It involves removing your body parts, one at a time.
Carmen watched from the porch as they unloaded them, one at a time.
You can apply for more than one at a time.
Care must be taken not to expose goods in the plating-bath to too high a current density, else they may be "burnt"; they must never be exposed one at a time to the full anode surface, with the current flowing in an empty bath, but either one piece at a time should be replaced, or some of the anodes should be transferred temporarily to the place of the cathodes, in order to distribute the current over a sufficient cathode-area.
The sign of the electrification imparted to the electroscope when so charged - that is, whether positive or negative - can be determined by rubbing the sealing-wax rod with flannel and the glass rod with silk, and approaching them gently to the electroscope one at a time.