19.(1) Except as otherwise provided by rule and subject to such conditions as may be prescribed thereby, no person shall send by post any explosive, dangerous, filthy noxious or deleterious substance, any sharp instrument not properly protected, or any living creature which is either noxious or likely to injure postal articles in course of transmission by post or any officer of the Post Office. (2) No person shall send by post any article or thing which is likely to injure postal articles in course of transmission by post or any officer of the Post Office.