The effect of NaOH concentration on the electrical nucleation of sodium acetate trihydrate crystals from solution was studied by measuring the current and voltage curves, and by observing interference fringes during the application of constant voltage. The interference fringes bent according to gradients of temperature and Ag+ ion concentration. Adding NaOH to the Supercooled solution shortened the induction time of the electrical nucleation. The applied voltage dependence of the induction time Could be explained by the theory of Kashchiev. The system of Ag electrode in sodium acetate trihydrate solution exhibited the ion Peltier effect. (C) 2002 Elsevier Science B.V. All rights reserved.