Diffusion and Diffusion Tension 15 



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

 The process goes on with extreme slowness, however, and 

 the details need not be stated here. 



IW. Spring, "UeberdiechemischeEinwirkungder KOrper in f estem Zustande," 

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

 gewisser for den FlQssigkeitS' oder Gaszustand charakteristischen Eigenschaften 

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

 the Diffusion of (Jold in Solid Lead at the Ordinary Temperature," Proceed. Boy. 

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



