That is a question which is agitating a good many people just now. Congress from time to time has seemed disposed to try it, in spite of misgivings as to the constitutionality of such legislation.[1] A recent Revenue Bill contained provisions taxing the income of future issues of such obligations, and a motion for the elimination of those provisions was defeated in the House 132 to 61. Meanwhile, protests were pouring in from state and municipal officers assailing the justice and expediency of such a tax. [Footnote 1: See, e.g., H. Report No. 767, 65th Cong., 2d Sess., accompanying House Revenue Bill of 1918 as reported by Mr. Kitchin from the Committee on Ways and Means, page 89.] It is not the purpose of this chapter to discuss the questions of justice and expediency (as to which there is much to be said on both sides) but rather to deal with the strictly legal aspects of the matter and indicate briefly why such a tax cannot be laid without a change in our fundamental law. Let it be said at the outset that no express provision of the United States Constitution forbids. On the contrary, that instrument confers on Congress the power to lay taxes without any restriction or limitation save that exports shall not be taxed, that duties, imposts, and excises shall be uniform throughout the United States, and that direct taxes must be apportioned among the states in proportion to population. The obstacle lies rather in an implied limitation inherent in our dual system of government and formulated in decisions of the Supreme Court. The founders of this republic established a form of government wherein the states, though subordinate to the Federal Government in all matters within its jurisdiction, nevertheless remained distinct bodies politic, each one supreme in its own sphere. In the famous phrase of Salmon P. Chase, pronouncing judgment as Chief Justice of the Supreme Court[1]: The Constitution in all its provisions looks to an indestructible Union, composed of indestructible states. [Footnote 1: _Texas v. White_, 7 Wall., 700, 725.] In a later case[1] another eminent justice (Samuel Nelson of New York) put the matter thus: The General Government, and the states, although both exist within the same territorial limits, are separate and distinct sovereignties, acting separately and independently of each other, within their respective spheres. The former, in its appropriate sphere, is supreme; but the states within the limits of their powers not granted, or, in the language of the 10th Amendment, "reserved", are as independent of the General Government as that government within its sphere is independent of the states. [Footnote 1: _The Collector v. Day_, 11 Wall., 113, 124.]