x CONTENTS 



CHAP. PACK 



VI. DETERMINATION OF ELECTROCHEMICAL EQUIVA- 

 LENT IN THE CASE OF ELECTRIC LEAKAGE 



IN ULTRA-VIOLET LIGHT, - - - . 58 



Positive and Negative Carriers, 66 



VII. lONISATION OF GASES, 70 



Behaviour of Hot Metals in Gases, - - - 71 



Measurements of lonisation Current, 73 



Condensation of Moisture Experiments, 75 



VIII. DETERMINATION OF THE MASS OF AN ELECTRON, 77 



Aitken and Cloud Nuclei, ----- 79 



J. J. Thomson and Electrical Nuclei, 81 



Wilson and Metrical Cloud Condensation, - - 84 



Professor Stokes and Falling Spheres, 86 



J. J. Thomson's Experiment of Counting, 87 



Result, --.- .... 90 



IX. FURTHER DETAILS CONCERNING ELECTRONS AND 



IONS, 91 



Confirmatory Measurements of Charge, 9t 



Thomson's Deductions, 94 



Estimate of Size, - - - - - - - 95 



Penetrability of Matter by Electrons, 97 



Effects of an Encounter, - - 100 



X. THE ELECTRON THEORY OF CONDUCTION AND OF 



EADIATION, .. . - - - - - 105 



Conduction, - -v - * - - - 106 



Radiation, 109 



XL FURTHER DISCUSSION OF THE ELECTRON THEORY 

 OF THE MAGNETISATION OF LIGHT AND 

 DETERMINATION OF THE m/e RATIO IN 



RADIATION, 116 



