It is obvious that these decisions in principle rule the case at bar if the word 'income' has the same meaning as the Income Tax Act of 1913 that it had in the Corporation Excise Tax Act of 1909, and that it has the same scope of meaning was in effect decided in Southern Pacific Co. v. Lowe, 247 U.S. 330, 335, where it was assumed for the purposes of decision that there was no difference in its meaning as used in the Act of 1909 and in the Income Tax Act of 1913. There can be no doubt that the word must be given the same meaning and content in the Income Tax Acts of 1916 and 1917 that it had in the Act of 1913. When to this we add that in Eisner v. Macomber, Supra, arising under the Corporation Excise Tax Act of 1909, with the addition that it should include 'profit gained through a sale or conversion of capital assets,' there would seem to be no room to doubt that the word must be given the same meaning in all of the Income Tax Acts of Congress that was given to it in the Corporation Excise Tax Act and that what that meaning is has now become definitely settled by decisions of this court.

Merchant's Loan & Trust Company vs. Smietanka 255 US 509