T 68 TABLES 163-164. 



DIFFUSION OF GASES, VAPORS, AND METALS. 



TABLE 168. Coefficients of Diffusion for Various Oases and Vapors.* 



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



TABLE 164,- Diffusion of Metals into Metals. 



dv _ d'^v where x is the distance in direction of diffusion ; v, the degree of concentration of 

 & ~ ' d x i ' the diffusing metal ; /, the time ; k, the diffusion constant = the quantity of metal 

 in grams 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, i 

 * These values are from Guthrie. 



p. 383, 1896. 



SMITHSONIAN TABLES. 



