64 Pa. Stat. § 353
All applications made since the first day of April, 1784, on the files or books of the land office, for lands within this commonwealth, for which the purchase money has not been paid, shall, from and after the passing of this act, be null and void: Provided, nevertheless, That all persons shall have the benefits of the act, passed March 29, 1792, entitled "An act to authorize the receiver general of the land office, to carry moneys received into that office since a given period, for such lands sold, and which have not been, nor shall be secured to the purchasers, to the credit of such purchasers, or their assigns, in payments already due, and hereafter to become due to the commonwealth, for the purchase of any lands within the same," agreeably to the provisions contained in a supplement to the said act, passed March 6, 1793: And provided also, That nothing herein contained shall, in any manner, be construed to abridge the time for patenting lands, as declared by an act, passed April 3, 1794, entitled "An act to extend the time for patenting lands:" Provided, That nothing in this act shall in any wise injure the rights of those persons who now hold or hereafter shall hold lands by virtue of actual settlements, and improvements made, or to be made, under the law passed April 3, 1792.
64 P.S. § 353