491. Breach of contract to attend on and supply wants of helpless person.-- Whoever, being bound by a lawful contract to attend on or to supply the wants of any person who, by reason of youth, or of unsoundness of mind, or of a disease or bodily weakness, is helpless or incapable of providing for his own safety or of supplying his own wants, voluntarily omits so to do, shall be punished with imprisonment of either description for a term which may extend to three months, or with fine which may extend to two hundred rupees, or with both.