INDIRECT ENCROACHMENT ON FEDERAL AUTHORITY 263 value.^^° But the tax in question was not on the real estate of the express companies, for that was assessed separately, and the assess- ment then deducted from the value of the "total property" deter- mined by the use of the unit rule. Mr. Justice White's dissenting opinion touches upon what ought to be the determining element in the case, when it points out that if the unit rule is good for express companies, it ought also to be appHed to bankers and merchants. But this is adduced in support of the contention that the tax is not confined to tangible property within the state but falls also on all kinds of property without the state. That the assessment on the express companies greatly exceeded "the true value in money" of their tangible chattels within the state was fully recognized in the opinion denying a rehearing, in which this excess was called the intangible property of the company. What should then have been discussed was the question whether the intangible property of the express companies was taxed no more heavily than that of others. The answer to the question depends upon whether similar busi- ness taxes were imposed on other businesses. Only by a general state-wide income tax can differences of treatment be avoided. And Ohio had no general income tax. Certainly the intangibles of the express companies were discriminated against in favor of intangibles enjoyed by many other businesses. But the doctrine of reasonable classification ought to go far enough to say that it is not necessary to treat express companies in the same way as other businesses that come into no competition with them. It can hardly be called a discrimination against interstate commerce to tax express companies more heavily than farmers. On the other hand, express companies may suffer if merchants escape what they must endure. An increase in the cost of interstate transportation by taxation of express companies may well reduce the volume of that kind of interstate commerce to the resulting increase of sales over the counters of local merchants. The Ohio tax on express companies might discriminate against interstate commerce even though similar taxes were imposed on all engaged in any form of trans- portation, intra-state or interstate. But the court was excused from considering these possibilities in dealing with the Ohio cases, since they were not specifically pressed and supported by evidence. ^0 165 U. S. 194, 225, 17 Sup. Ct. Rep. 305 (1897).
