638 HARVARD LAW REVIEW necessary to the existence of the States, namely, taxation upon all property within them, must be permitted, and the property employed in interstate commerce is not to be exempted. . . . Were it not sub- ject to taxation in this form the effect would be to confer upon it an affirmative advantage equivalent to a pecuniary bounty equal to the afmount of the tax from which it is exempted," ^* With the advent of general state- wide income taxes, the "ordi- nary system of taxation which is necessary to the existence of the states" is no longer confined to property taxation. The income tax has come to constitute one of the "ordinary and general" bur- dens of government. Reason and psychology combine to warrant the expectation that the Supreme Court will not exclude foreign corporations engaged exclusively in interstate commerce from the "corporations otherwise subject to the jurisdiction of the states" with respect to taxes on net incomes.^^ It seems safe, therefore, to state the principle of the Oak Creek case by saying that a general state-wide tax on net income is not "an unconstitutional interference with or regulation of commerce among the states" by reason of the inclusion of net income from " This passage is quoted more at length in 32 Harv. L. Rev. 261. " This position is taken by the supreme court of Wisconsin in Superior v. Allouez Bay Dock Co., 166 Wis. 76, 80, 164 N. W. 362 (1917), in which Chief Justice Winslow says: "It must be admitted that the defendant's income arose entirely from interstate commerce business. ... Is the levying of an income tax measured by the income so derived a burden upon interstate commerce? "The question is not free from difficulty, but we think it must be answered in the negative. Income taxation is not taxation of property, but is more nearly akin to taxes levied upon privileges or occupations. Its amount may be measured by the receipts of the business, but it is not in any true sense a tax upon the business itself. The subject is covered, as it seems to us, by the decisions of this court in United States Glue Co. v. Oak Creek, 161 Wis. 211, 153 N. W. 241, and Northwestern Mut. L. Ins. Co. v. State, 163 Wis. 484, 155 N. W. 609, 158 N. W. 328, and the cases therein cited." . The cases relied on do not involve concerns whose business was exclusively inter- state, so the declaration in the Superior case is no more than the assertion that this does not seem material to the court. Moreover, the decision in the Superior case that those engaged exclusively in interstate commerce may be constitutionally sub- jected to a tax on their net income was a declaration on a moot point, because the case held that the defendant was exempted from income taxation, for the reason that the property from which the income was derived was railroad property, and the complainant was therefore entitled to the benefit of the provision in the Income Tax Law which exempts "incomes derived from property and privileges by persons now required by law to pay taxes or license fees directly into the treasury of the state in lieu of taxes" (166 Wis. 76, 81).