November ii, 1909] 



A^A TURE 



59 



duce uniformity, and in consequence the E.M.F. of a cell 

 containing the amalgam is unstable for a considerable 

 length of time. When the amalgam is cooled to a tempera- 

 ture a little below the lower transition temperature, the 

 difTerence of concentration between the inner and outer 

 parts of the amalgam need be only small to enable the 

 outer skin to be a two-phase system. The diffusion 

 process will be slow, and the E.iM.F. may remain constant 

 for a long time. .Amalgams which were of uniform 

 cadmium concentration were obtained by chilling liquid 

 amalgams to a temperature of about —50° C. ; although 

 not initially stable, rapid diffusion processes resulted in 

 these amalgams becoming approximately uniform through- 

 out after a few days, and their electromotive properties 

 were different from those of slowly cooled amalgams. The 

 experiments indicate that a 12-5 per cent, amalgam may 

 be used safely at all temperatures betwt-en 12° C. and 

 60° C, and a 10 per cent, amalgam at all temperatures 

 between 0° C. and 51° C. Experiments were made on the 

 temperature coefficients of the anode and kathode limbs of 

 the Weston normal cell, and show that if a difference of 

 temperature of 1° C. exists an error of about 3 parts in 

 10,000 is introduced. — F. Soddy : Production of radium 

 from uranium. The measurements on the growth of 

 radium in the three uranium solutions purified between 

 three and four years ago have shown that in all the growth 

 of radium is proceeding at a rate proportional to the square 

 of the time. The ordinary error is not greater than 10-'- 

 gram of radium. This result indicates the existence of 

 only one long-lived intermediate product in the series 

 between uranium and radium. The period of average life 

 of this body is 18,500 years in the case of the oldest solu- 

 tion for which data are available ; but for the solution 

 prepared last, the period indicated is about half again as 

 long as in the first experiment. Had this solution grown 

 radium at the same rate, with reference to the square of 

 the time, as the older solution has done during the past 

 year, more radium should have been formed than the total 

 amount now actually present. This suggests the e.xistence 

 of at least one new intermediate product in the series 

 " uranium A." From a mathematical investigation of the 

 effect of such a body on the rate of growth of radium, it 

 is concluded that it would not, if it existed, appreciably 

 alter the production of radium over the period accurate 

 observations have been made ; but its existence would 

 vitiate the calculation of the period of the direct parent 

 of radium according to the simple formula neglecting short- 

 lived products. — F. Soddy : The rays and product of 

 uranium X. Experiments have been made with the 

 uranium X preparations separated from 50 kilograms of 

 pure uranyl nitrate. There occurred the growth of a feeble 

 a radiation as the intense /3 radiation decayed. Such a 

 growth of a rays, concomitant with the decay of rays, 

 is to be expected if the parent of radium is the direct 

 product of uranium X. From tlie period of the parent of 

 radium, the uranium X in equilibrium with i kilogram 

 of uranium should give by its complete disintegration a 

 product having the o activity of 2 milligrams of uranium 

 if no new intermediate bodies intervened. The preparations 

 of uranium X were examined in a magnetic field sufficient 

 to deviate all rays having a value for Hp less than S640, 

 but the still undeviated S radiation produced a leak in 

 the electroscope several times greater than that due to 

 the 7 rays. These difficultly deviable /3 rays are similar 

 in general character and in the value of their absorption 

 coefficient to ordinary 3 rays. The first measurements 

 were made in an electroscope filled with air. Later, the 

 electroscope was filled with hydrogen, which constituted 

 an enormous advance, and these experiments have shown 

 that the a. radiation of the preparation remains constant 

 as the ;6 radiation decays. Anomalies have been 

 encountered with the difficultly deviable j8 radiation, which 

 appears to \axy in intensity according to the conditions ; 

 but throughout the " difference leak " between the pre- 

 paration bare and covered, due to a rays, has remained 

 constant in all the preparations examined. These measure- 

 ments of the a rays, for different preparations, cover a 

 period from immediately after preparation to nearly a year 

 in the case of the main preparation, and longer periods 

 in the case of weaker preparations. The two most recent 

 preparations each contained the uranium X in equilibrium 

 NO. 208g, VOL. 82] 



with about s kilograms of uranium, and the growth of 

 o rays if the change of uranium X into the parent of 

 radium were direct should be equal to the a radiation of 

 10 milligrams of uranium. The parent of radium cannot 

 be the direct product of uranium X. The experiments 

 indicate that it is not a product of uranium X at all, but 

 the subsequent history of the uranium X preparations must 

 be awaited before this can be decided. — F. Soddy : The 

 production of helium from uranium and thorium. Helium 

 has been detected in four experiments with uranium, in 

 three with thorium, and in one with pitchblende solutions 

 carried out according to the methods already published. 

