I40 



Tables 126-127. 

 DIFFUSION OF GASES, VAPORS, AND METALS. 



TABLE 126. — Coefllclents ol Diituslon lor Various Gases and Vapors.* 



Gas or Vapor diffusing. 



Air .... 



Carbon dioxide 



Carbon disulphide 

 Carbon monoxide 



Ether . . 

 Hydrogen 



Nitrogen 

 Oxygen . 



Sulphur dioxide 

 Water . . 



Gas or Vapor diffused into. 



Hydrogen . . . 

 Oxygen . . . . 

 Air 



Carbon monoxide 



Hydrogen . . . 



Methane . . . . 



Nitrous oxide . . 



Oxygen . . . . 



Air 



Carbon dioxide 



Ethylene . . . . 



Hydrogen . . • 



Oxygen . . . . 



Air 



Hydrogen . . . 



Air 



Carbon dioxide 



" monoxide 

 Ethane . . . . 

 Ethylene . . . , 

 Methane . . . . 

 Nitrous oxide . . 

 Oxygen . . . , 



Carbon dioxide 

 Hydrogen . . 

 Nitrogen . . . 

 Hydrogen . . 

 Air 



Hydrogen . . 



Temp. 

 °C. 



Coefficient 

 of Diffusion, 



0.661 



0.1775 



0.1423 



o. 1 360 



0.1405 

 O.I314 



0-5437 

 0.1465 

 0.0983 

 0.1802 

 0.0995 

 0.1314 



O.IOI 



C.6422 

 0.1802 

 O.IS72 

 0.0827 



0.3054 



0.6340 



o.53«4 

 0.6488 



0.4593 

 0.4863 

 0.6254 



0.5347 

 0.6788 

 0.1787 



0.1357 

 0.7217 



O. I 7 1 o 



0.4828 

 0.2390 

 0.2475 



0.8710 



Authority. 



Schulze. 



Obermayer. 



Loschmidt. 



Waitz. 



Loschmidt. 



Obermayer. 



Loschmidt. 



Stefan. 

 Obermayer. 



Loschmidt. 



Obermayer. 

 Stefan. 



Obermayer. 



Loschmidt. 

 Obermayer. 

 Loschmidt. 

 Guglilemo. 



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



= i 



d'^v 



TABLE 127. — Dilluslon of Metals Isto Uetala. 

 where x is the distance in direction of diffusion; v, the degree of concentration of 



^_y2 ' 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, i87A, p. 383, 1896. 

 * These values are from Guthrie. 



Smithsonian Tables. 



