Flotation of Miverals. 585 



bubble of gas under the surface of a liquid, or (3) the surface 

 of a bubble of gas above the surface of a liquid. Once the par- 

 ticles are entangled in this film they are sustained there. That 

 a considerable weight may be supported by this surface film is 

 shown by the ex2')eriment of floating fine-grained mineral on 

 the surface film of water. 



The writer is umch indebted to Mr. Donald Clark, of the 

 Melbourne University, for the interest he has taken in the 

 work and for his many suggestions and help in procuring 

 samples. He also desires to acknowledge the heljj of Mr. T. J. 

 Greenway, of the Potter Sulphide Company, for his help in 

 procuring samples, etc. Much information and help by sug- 

 gestion was obtained from Swinburne and Rudorf's paper, 

 already referred to. 



LITERATURE. 



'■ Physics of Ore Flotation," J. Swinburne and G. lludorf, 

 "Chemical News," 29/12/05. 



'' Oil Concentration Process," H. L. Sulman, in '" Mining and 

 Metallurgy in West Australia," by A.G. Charleton (page 409). 



Article on " Flotation," by Prof. A. K. Huntington, Trans. 

 F'araday Society, Dec. 12, 19U5. 



The evidence in Potter v. the Broken Hill Proprietary Com- 

 pany, Melbovu-ne, August, 1904. 



The evidence in Potter v. the Broken Hill Proprietary Com- 

 pany, London. 



" Attraction of Common Minerals for Residuum Oil," J. F. 

 Hamilton, " Journal of Canadian Mining Listitute," Vol. 

 VII. (page 185), 1904. 



" Surface Tension," Encyclopaedia Britannica. 



'' Oil in the Potter Process," W. E. Simpson, '' Mining Maga- 

 zine," June, 1910 (page 434). 



■■ The Concentration of Ores by Oil," AYalter McDermott, 

 Mineral Industry, 1902 (page 697). 



'■ The Potter Process," Donald Clark, " Australian Mining and 

 Metallurgy," page 397. 



A useful bibliography is given in Richards' " Ore Dressing," 

 Vol. III.' 



