64 Pa. Stat. § 153
In all cases where an actual settler has, adverse to the original warrantee, taken possession of any tract of land heretofore surveyed on any original warrant, and who has made on the same such actual settlement, residence and improvement, as is required in the ninth section of the said act of April 3, 1792, and who has purchased any part of the said tract of the warrantee to include and secure his said improvement, that in all such cases, where the said warrantee or his legal representative, on or before the first day of June, 1813, shall release to the said actual settler, or his legal representative, his claim to one hundred and fifty acres and allowance of six per cent. of said tract, clear of expense, as a consideration for making said improvement, settlement and residence, to be surveyed and laid off by the proper deputy surveyor, in such case the commonwealth shall cease to have any further claim to such tract.
64 P.S. § 153