662 HARVARD LAW REVIEW the subjection of the recipient to the power of Wisconsin, but the actual earning of the income in Wisconsin, Judge Siebecker dis- misses too cavalierly the alleged importance of the transactions without the state. The sales in another state to customers in that state are taxable in that jurisdiction as intra-state sales.^® If the United States Glue Company is a wholesaler in Chicago as well as a manufacturer at CarroUville, Wisconsin, it must be subject to an Illinois income tax on all its Illinois business, unless the Supreme Court is going to insist that power over the person is the only basis on which income taxes may be levied. Even such insistence would not forbid Illinois taxation of Illinois intra-state sales. And if income from interstate commerce carried on by non-residents or by foreign corporations may be included in a state-wide tax on business income, Illinois may lay a tax on income from sales by IlHnois wholesalers to customers in other states, even though the sales are of goods manufactured by the wholesaler at a Wisconsin factory. Plainly enough the manufacture, the wholesale establish- ment and the work of securing customers and of collecting bills are all essential to the making of a profit. No one of these three elements in the combined enterprise is a mere incident. A portion of the net income is due to each element. If sufficiently exquisite book-keeping were possible, each state should take only that por- tion of the income which is contributed by the acts done within its own borders. Judge Siebecker considers only two extreme al- ternatives, both of which miss the ideal solution. It may well be that the ideal solution is not attainable in prac- tice. But this is no reason why it should be neglected in consid- ering what is the best approximation that is feasible. Though manufacturing is for profit, the profit appears only in income from sales. The price which the product brings depends only in part on the excellence of raw materials and of shop management. The need or susceptibility of customers, the skill of the sales force, the wisdom in extending credit and energy in collecting accounts are not mere incidents, as Judge Siebecker would have us believe.^^ Indeed they may in many instances be "controlling" in the " Ratterman v. Western Union Telegraph Co., 127 U. S. 411, 8 Sup. Ct. Rep. 1127 (1888). " Judge Siebecker recognizes that these elements are of practical importance (161 Wis. 211, 217), but calls them but "incidents" from a legal standpoint.
