Induction period of nucleation and metastable zone width

Induction periods of nucleation and metastable zone width were measured for the system KCl-H 2 O at 40 °C. The data for the induction period measured at constant undercooling produced at a finite rate were treated using relationships allowing for the time period of lower supersaturation. The relation N N = 1/ t N has been found to apply to the system studied. The treatment of literature data for metastable zone width and induction period of nucleation in the systems KAl(SO 4 ) 2 -H 2 O and (NH 4 ) 2 Ni(SO 4 ) 2 -H 2 O showed satisfactory agreement between values of nucleation exponent obtained by the two methods.