Section 4 and no oath to be administered in lieu of which such declaration has been directed.

After the expiration of the said twenty-one days it shall not be lawful for any commissioner, collector, officer, or other person to administer or cause to be administered, or receive or cause to be received, any oath, solemn affirmation, or affidavit, in the lieu of which such declaration as aforesaid shall have been directed by the Treasury to be substituted.