No deed of lands situate in this state heretofore or hereafter executed, shall be deemed defective by reason of any informality or imperfection in the certificate of acknowledgment, if it shall sufficiently appear by such certificate that the person making the same was legally authorized to take such acknowledgment, and that the grantor or grantors named in such deed were personally known to him, and that he or they personally appeared before him and acknowledged such deed to be his or their free act, and if such deed was executed out of this state, it shall be sufficient if the certificate under the seal of office of the clerk or other proper certifying officer of the court of record of the county or district within which such acknowledgment was taken, in cases where any such certificate was required, sufficiently shows that the person before whom such acknowledgment was taken, was at the date thereof such officer as he is therein represented to be. And whenever such deed has been recorded in the office of the register of deeds of the proper county, such record shall be effectual for all purposes of a legal record, and the record of such deed or a transcript thereof may be given in evidence as in other cases: Provided, That nothing in this section, or in the preceding 2 sections contained, shall impair the rights of any person under a purchase heretofore made in good faith, and on valuable consideration.