It shall be the duty of the grand jury to examine into the condition of the county treasury and the bonds of all county officers with regard to their correctness and sufficiency and to report upon the same, to inquire into all indictable offenses committed or triable within the county, which, as they may be advised by the court, are not barred by the lapse of time or some other cause, and to perform such other duties as are or may be by law required of them.