November ii, 1922J 



NA TURE 



655 



much greater for the higher-order spectra, and different 

 curves were obtained for the Ka (333) and K/3 (333) 

 spectra. Graphite : Only for the cleavage-plane 

 reflection was it possible to obtain a definite tem- 

 perature-intensity curve, and for the direction 

 perpendicular to this plane an unusually high co- 

 efficient of expansion was measured. Diamond : 

 No decrease in intensity was found that could be 

 measured with certainty, and a very small thermal 

 agitation would be expected on account of the 

 diamond structure's great strength. Ruby and 

 sapphire : An anomalous effect was observed, since 

 the decrease of intensity of the (in) spectra was 

 greater than that of the (222). This may be com- 

 pletely explained by assuming that the atoms of 

 the aluminium pair remain in contact and do not 

 share in the expansion of the lattice. — S. Datta : 

 The absorption spectrum of potassium vapour. The 

 principal series lines up to m = 42 have been observed 

 as absorption lines and their wave-lengths accurately 

 measured. The series equation shows satisfactory 

 agreement between the observed and the calculated 

 values, with the exception of deviations for the last 

 few lines, for which a possible explanation has been 

 given. The first seven members of the series have 

 been resolved into their components. Besides the 

 absorption of the lines of the principal series, new 

 lines have been found to be absorbed at higher 

 pressures, which seem to have no correspondence 

 with the known lines in the emission spectrum. The 

 combination lines 15— id and xs-^d have been found 

 to be absorbed, the first as a pair, confirming the 

 presence of a satellite to the lines of the diffuse 

 series. Their appearance in the absorption spectrum 

 gives distinct evidence of contradiction of the 

 selection principle. — K. R. Ramanathan : The 

 molecular scattering of light in vapours and in 

 liquids and its relation to the opalescence observed 

 in the critical state. Three instances of light scatter- 

 ing by homogeneous media are known — opalescence 

 near critical point, scattering of light by gases, and 

 scattering of light by liquids. Experiments on 

 scattering of light by ether, in vapour and liquid 

 phases, at different temperatures from 33° C. up to 

 critical temperature 193-6° and in gaseous phase 

 from 193-6° to 2 1 7 , give results in accord with the 

 Einstein-Smoluchowski formula and not with the 

 Rayleigh law. The Einstein-Smoluchowski formula 

 is inapplicable in immediate neighbourhood of critical 

 point. The scattered light is markedly less blue 

 here. Following the theoretical work of Ornstein 

 and Zernike, from maximum value of intensity of 

 scattered light the value of c, radius of action of 

 ether molecule, is deduced to be 4-6x10"' cm. 

 Light scattered at right angles to incident beam is 

 imperfectly polarised ; ratio of weak component to 

 strong is throughout nearly 1-2 per cent., in case of 

 vapour, while in case of liquids, ratio is 8 per cent, 

 at ordinary temperatures, remaining constant till 

 about 120° and then falling off to about 1-2 per 

 cent, at critical point. There is no change of im- 

 perfection of polarisation on passing through critical 

 point. Correction due to this in the expression for 

 intensity of scattered light is given. 



Paris. 



Academy of Sciences, October 16. — M. Albin 

 Haller in the chair. — The president announced the 

 death of F. P. A. Barbier, correspondant for the 

 section of chemistry. — Maurice Hamy : The calcula- 

 tion of a double integral which occurs in the theory 

 of the diffraction of solar images by a rectangular 

 slit. — An. Bilimovitch : The lines of inertia on a 

 surface. — Ed. Le Danois : The hydrology of the 



NO. 2767, VOL. I IO] 



North Atlantic. It is considered that the name 

 Gulf Stream should be restricted to the return current 

 from the equatorial region. The variations in tem- 

 perature and salinity of the surface water are due to 

 a seasonal phenomenon and not to ramifications of 

 the Gulf current. — C. Raveau : Demonstration of 

 Fresnel's law of asther drift, without reference to 

 the relativity of time and space. — Andre Guilbert : 

 The calculation of the attraction of electro-magnets. 

 — Maurice Curie : The refractive indices of the 

 phosphorescent sulphides. The refractice indices 

 of phosphorescent sulphides of calcium, strontium, 

 barium, and zinc have been measured directly by 

 the observation under the microscope of particles 

 of the sulphides in a transparent homogeneous liquid 

 of the same refractive index. The values found 

 differ considerably from the square root of the 

 dielectric capacity and lend no support to the theory 

 of P. Lenard. — L. J. Simon and I.. Zivy : The 

 neutralisation of tartaric acid by potash in presence 

 of the chlorides of the alkaline earths. In the 

 presence of calcium (or barium) chloride, the titration 

 of tartaric acid requires the same volume of caustic 

 potash solution for neutralisation with either methyl 

 orange or phenolphthallin as indicator. — Albert 

 Perrier and B. de Mandrot : The elasticity and 

 symmetry of quartz at high temperatures. Flat 

 plates were cut from quartz crystals in four 

 directions : along the binary and ternary axes, 

 then in two directions normal to the binary axis. 

 The quartz plates were worked with optical precision 

 and the flexures caused by a load at the centre 

 determined for temperatures ranging from 18° C. to 

 1 140° C. There is a rapid change in the value of 

 Young's modulus at 576° C, a rise of 1° increasing 

 the modulus to three times its value. Aime Azam : 

 The origin and process of formation of the soils at 

 the Hague. — Jean Mascart : The proportion of 

 successes in weather prediction. The question as to 

 what constitutes a successful weather prediction is 

 discussed, and it is pointed out that many predictions 

 are too vaguely drawn and cover too many possi- 

 bilities. If the forecast is drawn in precise terms, 

 weather prediction may be considered satisfactory 

 if the proportion of successes is more than 60 per 

 cent. — P. Bugnon : The systematic position of the 

 Euphorbiaceas. J. Beauverie : The " critical period 

 of wheat." — L. Blaringhem : A sterile hybrid of 

 spelt and rye. — Adrien Davy de Virville and Fernand 

 Obaton : Observations and experiments on ephemeral 

 flowers. Light has no action on the opening or 

 closing of the corolla in ephemeral flowers, and 

 hygrometric state has a very slight influence. The 

 temperature is the main factor in these movements. 

 — Marc Bridel and Mile. Marie Braecke : Rhinanthine 

 and aucubine. Rhinanthine is impure aucubine. 

 Rhinanthine was extracted by Ludwig from the 

 seeds of Rhinanthus Crista-galli, and aucubine was 

 discovered by Bourquelot and Herissey in the seeds 

 of Aucuba japonica. Rhinanthine is regarded by 

 the authors as a mixture of saccharose and aucubine, 

 and experimental data are given in support of this 

 view. — Fred Vies : The variations of the hydrogen 

 ion concentration in the neighbourhood of eggs 

 undergoing division. — J. Legendre : The trophic role 

 of birds as regards the culicines. Further studies on 

 the part played by domestic animals and birds in 

 the protection of man against insects (Culex, Stego- 

 myia). — Paul Wintrebert : Movement without nerve 

 and nervous movement of the embryos of Raia. — 

 A. Gruvel : Two species of lobster from the coasts 

 of Indo-China. — J. Dumas and D. Combiesco : 

 Dysenteric intoxication of the rabbit and cholera 

 intoxication of the guinea-pig by ingestion of soluble 

 dysenteric and cholera toxins. 



