July i6, 1908] 



NATURE 



263 



^,upplyiIlg the true pressures as indicated by the air and 

 hydrogen manometers used by Andrews in his well-known 

 experiments. See a letter bv K. Tsuruta, of Tokyo, in 

 Nature, February 2, 1899, which directed attention to the 

 importance of finding the true pressures instead of those 

 gi\'en by Andrews and explicitly referred to by him as 

 only provisional. With the assistance of Dr. Andrews's 

 daughter, Miss M. K. .Andrews, the experimental note- 

 books had been carefully and successfully investigated, and 

 the data obtained from which the true pressures could be 

 calculated. 



Paris. 



Academy of Sc iences, July 6. — M. Bouchard in the 

 chair. — .\ fundamental hypothesis implicitly admitted in 

 I he classical treatment of astronomy : J. Boussinesq. 

 It has been implicitly assumed that the path of any plam-t 

 with respect to the sun forms a closed trajectory described 

 periodically. The tendency to make the simplest hypo- 

 thesis consistent with the observed facts is unavoidable ; 

 ihus the ancient astronomers assumed circular uniform 

 motion for the stars, an assumption which had to be 

 complicated as observations became more exact. — The tribo- 

 luminescence of racemic compounds : D. Gernez. It has 

 been shown by Tschugaeff that whilst with certain optically 

 active bodies both the right- and left-handed constituents 

 are triboluminescent, the racemic compound is not so. The 

 author has filled up some gaps in Tschugaeff's table, and 

 added fresh optically active substances, but is unable to 

 confirm his hypothesis. There seems to be no general 

 relation of cause and effect betw'een triboluminescence of 

 bodies and their symmetrical or unsymmetrical constitution. 

 — The eclipse of the sun of June 28, iqoS, at the Observ- 

 atory of Lyons : Ch. Andre. The results of observations 

 of contacts, chords, and angles of position. The last 

 contact was partially obscured by clouds. — The action of 

 metallic oxides on primary alcohols. The case of oxides 

 undergoing reduction : Paul Sabatier and A. Mailhe. 

 The simplest case is that of the o.xides of antimony and 

 bismuth, which, at 360° C, are reduce.d to metal, water 

 and aldehyde being the only products. With HgO and 

 MnO, the oxidation goes further, some carbon dioxide being 

 formed. The reduced metal in these cases shows no 

 catalytic power, but with nickel, cobalt, lead, and copper the 

 catalytic effects of the reduced metal are added to the 

 reducing power of the oxides, and the reaction becomes 

 more complicated. With some metals (iron, cadmium, tin) 

 the oxides also can act catalytically. — The floating population 

 on canals and public health : ^IM. Chantemesse and 

 Pomes. The possibility of infection being carried in 

 this way was overlooked in the legislation of 1902. Cases 

 arc cited showing how widely infection has been carried 

 by canal boats, and the necessity of suitable prophylactic 

 measures is pointed out. — Some new peculiarities of short- 

 period variable stars : a method of distinguishing their 

 effects from those due to dispersion in a vacuum : Charles 

 Nordmann. It is shown that the results obtained "by 

 the niithod of monochromatic images can separate, for 

 a numerous class of variable stars, the two classes of 

 phenomena in question. — The variations of duration of 

 twilight : Ernest Esclangron. The visibility of celestial 

 objects, depending as it does on two factors, the apparent 

 brightness of the sky and the transparency of the air, 

 is a faultv method of observation ; the photometric state 

 of the sky is more suitable for quantitative study. The 

 great influence of suspended particles in the air is pointed 

 out, and the abnormal twilight of July i considered from 

 this point of view.— The partial eclipse of the sun observed 

 It the Observatory of Besancon on June 28, iqoS : MM. 

 Briick, Chofardet, and Pernet. — Observation at the 

 Observatory of Marseilles of the partial eclipse of the sun 

 of June 28, iqoS : Henry Bourgret. — .\ problem relating to 

 the theory of partial differential equations of the hyperbolic 

 type : \. Myller, — .A new integrometer : M. Jacob. Tlie 

 apparatus described on May ii, 1908, allows the integration 

 of the equation 



y' = Ay='-|-By=4-Cy-|-D, 



if a particular solution of this equation is known. By 

 slightly modifying the apparatus, the latter restriction 



XO. 2020, VOL. 7S] 



