But the section was attacked on an independent ground much more serious. Sub-sec. 3 of sec. 28, on which the objection is founded, is in these terms: "A taxpayer who is dissatisfied with the decision of the Commissioner under this section may require the Commissioner to refer his case to a Board of Appeal, and the Commissioner shall refer the case accordingly." It is contended on behalf of the taxpayer, in the first place, that sub-sec. 3 is invalid because it purports to invest a tribunal which is not a Court with judicial power, and thereby it violates sec. 71 of the Constitution; and, in the next place, that the sub-section is inseparable from the rest of the section and consequently the whole is void. It is necessary to examine this objection step by step. Assuming the existence of a Board of Appeal free from any constitutional objection, sub-sec. 3, if nothing more were said as to the functions of the Board, would be unimpeachable. It would raise an implication that in the event of the taxpayer's dissatisfaction with the Commissioner's decision the Legislature entrusted the Board with the duty of reviewing the decision of the Commissioner, and, in case of difference, of substituting its opinion for his, with the legal effect that would otherwise have attached to the Commissioner's decision. The Board of Appeal would in that case be a mere revisory body of the same nature as the Commissioner and in no way exercising judicial power, because its decision would not be one determining existing rights and duties as they already stand, but would be one merely ascertaining a fact which the Legislature adopted as the standard upon which its will operated to create rights and duties. And that is the position asserted for it now by learned counsel for the Commissioner. That simple position, however, does not exist. The Legislature has certainly not left the Board's functions to implication. They have been expressed, and therefore there is no room for implication. Sec. 41 provides for a Board, consisting of a chairman and two other members, and fixes the tenure of its members at seven years. The nature of the tenure makes it impossible to be a Court (sec. 72 of the Constitution). Consequently no portion of the Commonwealth judicial power can be vested in a Board so constituted. This is, if possible, accentuated by the provisions of sec. 43 providing for temporary membership. Sec. 41 (1), however, distinctly states that the Board is to be created "for the purposes of this Part," which means that, if those purposes were inapplicable, no Board would be created. Then sec. 44, which is extremely important in this connection, says: - "(1) A Board of Appeal shall have power to hear such cases as are prescribed, or are referred to it by the Commissioner under this Act. (2) The provisions of section fifty-one, fifty-two, and fifty-three of this Act shall apply, so far as applicable, to references by the Commissioner to the Board as if those references were appeals." "References" are thus placed, as far as they can be, in precisely the same position as "appeals" so far as the Board's duty and powers are concerned; and this compels us to examine the provisions as to appeals. Turning then to sec. 50, dealing with "appeals," it provides by sub-sec. 4 that a taxpayer dissatisfied with the decision of the Commissioner may, by the method stated, require the Commissioner to forward his case, where the objection does not raise questions of law only, to (1) the High Court or (2) a Supreme Court or (3) a Board of Appeal. Pausing there for a moment, it is quite evident that judicial power is thereby conferred on the Board, because the power invested in the High Court is necessarily judicial (In re Judiciary and Navigation Acts[2]) and it is the identical power given by sec. 50 to the Supreme Court and the Board. The power thus given is one of ascertaining and determining whether and how far the rights and duties independently enacted have been accurately declared by the Commissioner, and not for the purpose of superseding his discretionary judgment to create a constitutive element of liability. This at once affects the third sub-section of sec. 28 in two ways. First, even assuming the Board's functions under that sub-section to remain always non-judicial, still a validly constituted Board is necessary. But, if the only Board intended by sub-sec. 3 is a Board as constituted under Part V., the invalidity of Part V. strikes also at sub-sec. 3 of sec. 28. Again, sub-sec. 3 is affected as to functions by force of sub-sec. 2 of sec. 44 and sec. 51, which carries on the judicial functions of sec. 50, because the Board, when sitting on a "reference" under sec. 28, would in deciding the "case" have to determine, if disputed, even the applicability of sec. 28 to the "case." That is, the Board would have to determine whether the "business which is carried on in Australia is controlled principally by persons resident outside Australia." Unless that is so, sec. 51 does not apply to a reference at all in any intelligible sense.