DIFFUSION AND DIFFUSION TENSION 15 



cases at least, 1 a diffusion of the substances into each other. 

 The process goes on with extreme slowness, however, and 

 the details need not be stated here. 



1W. SPRING, "Ueber die chemische Einwirkung der KOrper in festem Zustande," 

 Zeitschr.f. physik. Chem., Vol. II (1888), pp. 536-8; IDEM, "Ueber das Vorkommen 

 gewisser fur den Flilssigkeits- oder Gaszustand charakteristischen Eigenschaften 

 bei festen Metallen," ibid., Vol. XV (1894), pp. 65-78; W. ROBERTS-AUSTEN, " On 

 the Diffusion of Gold in Solid Lead at the Ordinary Temperature," Proceed. Roy. 

 Soc. London, Vol. LXVII (1901), pp. 101-5. 



