420 



NA TURE 



[June 3, 1909 



kathode rays, and canal rays associated with double 

 kathodes (as devised by Goldstein), and pairs of simple 

 kathodes. The conclusions of Goldstein and Kunz with 

 respect to the form of beams of canal rays are contro- 

 verted. Remarliably well-defined beams of kathode rays 

 were obtained with some arrangements. Schuster's rela- 

 tion between thickness of dark space and strength of 

 current was confirmed. The records are photographic 

 throughout. — Some fatigue effects of the kathode in a dis- 

 charge tube : R. Whiddingrton. The kathode phenomena 

 vary with time of running in such a way as to suggest 

 that the emitted kathode rays become more homogeneous 

 in velocity and more slowly moving. Restoration of the 

 kathode cannot be effected by causing the absorption of 

 hydrogen, oxygen, nitrogen, carbon dioxide, carbon 

 monoxide, or helium, even at the temperature of liquid 

 air. A transient recovery occurs on momentarily running 

 the fatigued kathode as anode. Kathodes of carbon, 

 platinum, and aluminium were tried. The kathode fall of 

 potential shows a falling off with the time. — The influence 

 of dilution on the colour and the absorption spectra of 

 various permanganates : J. E. Purvis. Dilute solutions 

 of the permanganates of barium, zinc, and potassium were 

 compared in tubes of different lengths, and so that each 

 tube contained the same amount of dissolved salt. The 

 highly diluted solutions gradually changed from the well- 

 known permanganate colour to reddish-brown and to 

 yellow colours. At the same time several of the absorp- 

 tion bands became narrower, and others wider, until, when 

 the colour had become quite yellow, the bands disappeared 

 and only marked general absorption remained. These 

 changes took place, not onlv when the solutions were sub- 

 jected to the influence of light, but the phenomena were 

 observed after the solutions had remained in the dark, 

 although light appeared to accelerate the changes. The 

 changes also occurred when the solutions were kept out of 

 contact with the atmosphere and light. The explanation 

 was that the MnO, ion broke down with the production of 

 MnO, and O,, and the MnO, was dissolved in the colloidal 

 condition. — Note on the his'tologv of the " giant " and 

 ordinary forms of Priintda sinensis : R. P. Gregory. 



GOTTINGEN. 



Royal Society of Sciences.— The 7V^<7,7;r/,7;/<.;; (phy.sico- 

 mathematical section), part i. for 1909, contains the 

 following memoirs communicated to the society : — 



January g.- — The representation of unsaturated cyclic 

 acids and carbohydrates with semi-cyclic connection : O. 

 Wallach. 



February 6. — In memoriam Hermann Minkowski. A 

 proof that integers may be represented by a fixed number 

 of Hth powers (Waring's problem) : David Hilbert. — 

 Ordinary linear differential equations with singular regions 

 and their particular functions : H. Weyl. — The concept of 

 deformation-work in the theorv of elastic solids : J. 

 Weingrarten, 



February 20. — The uniformisation of algebraic curves by 

 means of automorphous functions with imaginary substitu- 

 tion-groups : P. Koebe. 



March fi. — The decomposition of matrices : J. Wellstein. 



March 20. — Molecular free vibrations : E. Madelungr- 



DIARY OF SOCIETIES. 



THURSDAY, [unt: -,. 

 RoVAl. IN.STITUT10N. at -i.— K Modern Railw.-iy Problem : Steam v. 



Electricity : Prof. W. E. n.ilby. 

 Li»JNE.4N Society, at 8.— On the Alcvonaria of the Sealark EnpeHitlon : 



Prof. J. A. Thomson.— On ihe Cephalochordaof the Sea/ark Expedition : 



H. A. S. Gihion.— Repo't on the Porifera collected by Mr. C. Cros.sland 



m the Red Sea : R. W. Harold Row. 

 R^NTGEN Society, at 8.T5.— Annual General Meeting. 

 IN-STITUTE OF Actuaries, at 5.— Anni:al General Meeting. 



FRIDAY, June 4. 

 Royal Institution, at 9.— Researches in Rodiolelesraphy : Prof. 1. A. 



Fleming, F.R.S, = 1 J J 



GEOLOtnsTs' .Association, at 8.— The Fossiliferous Lower Keuper Rocks 



of Worcestershire : L. J. Wills. 



SATURDAY. Tune 5. 

 Royal Institution, at 3.— The Vilality of Seeds and Plants: (.) A 



Vindication of the Vil.ilitv of Plants : Dr. F. F. Blackm.an, F.R.S. 

 TUESDAY, June S. 

 Royal Institution, at 3 —Biological Chemistry ; Dr. F. Gowl.ind 



Hopkins, F.R.S. 

 Royal Akthroi.ologic.al Institute, at 8.15. — Prehistoric Human 



Remains from \anous Paris of England : Dr. A. Keith. 



NO. 2o56, VOL. 80] 



WEDNESDAY, June q. 



