Abstract
The evaporation rate of D. B. P. was measured by a pot still under high vacuum (2.0×10-41.2×10-2Torr) with or without applying agitator. The following results were obtained : (1) Uyeha's statements concerning the mechanism of high vacuum evaporation were supported by the curves in Fig. 3 in this study. Ds was observed as constant value (6.5×10-4 mol/cm2 sec), which was independent from the residual air pressure. (2) In regard only to the phenomena evaporation, the residual air pressure of 1.5×10-3 Torr or below does not effect to the evaporation rate. (3) The effect of applying agitator (magnetic stirrer) was shown in Fig. 12, 13 and 14.
