lOO 



NATURE 



[March i6, 191 i 



suitable canclidntps at rccofjnised schools. To be recog- 

 nised by the Council, a school must be inspected by an 

 approved educational Iwdy and reported as fulfilling the 

 necessary educational requirements, and maintain a con- 

 tingent of the Officers Training Corps. A certain number 

 of prize cadetships is to be awarded to successful com- 

 petitors at each half-yearly examination for admission to 

 the Royal Military Academy and Royal Military College 

 with the view of encouraging a higher standard of educa- 

 tion among candidates for commissions in the Army, and 

 of reducing in the case of the better qualified candidates 

 the expenses incurred. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, March 9.— Sir Archibald Geikie, K.C.B., 

 president, in the chair.— Prof. P. V. Sevan : The absorp- 

 tion spectra of lithium and caesium. This paper gives an 

 account of the continuation of work done on the absorption 

 spectra of vapours of the alkali metals. Difficulty was 

 found in obtaining tubes which were not acted on by 

 lithium vapour, and this difficulty was never completely 

 surmounted. By the use, however, of considerable quantity 

 of lithium in a steel tube, the absorption spectrum was 

 obtained, and twenty-.sev<en lines of the principal series were 

 observed. The measurements for the whole series are given 

 in the paper, the lines from the tenth to the twenty-seventh 

 being new. The paper further gives measurements of 

 wave-lengths for the similar lines for cassium. The series 

 has been extended to include twenty-four lines, and re- 

 measurements were made, as there was pointed out by 

 Prof. Hicks some probable errors in former determinations. 

 The two series for lithium and caesium are compared with 

 the foimula; suggested by Hicks, and it is found that the 

 agt^ernent of calculated and observed wave-lengths is 

 exceedingly good, a slight change in one of the constants 

 for caesium being indicated. — Prof. P. V. Bevan : Dis- 

 persion in vapours of the alkali metals. This paper gives 

 an account of measurements of the dispersion in rubidium 

 and sodium vapours. The work is of the same character 

 as that on the dispersion in potassium vapour described in 

 the Proceedings of the Royal Society, A, 84, 19 10. Dis- 

 persion curves for the rubidium vapour were obtained for 

 the region of wave-lengths 6000 to 3000. Anomalous dis- 

 persion effects were observable at the first eight members 

 of the principal series lines. These lines being pairs, 

 interesting curves are obtained for the second and third 

 pairs. _ The relative values of the constants in the Maxwell- 

 Sellmeier formula are obtained, and similar conclusions 

 drawn from them, as in the case of the paper already re- 

 ferred to concerning the numbers of atoms taking part in 

 the absorption of light. Measurements of wave-lengths of 

 the lines of the principal series are given, and these are 

 shown to be in good agreement with the values calculated 

 from the Hicks modification of the Rvdberg formula. 

 Similar measurements were made in the 'case of sodium. 

 In this case the effects are not so large or so easily obtain- 

 able as in the cases of rubidium and potassium. Measure- 

 ments were also made to see if any temperature effect could 

 be delected in the ratios of the constants of the dispersion 

 formula. These go to show that the ratios ntjm^, mjm^, 

 c\c., where nnjm^, &c., are the constants corresponding to 

 the first, second, &c., lines of the principal series, increase 

 with increase of temperature. This result is what might 

 be expected if the absorbing atoms are ordinary atoms to 

 which corpuscles become attached, more complex systems 

 corresponding to higher members of the series of lines in 

 the spectrum.— J. Kendall: The ionic solubilitv-product. 

 Previous mvestigations upon the simultaneous solubility in 

 water of two substances containing a common ion have 

 been confined to those cases in which the substances 

 examined have been of the same type— i.e. either both 

 strong or both weak electrolytes. In each case the experi- 

 mental results have been considered to be consistent with 

 the hypothesis of a constant ionic solubilitv-product. 

 although, even in dilute solutions, the agreement is onlv 

 approximate. The primary object of this research was to 

 test the applicability of the theory to substances of opposite 

 types, one strong and one weak electrolyte. Preliminary 

 NO. 2159, VOL. 86] 



experiments showed that here also small divergencies were 

 obtained. Finally, a series of experiments on all the 

 possible r>'pes of combination of two electrolytes was carried 

 out, first with dilute and afterwards with more concen- 

 trated .solutions, in order to ascertain the cause of ' 

 divergencies and their bearing upon the solidity <>: 

 theory. The results obtained show that the mutual !» 

