Notice of dishonour unnecessary: specified exceptions relieve the duty to give notice under negotiable instruments law. Notice of dishonour is unnecessary where the party entitled dispenses with it; where a drawer countermanded payment; where no prejudice would result from non notice; where the entitled party cannot be found after due search or the notifier is unable without fault to give notice; where the acceptor is also a drawer; for a non negotiable promissory note; and where the entitled party, knowing the facts, unconditionally promises to pay.