In all cases where, in the administration of the affairs of the office of Register of Wills in the several counties of the State, it is necessary or proper to administer an oath of affirmation, such oath of affirmation may be administered by a deputy register; and, where the Register might have done so, such deputy register may probate wills and grant letters testamentary and of administration. The appointment of each deputy shall be recorded in the office of the Recorder of Deeds of the county for which the deputy shall be appointed.