The next argument is that, even if this association can possibly be a party to a two-State dispute, sec. 55 is too wide in that it allows associations to be registered which cannot by any possibility be parties to such a dispute, and that therefore the whole of sec. 55 is unconstitutional and void. The instances suggested by Mr. Mitchell of associations that cannot by any possibility be parties to such a dispute -- Melbourne railway employés, Melbourne corporation employés, employés in a Queensland industry -- are not, indeed, very convincing as illustrations. But let it be assumed that there are associations which can never be parties to such a dispute; what follows? In the first place, as the words of sec. 55 are general, it would be the duty of the Court to presume that the legislature meant to keep within the bounds of the Constitution, and to allow registration to such associations only as could be interested in such disputes: D'Emden v. Pedder [5], at p. 119; United States v. Coombs [6], at p. 75; Parsons v. Bedford [7]; Grenada County Supervisors v. Brogden [8]; Presser v. Illinois [9], at p. 269. But even if this rule of construction were not applicable, even if sec. 55 means that all industrial associations of 100 members are free to register whether they can be interested in a two-State dispute or not, even if sec. 55 is too wide as to the kind of associations that may register, is sec. 55 therefore to be treated as void altogether? Is it to be held that no association can register because the section purports to allow some associations to register which are not within the constitutional power? Mr. Mitchell admits that, if his argument is right, no association can be registered; and so there can be no "organization" under the Act; and there can be no industrial dispute entertained by this Court, and no award can be given; and, in short, the whole Act becomes nugatory. This seems to be a conclusion revolting to common sense; but it must be accepted if in accordance with law. It is urged that where we find an enactment in general terms in one section, terms that may include some things that Parliament has not power to legislate about, the whole enactment is void. In my opinion, there is no such rigid rule of law. Whenever Parliament transcends its powers in legislation, the Court has to determine, as in the case of any other agent exceeding its powers, whether the part intra vires is so bound up with the part ultra vires that it cannot be disentangled. If a man wrongfully mix up another's property with his own so that it cannot be ascertained which is his and which is not his, he loses the whole; and so with legislatures of limited powers. If the legislature has power to deal with matters called A, and not with matters called B, and it pass a clause dealing with A and B as one united indivisible whole, or in some other fashion indicating that its dealing with A is dependent on its dealing with B, then the whole clause is void. If the Commonwealth Parliament had power under the Constitution to make laws for the government of the tropical part of South Australia, and passed an Act providing for the government of all tropical Australia as one whole, the Act would be invalid. But if it passed an Act providing for the government of the tropical part of South Australia, and also enacted -- in the same Act, or in a subsequent Act -- that the same provisions should apply to the tropical part of Queensland, and to the tropical part of Western Australia, severally, the Act would be valid as to South Australia and invalid as to Queensland and Western Australia. The same result would follow if South Australia, Queensland and Western Australia were all referred to in the same section and the same sentence. The doctrine of unconstitutionality in legislation is really a branch of the law as to powers -- a part of the law that has been developed with more logical completeness than most parts. If there be an appointment to several persons, some of whom are and some of whom are not objects of the power, and the appointment to the objects is severable from the appointment to the strangers, it will be valid, and the appointment to the stranger will fail. Contra, if it is impossible to say how much of the appointment falls within the power and how much not: Farwell on Powers, 2nd ed., pp. 298, 312; Adams v. Adams [10]; Hamilton v. Royse [11], at p. 332; In re Brown's Trusts [12]; In re Kerr's Trusts [13]; In re Farncombe's Trusts [14]. The test is, if Parliament had rightly understood the extent of its power, would it not have executed it in this manner as to the associations subject to its power. This test fits the Railway Traffic Employé_s Case_ [15], at pp. 545-7, and the American cases therein cited. In that case the Court was considering the validity of the definition of "industrial dispute" in sec. 4 of this Act. The question was (so far as now material), could the Federal Parliament deal with railway servants by virtue of the inter-state trade and commerce power (sec. 51, sub-sec. 1) taken in conjunction with sec. 98? The Court assumed, for the sake of argument, that it could, but "only so far as regards inter-state traffic and only as far as regards men engaged in that traffic" [16]. But, inasmuch as the Act dealt with New South Wales railway servants in connection with any kind of traffic, whether interstate or confined to New South Wales, and had no intention of dealing with, say, a shunter at Albury, in his inter-state functions -- as distinguished from his State functions -- acting in one set of functions for three minutes, and another set for the following thirty, the Court held that the power of legislating for railway servants as regards inter-state functions had simply not been exercised. Similarly in the Trade Mark Cases [17], at pp. 96, 98-9 cited by the Court the American Judges find that "the main purpose" of the Federal Act was to "establish a regulation applicable to all trades, to commerce at all points," and that "it was designed to govern the commerce wholly between citizens of the same State." In other words, the Act would not have been passed except as an entirety. Similarly in the electoral machinery case: United States v. Reese [18], at p. 221, the Court found that the Federal Congress, having power to legislate so as to prevent the States from denying the rights of citizens on account of race, colour &c., had actually prescribed for the State its electoral machinery for voting irrespective of race and colour, and as the parts could not be separated in administration, the whole provision had to be treated as void. The principle does not depend on the form of words used, whether they are found in one section or in several; whether in one general phrase or in successive specific expressions. As it has been expressed by Mr. Justice Cooley (Constitutional Limitations, 7th ed., 250), "a legislative Act may be entirely valid as to some classes of cases and entirely void as to others. A general law for the punishment of offences, which should endeavour to reach by its retroactive operation acts before committed, as well as to prescribe a rule of conduct for the citizen in future, would be void so far as it was retrospective; but such invalidity would not affect the operation of the law in regard to the cases which were within the legislative control." This passage was read with approval, and adopted by the Supreme Court in Jaehne v. New York [19], at p. 194. In the Massachusetts case of Commonwealth v. Hitchings [20], at p. 486, the Court said as follows -- "The constitutional and the unconstitutional provisions may even be contained in the same section, and yet be perfectly distinct and separable, so that the first may stand, though the last fall. The point is not whether they are contained in the same section, for the distribution into sections is purely artificial; but whether they are essentially and inseparably connected in substance." Again in Warren v. Charlestown [21], at p. 99, the same Court said: -- "if they (the parts) are so mutually connected with, dependent on each other, as conditions, considerations, or compensations for each other, as to warrant a belief that the legislature intended them as a whole, and that, if all could not be carried into effect the legislature would not pass the residue independently, and some parts are unconstitutional, all the provisions which are thus dependent, conditional or connected, must fall with them."