 actions of the two substances play an important part : 

 equilibrium. The general rule appears to be that tw<. 

 stances chemically similar in character give result* in 

 excess of theoretical, while with two chemically dissimilar 

 a diminution is observed. In dilute solutions all <!' 

 gencies are small, but fundamental, and in certain 

 the amount due to each of the two substances is calcul 

 In the more concentrated solutions, where the solvent ■ 

 is greater, the three possible types of solubility curv< - 

 obtained and discussed, and it is found that in all cases 

 experimental divergencies from values indicated by the con- 

 stant solubility-product hypothesis can be fully accounted 

 for by this solvent effect of the substances upon each other. 

 — Dr. W. H. Ecclee and H. Morrie-Airey : Note on the 

 electrical waves occurring in nature. The occurrence of a 

 lightning stroke must, in general, give rise to either a 

 solitary electric wave or a train of electric waves which 

 will be propagated from the centre of discharge to un- 

 known distances. These vagrant waves join with other 

 natural electric phenomena to cause disturbances — technic- 

 ally called " atmospherics " — in the receiving circuits of 

 wireless telegraph stations. Among these other phenomena 

 may be mentioned charged hail or rain striking the air- 

 wires and earth-air currents. The present communication 

 describes an endeavour to determine the proportion of 

 atmospherics of distant origin. The plan of attack was as 

 follows : — One of the authors in London and the other in 

 Newcastle arranged receiving apparatus just as for the 

 telephonic reception of signals, and simultaneously listened, 

 at prearranged times, for atmospherics. A hand record of 

 the time and intensity of each strong atmospheric was made 

 on paper ruled to represent ten seconds of time per inch. 

 By arranging the periods of observation to include the mid- 

 night time signals from the Eiffel Tower or from Nord- 

 deich, the time records of the two observers could be 

 accurately coordinated. The observers exchanged copies of 

 their records, and counted the number of marks coinciding 

 in time. The results tend to show that about 70 per cent, 

 of the atmospherics audible at two stations 270 miles apart 

 are due to vagrant waves propagated from electrical dis- 

 charges that take place at (possibly) very great distances. 

 — Prof. E. A. Sch&fer and K. Mackenzie : The Action of 

 animal extracts on milk secretion. 



Linnean Society, March 2.— Dr. D. H. Scott, F.R.S., 

 president, in the chair. — Dr. Burr : Dermaptera (earwigs) 

 preserved in amber. — Miss Laura Roscoe Thornely : 

 Report on the marine Polyzoa of the collection made by 

 Mr. J. Stanley Gardiner, in the Indian Ocean, in H.M.S. 

 SeaJark during 1905. — W. M. Tattersali : The Mysidacea 

 and Euphausiacea collected in the Indian Ocean during 

 1905. 



Royal Anthropological Institute, March 7.— Prof. 

 Gowland, F.R.S., in the chair. — Dr. Duckworth : Cave 

 exploration at Gibraltar in September, 1910. The object 

 of this research was to gain information on the spot as 

 to the exact conditions in which prehistoric human re- 

 mains occur on the Rock of Gibraltar. In addition to a 

 general survey of the locality, two caves were explored. 

 The first cave examined is in Forbes Quarry, whence the 

 human cranium, so well known as the Gibraltar skull, 

 was obtained in 1848. The cave in question proved very 

 difficult to work, owing to the great density of ten 

 successive stalagmite strata composing its floor. The 

 latter was exposed over a considerable area, and at a 

 depth of 4 feet 6 inches solid rock was always present. 

 No animal remains could be detected. Since this excava- 

 tion, Forbes Quarry has been almost completely filled, 

 owing to the fall of many tons of rock from the heights 

 above. The mouth of the cave is now hardly accessible. 

 The second cave was at a considerable height (800 feet) 

 above sea-level. The excavation yielded abundant evidence 

 that it had been a resort v\ prehistoric man in the early 

 Neolithic stage of culture. The conditions are best ex- 



