216 THE ROYAL SOCIETY OF CANADA 



ties of a liquid in equilil)rium with its vapour. (Hi) Simpler form of 

 apparatus for working at atmospiieiic pressure, {iv) Decomposition 

 temperature of calcium-cliloride-ammonia (v) Delayed reactions 

 supersaturation, etc. (Jour. Phijs. Chem. 16, pp. 519-526, 1912). 



No. 22. Frank B. Kcnrick: — Sonic lecture experiments on surface 

 tension. — (i) Mechanical model, shewing surface tension balanced by 

 a movable weight, (ii) Two drops, analogous to the well-known 

 experiment with large and small soap bubbles, (iii) Surface tension 

 and solubility; optical device to shew the difference in solubility be- 

 tween coarse and fine gypsum powder, (iv) Surface concentration in 

 saponin solution: shews that a freshly formed surface of saponin so- 

 lution has practically the same surface tension as pure water, (v) Sur- 

 face concentration of methyl violet solution; the foam has a different 

 composition to that of the body of the solution, shewn by double cell 

 in lantern. (vi) Oil films and water; (Jour. Phys. Chem. 16, pp. 

 513-518, 1912). 



No. 23. W. Lash Miller: — The influence of diffusion on the electro- 

 motive force produced in solutions by centrifugal action. In Tolman's 

 account of his measurements of the electi-omotive force produced 

 in solutions of potassium iodide and free iodine by centrifugal action, 

 the equations were deduced without allowing for any possible differences 

 in concentration at the two ends of the tube produced by the whirling. 

 As, in some of his experiments, these differences would become very 

 considerable if the rotation were sufficiently prolonged, it seemed pos- 

 sible that even in a few minutes the "concentration cell" effect might 

 become measureable, and that it might perhaps account for the 

 "residual electromotive force" observed by him. 



The calculations shewed, however, that the polarization produced 

 by concentration changes in short periods of centrifuging was very 

 slight; as it chanced that the effects produced by the iodine and the 

 iodide almost neutralized one another. 



As no previous attempt has been made to calculate the rate at 

 which diffusion would take place under the influence of centrifugal 

 force, the assumptions made in the calculation are being checked in 

 this laboratory. (Trans. Am. Electrochem Soc. 21, pp. 209-217, 1912). 



No. 24. J. T. Burt-Gerrans: — Electrolysis of solutions containing 

 Jree iodine and potassium iodide together with chromic, arsenic, or arseni- 

 ous acid. These experiments , carried out with students in the electro- 

 chemical laboratory, were suggested by the work of Mr. Welsh, above. 

 They shew that in solutions containing chromic or arsenic acids, the 

 iodine instead of the acid, is reduced by a cathode, while in solutions 

 where arsenious acid is being oxidized by iodine an anode oxidizes 

 the potassium iodide instead of the arsenic. Experiments with similar 



