CONTENTS. 



PAGE 



Annual General Meeting 1898, October 31 . . .1 



Mr A. Berry, On the evaluation of a certain determinant which occurs 

 in the mathematical theory of statistics and in that of elliptic 

 geometry of any number of dimensions ... . . . 2 



Mr J. H. Grace, (1) Metrical Relations between Linear Complexes. 



(2)' Apolar Systems of Quadrics . . . . . . .10 



Mr A. E. Western, Certain Systems of Quadratic Complex Numbers . 10 



Mr H. P. Baker, On Mitiag-Leffler's Theorem . . . . . 10 



■Professor J. J. Thomson, On the connection between the Chemical Com- 

 position of a Gas and the Ionization produced in it by Rontgen 

 Rays ... . . . . . . . . . .10 



Mr J. Zeleny, On Convection Currents and on the Fall of Potential at 



the Electrodes, in Conduction produced by Rontgen Rays . . 14 



Mr H. A. Wilson, On Velocity of Solidification ... . . 25 



Mr H. Gadow^ Orthogenetic Variation in the Shells of Chelonia . .35 



Dr A. Willey, Some points in the Morphology of the Enteropneusta . 37 



Mr A. C. Seward and Mr A. W. Hill, On Lepidodendron from the 



Calciferous Sandstone of Scotland ■ . ■ . 3S 



Professor Liveing, On the Flame-spectrum of Mercury, and its bearing 



on. the distribution of energy in gases . . . . . . "38 



Professor Liyeing, 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 40 



Professor Dewar, On the Comparative Colour of the Vapour of Iodine 



in Air at Atmospheric Pressure and in Vacuum . . . ,44 



Major MacMahon, On the Partitions of Numbers which possess sym- 

 metrical Graphs . . . . . . . . . .47 



