464 



NATURE 



[April 8, 1922 



state of the testicular interstitial gland and the 

 state of the nuptial adornment (change in colour of 

 plumage). There is no such connection between the 

 nuptial adornment and the intratubular seminal 

 gland. — C. Oberthur and C. Houlbert : Convergence 

 or parallel variation in the genus Holimede. — M. and 

 Mme. G. Villedieu : Contribution to the study of 

 anticryptogamic copper mixtures. The spores of 

 Phytophthora (potato " disease ") germinate freely 

 in solutions of copper bicarbonate, but solutions of 

 sodium sulphate (o-i8 per cent.), potassium chloride 

 (0-15 per cent.), sodium chloride (0-15 per cent.), or 

 potassium nitrate (0-2 per cent.) arrest completely the 

 germination of mildew. It would appear that the 

 presence of copper in Bordeaux or Burgundy mixtures 

 is of doubtful utihty. — M. Aron : The determinism 

 of secondary sexual characters in Tritons. — P. 

 Nottin : The increased solubility and diastatic 

 degradation of the nitrogenous materials of maize. 

 Application to yeast manufacture. 



Official Publications Received. 



Department of the Interior : United States Geological Survey. 

 Forty-second Annual Report of the United States Geological Survey 

 to the Secretary of the Interior for the Fiscal Year ended June 30, 

 1921. Pp. 108. (Washington : Government Printing Office.) 



Thirty-fifth Annual Report of the Bureau of American Ethnology 

 to the Secretary of the Smithsonian Institution, 1913-1914. (In 

 2 parts.) Part II. Pp. viil +795-1481. (Washington: Government 

 Printing Office.) 



Annual Report of the Director, United States Coast and Geodetic 

 Survey to the Secretary of Commerce for the Fiscal Year ended 

 June 30, 1921. Pp. 147+36 charts. (Washington: Government 

 Printing Office.) 



Department of the Interior : Bureau of Edusation. Bulletin, 

 1921, No. 8 : Foreign Criticism of American Education. By W. J. 

 Osburn. Pp. 158. (Washington : Government Printing Office.) 



Diary of Societies. 



FBIBAY, APRIL 7. 

 Diesel Engine Users' Association (at Institution of Electrical 



Engineers), at 3. — H. Moore : Some Characteristics of Petroleum 



Oil used in Diesel Engines. 

 London Society (at Royal Society of Arts), at 4.30. — Dr. C. W. 



Saleeby : More Light on London : or the Coal Smoke Curse and the 



Restoration of Daylight. 

 Food Education Society (at Caxton Hall, Westminster), at 5.30. — 



Miss A. D. Muncaster, and others : Discussion on Feeding in 



Institutions, with special reference to School Diet. 

 Royal Aeronautical Society (Students' Section) (at 7 Albemarle 



Street), at 6.45. — Prof. L. Bairstow : Some Aeronautical Problems of 



the Early Future. 

 Junior Institution of Engineers, at 8. — J. W. Maple : Engineering 



in Southern Persia. 

 Royal Institution of Great Britain, at 9.— Sir Ernest Rutherford : 



Evolution of the Elements. 



SATURDAY, April 8. 

 Royal Institution of Great Britain, at 3.— Sir Ernest Rutherford : 



Radioactivity (6). 

 International College of Chromatics (at Caxton Hall), at 3.15. — 



E. K. Robinson : Trees : their Colours and Coloration. 



MONDAY, April 10. 

 Victoria Institute (at Central Buildings, Westminster), at 4.30.— 



T. Roberts : Seven Decisive and Suggestive Scenes in the History 



of the Secular Contest between Conscience and Power. 

 Royal Geographical Society (at Lowther Lodge, Kensington Gore), 



at 5. — C. S. Fox, and others : Discussion on Dr. Heron's Report on 



the Geology of the Mount Everest Region. 

 Aristotelian Society (at University of London Club, 21 Gower 



Street, W.C.I), at 8.— Dr. G. E. Moore, Prof. G. Dawes Hicks, and 



Miss L. S. Stebbing : Discussion on Dr. McTaggart's " Nature of 



Existence." 

 Surveyors' Institution, at 8.— R. Cobb : Agricultural Valuations. 



TUESDAY, April 11. 

