Instruments, which have been heretofore acknowledged or proved before any alderman of this commonwealth, duly required by law to be provided with a public aldermanic seal to authenticate all his acts and attestations, the certificate of which shall have been made under the hand or private seal of the alderman, such certificate shall be taken to be as valid for all purposes as if the said acknowledgment or proof had been certified or authenticated under their aldermanic seal, and the recording of such deeds and other instrument is hereby ratified and confirmed.