is removed. — The useful weight of aeroplanes : Rodolphe 

 Soreau. — The use of detectors, sensitive to electric oscilla- 

 tions, based on thermoelectric phenomena : C. Tissot. — 

 Researches on ionised gases : A. Blanc. The method of 

 measurement used was a modification of the alternating 

 field method of Rutherford, and was applied to the study 

 of mixtures of carbon dioxide and hydrogen, and air and 

 carbon dioxide. The mobility in air of an ion produced 

 in carbon dio.xide is the same as if this ion had been 

 directly produced in air, and this is true for ions of both 

 signs. — The influence- of temperature on the electromotive 

 force of the cadmium element : R. Jouaust. The formula 

 given in 1901 by Jager and Lindeck for the variation 

 in the electrornotive force of the cadmium cell between 

 o and 20 for an amalgam containing between 12 and 13 

 per cent, of cadmium has been confirmed. More recently, 

 Smith has stated that between 10° and 20° C. amalgams 

 of 10 per cent, and 12-5 per cent, show an identical 

 relation ; this, however, is now shown not to be true 

 at 0° C, and the anomalies shown by the cells with 

 10 per cent, amalgam require further investigation. — Inter- 

 ference fringes shown by colour photographs ; E. Rothe. 

 — A repeating auto-ballistic galvanometer : A. Guillet. 

 If successive small impulses are imparted to the ballistic 

 needle at periods corresponding to its vibration period, 

 a large increase of sensibility results. .An automatic 

 arrangement for effecting this is described in the present 

 paper. — Dynamos without a collector : C. Limb. The 

 application of electrolytic values to dynamos. — The stabilitv 

 of the alternating arc as a function of the atomic weight of the 

 metals forming the electrodes : C. E. Guye and A. Bron. 

 — The orientation of crystals by the magnetic field. The 

 importance of the optical properties of mixed liquids from 

 the point of view of crystalline symmetry : .A. Cotton 

 and H. Mouton. — The phenomena of Bose and the laws 

 of contact electrification : Edouard Guillaume. — The Bose- 

 (iuillaume phenomenon and contact electrification : Jean 

 Perrin. — A relation between the magnetic and chemical 

 properties of complex iron salts : P. Pascal. — The total 

 heats of baryta, w'itherite, and fused lime : M. 

 Latschenko. — The development of negatives in radio- 

 graphy : Maxinie Menard. A description of the modifi- 

 cation in the details visible in the negative which can be 

 produced by variations in the method of working with 

 the same developing bath. — The influence of the medium 

 on the Brownian movements : Victor Henri. A quantita- 

 tive study by means of a kinematograph microscope of 

 the effects produced by the addition of various amounts 

 of acids and alkalis to the latex of india-rubber. A new- 

 iodide of titanium, titanous oxide, Til, : Ed. Defacqz 

 and H. Copaux. The new iodide is obtained by the 

 action of mercury vapour upon Til, in an atmosphere 

 of hydrogen at a red heal. — The heat of neutralisation of 

 picric acid by various aromatic bases in benzene solution : 

 L^o Vigrnon and M. Evieux. Picric acid differs from acetic 

 and benzoic acids in that it forms salts readily with 

 aromatic bases in benzene solution. It furnishes examples 

 of formation of salts in the absence of ionisation. — The 

 direct transformation of borneol into campholic and iso- 

 camphoHc acids : Marcel Guerbet. If borneol is heated 

 in sealed tubes at 250° to 280° with recently fused potash 

 it is almost quantitatively converted into the potassium 

 salts of campholic and f.-iocampholic acids, hydrogen being 

 evolved. — The preparation of benzoylacetic esters:, A. 

 Wahi. By the action of sodium upon an ethereal solution 

 of ethyl benzoate, benzoin is produced. Hence, in the con- 

 densation of ethyl acetate and benzoate with sodium, three 

 distinct reactions are produced. — Ergosterin and fongo- 

 sterin : C. Tanret. — Study of the role of yeasts in the 

 aldehydification of alcohol : MM. Trillat and Sauton. — 

 The influence of formic acid vapours on the growth of 

 Rhizcpus nigricans : Henri Coupin. — The recollection of 

 the tides in Convoluta Roscoffetisis and its alteration : Louis 

 Martin. — The structure of the renal cell : L. Bruntz. — 

 The first venous circulation of Carassius aurattis : P. 

 Wintrebert. — Study of the immunising action of chlor- 

 inated derivatives of bacilli : MM. Moussu and Goupil. 

 — The quaternary alluvium of the Loire and Allier : E. 

 Chaput. 