 Royal Society of Medicine (Therapeutics and Pharmacology 



Section), at 4.30. — Annual General Meeting. 

 Royal Society of Medicine, at 5. — General Meeting. 

 Institution of Petroleum Technologists (at Royal Society of Arts), 



at 5.30. — A. Millar : Galicia and its Petroleum Industry. 

 Royal Photographic Society of Great Britain, at 7. — Dr. H. B. 



Goodwin : Photographic Portraiture, Pure and Simple. 

 QUEKETT Microscopical Club, at 7.30.— J. Wilson : A Short Account 



of the Genus Closterium. — L. E. Brown : Imitative and Windowed 



Plants. 



Royal Anthropological Institute, at 8.15. — Capt. T. A. Joyce : 

 The Paquecha of Ancient Peru. — Miss A. C. Breton : Notes on 

 Some Peruvian Antiquities. 



Royal Society of Medicine (Psychiatry Section), at 8.30. — Dr. B. 

 Pierce : Recovery. 



WEDNESDAY, April 12. 



Royal Astronomical Society, at 5.— Major W. J. S. Lockyer : The 

 Relationship between the Solar Prominences and the Corona. 



Geological Society of London, at 5.30. — Prof. A. C. Seward : A 

 Collection of Carboniferous Plants from Peru. — F. W. Edwards : 

 Oligocene Mosquitoes in the British Museum, with a Summary of 

 our present Knowledge concerning Fossil Oulicidae. — ^Miss M. E. J. 

 Chandler: The Geological History of the Genus StratiMes : an Account 

 of the Evolutionary Changes which have occurred within the (Jenus 

 during the Tertiary and Quaternary Eras. 



Institution of Automobile Engineers (at Institution of Mechanical 

 Engineers), at 8. — A. F. Evans : Marine Engine Design as affected 

 by Lifeboat Service Conditions. 



Association of Engineers-in-Chief (at St. Bride's Institute, Bride 

 Lane, E.C.4), at 8.— W. H. Booth : The Artesian WeUs and Geo- 

 logical Strata of London. 



THURSDAY, APRIL 13. 



Optical Society (at Imperial College of Science and Technology), 

 at 7.30. i_^_ fc.^, ^. 



'*^^:^^'^v Vw ■■ FRIDAY, AmiL 1A. -—"—-. 

 Malacological Society of London (at Linnean Sodety). 



CONTENTS. PAGE 



The Development Fund 433 



The Teaching- of Physics 433 



The Principles of Distillation 434 



Mathematical Analysis. By Prof. G. H. Hardy, 



F.R.S 435 



Greek and Arab in Medicine. By Dr. Charles Singer 438 



Elementary Meteorology. By Capt. C. J. P. Cave 440 

 Freshwater Ciliate Infusoria and Heliozoa. By 



S. J. H 441 



Our Bookshelf 443 



Letters to the Editor : — 



Atmospheric Refraction.— Dr. John Ball . . 444 

 Diffraction by Molecular Clusters and the Quantum 



Structure of Light.— Prof. C. V. Raman . . 444 

 The Radiant Spectrum. {IVt^k illustration.) — 



Dr. H. Hartridge 445 



Land Snails of the Madeira Islands.— Prof. T. D. A. 



Cockerell 446 



Optical Rotatory Dispersion. {With dias^rams.) By 



Prof. T. M. Lowry, F.R.S., and Dr. P. C. Austin 447 

 Obituary :— 



Dr. G. B. Mathews, F.R.S. By W. E. H. B. . 450 



Dr. J. T. Merz .451 



Col. Sir Henry Thuillier, C.B 452 



Prof. J. A. Green. By H. R 452 



Current Topics and Events 453 



Our Astronomical Column :— 



A Study of Obscure Nebulae 455 



Spectroscopic Study of Procyon's Orbit . . . 455 



Recent Magnitudes of Novse 455 



Research Items 45^ 



The British Cotton Industry Research Institute. 



{With illustrations.) 457 



The National Institute of Industrial Psychology . 459 



Gas Cylinders Research 460 



University and Educational Intelligence . . . 460 

 Calendar of Industrial Pioneers . .461 



Societies and Academies 461 



Official Publications Received 4^4 



Diary of Societies , 464 



NO. 2736, VOL. 109] 



