55 ILCS 5/3-10005
The treasurer has those functions, powers and duties as provided in the Sections following this Section and preceding Section 3-10006. He shall receive and safely keep the revenues and other public moneys of the county, and all money and funds authorized by law to be paid to him, and disburse the same pursuant to law. He shall appoint his deputies, assistants and personnel to assist him in the performance of his duties. His deputies shall take and subscribe the same oath for the discharge of their duties as is required of him, which oath shall be entered of record in the office of the county clerk. The Treasurer shall, in all cases, be responsible for the acts of his deputies. The functions and powers of the county treasurers shall be uniform in the various counties of this State.
55 ILCS 5/3-10005