The prosecutors, at least, went as far as to contend that prohibition would lie if the directions were not of such a nature or character as could, upon the true construction of s. 96M (6) of the Act, properly be given and it is this contention, as I understand it, which has led me to make these separate observations. No doubt the Arbitration Court concluded that the directions were of such a nature and character and was satisfied of the existence of the facts which constituted a prerequisite to their validity, i.e., a decision under sub-s. (4) by the Industrial Registrar, the due appointment of a Commonwealth electoral officer to conduct the election and the due formation of an opinion on his part that the giving of such directions was necessary in order to ensure that no irregularities should occur in or in connection with the election. I should have thought that it was not open to us on an application for prohibition to receive evidence for the purpose of showing that there had been no proper decision of the Industrial Registrar, or that arrangements had not been made by him with the Chief Electoral Officer for the Commonwealth for the conduct of the election by a Commonwealth electoral officer, or that such an officer had not formed the necessary opinion under sub-s. (6). Although it would be necessary to establish each of these matters to prove the commission of an offence against sub-s. (7), it is, I think, impossible to conclude that the legislature intended that the jurisdiction of the Arbitration Court under s. 29 (c) should depend for its proper exercise upon anything, in relation to these matters, other than a finding by that Court that these events had taken place; or that it was intended that that Court should be subject to prohibition if, upon a review of the facts, this Court should come to a contrary conclusion. As Jordan C.J. said in Ex parte Mullen; Re Hood [1] : - "When the jurisdiction of a court is limited, the question whether a particular matter is one the actual existence of which, notwithstanding any decision of that court, is a condition of its having jurisdiction to proceed to determine the matters which lie within its general jurisdiction, or is merely one of the matters which arise for its decision in the exercise of its general jurisdiction, is frequently one of considerable difficulty. It commonly arises in relation to a statute conferring jurisdiction in which the legislature has made no express pronouncement on the subject, and in which its intention has therefore to be extracted from implications to be found in or inferences to be drawn from the language which it has used. The matter was discussed by the Privy Council in Colonial Bank of Australasia v. Willan [2] , where a distinction was drawn between conditions of right to exercise jurisdiction founded, on the one hand, on the character and constitution of the tribunal or the nature of the subject matter of the inquiry or upon proceedings which have been made essential preliminaries to the inquiry, and, on the other hand, upon a fact or facts to be adjudicated upon in the course of the inquiry. It is pointed out that conditions of the last mentioned type differ materially from the others, and that "an objection that a judge has erroneously found a fact which, though essential to the validity of his order, he was competent to try, assumes that, having general jurisdiction over the subject matter, he properly entered upon the inquiry, but miscarried in the course of it. The superior court cannot quash an adjudication upon such an objection without assuming the functions of a court of appeal, and the power to retry a question which the judge was competent to decide" " [1] .