Meetings held during the Session 1898 — 1899. 185 



The following Communications were made : 



1. On the Flame-spectrum of Mercury, and its bearing on the 

 distribution of energy in gases. By Professor G. D. Liveing. 



2. On the Variation of Intensity of the Absorption Bands of 

 different Didymium Salts dissolved in water, and its bearing on the 

 ionization theory of the colour of solutions of salts. By Professor 



LlVEING. 



3. On the Comparative Colour of the Vapour of Iodine in Air at 

 Atmospheric Pressure and in Vacuum. By Professor Dewar. 



4. On the Partitions of Numbers which possess symmetrical 

 Graphs. By Major MacMahon, Sc.D., F.R.S. 



January 23, 1899. 



Mr J. Larmor, President, in the Chair. 



The following were elected Fellows of the Society : 



E. J. Bles, B.A., King's College. 

 A. Willey, M.A., Christ's College. 



The following was elected an Associate, having been nominated by 

 the Council : 



J. Burke, Trinity College. 



The following Communications were made : 



1. On Clouds formed by Ozone. By J. S. E. Townsend, M.A. 



2. (a) On Detectors of Radiant Heat, (b) on the Symbolic Inte- 

 gration of certain Differential Equations in Quaternions. By H. C. 



POCKLINGTON. 



3. On the Motion of a charged Ion in a magnetic field. By Pro- 

 fessor J. J. Thomson. 



February Qth, 1899. 

 Mr J. Larmor, President, in the Chair. 

 The following was elected a Fellow of the Society : 

 Dr E. Barclay Smith, Downing College. 



