In an increasing applied electrical field from zero, the helical pitch in the chiral-smectic-C (SmC*) phase will disappear at a critical field (E//u). In a decreasing electrical field, the helical pitch will reappear at another critical field (E//r). Both E//u and E//r have been measured in the SmC* phase of DOBAMBC and behave like (T//c - T)**c with exponent c approximately equal to 0. 5. The hysteresis DELTA E equals E//u minus E//r seems to approach zero with (T//c - T)**x and x equals 0. 57 plus or minus 0. 09.