Society of Public Analysts, at 8.— The Estimation of Iron by Per. 

 manganate in Presence of Hydrochloric Acid : G. C. Jones and John H. 

 Jeffery.— On Jaffis Colorimetric Method for the Estimation of Creatinine : 

 A. C. Chapman.— The Estimation of the Alkalinity of Bleaching Powder 

 Solutions : Dr. K. J. P. Orton and W. J. Jones.— (i) The Sabatier- 

 Senderens Test for Distinguishing between Primary, Secondary and 

 Tertiary Alcohols ; (2) Note on a New Test for the Halogens : Dr. G. B. 

 Neave. 



THURSDAY, June 10. 



Royal Society, at 4.30.— Crooniau Lecture : The Functions of the 

 Pituitary Body: Prof. E. A. Sch.ifer, F.R.S. 



Royal Institution, at 3. — A Modern Railway Problem — Steam v. 

 Electricity : Prof. W. E. lialby. 



Mathematical Society, at 5.30. — On the Behaviour at the Poles of a 

 Series of Legendre's Functions representing a Function with Infinite 

 Discontinuities : F. J. W. Whipple.— An Analogue of Pascal's 1 heorem 

 in Three Dimensions : W. H. Salmon. 



Royal Institution 

 Dewar, F.R.S. 



Physical Society, 

 evaluating Formuk 

 Wright.— The Ech 

 ture of the Green H 

 Unit of Candle Po 

 Telephone and other 

 Magnetism : G. W. 

 White Light : A. E.i 



Royal Astronomical 



Malacological Socii 

 North Queensland : 

 in the Paris and Gei 

 of British Helicidae : 



FRIDAY, June ii. 

 9. — Problems of Helium and Radii 



Sirja 



: 8.— The Arthur Wright Electrical Device for 

 nd solving Equations: Dr. A. Russell and Arthu 



Spe. 

 g line : 



Walkl 

 gle. 

 Socie' 



roscope, its Secondary .\ction and the Stru 

 H. Stansfield. — The Proposed International 

 C. Paterson. — Inductance and Re.sistance in 

 s : Dr. J. W. Nicholson.— Note on Terrestrial 

 r.- On the Form of the Pulses constituting 



■\-, at 5. 



8. — Diagnoses of new Trochoid Shells from 

 Weston. — Notes on some of the Ampullariida: 

 useums : G. B. Sowerbv.— On the Radula 

 :. W. W. Howell. 



SATURDAY, June 12. 

 Royal Institution, at 3.— The Vitality of Seeds and Plants : (2) The 

 Life arid Death of Seeds : Dr. F. F. Blackman, F.R.S. 



CONTENTS, PAGE 



The Evolution of the Vascular System in Ferns. 



By D. H. S 391 



Electrical Engineering. By Prof. Gisbert Kapp . . 392 



Why Leaves are Green. By H. W. . . 393 



The Foundations of Geometry. By G. B. M. . . . 394 



Valency. }!yj. C. P. 395 



Economic Geology in British Guiana and South 



Africa. By J. W. G 395 



Our Book Shelf:— 



Bateson : "The Method and Scope of Genetics." — 



J. A. T 396 



Boulanger : " Hydraulic Generate" 396 



Scott-Moncrieff : "The Chadwick Lectures, Univer- 

 sity of London, Session 1907-S" 397 



Letters to the Kditor : — 



The Temperature of the. Upper Atmosphere. — Dr. C. 



Chree, F.R.S. . ." 397 



An Optical Phenomenon. — V. P. 398 



The Oldest Remains of Man. {Il/:istia/id.) By 



Dr. William Wright 398 



A Great Endowment and its Influence. By Prof. 



John Edgar 399 



Germany and the Patents and Designs Act, 1907 401 



Dr. von Neumayer, For. Mem.R.S. By Hy. Harries 402 



T. Mellard Reade. By H. B. W 404 



Notes 404 



Our Astronomical Column : — 



Astronomical Occurrences in June 409 



The Dispersion of Light in Interstellar Space . . . 409 



A Remarkable Transit of Jupiter's Third Satellite . . 409 



The Spectrum of Magnesium in Hydrogen 410 



The Perturbations of Brooks's Comet (1SS9 V) by 



Jupiter in 1SS6 410 



Recent Observation of Daniel's Comet, 1907(1' . . . 410 



The Variable Sl.ir 6. 1909 Ursa: Majoris 410 



Polar Magnetic Storms. By G. W. W 410 



Rock-Engravings in South Africa. {I//nstia/,-d.)\ . 411 

 Centenary of the Physico-Medical Society of 



Erlangen 411 



The International Congress of Applied Chemistry . 412 

 Education and Research in Applied Chemistry. By 



Prof. Raphael Meldola, F.R.S 413 



The Campaign against Malaria. By Prof. Ronald 



Ross, F.R.S 415 



University and Educational Intelligence 418 



Societies and Academies 419 



Diary of Societies 420 



