Acknowledgments of deeds, mortgages and other instruments in writing, required to be acknowledged may be taken in this state before a justice of the supreme court, or the clerk thereof, or the deputy of such clerk, before a judge of the court of appeals, or the clerk thereof, before a judge of the superior court, or qualified court commissioner thereof, or the clerk thereof, or the deputy of such clerk, or a county auditor, or the deputy of such auditor, or a qualified notary public, or a qualified United States commissioner appointed by any district court of the United States for this state, and all said instruments heretofore executed and acknowledged according to the provisions of this section are hereby declared legal and valid.