214 THE ROYAL SOCIETY OF CANADA 



No. 15. J. T. Burt-Gerrans: — Tfie electrolysis of acid solutions 

 of copper sulphate ivith alternating current. — Mr. Redman's work 

 {These Transactions Vol. II, Sec. Ill p. 244) having shewn tlie appli- 

 cability of the equations deduced by Rosebrugh and Lash Miller 

 (see above) to the electrolysis of solutions of copper sulphate in maxi- 

 mum conducting sulphuric acid, Mr. Burt-Gerrans undertook a simi- 

 lar study with alternating current, using a Siemens and Halske oscil- 

 lograph, and inferring the concentrations at the electrode from the 

 voltage curves. In every case be found that the reduction of con- 

 centration b}^ the alternating current — whether with pure sine current 

 or with direct current superposed — was less than that calculated 

 from the mathematical theory. As, however, experiments with in- 

 terrupted direct current gave results at the cathode in fair agreement 

 with the calculations, a study of the anodic behaviour of copper in 

 this solution seems needed to clear up the situation. (Wiyiter 1911-1912). 



No. 16. H. P. Corliss: — I'he distribution of colloidal arseyiious 

 sulphide between the two phases in systems containing ether, water, and 

 alcohol. — In continuation of the work of Lash Miller and McPherson, 

 and of Bonner, referred to above, Mr. Corliss made accurate determin- 

 ations of the binodal curve and tie-lines for the system water-ether- 

 alcohol at 0°C, and quantitative measurements of the distribution of 

 arsenious sulphide between the two phases. The results, as in all 

 work with colloids, depend largely on the age of the colloid, the order 

 of mixing the reagents, etc., and, as was to be expected, the distribution 

 became less equal as the tie lines receded from the plait-point. They 

 shew clearly, however, when standard conditions are adhered to, 

 that within a wide range the distribution of the colloid is fairly inde- 

 pendent of the concentration of the arsenious sulphide; and furnish 

 the first instance in which an equilibrium of this kind has been fol- 

 lowed out. {Winter 1911-1912). 



No. 17. Chas. G. Fraser: — Improvernent in the technique of toxi- 

 city experiments. — The experience of Mr. Laird and of others who have 

 worked here on the rate at which microbes succumb to phenol solu- 

 tions and other poisons, shews clearly that the chief experimental 

 difficulty in carrying out such expeiiments lies in the lack of some 

 quickly applicable criterion of death. To find out how many micro- 

 cocci, for instance, have been killed in a given culture, it is customary 

 to pour gelatine or agar plates and to wait a couple of days until those 

 surviving grow into colonies large enough to count. In many in- 

 stances the results only shew that either all or none have deceased, 

 and that the work must be done all over again. 



To overcome this difficulty, Mr. Fraser has developed a technicjue 

 involving staining and examination under the microscope, which 



