§ 40 — Relevancy of statements as to any law contained in law books

40. When the court has to form an opinion as to a law of any country, any statement of the law contained in a book purporting to be printed or published under the authority of the government of the country, and to contain any such law, and any report of a ruling of the courts of the country contained in a book purporting to be a report of the rulings, is relevant.