CONTENTS. 



Professor J. J. Thomson, On the motion of a charged ion in a magnetic 



fieU . . . . . . . . . . ... 49 



Mr John S. Townsend, The formation of clouds with ozone . . . 52 



Mr H. C. Pocklington, On the Symbolic Integration of certain 



Differential Equations in Quaternions . . . . . , 59 



Mr H. C. Pocklington, On the conditions of sensitiveness in Detectors 



of Radiant Heat . \ . . . . . . . 66 



Mr J. Stanley Gardineb, On the Anatomy of a supposed = New 



Species of Coenopsammia from Lifu .... 72 



Professor J. J. Thomson, On the Conductivity of Gases exposed to 



Entladungsstrahlen . . . . . . . . . .74 



Mr W. Bateson and Miss D. F. M. Pertz, Notes on the inheritance 



of Variation in the Corolla of Veronica Buxbaumii (Plate) . .78 



