8oo 



NATURE 



[August i8, 192 i 



stage, so that the cycle has not been quite completed, 

 and the length of time passed in the larval state is 

 still unknown.— Dr. R. J. Tillyard : Revision of the 

 familv Eustheniidae (order Perlaria), with descriptions 

 of new genera and species. The Eustheniidae are 

 described as a distinct family possessing only archaic 

 family characters. To the three genera and four 

 species which have been described the author adds 

 two genera and seven species, all of which are de- 

 scribed for the first time. The known distribution of 

 the family is Tasmania, Victoria, New Zealand, 

 mountains of East Australia, and southern Chile, and 

 is regarded as an argument in favour of an Antarctic 

 origin of the Perlaria. — Margaret H. O'Dwyer : Pre- 

 liminary report on the nutritive value of certain Aus- 

 tralian grasses. A number of grasses grown at the 

 Botanic Gardens and at various State experiment 

 farms have been analysed with the view of deter- 

 mining their value as foodstuffs. In order that the 

 results might be of value for comparative purposes 

 the material was obtained so far as possible at the 

 following well-defined stages of growth :— (i) About 

 half-wav between the time when it begins to shoot 

 and the flowering period, (2) eafty 1!ow«ring period, 

 and (3) when the seed is quite set. The paper com- 

 prises a preliminary discussion of the methods used 

 and the results of the analyses. \ 



Cape Town \ 



Royal Seciety of South Africa, June^ 15. — Dr.i A. 

 Young in the chair. — V. H. Rrfnk : A preliminary 

 genetic study on the osteology of the Griquas. — E. 

 Newbery : Note orr the life-period of the over-voltage 

 compounds. A series of experiments has been 

 carried out to determine the effect of changes in the 

 speed of the commutator upon the measured over- 

 voltage of various cathodes in dilute sulphuric acid. 

 The commutator was rotated at speeds varying be- 

 tween 300 and 1500 revs, per minute, and an interest- 

 ing set of curves was obtained bv plotting the observed 

 over-voltages against these speeds. The relative rates 

 of decomposition or decay of the over-voltage com- 

 pounds are shown by these curves. Those of zinc and 

 chromium are so stable that no perceptible change of 

 potential occurs within the time-limits of the experi- 

 ments. The hydrides of silver, platinum, and graphite 

 show signs of decay after one-twentieth of a second, 

 those of copper and cadmium after one-thirtieth of 

 a second, whilst those of lead and nickel appear to 

 be decomposed with very great rapidity. 



Julv 20. — Dr. J. D. F. Gilchrist, president, in the 

 chair! — E. J. Hamlin : The effect of sunlight on 

 secondary batteries.— Dr. J. D. F. Gilchrist : Note on 

 the pectoral fin of Achirus (a species of sole). 



Books Received. 



Memoirs of the Geological Survev : England and 

 Wales. The Geology of the South 'Wales Coalfield. 

 Part xiii. : The Country around Pembroke and 

 Tenby. By E. E. L. Dixon. Pp. vi+220+5 plates. 

 (Southampton : Ordnance Survev Office ; London : 

 E. Stanford, Ltd.) 85. net. 



Greek Atrocities in Turkey. First Book, Publica- 

 tion No. 4. Pp. 153 + 5. (Constantinople: Ministry 

 of Interior, Dept. of Refugees.) 



Ministrv of Finance, Egypt : Survey of Egypt. The 

 Soils and' Water Supply of the Maryut District, West 

 of Alexandria. By Dr.' W. F. Hume and F. Hughes. 

 (S.D.P. No. 37.) Pp. v+52 + xiii plates. (Cairo: 

 Government Press.) P.T.io 



Loughborough College, Leicestershire. Calendar : 

 Session 1921-22. Pp. xviii+190. (Loughborough: 

 The Echo Press.) 25. 6d. net 



NO. 2703, VOL. 107] 



A Text-book of Physics. Edited by A. W. Duff. 

 Fifth edition, revised. Pp. xiv+700. (London : J, 

 and A. Churchill.) 165. net. 



Department of Mines and Explosives, Mysore 

 State. Report of the Chief Inspector of Mines in 

 Mysore for the Year 1919-20; with Statistics for the 

 Calendar Year 1919. Pp. 34+45. (Oorgaum.) 

 2 rupees. 



The Law of Births and Deaths : Being a Study of 

 the Variation in the Degree of Animal Fertility under 

 the Influence of the Environment. By Charles 

 Edward Pell. Pp. 192. (London : T. Fisher Unwin, 

 Ltd.) 125. 6d. net. 



Magnetizzazione della Elettricit^ : Rotazione Elet- 

 tro-Magnetica del Sistema Planetario e Specialmente 

 del Terreno e dei Vegetali Terrestri. By Niccol(') 

 Mancini. Pp. iv + 91. (Firenze : B. Seeber.) 



Die Ursachen der diluvialen Aufschotterung und 

 Erosion. By W. Soergel. Pp. v + 74. (Berlin : 

 Gebriider Borntraeger.) 18 marks. 



Department of Scientific and Industrial Research,: 

 Report of the Fuel Research Board for the Years 

 1920, 192 1. First Section : Steaming in Vertical Gas 

 Retorts. Pp. viii+54. (London : H.M.S.O.) 15. 6d. 

 net. 



.An Introduction to the Flora of Natal and Zulu- 

 land. By Prof. J. W. Bews. Pp. vi + 248. (Pieter- 

 maritzburg : City Printing Works ; London : Wheldon 

 and Wesley, Ltd.) 155. 



CONTENTS. PAGE 



A Suggested Institute of Human Sciences . . . 769 



Astrology. By Dr. Charles Singer 771 



Physical Chemistry, Pure and Applied. By 



T. M. L 772 



The Realm of Man. By Geo. G. Chisholm . . . 774 



Calculus for Students. By G. B. M 775 



Our Bookshelf 775 



Letters to the Editor: — 



Biological Terminology.— Dr. F. A. Bather, F. R. S. 778 



The Fauna of Scottish Lochs. — Dr. N. Annandale 778 



Magnetic Double Refraction in Smokes. — L. Tieri . 778 

 The Exploitation of Irish Peat. — Dr. Alexander 



Fleck . ^ • 779 



Scarcity of Swallows. — Andrew Pride ... . 779 



Earthworms Drowned in Puddles. — R. B. Marston 779 

 The Neglect of Science.— Prof. Sydney J. Hickson, 



F.R.S 779 



The Determination of Sex. {With Diagram.) By 



Prof. R. Goldschmidt -..780 



Further Remarks on Relativity. III. By Sir 



Oliver Lodge, F.R.S 784 



Cohesion. By Dr. Herbert Chatley 786 



International Conference of Chemistry 787 



Obituary: — 



Prof. G. Lippmann, For.Mem.R.S 788 



Capt. W. E. Rolston 789 



Samuel Alfred Varley. By C. B 789 



Notes ... .... 790 



Our Astronomical Column : — 



The August Meteoric Display 793 



The Bright Object near the Sun 793 



Continuation of the Ephemeris of Eros 793 



University Education in the United States . , 794 

 Recent Work on Minerals and Rocks. By 



G. A. J. C 794 



Plant Pests and their Control. By Dr. Wilham B. 



Brierley 795 



Studies of Shore Fishes. By W. C. M 796 



The Lac and Shellac Industry in India. By Dr. 



A. D. Imms 797 



Flight of Flying-fishes . . . • .797 



University and Educational Intelligence . ... 798 



Calendar of Scientific Pioneers 79^ 



Societies and Academies 799 



Books Received 800 



