640 



NATURE 



[July 14, 1921 



mean pressure for Geneva.— E. Moles, T. Batnccas, 

 and M. Payi : The density of the air at Madrid and 

 its small variations. The results of thirty series of 

 measurements are given, each series comprising two 

 or three observations. The mean is 1-29303, and the 

 deviations are regarded as being outside the experi- 

 mental error. In agreement with the Loomis-Morley 

 hypothesis, the minima of density correspond with 

 the maximum of atmospheric pressure and conversely. 



L. Blaringhem : The pollen of flax and the de- 



generescence of the varieties cultivated for the fibre. 

 The study of the quality of the pollen of isolated 

 pedigrees, followed during several generations, is 

 recommended for the selection of flax grown for the 

 flbre. — C. Porcher and A. Chevallier : The distribution 

 of the saline substances and the mineral elements in 

 milk.— W. Mestrezat and Mile. S. Ledebt : The com- 

 pensating r6\e of chlorides in its relations with the 

 chemical composition of the body fluids. — P. Chailley- 

 Bert, R. Faillie, and J. P. Langloig : The "second 

 wind " of runners. Experiments are given showing 

 that the " second wind " is brought about by a 

 diminution in the respiratory exchanges, and that this 

 diminution, the work remaining constant, is the result 

 of a better adaptation of the subject, an improvement 

 in the yield of the human machine. — H. Piiron : The 

 importance of the peripheral phase in the margin of 

 the variation of the times of sensorial latency as a 

 function of the intensities of stimulation. — A. Vandel : 

 The question of cellular specificity in Polycelis cor- 

 nuta. — F. Picard : The determination of egg-produc- 

 tion in Pimpla instigator. Experiments proving that 

 the sight plays no part in the act of depositing the 

 «gg. — P. Reiriy : The action of the vapours of chloro- 

 picrin on Argas reflexus. This parasite of the pigeon 

 has proved to be extremely difficult to destroy by the 

 ordinary insecticides; it is now proved to be destroyed 

 by the vapours of chloropicrin, the amounts required 

 being small enough for practical use. — A. Goris and 

 A. Liot : Observations on the culture of the pyocyanic 

 bacillus on artificially defined media. — E. Sergent 

 and M. Biguet : The mycosic nature of a new disease 

 of the date-palm threatening the Morocco oases. 



Sydney. 

 Linnean Society of New South Wales, Mav 25. — Mr. 



G. A. Waterhouse, president, in the chair. — T. G. 

 Sloane : Revisional notes on Australian Carabidae, 

 pt. vi. The tribes Bembidiini is reviewed so far as 

 the Australian fauna is concerned. The synonymy is 

 given, and seven sjjecies of Tachys are described as 

 new. The tribe, as represented in Australia, consists 

 of five genera, of which only Illaphanus is peculiar 

 to Australia ; the five genera comprise fifty-eight 

 species.— Dr. A. J. Turner : Revision of Australian 

 Lepidoptera — Hypsidae, Anthelidae. Six genera, one 

 of which is new, and fourteen species of Hypsidae 

 and seven genera and forty-seven species (twelve new) 

 of Anthelidae are described.- — T. Steel : Ulmite, a con- 

 stituent of black sandstone. A black friable sand- 

 stone which outcrops frequentlv on the coast of New 

 South Wales consists of sand grains with a thin, 

 dark-coloured coating. This coating is identical with 

 humus .extracted from soil. — W. P. Hiern : A new 

 species and a new variety of Diospyros. A new 

 species is described from New Caledonia, and a new 

 variety of D. samoensis from Apia, Samoa. 



Books Received. 



Power House Design. By Sir J. F. C. Snell. 

 Second edition. Pp. xi+535. (London : Longmans, 

 Green and Go.) 42s. net. 



The Garden of Earth. By A. Giberne. Pp. xiv+ 

 178. (London : S.P.C.K.) 65. 6d. net. 



