Depositions, warrants, or other papers or copies thereof offered in evidence upon the hearing of any extradition case shall be received and admitted as evidence on such hearing for all the purposes of such hearing if they shall be properly and legally authenticated so as to entitle them to be received for similar purposes by the tribunals of the foreign country from which the accused party shall have escaped, and the certificate of the principal diplomatic or consular officer of the United States resident in such foreign country shall be proof that the same, so offered, are authenticated in the manner required.