3^4 



NATURE 



[May 19, 192 1 



ROnigen Societi (in Physics Lecture Theatre, Uniyersity College), 

 at 8.15. — Prof. A. V. Hill : Electrical Instruments and Phenomena 

 in Physiology (Fourth Silvanus Thompson Memorial Lecture). 



FRIDAY, Mat 20. 



RoTAL SociETT OF MEDICINE (Otology Sectiou) (Annual General 

 Meeting), at 5. — F. J. Cleminson : Sinusitis in Children. 



..Jixioa Institution^ of Enkineers, at 8. — A. Arnold: Liquid Fuels. 



RorAt Society of Tbopical Medicine and Hygiene (at 11 Chandos 

 Street, W.l), at 8.15.'— Lt.-Col. H. Kirkpatriok: Trachoma.— C. H. 

 Marshall : New Method of Treatment of Human Trypanosomiasis. 

 — C. Franca : An Early Portuguese Contribution to Tropical 

 Medicine. 



Royal Society or Medicine (Electro-Therapeutics Section) (Annual 

 General Meeting), at 8.30.— Discussion : The Stomach. 



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

 The Law of the Heart. 



SATURDAY, Mai 21. 



Royal Institution of Qreat Britain, at 3.— F. Legge : Gnosticism 

 and the Science of Religions. I. 



MONDAY, May 23. 



Victoria Institute (at the Central Hall, Westminster), at 4.30.— 

 Rev. Dr. W. St. Clair Tisdall : The Date of Daniel. 



Institution of Electrical Enoineers (Informal Meeting) (at Char- 

 tered Institute of Patent Agents), at 7. 



Royal Institute of British Architects, at 8. 



Aristotelian Society (at University of London Club), at 8.— Very 

 Rev. Dean Rashdall and Others : Discussion on Dr. Inge's " The 

 Idea of Progress." 



Medical Society of London (at 11 Chandos Street, W.l), at 8.— 

 General Meeting. 



Royal Society of Medicine (Odontology Section) (Annual Meet- 

 ing), at 8.— J. H. Mummery and G. J. Harborow : A Composite 

 Odontome.— A. T. Pitts: The Prophylactic Extraction of the 

 Third Molars. 



Royal Geographical Society (at .Slolian Hall), at 8.30.— Mrs. Rosita 

 Forbes : Across the Libyan Desert to Kufara. 



Medical Society of London (at 11 Chandos Street, W.l), at 9.— 

 Lord Dawson of Penn : The Colon and Colitis (Annual Oration). 

 TUESDAY, Max 24. 



Institution of G.as Engineers (at Institution of Civil Engineers), 

 at 10 a.m. 



Royal Hokiicultuhal Society (at Chelsea), at 3. 



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

 Its Origin and Development. 



Linnean Society, at 3.— Anniversary Meeting. 



Royal Statistical Society (at Surveyors' Institution), at 5.15.— 

 G. Udny Yule : The Time-correlation Problem, with Especial 

 Reference to the Variate-difCerence Method. 



R0Y.4L Society or Medicine (Medicine Section) (Annual General 

 Meeting), at 5.30.— Dr. C. Riviere and Others: Discussion on 

 Artificial Pneumothorax. 



Zoological Society of London, at 5.30.— The Secretarv : Report on 

 the Additions to the Society's Menagerie during the month of 

 April, 1921.— Dr. C. P. Sonntag : The Comparative Anatomy of 

 the Tongues of the Mammalia. IV. Families 3 and 4. Cebida 

 and Hapalida;.— R. Broom : Some New Genera and Species of 

 Anomodont Reptiles from the Karroo Beds of South Africa.— R. 1. 

 Pocock : The External Characters of some Species of Lutrin« 

 (Otters).— Dr. C. W. Andrews : Note on the Skull of Dinotherium 

 giganteum in the British Museum. 



JlOYAL Photographic Society of Great Britain, at 7.— (Technical 

 Meeting.) Scientific Aspects of Studio Lighting.— L. Gaster : 

 The Selection and Use of Illuminants for the Studio.— J. C. 

 Elvy : Illumination Problems in Kinematography.— J. W. P. 

 Walsh and H. Buckley: Methods of Light Distribution.- 1. G. 

 Priest: A Possible Standard of White Light. 

 MEDNESDAY, May 25. 



Institution of Qas Engineers (at Institution of Civil Engineers), 

 at 10 a.m. 



Royal Horticultural Society (at Chelsea), at 3. 



•Geological Society of London, at 5.30.— G. W. Lamplugh : The 

 Junction of Gault and Lower Greensand near Leighton Buzzard 

 (Bedfordshire). 



Institution of Electrical Engineers (Wireless Section) (at In- 

 stitution of Mechanical Engineers), at 6.— C. F. Elwell and 

 Others : Discussion on Long-Distance Wireless Transmission. 



Royal Microscopical Society (Leather Industries Section), at 7.30. 

 —P. Hampshire : " Run " Pelts in Sweating Process of De- 

 woolling. 



Royal Society of Arts, at 8.— Dr. C. M. Wilson: The War and 

 Industrial Peace : An Analysis of Industrial Unrest. 

 THURSDAY, Max 26. 



Institution of Gas Engineers (at Institution of Civil Engineers), 

 at 10 a.m. 



Royal Horticultural Society (at Chelsea), at 3. 



