Provided always, that any person who shall be tried and acquitted or convicted of any offence against this Act shall not be liable to be indicted, prosecuted or tried again for the same offence or fact as high treason or misprision of high treason; and that nothing in this Act contained shall be construed to extend to prevent any persons guilty of any offence against this Act, and who shall not be tried for the same as an offence against this Act, from being tried for the same as high treason or misprision of high treason, in such manner as if this Act had not been made.