Whenever a deed has been registered twenty (20) years or more, the same shall be presumed to have been properly acknowledged or proved, though the certificate of acknowledgement or probate has not been transferred to the registers book, and without regard to the form of the certificate; provided, that an acknowledgment to an instrument which has been of record in the register's office for a period of seven (7) years shall be presumed valid so as to comply with the form of acknowledgments set out in §§ 66-22-107 and 66-22-108.
T.C.A. § 66-26-106