Guerault, and 



