NATURE 



[March 31, 192 1 



Societies and Academies. 



London. 

 ' Royai Society, March 17.— Prof. C. S. Sherrington, 

 president, in the chair.— Lord Rayleigh : The colour 

 of the light from the night sky. Photographic ex- 

 posures were made under coloured media selected for 

 isolating various parts of the spectrum. Comparison 

 with direct sunlight or moonlight showed that the 

 night sky was of the same quality as these. Visual 

 comparisons through coloured films showed that a blue 

 film, which was equally bright with a yellow one 

 against the night sky, was brighter against the twi- 

 light sky. These comparisons were not embarrassed 

 by colour differences, because the light w'as so faint 

 as to give purely monochromatic vision. The require- 

 ments as regards colour and polarisation of the light 

 would be satisfied if we regarded it as coming from 

 an unresolved background of stars. They would 

 equally be satisfied if we regarded it as due to sun- 

 light scattered by meteoric matter. — R. O. Street : 

 The dissipation of energy in permanent ocean cur- 

 rents, with some relations between salinities, tem- 

 peratures, and currents. On the assumption of slow, 

 non-turbulent motion a formula for the mean rate 

 of energy dissipation in permanent ocean currents is 

 obtained which, when integrated over the whole of 

 the oceans, gives a dissipation at the mean rate of 

 approximately 3 x 10" ergs per second. Simple rela-- 

 tions between the strength of the current, the salinity, 

 and the temperature of the water are also found ; 

 satisfactory estimates of the currents in mid-ocean 

 can thus be made.— S. Datta : The vacuum arc spectra 

 of sodium and potassium. Definite improvements in 

 the measures for the spectra of sodium and potassium 

 have been obtained by the use of sodium and potassium 

 vapour lamps as sources. With potassium an interest- 

 ing combination pair indicating satellites to the diffuse 

 series has been observed. The presence of potassium 

 in the sun has been established, and some additional 

 sodium lines have been identified with solar lines. — 

 W. E. Garner and C. I^. Abernethy : Heats of com- 

 bustion and formation of nitro-compounds. Part i. : 

 Benzene, toluene, phenol, and methvlaniline series. 

 In this paper the heats of combustion of all the 

 isomerides of the mono-, di-, and tri-nitro-toluenes 

 and -benzenes, together with a number of nitro- 

 derivatives of phenol and methylaniline, have been 

 determined, and the heats of formation and nitration 

 calculated. The heats of formation and nitration of 

 the isomerides of the di- and tri-nitro-toluenes and 

 -benzenes show considerable variation, the values tend- 

 ing to a minimum when the nitro-groups are adjacent 

 to one another or to a methyl group. The heats of 

 formation in anv series increase to a maximum value 

 with the introduction of the nitro-grouos. which is 

 reached in the toluene, phenol, and methylaniline 

 series (when svmmetrical substitution takes place) at 

 the dinitro-derivative. The introduction of the methyl 

 jrroup into benzene modifies only slightly the shape 

 of the curves showing the -heats of formation of the 

 derivatives, but the hvdroxyl or methvlaniline group 

 has a much tfreater effect. — E. K. Rideal : The cata- 

 Ivtic dehvdrogenation of alcohols. Application of the 

 approximation formula of the Nernst heat theorem to 

 the equilibria : 



aH5-OH^CH3-CHO + H, 

 and 



(CH,),CH.OHz^(CH,,)3CO+H,. 

 The variation of the dissociation constants with the 

 temperature was determined by means of a constant- 

 volume gas thermometer containing reduced copper as 

 catalytic material. The velocity of decomposition of 



NO. 2683, VOL. 107] 



the alcohol at the surface of the solid catalyst was 

 found to be much more rapid than the reverse bi- 

 molecular reaction. Concordant values for the equili- 

 brium constants at various temperatures could be 

 obtained only at low pressures. 



Geological Society, March 9.— Mr. R. D. Oldham, 

 president, in the chair. — \V. l3. R. King : The surface 

 of the marls of the Middle Chalk in the Somme 

 Valley and the neighbouring districts, and the effect 

 on the hydrology. Chalk forms the main deposit of 

 the area ;' water' was obtained for troops largely from 

 boreholes made by the percussion method. The great 

 number of bores enables one to construct a map of 

 the contours of the marl-surface. These curves show 

 that (i) the main anticlinal crest (axis of Artois) is 

 not continuous, but consists of a series of curved axes 

 arranged en echelon; (2) the close relationship of the 

 river-systems to the tectonic axes ; and (3) the capacity 

 of the Chalk to yield water for boreholes measuring 

 about 6 in. in diameter depends more on the topo- 

 graphy of the neighbourhood than on the larger tec- 

 tonic features, provided about 50 ft. of chalk occurs 

 between the marl-surface and the surface of the water, 

 table in the Chalk.— Dr. Gertrude L. EHes : The Bala 

 country : its structure and rock-succession. The de- 

 tailed mapping of the beds, as now classified, has 

 brought out the structure of the country, and a modi- 

 fication of views previously held with regard to the 

 Bala fault seems to be necessary. It appears to be 

 one of a series of compressional faults affecting the 

 whole of the country south-east of Bala Lake. The 

 initiating structural factor was probably compression 

 of the rocks as a whole against the Harlech Dome, 

 controlled by the resistance offered by the Ordovician 

 volcanic mass to the compressional force. The 

 country was first folded, and then affected by thrust- 

 movenients. The six main structural lines of displace- 

 ment are given, ('ombined with these major displace- 

 ments there has been much differential minor thrust- 

 ing (tears), which is most conspicuous above the Llan- 

 gower thrust. Comparison is made between the suc- 

 cession here seen and that of other areas in Great 

 Britain, and the faunal features are noted and 

 tabulated. 



Zoological Society, March 8.— Sir S. F. Harmer, vice- 

 president, in the chair.— E. G. Boulenger : Experi- 

 ments on colour-changes of the spotted salamander 

 (Salamandra maculosa) conducted in the society's 

 Gardens.— Miss Joan B. Procter : The variation of the 

 scapula in the Batrachian groups Aglossa and Arci- 

 fera.^ — Dr. W. T. Caiman •/ Notes on marine wood- 

 boring animals. II. : Crustacea.— Dr. A. A. Christie- 

 Linde : The reproductive organs of the Ascidian Kiiken- 

 thalia borealis, Gottschaldt.— B. P. Uvarov : The geo- 

 graphical distribution of Orthopterous insects in the 

 Caucasus and in Western Asia. 



Paris. 

 Academy of Sciences, March 7. — M. Georges Lemoine 

 in the chair. — G. Lippmann ■ The determination of 

 the axis of rotation and the velocity of rotation of 

 a solid body, and the realisation of a solid bodv with- 

 out rotation. — M. de Sparre : The ma.ximum yield of 

 turbines. — G. Julia : The variation of the function 

 which furnishes the conformal representation of an 

 area on a circle when the contour of the area varies. — 

 B. Gambler : .\rticulate deformable systems and 

 couples of surfaces deduced from them. — A. Talon : 

 The reversal of the stresses in bridge lattice bars. — R. 

 Feret : The law of equilibrium of solid grains in a 

 vertical ascending current of water. Experiments on 

 the relation between the linear dimensions of solid 



