It shall be the duty of the Auditor General, at the request of any person who may be authorized for that purpose, to deliver up the bonds and obligations, entered into by the County Treasurers of the several Counties of the State, for the faithful performance of their duties, after the Auditor General and State Treasurer shall be fully satisfied that the said County Treasurer has settled his accounts and paid all demands due the Commonwealth: Provided, such bond shall be held by the Auditor General one year after the settlement of said accounts.