35^ 



NATURE 



[May 12, 192 1 



Sir William A. Tilden. Pp. xvi+296. (London : G. 

 Routledge and Sons, Ltd. ; New York : E. P. Button 

 and Co.) 125, 6d. net. 



A Handbook of Laboratory Glass-Blowing. By 

 Bernard D. Bolas. Pp. vii+io6. (London: G. Rout- 

 ledge and Sons, Ltd. ; New York : E. P. Dutton and 

 Co.) 35. 6d. net. 



The West Riding of Yorkshire. By Bernard 

 Hobson. Pp. xii+i88. (Cambridge: At the Uni- 

 versity Press.) 4.V. 6d. net. 



Mededeelingen van de Landbouwhoogeschool en 

 van de Daaraan verbonden Instituten. Deel xix., 

 Bijdrage tot de Kennis der Zuidelijke Zwerfsteenen 

 in Nederland en Omgwing. By C. H. Oostingh. 

 Pp. iv+165+iv plates. (Wageningen : H. Veenman.) 



Diary of Societies. 



TUUliSDAY, Mai 12. 



RoxAL INSTITL'TION OF Grkat Bhitain, at 3.— Dr. C. 8. llyers : 

 Psychological Studies : (2; The Appreciation of Blusic. 



Harveian SociETi or London (at Paddington Infirmary), at 4.30. — 

 Clinical Meeting-. 



Institctk of Pathologi and Reseauch (St. Mary's Hospital, Pad- 

 dington), at 4.30. — Sir James Mackenzie: The Opportunities of 

 the General Practitioner are Essential for the Investigation of 

 Disease and for the Progress of Medicine. 



RoxAL SociETX, at 4.30.— G. W. Walker: The Problem of 

 Finite Focal Depth revealed by Seismometers. — E. A. Griffiths : 

 A Liquid Oxygen Vaporiser.— Dorothy M. Palmer and W. G. 

 Palmer : Some Experiments on the Catalytic Reduction of 

 Ethylene to Ethane.— W. G. Palmer : The Catalytic Activity of 

 Copper. Part II.— Prof. J. F. Jenkin and D. N. Shorthose : The 

 Total Heat of Liquid Carbonic Acid.— Dr. A. 0. Rankine : The 

 Viscosity and Molecular Dimensions of Gaseous Cyanogen. 



London Mathematical Society (at Royal Astronomical Society), 

 at 5.— H. W. Turnbull : Invariants of Three Quadrics.— G. H. 

 Hardy and J. E. Littlewood : (1) Some Problems of Diophantine 

 Appro-ximation ; (2) The Lattice Points of a Right-angled 

 Triangle (Second Paper). 



Child-Studt Society (at 90 Buckingham Palace Road), at 6.— 

 Discussion on Individual Training.- Miss F. E. Webb : Individual 

 Training in the School.— Miss Sabina Salt : Preparation in the 

 Training College for Individual and Group Work in the School.— 

 Miss C. M. A. Coombs : Vertical Classification in an Infants' 

 School. 



Sociological Society and Regional Association (at 65 Belgrave 

 Road), at 8.15.— Prof. P. Geddes : Co-operation in Social Studies. 



ROTAL Society of Medicine (Neurology Section) (Annual General 

 3Ieeting), at 8.30.— Prof. Marinesco : Encephalitis Lethargica. 



FRIDAY, May 13. 



Royal Asteonomical Society, at 5.— A. N. Brown : Observations of 

 V Cassiopeise (Ch. 8324) in 1916-21.- A. A. Rambaut : Observations 

 of the Solar Eclipse of 1921, April /, at the Radoliffe Observa- 

 tory, Oxford.— W. H. Van Den Bos: The Orbit of i 554 = 80 Tauri. 

 —Rev. A. L. Cortie and Rev. J. Rowland : The Partial Eclipse 

 of the Sun, 1921, April 7.— C. Martin and H. C. Plummer ; 

 Magnitude Curves of Three Short-period Variable Stars, RR 

 Leonis, Y Aurigse, and UU Cassiopeise.- Rovai Observatory, 

 Greenwich: Observations of the Solar Eclipse of 1921, April 7.— 

 Royal Observatory, Greenwich : Observations of Comets, 1921, 

 a, b (Reid and Pons-AN'innecke) .— L. J. Comrie : Eclipse of Rhea 

 by the Shadow of Titan.— Dr. T. Royds : Lantern Slides illus- 

 trating Recent Work at the Kodaikanal Observatory.— Prof. 

 ^^ . H. Pickering : Observations of the Moon at the Harvard 

 College Observatory, Jamaica. 



Physical Society of London (at Imperial College of Science and 

 Technology), at 5.— L. Hartshorn and E. S. Keeping: Notes on 

 Vacuum Tubes used as Detectors of Electrical Oscillations.— 

 B. W. Clack : The Coefficient of Diffusion of Certain Saturated 

 Solutions.— Dr. G. D. West: Experiments on Thermal Transpir.v- 

 tion Currents. 



Institute of Transport (at Royal Society of Arts), at 5. 



RoTAL Society of Medicine (Clinical Section), at 5.30.— Annual 

 General Meeting. 



Junior Insiitution of Engineers, at 8.— H. G. Brown : Scientific 

 Developments in Gas Measuring Instruments. 



RoTAL Society of Medicine (Ophthalmology Section), at 8.30.— Dr. 

