December i, 1923] 



NA rURE 



81 



Societies and Academies. 



London. 



Royal Society, November 22. — F. Simeon : The 

 carbon arc spectrum in the extreme ultra-violet — II. 

 The spectrum of the carbon arc in vacuum extends 

 as far in the extreme ultra-violet as that of the spark, 

 with the exception of a very faint line at 360-5 A, 

 and about 25 lines have been added to the arc spectrum 

 as already recorded. The L series of carbon can be 

 excited by a potential of between 30 and 40 volts. 

 A number of lines in the carbon spectrum are probably 

 true " arc " lines. Providing the grating will give 

 radiation in the short-wave region, the same technique 

 suffices to photograph the spectrum from 1850 A to 

 370 A. — H. J. Gough and D. Hanson: The behaviour 

 of metals subjected to repeated stresses. The effect 

 of static and alternating stresses on the micro- 

 structure of metals was examined, the main object 

 of the research being to determine whether the 

 crystalline structure of a metal can be affected when 

 subjected to ranges of stress less than the limiting 

 range of stress (fatigue range). With " Armco " iron, 

 mild steel, and copper, crystalline " slip " occurs at 

 ranges of stress considerably less than the fatigue 

 range. It is suggested that metals can be " strain- 

 hardened " under the action of alternating stresses, 

 as well as under static stresses ; fracture occurs, in 

 a metal subjected to alternating stresses, when a 

 certain limiting strain for the material is exceeded. — 

 W. Sucksmith and L. F. Bates : On a null method of 

 measuring the gyro-magnetic ratio. A new method 

 is described of determining the gyro-magnetic ratio ; 

 as in the ordinary resonance method, the specimen, 

 suspended vertically by a fine wire along the axis 

 of a helix, is magnetised by an alternating current 

 of the same frequency as the natural frequency of 

 the system ; but the resulting resonance amplitude 

 is reduced to zero by a series of impulses timed to 

 oppose those due to gyro-magnetic effect. As no 

 measurement of magnetic moment, frequency, or 

 damping is involved, a considerable gain in precision 

 is obtained. The method is independent of time-lag 

 in magnetisation, and so can be applied to Heusler 

 alloys. The following mean values of the ratio 

 obtained for iron, nickel and Heusler alloys were 

 obtained : Iron 0-503 ; nickel 0-501 ; Heusler alloys 

 0-501. — J. H. Shaxby : Studies in Brownian move- 

 ment. — II. The determination of Avogadro's number 

 from observations on bacteria (cocci). A determina- 

 tion of Avogadro's number by measuring the dis- 

 placements, due to their Brownian movements, of 

 small spheres suspended in water was carried out 

 with cocci. Their surfaces may be supposed to be 

 " wetted " so that there is no slip between the water 

 immediately adjacent and the spheres themselves, 

 and the resistance which might arise from electrical 

 sources depending on slip is avoided. Tlie value of 

 N thus found, from the large number of observations 

 made on Staphylococcus albus, is 6-o8 x 10*' — H. 

 Hartridge and F. J. W. Roughton : Tne kinetics of 

 Haemoglobin. — II. — A. F. A. Young : The thermionic 

 and photo-electric properties of the electro-positive 

 metals. — O. F. T. Roberts : The theoretical scattering 

 of smoke in a turbulent atmosphere. 



Zoological Society, November 6. — Sir S. F. Harmer, 

 vice-president, in the chair. — A. Loveridge : (i) East 

 African birds (chiefly nesting-habits and endo- 

 parasites), collected 1920-1923. (2) East African 

 snakes, collected 191 8-1923. (3) East African tor- 

 toises, collected 1921-1923, with description of a 

 new species of soft land -tortoise. (4) East African 



NO. 2822, VOL. I I 2] 



Uzards, collected 1920-1923, with descriptions of two 

 new races of Agama lionotus Blgr. (5) East African 

 insects, collected 1915-1922. — I. G. S. Montagu : On 

 some mammals from Jugo-Slavia. — I. G. S. Montagu 

 and Miss Grace Pickford : The Guernsey Crocidura. — 

 G. H. Goldfinch : Notes on the African crested rat 

 {Lophiomys imhaiisi).—il. G. Jackson : A revision 

 of the isopod genus Ligidium Brandt (Crustacea). — 

 S. S. Flower : On additions to the snake fauna of 

 Egypt. — S. Hirst : On some new or little-known 

 species of Acari. — C. F. Sonntag : On the pelvic 

 muscles and generative organs of the male chimpanzee. 



Geological Society, November 7. — Prof. A. C. 

 Seward, president, in the chair. — R. W. Hooley : On 

 the skeleton of Iguanodon atherfieldensis sp. nov., 

 from the Wealden shales of Atherfield (Isle of Wight). 

 The nearly complete specimen was obtained in 191 4. 

 There is an essential similarity as regards the relation- 

 ship of the bones of the skull to the American pre- 

 dentate dinosaurs. Grooves on the premaxillae prove 

 that the tip of the snout was sheathed in horn. The 

 quadrate bone articulated freely with the squamosal, 

 and there was a fore-and-aft action of the mandible. 

 The tongue must have been extremely narrow, with a 

 broad tip, and prehensile. The neck was habitually 

 flexed, the point of greatest arching being at the 

 ninth cervical. All the pre-sacral vertebrae carry 

 ribs. The sacrum comprises six fused vertebrae. 

 The ossified elements of the left carpus were preserved. 

 The integument was very thin and covered with 

 small tubercles, interspersed with groups of large 

 polygonal plates, as in Trachodon. The estimated 

 length of the skeleton is 6-3 m. (about 21-6 feet). 

 /. atherfieldensis is distinct from any known species, 

 and the skull and bones are intermediate in form 

 between that of /. mantelli and /. bernissartensis. — 

 S. H. Reynolds : The igneous rocks of the Tortworth 

 inlier. The igneous rocks occur in two bands, the 

 upper of which is associated with calcareous tuffs 

 containing Silurian fossils and is doubtless lava. 

 The lower band appears to be intrusive. The rocks 

 of the two bands have several features in common. 

 The rocks of the lower band are characterised by the 

 presence of pseudomorphs after olivine, and may be 

 grouped as olivine-enstatite-basalts. Those of the 

 upper band are devoid of ohvine, and consist of 

 pyroxene-andesite. They are characterised by the 

 presence of highly corroded xenocrysts of quartz and 

 felspar, and by the occurrence of variolitic and glassy 

 patches in the ground-mass. 



Linnean Society, November 15. — Dr. A. B. Rendle, 

 president, in the chair. — E. J. Salisbury : The relation 

 of earthworms to soil reaction. Natural undisturbed 

 soils usually show a definite gradient with respect to 

 organic material and acidity, both of which tend to 

 attain a maximum at the surface. Analyses of worm 

 casts show that these have a high organic content 

 indicating their origin from the superficial and most 

 acid layers. Comparison of the hydrogen ion con- 

 centration of worm casts and surface soil shows that 

 acid soils tend to be rendered much less acid by 

 passage through the worm. Markedly alkaline soils 

 may similarly be rendered less alkaline. The former 

 action may be attributed to the calciferous glands. 

 The greatest frequency of worms is met with in soils 

 with approximately neutral reaction. — Miss E. M. 

 Blackwell : The flora of Solomon's Pools. Solomon's 

 Pools lie about six miles south of Jerusalem, 2616 

 feet above sea level, in a valley, W&dy ArtAs, which 

 runs east and west between low hills of red-brown 

 ferruginous earth through which limestone bosses 

 project. The pools, three in number, are obviously 

 artificial. The middle and lowest pools have been 



