Every rule made under this Act and every order issued under section 20, shall be laid as soon as may be after it is made or issued before each House of the State Legislature, while it is in session for a total period of thirty days which may be comprised in one session or in two or more successive sessions, and if before the expiry of the session in which it is so laid or the session or sessions immediately following, both Houses agree in making any modification in the rule or order or both Houses agree that the rule or order should not be made, the rule or order shall thereafter have effect only in such modified form or be of no effect, as the case may be; so however that any such modification or annulment shall be without prejudice to the validity of anything previously done under that rule or order.