 D. L. Davies : Lachrymal Obstruction, Results of Anastomotic 

 Method of Treatment (Toti).— E. Clarke: Lessons from Forty 

 Tears of Refraction Work.— Miss J. C. Mann : Aphakia in a 

 Human Embryo of Five or Six Weeks. 



Royal Institution of Great Britain, at 9.— Dr. W. Bateson : 

 The Determination of Sex. 



SATURDAY, May 14. 

 Royal Institution of Great Britain, at 3.— Prof. E. C. C. Baly : 

 Chemical Reaction. 



TUESDAY, May 17. 

 Royal Institution of Great Britain, at 3.— E. Clodd : Occultism : 

 Its Origin and Development. 



NO. 2689, VOL. 107] 



WEDNESDAY, May 18. 



Royal Hobticuliubal Society, at 3. 



RoY.AL Meteorological Society, at 5.— J. E. Clark and H. B. 

 Adames : Report on the Phenological Observations for 1920. — 

 Dr. E. J. Salisbury : Phenology and Habitat, with Special 

 Reference to the Phenology of Woodlands. 



RoY.AL Society of Medicine (History of Medicine Section) (Annual 

 General Meeting), at 5. — Dr. C. G. Cumston : A Brief Historical 

 Summary of the Treatment of Trachoma, with Special Reference 

 to the Arabian School and the Writings of Ali Ibu-el-Aissa. 



Royal Society of Medicine (Surgerv Section) (Annual General 

 Meeting), at 5.30. 



Royal Microscopical Society, at 8. 



THURSDAY, May 19. 



Royal Institution of Great Britain, at 3. — E. Law : The Archi- 

 tecture and Art of Hampton Court Palace : In Tudor Times. 



Institute of Pathology and Research (at St. Mary's Hospital, 

 Paddington), at 4.30. — Dr. H. H. Dale: Anaphylaxis and Im- 

 munity. 



Royal Society of Medicine (Dermatology Section) (Annual General 

 Meeting), at 5. 



Institution of Mining and Metallurgy (at Geological Society), 

 at 5.30.— E. H. Clifford : Scheme for Working the City Deep Mine 

 at a Depth of 7000 ft.— The following Papers will be submitted 

 for Discussion :— F. P. Caddv : Stope Measuring at the Passagem 

 Mine of the Gold Mines of Oiiro Preto, Ltd.— J. A. P. Gibb : Notes 

 on Some Useful Alignment Charts. 



Chemical Society (Informal Meetingl, at 8. 



RttNTGEN Society (in Phvsics Lecture Theatre, University College), 

 at 8.15. 



FRIDAY. May 20. 



Royal Society of Medicine (Otology Section) (Annual General 

 ;\reeting), at 5. — P. J. Cleminson : Sinusitis in Children. 



Royal Society of Medicine (Eleetro-Therapeuticg Section) (Annual 

 General Meeting), at 8..30.— Discussion : The Stomach. 



Royal Institution of Great Britain, at 9. — Prof. E. H. Starling : 

 The Law of the Heart. 



SATURDAY, May 21. 



Royal Institution op Great Britain, at 3. — F. Legge : Gnosticism 

 and the Science of Religions. 



CONTENTS. PAGE 



The Potash Position ... 321 



Human Palaeontology. By Prof. Arthur Keith, 



F.R.S 322 



British Scientific Instruments . . 324 



Text-books of Organic Chemistry. ByJ.B. C. . . 325 



Forestry in the United States 326 



Our Bookshelf 327 



Letters to the Editor: — 



Earthworms Drowned in Puddles. — Sir E. Ray 



Lankester, K.C B., F.R.S. . 329 

 A "New" Type of Tool of Mousterian Age. {///us- 



. /ra/£^)— Prof C. G. Seligman, F.R.S. . 330 

 Molecular Structure and Energy. — Prof. Alan W. C. 



Menzies .... 33^ 



British Laboratory and Scientific Glassware. — ^J. H. 



Davidson ... 331 

 Trotozoa and the Evolution of the Gregarious Instinct. — 



Reginald James Ludford 332 



The Nature of Vowel Sounds. — Prof. C. V. Raman ; 



Prof. E. W. Scripture . .... 332 

 Literature for Jerusalem University. — Prof. S. 



Alexander, Israel M. Sieff, D. B. Stanhill . 333 



Waste Oil from Ships.— Prof. T. D. A. Cockerell 333 

 Organism in Flint. — Prof. Grenville A. J. Cole, 



F.R.S . .333 



Isotopes and Atomic Weights. {I//ustrated.) By 



Dr. F. W. Aston 334 



Natural Camouflage. {Il/ustrateJ.) By E. B. P. . . 338 

 Obituary : — 



Prof. W. R. Brooks. By W. F. Denning ... 340 



Notes . ... ... .... 341 



Our Astronomical Column : — 



Eclipse of Rhea by Titan 345 



Comets . 345 



The Stone-axe Factory of Graig-lwyd, Penmaen- 



mawr 34^ 



Descriptive Botany 346 



Origin of Petroleum and Cause of Gas Pressure. 



By T. O. B 347 



The University of London 348 



University and Educational Intelligence . . . 348 



Calendar of Scientific Pioneers 349 



Societies and Academies 35° 



Books Received 35^ 



Diary of Societies 35* 



