19The arbiter may at any stage of the proceedings, and shall, if so directed by the sheriff (which direction may be given on the application of either party), state a case for the opinion of the sheriff on any question of law arising in the course of the arbitration.
20The opinion of the sheriff on any case stated under the last foregoing paragraph shall be final unless, within such time and in accordance with such conditions as may be specified by act of sederunt, either party appeals to the Court of Session, from whose decision no appeal shall lie.