20 U.S. Code § 56 - Disposal of unappropriated money
The Regents are authorized to make such disposal of any other moneys which have accrued, or shall hereafter accrue, as interest upon the Smithsonian fund, not herein appropriated, or not required for the purposes herein provided, as they shall deem best suited for the promotion of the purpose of the testator.
Source(R.S. § 5592.)
R.S. § 5592 derived from act Aug. 10, 1846, ch. 178, § 9,9 Stat. 105.