81. Presumption as to Gazettes, newspapers, private Acts of Parliament and other documents.- The Court shall presume the genuineness of every document purporting to be the London Gazette or any Official Gazette, or the Government Gazette of any colony, dependency of possession of the British Crown, or to be a newspaper or journal, or to be a copy of a private Act of Parliament of the United Kingdom printed by the Queen's Printer and of every document purporting to be a document directed by any law to be kept by any person, if such document is kept substantially in the form required by law and is produced from proper custody.