The circumstances appearing on the face of the will which make it open to objection may either avoid it altogether or create a partial intestacy, the will remaining good as a whole. Where the will is not duly executed, e.g. if it is a forgery or if it is not signed by the testator or the proper number of witnesses, the will is not admitted to probate at all. Where it contains devises or bequests bad in law, as in general restraint of marriage, or tending to create perpetuities, or contrary to public policy, or to some particular enactment, only the illegal part is void. A remarkable instance is a well-known case in which a condition subsequent in a devise was held void as against public policy, being a gift over of the estate devised in case the first devisee, the eldest son of an earl, did not before his death obtain the lapsed title of Duke of Bridgewater.