July 3, 19 19] 



NATURE 



359 



scholarship is of the value of 50/. per annum for five 

 years. Applications must reach the Warden and 

 Secretary of the Medical School, 8 Hunter Street, 

 Brunswick Square, W.C.i, not later than July 12. 



We learn from Science that the Washington School 

 of Medicine, St. Louis, has been offered the sum of 

 30,oooi. by the General Education Board on condition 

 that an equal amount be raised by subscription. This 

 fund of 60,000/.. is to be used for the endowment of 

 the department of pharmacology. From the same 

 source we learn that the board of trustees of the 

 University of Tennessee have voted 2o,oooi. to the 

 medical school to be used for a new laboratory build- 

 ing to be erected in the rear of the Memphis City 

 Hospital. The new building will have laboratories for 

 pathology, bacteriology, chemistry, and physiology. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, June 19.— Sir J. J. Thomson, presi- 

 dent, in the chair. — The Hon. R. J. Strutt : Bakerian 

 lecture : A study of the line-spectrum of sodium as 

 excited by fluorescence. An improved form of sodium 

 vapour lamp, in quartz, was described, giving an 

 intensely bright sodium spectrum, admirably adapted 

 for exciting sodium vapour to resonance. It is found 

 that excitation of sodium vapour by the second line of 

 the principal series leads to the emission of both A 3303 

 and the D line. On tl]e other hand, as might be 

 expected, excitation by the D line leads to the emis- 

 sion of the D line only, without 3303. H only one of 

 the components of the doublet 3303 is stimulated, both 

 the D lines are emitted. When D light falls on sodium 

 vapour of appropriate density, it is known that an 

 intense surface emission occurs from the front layer, 

 and a weaker one from succeeding layers. Analysis 

 by absorption in an independent layer of sodium 

 vapour shows that the superficial emission is more 

 absorbable, and therefore nearer the centre of the 

 D lines. The breadth of the D lines in superficial 

 resonance has been estimated by interferometer 

 methods. It is found to correspond with the breadth 

 conditioned by the Doppler effect, calculated on the 

 assumption that the luminous centre is the sodium 

 atom. Polarisation could not be detected in the ultra- 

 violet resonance radiation, though, in accordance with 

 previous observers, it was readily observed in D reson- 

 ance. 



Mineralogical Society, June 17. — Dr. -\. E. H. Tutton, 

 past-president, in the chair. .V. E. Kitson : Diamonds 

 from the Gold Coast. The crystals and their occur- 

 rence were described. — A. Brammall : Andalusite 

 (chiastolite) : its genesis, morphology, and inclusions. 

 In a survey of thermometamorphic " spotted " rocks, 

 <vidence based on structural features, optical proper- 

 ties, and microchemical reactions is adduced to show 

 that certain types of spots, convergent towards such 

 minerals as chiastolite, andalusite, cordierite, mica, and 

 chloritoid, record arrested development, and that they 

 are probably ontogenetically related. The spot is a 

 complex system containing a volatile phase, water, 

 and its development involves metamorphic diffusion 

 :md differentiation, controlled by changing conditions of 

 temperature and stress, the tendency being towards the 

 attainment of an equilibrium end-point in a metastable 

 mineral. Thermal and stress conditions adequate to 

 initiate the tendency may be inadequate to sustain 

 it, the time factor also bein^ involved ; development 

 may be arrested and abortive effort recorded as a 

 mineral "spot," the nature of which is determinable, 

 but is often vag-ue or wholly conjectural. The chemi- 

 cal and physical characters of argillaceous sediments 



NO. 2592, VOL. 103] 



are considered, with special reference to the genesis 

 of chiastolite. Clays contain a high proportion of 

 hydrated silicates of alumina, readily soluble and in 

 part probably colloidal. On rise of temperature 

 diffusion effects the segregation of the primary clot ; 

 diffusion inwards of allied molecules and diffusion out- 

 wards of alien substances tend to promote homo- 

 geneity and reconstitution within the spot, the peri- 

 pheral zone being maintained for a time in a relatively 

 high state of hydration. In this connection the 

 peripheral zone of yellow-brown, non-pleochroic, and 

 isotropic stain is significant ; microchemical tests show 

 that it is due to ferric hydrates, which are known to 

 be liable to sp>ontaneous dehydration, and it is sug- 

 gested that the ferric hydrate in the peripheral stain 

 acts as a catalyst, assisting dehydration within the 

 spot and transmitting water to the base. For chiasto- 

 lite (andalusite)', a mechanism of formation is sug- 

 gested to cover the observed facts, to explain the 

 characteristic distribution of its opaque inclusions, and 

 to account for crystals -which have the superficial 

 aspect of cruciform twins. — R. H. Rastall : The mineral 

 composition of oolitic ironstones. In many oolitic iron- 

 stones the ooliths contain more iron or are more 

 highly oxidised than the matrix. Assuming that the 

 iron-content of such rocks is introduced by metaso- 

 matism of calcium carbonate, this may be explained 

 in the following way : Many ooliths and organic 

 fragments in limestones consist of aragonite, while the 

 cement is calcite. Aragonite is less stable than calcite 

 and more readily decomposed by iron-bearing solu- 

 tions, which therefore attack the aragonite first, while 

 the calcite is replaced later. Hence we have the fol- 

 lowing scheme in successive stages : — 



Ooliths. aragonite — y chalybite — >■ limonite. 



Matrix, calcite calcite — >- chalybite. 



The ooliths are always a stage ahead of the matrix 

 in replacement and oxidation. The origin of the green 

 silicate of iron, found in many ironstones, requires 

 further investigation.— L. J. Spencer: Eighth list of 

 mineral names. 



Royal Anthropological Institute, June 17. — Prof. A. 

 Keith, oast oresident, in the chair.— J. Raid Moir : 

 Flint implements from Glacial gravel north of Ipswich. 

 This gravel is covered bv a definite Glacial boulder 

 clav, and is therefore "of Glacial age. Mr. W. 

 Whitaker states that the gravel is what is usually 

 called " Middle Glacial," and this view is shared by 

 the author. .As, however. Lower Glacial deposits do 

 not occur in the loswich district, the use of the term 

 Middle Glacial is deprecated. The flint implements 

 comprise small platessiform specimens, verv similar 

 in their outlines to some of the Early ChelUan arte- 

 facts, points, radoirs. and well-made scrapers. These 

 and the numerous flakes recovered exhibit all the 

 usual characteristics of flints ascribed to human work- 

 manship. Quartzite hammer-stones and burnt flints 

 occur in the gravel, and the deposit probably repre- 

 sents, in oart, a land surface broken up and re- 

 deposited bv water resulting from melting ice. It is 

 not at present possible to correlate the Ipswich gravel 

 with others in different parts of the country containing 

 similar implements, but further investigation may 

 enable this to be done. 



Zoological Society, June 17.— Prof. E. W. MacBride, 

 vice-president, in the chair.— J. T. Carter : Occurrence 

 of denticles on the snout of Xiphias.— Dr. C. W. 

 Andrews : New species of Zeuglodons and a leatherv 

 turtle from the Eocene of Southern Nigeria.— E. 

 Heron-Allen and A. Earland : Experiments on the cul- 

 tivation of Vernettilina polystropha Reuss, in hyper- 

 tonic sea-water and gem sand. — C. Motley : Equatorial 



