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. 



1 W. SPRING, "UeberdiechemischeEinwirkungder KOrper in festem Zustande," 

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

 gewisser fur den Fltissigkeits- 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. 



