When, in any case arising under the provisions of this chapter, the Compensation Review Board is of the opinion that the decision involves principles of law which are not free from reasonable doubt and which public interest requires shall be determined by the Appellate Court, in order that a definite rule be established applicable to future cases, said Compensation Review Board may, on its own motion and without any agreement or act of the parties or their counsel, reserve such case for the opinion of the Appellate Court. Upon a reservation so made, no costs shall be taxed in favor of either party, and no entry fee, record fee, judgment fee or other clerk’s fee in either court shall be taxed. Upon the filing of such a reservation, the question shall come before the Appellate Court as though an appeal had been taken, and said court shall thereupon reserve the case for the opinion of the Supreme Court in the manner herein indicated; but if, in the opinion of the Appellate Court, the principles of law involved in the decision are in fact free from reasonable doubt and the public interest does not in fact require that they be determined by the Supreme Court, the Appellate Court may, in its discretion, hear and determine the controversy as in other cases.