INDIRECT ENCROACHMENT ON FEDERAL AUTHORITY 393 without quoting it, seeming to imply thereby that the tax in the Erie case was in Ueu of others. No reference is made to the Hender- son Bridge case. This case and the Erie case can both be rested on the doctrine that receipts from rent are not receipts from inter- state commerce.^^ In the Henderson Bridge case the receipts were not the direct measure of the tax on intangible property; they were merely used by the assessors as a guide in fixing the value of that property. Plainly, therefore, neither of these cases can be securely relied on to support the contention that a gross-receipts tax is a good substitute for an assessment of the intangible property of the taxpayer, even though no tangible property has been re- lieved from the ordinary ad valorem tax. But such a contention is not foreclosed by either of these cases or by the Galveston case. The possible distinction between taxes on gross and on net receipts will be considered later in connection with the cases dealing with the net income taxes of Wisconsin and of the federal government.®' Those who before 1908, when the Galveston case was decided, had struggled in vain to reconcile the decisions on the subject under consideration may still remember vividly the relief afforded by Mr. Justice Holmes' opinion in that case. It would perhaps be too much to say that he straightens out the tangle ; but at any rate he tells us what methods will hinder and what will help in accomplishing the task. He makes it clear that no mechanical logic can minister to our needs. He frees us from the tyranny of terms. He exposes the assumption that there is any magic in words. He tells us that "regulation" is a word of art, which the court uses, not for all that regulates, but only for that which regulates too much or in some disapproved way. "It being once admitted, as of course it must be, that not every law that affects commerce, among the States is a regulation of it in a con- stitutional sense, nice distinctions are to be expected. Regulation and commerce among the States both are practical rather than technical conceptions, and, naturally, their limits must be fixed by practical lines." 84 ^ This doctrine appears to be now abandoned, at least with respect to rental for the use of cars which journey in interstate commerce. See the sentence from Mr. Justice Van Devanter quoted on page 402, infra. " See pages 415-16, infra. w 210 U. S. 217, 225, 28 Sup. Ct. Rep. 638 (1908).
