TABLE OF CONTENTS V 



On the Mobilities of Ions of Air at High Pressures. By J. C. 



McLennan and David A. Keys 127 



Measurement of Surface Tension by Means of a Vertical Jet. By 



Otto Maass 133 



A Physical Test on a Natural (Methane) Gas Well. By R. W. 



Boyle and H. M. Tory 139 



Effect of Strain on the Coefficient of Expansion of Quartz. By 



H. T. Barnes 147 



A Certain Projective Configuration and the Integration of its 



Normal Equations. By Charles T. Sullivan 151 



On the Absorption Spectra of Mercury, Cadmium, Zinc and other 



Metallic Vapours. By J. C. McLennan and Evan Edwards. 167 

 On the Infra-Red Emission Spectrum of the Mercury Arc. By 



J. C. McLennan and Raymond C. Dearle 179 



An Application of the ^^ Calculus of Finite Differences'' to Correct 



an Experimental Curve, and thus obtain by a graphical method, 



an accurate representation of the integral of this Curve. By S. 



Douglas Killam 195 



Certain Sets of Orders of Coincidence, Associated with a?i Alge- 

 braic Equation. By J. C. Fields 199 



Liquid Chlorine as a Solvent: Cryoscopic Determinations at Low 



Temperature. By P. Waentig and D. M. McIntosh 203 



On the Ionisation Tracks of Alpha Rays in Hydrogen. By J. C. 



McLennan and H. N. Mercer 211 



On the Delta Rays Emitted by Zinc when Bombarded by Alpha 



Rays. By J. C. McLennan and C. G. Found 219 



On the Ultraviolet Spectrum of Elementary Silicon. By J. C. 



McLennan and Evan Edwards 237 



SECTION IV. 



Presidential Address. By A. H. R. Buller 1 



The Cretaceous Sea in Alberta. By D. B. Dowling 27 



The Swarming of Odonlosyllis. By C. McLean Fraser 43 



On an Accumulation of Gas in the Tissues of the Frog as a Result 



of Prolonged Submersion in Water. By A. T. Cameron and 



T. I. Brownlee 51 



The Upper Limit of Temperature Compatible with Life in the Frog. 



By A. T. Cameron and T. I. Brownlee 67 



On the Resistance of B. Anthracis Spores to High Temperature. 



By R. H, M alone and E. Shanly 85 



Pre-Cambrian Goldfields of Central Canada. By J. B. Tyrrell 89 



