It will be noticed that the words “beyond the power of the Irish Legislature” referred to the subjects expressly excepted in the Bill itself. This is one of the points in which the Irish Constitution will bear at any rate a superficial resemblance to that of a Province or State within a Federation rather than to that of a self-governing Colony. The practice of expressly, and in the text of a Constitution, forbidding a self-governing Colony to legislate upon certain subjects, or of expressly reserving concurrent or exclusive powers of legislation to the Mother Country, has fallen into disuse since the establishment of the principle of responsible government. Such restrictions were inserted in the Canadian Union Act of 1840, where the old right of the Mother Country to impose customs duties in the Colonies for the regulation of commerce was reaffirmed, and even in the Acts of 1855 for giving full powers of self-government to the Australian Colonies, which were forbidden to impose intercolonial customs, though they were expressly granted the power of imposing any other customs duties they pleased,[91] but they do not appear in modern Constitutions, for example in the Transvaal Constitution of 1906. As I have indicated, this implies no change in the strict legal theory of Colonial subordination to the Mother Country; for, although the tendency of modern juristic thought is to ascribe “plenary” power to a Colony, restrictions nevertheless do exist in practice, and are contained, express or implicit, in a number of disjointed Acts.
A Federating Colony, on the other hand, like a foreign Federation, has in its own self-made, domestic Constitution to apportion powers with some approach to precision between the federal and the provincial authorities, and in this respect the Irish Bill, in reserving certain powers to the Imperial Parliament, will resemble a federating Bill, and it should follow the American and Australian precedents in leaving residuary powers to the subordinate or Irish Legislature, not, in accordance with the Canadian precedent, to the Parliament at Westminster. That is an indispensable corollary of excluding Irish Members from Westminster.