There shall be a department of city treasurer of which the city treasurer shall be the head. He shall be elected and give bond as now provided by law, and shall hold office for a term of four years and until his successor is elected and qualified, but shall not be eligible to the office for the next succeeding term. The duties of the city treasurer shall remain as now provided by law, except as modified by the provisions of this act.
53 P.S. § 12391