Abstract
PARIS. Academy of Sciences, September 5.—M. Bouchard in the chair.—Madame P. Curie and A. Debierne: Metallic radium. Starting with 0.106 gram of the purest radium chloride (atomic weight 226.5), the method of Guntz for the preparation of metallic barium was followed. The radium chloride in aqueous solution was electrolysed with a mercury kathode and a platino-iridium anode. After the electrolysis the solution contained 0.0085 gram of the salt. The amalgam decomposed water and was readily attacked by the air. The dry amalgam was rapidly transferred to a clean iron boat, the latter placed in a quartz, tube, and was rapidly evacuated. The distillation of the mercury from the amalgam offered some difficulties; to prevent visible ebullition, which resulted in loss by projection, the tube was o filled with carefully purified hydrogen, the pressure of which was kept slightly above the pressure of the mercury vapour at the temperature of the boat. At the close of the operation the metal was left in the boat, brilliantly white, and melting sharply at 700° C. The authors regard this as sensibly pure radium. The metal alters very rapidly in air, blackening immediately, probably owing to the formation of a nitride. Some particles detached from the boat, falling on white paper, produced a blackening similar to a burn. Radium energetically decomposes water going into solution, indicating that the hydroxide is soluble. Radio-active measurements showed that the increase of activity followed the usual law for the production of the emanation, the limiting activity of the metal becoming normal. Since it was found that the metallic radium was much more volatile than metallic barium, it is proposed to purify the metal by sublimation in a vacuum.—Leéon Kolowrat: The β rays of radium at its minimum activity. The author has repeated the experiments of O. Hahn and Mile. Meitner, and has arrived at conclusions confirming the existence of a very absorbable β radiation.—Georges Baume and F. Louis Perrot: The fusibility curves of gaseous mixtures: compounds of methyl oxide and methyl alcohol with ammonia gas. The results of these cryoscopic researches are given in graphical form.—J. B. Senderens: The preparation of acrolein. It has been found that potassium bisulphate reacts catalytically with glycerol, so that, instead of adding the bisulphate in the proportion of twice the weight of glycerol, as is customary, one-fiftieth of this amount of the bisulphide is sufficient.—Paul Gaubert: Soft crystals and the measurement of their indices of refraction. Figures are given for the refractive indices of crystals of beeswax, ammonium oleate, ozokerite, paraffin, and lecithine.—R. Robinson: The vessels of the fork of the median nerve. A contribution to the study of the manual dexterity of man.
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Societies and Academies . Nature 84, 356 (1910). https://doi.org/10.1038/084356a0
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DOI: https://doi.org/10.1038/084356a0