All Powers vested in the Privy Council by this Act may be exercised by any Three or more of the Lords and others of the Privy Council, the Vice-President of the Committee of the said Privy Council on Education being One of them; and all Orders and Acts of the Privy Council under this Act shall be sufficiently made and signified by a written or printed Document, signed by One of the Clerks of the Privy Council, or such Officer as may be appointed by the Privy Council in this Behalf; and all Orders and Acts made or signified by any written or printed Document purporting to be so signed shall be deemed to have been duly made, issued, and done by the Privy Council; and every such Document shall be received in Evidence in all Courts, and before all Justices and others, without Proof of the Authority or Signature of such Clerk or other Officer or other Proof whatsoever, until it be shown that such Document was not duly signed by the Authority of the Privy Council.