A method of releasing mercury into an arc discharge lamp is disclosed. The method includes the step of disposing an insulating coating (e.g., zirconium dioxide) at the end of the lamp containing a mercury releasing target. The insulating coating is disposed over the lead-in wires, portions of one of the coil electrodes, and a portion of the mercury dispensing target. The main body portion of the target containing the mercury is devoid of the insulating coating. Thereafter, the mercury dispensing target is bombarded with a directed stream of electrons produced by the other coil electrode of sufficient energy to rupture the target causing the mercury to be released. The insulating coating focuses the directed stream of electrons directly on the target, thereby reducing the amount of time necessary to rupture the target.