 Recent experiments with nearly a year's accumulation of 

 helium from about 2 kilograms of uranium and thorium 

 respectively have ended in failure owing to accidents. 



Challenger Society, October 28.— Sir John Murray, 

 K.C.B., F.R.S., in the chair.— Prof. d'A. W. Thompson : 

 .\ new method of estimating the number of fish which 

 escape through the meshes of the trawl. The first step 

 was to envelop the trawl-bag loosely in a net of finer mesh, 

 so that the catch was divided into larger specimens inside 

 the trawl and smaller specimens between the trawl and 

 the outer envelope. When curves of these two classes were 

 plotted on the basis of numerous experiments, they 

 naturallv overlapped, the overlap representing fish of a 

 length intermediate between those which could not possibly 

 get^through the trawl-mesh and those which were certain 

 to slip through it. From the overlapped area a ratio could 

 be deduced and tested in both directions against the curves, 

 which appeared to give a fair measure of the small fish 

 lost by an ordinary trawl without a finer envelope. 

 Paris. 

 Academy of Sciences, November 2.— M. Bouchard in 

 the chiir.— M. Le Chatelier and S. Wologdine : The 

 phosphides of iron. Of the nine apparent phosphides 

 examined, only four have a certain existence, viz. Fe.,?, 

 Fe,P, FeP Fe,P3, but the composition of the last two is 

 not so certainly established as that of the first two.— 

 \ Calmette and C. Guerin : Some properties of tuber- 

 culous bacillus of bovine origin, cultivated on glycennated 

 beef bile. Experiments had shown that when guinea-pigs 

 were inoculated with bacillus cultivated in this manner, a 

 much greater virulence was developed, this, however, be- 

 coming steadilv diminished by successive cuUures. Further 

 experiments on horses and heifers showed that with the 

 former the virulence was not only increased, but remained 

 so, while the latter showed the decreasing virulence evident 

 in the guinea-pig.— M. de Forcrand : The bicarbonates of 

 rubidium and ciEsium. They form anhydrous crystals, 

 stable on exposure at ordinary temperatures, neither absorb- 

 ing water nor evolving carbon dioxide. The solubilities 

 are much greater than that of potassium bicarbonate, 

 whilst thev are also more stable under heat. — J. Bosler : 

 Magnetic 'perturbations and solar phenomena. Observa- 

 tions were made on the violent magnetic storm of Sep- 

 tember 25.— A. Perot : A means of protecting the silver- 

 in'' of mirrors. This consists in re-covering the mirror with 

 an'' extremely thin layer of transparent celluloid. If the 

 layer is only sufficiently thin, images remain intense, com- 

 plete, and do not show diffusion.— P. Helbronner : The 

 geodetic complementary triangulations of the high regions 

 of the French Alps. The number of geodetic stations in 

 this district has been raised to 126, of which fifteen are 

 above -jooo metres and forty between 2000 and 3000 metres. 

 — M. 'oarmois ; The composition of the essences of 

 terebenthine. The method indicated, based on the measure- 

 ment of rotatory dispersion, suggests that the essences of 

 terebenthine contain (i) pinene under its two forms ; (2) a 

 Iffivo-carbide in large quantity.— M. Devaux-Charbonnel : 

 Note on an attempt to realise an artificial telephonic line. 

 — H. Baubigny : Action of heat on the sulphite and double 

 alkaline sulphites of silver. Formation of dithionate. ^ The 

 author believes that during decomposition at 100 , in 

 presence of water, of silver sulphite, and the double alka- 

 line sulphites, the production of di-thionic acid is the prin- 

 cipal result. — C. Gerber : Localisation of proteolytic^ fer- 

 ments in VasconceWea qticrcifoUa. There seems to exist a 

 relation between the enzyme-forming character of certain 

 plants and the coagulability of their latex.— E. Kayser 

 and E. Manceau : The viscosity ferments of wines. 



