This Act shall apply to every undertaking authorized by any subsequent enactment (called “Special Statute”) which shall authorize the purchase or taking of lands for such undertaking and this Act shall be incorporated with such enactment. All the clauses and provisions of this Act, save so far as they shall be expressly varied or excepted by any such enactment, shall apply to the undertaking authorized thereby, so far as the same shall be applicable to such undertaking, and shall form part of su