A conveyance, settlement, deed, or other act of a testator, by which his estate or interest in property, previously devised or bequeathed by him, shall be altered, but not wholly divested, shall not be deemed a revocation of the devise or bequest of such property; but such devise or bequest shall pass to the devisee or legatee, the actual estate or interest of the testator, which would otherwise descend to his heirs, or pass to his next of kin; unless in the instrument by which such alteration is made, the intention is declared, that it shall operate as a revocation of such previous devise or bequest.