CONTENTS. 



PAGE 



Sa7ne fatigue effects of the cathode in a discharge tube. By R. Whid- 



DINGTON. (Communicated by Professor Sir J. J. Thomson) . , 183 

 ^ote on the electrical behaviour of fluorescing iodine vapour. By E. 



Whiddington. (Communicated by Professor Sir J. J Thomson) . 189 

 On the Reflection of Sound at a Paraboloid. By the Rev. H. J. 



Sharfe , . .190 



Discussion of a difference equation relating to the tension of overhead 



wires supported by equidistant poles. By A. A. Robb . .. . 198 

 On a property of summable functions. By A. C. Dixon . . . 210 

 On certain phenomena of the kathode region. By J. A. Orange. (Com- 

 municated by Professor Sir J. J. Thomson). (Plates IV— IX) . 217 

 Note on two new Leeches from Geylon. By W. A. Harding . . . 233 

 Note on the ahnormal pair of appendages in Lithobius. By F. G. 



Sinclair 235 



On a specimen of the cone Calamostachys binueyana (fjarr.). By H, 



Hamshaw Thomas. (Communicated by Mr E. A. Newell 



Arber) 236 



Note on the Histology of the Giant and Ordinary Fornix of Primula 



sinensis. By R. P. Gregory. (Plate X) 239 



The influence of dilution on the colour and the absorption spectra of 



various permanganates. By J. E. Purvis. (Plate XI) . . . 247 

 Phenomena of X-Ray Trarismission. (Preliminary Paper.) By C. G. 



Barkla. (Communicated by Professor Sir J. J. Thomson) . . 257 

 The Emission of Rontgen Rays from Thin Metallic Sheets. By G. W. C. 



Kate. (Communicated by Professor Sir J. J. Thomson) . . 269 

 On the Scattering of the ^-rays from Radnmi by Air. (Preliminary 



Note.) By J, A. Crowther . 273 



On some general Properties of Mixed Solutions. By L. Vegard . . 275 



Proceedings at the Meetings held during the Session 1908 — 1909 . 291 