NO. 2698, VOL. 107] 



Mountain and Moorland. By Prof. J. A. Thomson. 

 (Nature Lover's Series.) Pp. 176. (London : 

 S.P.C.K.) 6s. net. 



Engineering Steels. By Dr. L. Aitchison. (Recon- 

 structive Technical Series.) Pp. xxxi4-348+48 plates. 

 (London : Macdonald and Evans.) 255. net. 



The Beloved Ego. By Dr. W. Stekel. Authorised 

 translation by R. Gabler. Pp. xv+238. (London : 

 Kegan Paul and Co., Ltd.) 6s. 6d. net. 



Whitherward? Hell or Eutopia. By V. Branford. 

 Pp. xv+ 1 16. (London : Williams and Norgate.) 

 2S. 6d. net. 



Air Ministry : Meteorological Office. Professional 

 Notes No. 19. Cracker Balloons for Signalling Tem- 

 perature. By L. F. Richardson. (M.O. 2401.) Pp. 

 95~ii5- (London: H.M. Stationery Office.) is. net. 



Diary of Societies. 



THURSDAY, Jtjlt 14. 

 RoTAL SociETr OF ARTS, at 8.— Prof. H, E. Armstrong and A. C. 

 Klein : Paints, Painting, and Painters, with Reference to Tech- 

 nical Problems, Public Interests, and Health. (To be followed 

 by a discussion.) 



FRIDAY. JtLT 15. 

 Institvtion of PEODrcTio.v Engineebs (at Institution of Mechani- 

 cal Engineers), at 7.30. — M. Lawrence : Production and the 

 Engineer. 



MONDAY, JrLT 18. 

 RoTAL Botanic Society or London, at 3. — Prof. A. R. Bickerton : 

 The Generic Simplicity and Great Importance of Basic Principles 

 in all Scientific Work. III. The Importance of the Cosmic 

 Theory of the Third Bodv. 



CONTENTS PAGE 



The London Electricity Inquiry 609 



Congress of Universities .... 610 



A Psychology of Logic. By Prof. H. Wildon Cart 612 



Text-books on Theoretical Chemistry . . 613 



A Jungle Book 615 



Elementary Pure Mathematics. By Dr. S. Bro- 



detsky 616 



Our Bookshelf . . 618 



Letters to the' Editor: — 



The Separation of the Isotopes of Chlorine. — Prof. 



J. N. Bronsted and Prof. G. Hevey 619 

 AXovel Magneto Optical Effect. — Dr. R. Whytlaw- 

 Gray and J. B. Speakman ; Prof. Elihu 



Thomson , 619 



The Japanese Artificially Induced Pearl. (///us- - 

 trated.) — Dr. Wyatt Wingrave ; Dr. H. Lyster 



Jameson 620 



Sources and Sinks. — Dr. H. S. Allen 622 



Helicopters. — A. R. Low 622 



A I'rehistorlc Cooking-place in Norfolk. — Nina F. 



Layard • . 623 



Science and Civilisation.— Capt. B.J. Marden . . 623 



Measurement of Small Inductance. — F. B. Pidduck 623 

 A New Acoustical Phenomenon. — Dr. G. A. 



Shakespear 623 



Large-scale Chemistry at the Imperial College of 

 Science and Technology. \l//ustraied ) By 



J. F. T. . , 624 



Great British Droughts. By Chas. Harding . . . 627 

 The Scarcity of Swallows. By Dr. Walter E. 



Collinge ... . . 628 



The King George V. Dock, London 628 



Notes ... 629 



Our Astronomical Column : — 



Recent Meteors ..... 634 



Another Plan of Calendar Reform 634 



The Variable Nebula in Corona Australis . • . ... 634 

 An Interferometer for Testing Camera Lenses. 



{///ustrared) 635 



Mutations and Evolution 636 



University and Educational Intelligence . ... 637 



Calendar of Scientific Pioneers 638 



Societies and Academies 638 



Books Received . . 640 



Diary of Societies . . .- . . . . 640 



