The first observation to make upon the terms of s. 86 (1) is that the power conferred is a power exercisable "in proceedings under this Act". If this expression meant "in proceedings under this sub-section", so that the intention appearing were to create a jurisdiction exercisable independently of proceedings for divorce or any other matrimonial cause, there might well be strength in a contention that the enactment could not be supported under any head of federal power. No doubt it would properly be characterized only as a law with respect to property, notwithstanding that the persons whose interests might be affected are confined to spouses and children; and the Parliament has no general power to make laws with respect to property. But I think it is clear that the sub-section creates only a power to make an ancillary order in substantive proceedings which themselves are within the constitutional concept of "divorce and matrimonial causes". In order to demonstrate that this is so, reference must be made to several provisions of the Act. The expression "the court" is defined in s. 5 (1) to mean, in relation to any proceedings, the court exercising jurisdiction in those proceedings by virtue of the Act. By s. 23 (2), the Supreme Court of each State is invested, subject to certain provisions which there is no need to mention here, with federal jurisdiction to hear and determine matrimonial causes instituted under the Act. The expression "matrimonial cause" is given by s. 5 (1) an exclusive definition, extending it, but at the same time confining it, to proceedings described in five paragraphs lettered from (a) to (e). The kinds of proceedings comprised in pars. (a) and (b) are of a substantive character, having no necessary relation to any other proceedings. They are (a) proceedings for a decree of dissolution of marriage, nullity of marriage, judicial separation, restitution of conjugal rights or jactitation of marriage, and (b) proceedings for a declaration of the validity of the dissolution or annulment of a marriage, or of a decree of judicial separation, or for a declaration of the continued operation of a decree of judicial separation, or for an order discharging a decree of judicial separation. Paragraph (c) comprises proceedings of various descriptions, including proceedings "with respect to settlements", but all the descriptions are qualified by the words "being proceedings in relation to concurrent, pending or completed proceedings of a kind referred to in either of the last two preceding paragraphs, including proceedings of such a kind pending at, or completed before, the commencement of this Act". Paragraphs (d) and (e) need not be here considered.