138 TABLES 1 19-11 QA. 



DIFFUSION OF GASES, VAPORS, AND METALS. 



TABLE 119. Coefficients of Diffusion for Various Gases and Vapors.* 



Compiled for the most part from a similar table in Landolt & Bernstein's Phys. Chem. Tab. 



TABLE 119 A. -Diffusion of Metals Into Metals. 



dv ,</ 2 z> where x is the distance in direction of diffusion; v, the degree of concentration of 



dl dx** tfte diffusing metal; /, the time; k, the diffusion constant = the quantity of metal 



in grammes diffusing through a sq. cm. in a day when unit difference of concentra- 

 tion (gr. per cu. cm.) is maintained between two sides of a layer one cm. thick. 



From Roberts- Austen, Philosophical Transactions, 1896 A. 

 * These values are from Guthrie. 



SMITHSONIAN TABLES. 



