In all cases of application for continuance, it shall be lawful for the state or the defendant to make any admission of any fact sought to be proved by the other party by any absent witness, and such admission shall have the same effect as if the absent witness or other evidence were present in court, and no more; but if compulsory process will probably obtain the attendance of the absent witness, and the defendant have not had opportunity of obtaining such process, the cause shall be continued, unless the defendant desire a trial.