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

 tecture and Art of Hampton Court Palace. II. In Stuart and 

 Later Times. 



HoYAL Society, at 4.30.— Probable Papers.— Sir Alfred Ewing : The 

 Atomic Process in Ferro-magnetic Induction.— C. D. Ellis : The 

 Magnetic Spectrum of the /3-ravs excited bv the y-rays.- 

 S. Datta : The Spectra of the Alkaline Earth Fluorides and their 

 Relation to Each Other.— Dr. W. L. Balls : A Simple Apparatus 

 tor Approximate Harmonic Analysis and for Periodicity Measure- 

 ments.— Dr. G. R. Goldsbrough : The Influence of Satellites upon 

 , J^^^ °* Saturn's Ring.— Dr. H. Jeffrevs : Certain Geologi- 

 cal Effects of the Cooling of the Earth.— T. Kikuchi : The Moving 

 Striations in a Neon Tube (title only). 



iNSTiTrTE of Pathology and Research (at St. Marv's Hospital. 

 Paddington), at 4.30.— Dr. J. A. Murray: Alms and Progress of 

 the Experimental Studv of Cancer. 



Institution of Electrical Engineers (at Institution of Civil En- 

 gineers), at 6. 

 Concrete Institute (Annual General Meeting), at 7.30. 



FRIDAY. Mai 27. 



Royal Society of Arts (Indian and Colonial Sections), at 4.30.— 

 Sir Charles H. Bedford : Industrial (including Power) Alcohol. 



Physical Society of London (at University College), at 5.— The 

 General Electric Co. (communicated by C. C. Paterson) : A 

 Method for the Micro-analysis of Gases by the Use of the Pirani 

 Pressure Gauge.- H. Pealing : The Reflection of the K-ray 

 Spectrum of Palladium from Fluorspar.— Sir W. H. Bragg : The 

 Intensity of X-rays reflected by the Diamond. — Exhibits of 

 Crystal Models, and of Photographs by the Due de Broglie of 

 Cathode Ray Spectra attendant on the production of X-ravs. 



Institution of Mechanical Engineers, at 6.— J. Q. Graves : The 

 World's Money System. 



Royal Institution of Great Britain, at 9.— A. Mallock : Elasticity. 



SATURDAY, Mai 28. 

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

 and the Science of Religions. II. 



CONTENTS. PAGE 

 The Treatment of Tuberculosis by Public Authori- 

 ties • • 353 



Health and Work. By Dr. Charles S. Myers, F.R.S. 354 



British Stratigraphy. By G. W. L 355 



Chemical Research in the Elementary Laboratory. 



By T. M. L 356 



Cocoa and Chocolate. By T. A. H 357 



Our Bookshelf 357 



Letters to the Editor: — 



Tlie Magnetic Storm of May 13-17. — Dr. C. Chree, 



F.R.S 359 



The Reparation Act and the Cost of German Publica- 

 tions. — Prof J. Stanley Gardiner, F.R.S. . . 359 

 Auroral Display. — A. E. L. Hudson . , 359 

 The Colours of Primroses. — Dr. J. W. Heslop 



Harrison ... 359 



Earthworms Drowned in Puddles.— J, H. Coste . . 360 

 The Physical Continuity of "Space." — Commdr. 



John G. McHardy 360 



The Production of Metallic Zinc— Sir R. A. S. 



Redraayne, K.C.B. ; The Writer of the Note 361 

 The Theory of Vision.— Dr. F. W. Edridge- 



Green, C.B.E. 361 



A New British Land Planarian. — Dr. R. F. Scharff 361 

 Cutting Sections of Cotton Hairs. — Dr. W. 



Lawrence Balls and H. A. Hancock .... 361 



British Scientific Instruments. — ^J. W. Williamson . 361 



Picture-hanging Wire. — R. B. Marston .... 362 

 The Occurrence of Bombus in the Indian Plains. — 



Cedric Dover . 362 



Symbols in Vector Analysis. — R. H. Nisbet .... 362 

 Young's Interference Experiment. — Prof. P. N. 



Ghosh 362 



The Origin of "Churning at 62°" on Dairy Ther- 

 mometers. — A. C. Cossor and Son 362 



Organism in Flint. — C. Carus- Wilson .... 362 

 Direction-finding Wireless and Marine Navigation. 



{Illustrated.') By J. J. Bennett 363 



Cloud Forms. {Illustrated) By Capt. C.J. P. Cave 365 

 Unveiling the Senussi Shrines. By Arthur Silva 



White 366 



Obituary: — 



Prof. H. W. G. von Waldeyer. By Prof. G. 



Elliot Smith, F.R.S 368 



Notes . . 369 



Our Astronomical Column : — 



Comets 373 



The Eclipsing Variable U Cephei 373 



i^ther Waves and Electrons. By Sir William 



Bragg, K.B.E, F.R.S. . . 374 



The Natives of the Gilbert Islands 374 



Parliamentary Visit to the Rothamsted Experi- 

 mental Station 375 



Habits of the Hedgehog 375 



The "Flight" of Flying-fish 376 



The Royal Society Conversazione 377 



University and Educational Intelligence . . . 379 



Calendar of Scientific Pioneers 381 



Societies and Academies 381 



Books Received 3^3 



Diary of Societies . 3^3 



NO. 2690, VOL. 107] 



