55 ILCS 65/3
It shall be the duty of the treasurer to keep a correct account of all moneys received and paid out by him, in a book to be provided for that purpose, and to loan, at interest, on notes with approved security, all amounts not necessary to be reserved for expenses, to keep the grounds in good repair, under the direction of the trustees, and shall make settlement with the trustees in January of each year, and the trustees or county board may, at any other time, require the treasurer, as often as they may deem best, to make full report, and for a failure to make satisfactory report, may be discharged and some other shall be appointed in his place, and suit shall be commenced on his bond, whenever deemed necessary, for the safety of the funds that shall have been received by him, in his official capacity.
55 ILCS 65/3