Periodically reversing the direction of current in an electrolytic cell has been shown to lead to effective drying of hydrogen fluoride because it causes extensive depolarization. Its obvious advantage is that, by allowing a higher average current to pass, the time required for drying is greatly shortened and, thereby, the attack on the nickel electrode is reduced markedly. The portion of the current used for nickel dissolution was never greater with current reversal than in the conventional procedure where the current was not periodically reversed.