Abstract
The separation factor for argon isotopes has been measured as a function of the gas pressure in a hot wire type of Clusius and Dickel column. The variation obtained is in accord with the predictions of the Furry, Jones, and Onsager theory. It is found empirically that the explicit expressions given by Furry, Jones, and Onsager for the flat, parallel wall case can be modified to give correct results for the extreme cylindrical case if the constants of the gas are evaluated at the proper mean temperatures. The existence of turbulence in the gas causes a slight, if any, decrease in the separation factor determined by extrapolation from the experimental data obtained under conditions of lamellar flow.