law: Indian Post Office Act, 1898 
  19. Transmission by post of anything injurious prohibited 
  (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.