64 Pa. Stat. § 142
The lands actually settled and improved according to the provisions of this act, to whosesoever possession they may descend or come, shall be and remain liable and chargeable for the payment of the consideration or purchase money at the rate aforesaid, for every hundred acres, and the interest thereon accruing from the dates of such improvements; and if such actual settler, not being hindered as aforesaid, by death, or the enemies of the United States, shall neglect to apply for a warrant for the space of ten years after the time of passing this act, it shall and may be lawful to and for this commonwealth to grant the same lands, or any part thereof, to others, by warrants, reciting such defaults; and the grantees, complying with regulations of this act, shall have, hold and enjoy the same to them, their heirs and assigns; but no warrant shall be issued in pursuance of this act, until the purchase money shall be paid to the receiver general of the land office.
64 P.S. § 142