64 Pa. Stat. § 106
All islands within the bed of the river Susquehanna, and of the east or west branches thereof, and of the rivers Ohio, Allegheny and Delaware, which be within the said new purchase, together with the appropriated lands north-westward of the rivers Ohio and Allegheny, and the right of pre-emption of one thousand acres of land in the forks of Sinnemahoning, near the Great or Buffaloe Swamp, which is hereby reserved and granted to General James Potter, shall be excepted and reserved from all such applications as are herein before mentioned, and from all surveys under the same; and the said islands, and every of them, may and shall be sold by public sale, or otherwise, by special order of the President or Vice-President in Council, concerning each of them, for the best prices that can be gotten for the same islands; and all occupancy, and every survey, claim, or pretences for holding the same islands, or any of them, by any other title, shall be utterly void, saving always the pre-emption heretofore granted to William Irwin, Esq., of Montour's Island in the river Ohio, and other preemption rights heretofore granted by law.
64 P.S. § 106