In a will, this is a sentence or secret character inserted bythe testator, of which he reserves the knowledge to himself, with a condition that nowill he may make thereafter should be valid, unless this clause be inserted word forword. This is done as a precaution to guard against later wills being extorted byviolence, or otherwise improperly obtained. By the law of England such a clause wouldbe void, as tending to make the will irrevocable . Wharton.Derogatur legi, cum pars detrahitur; abcrogatur legi, cum prorsus tollitur. Toderogate from a law is to take away part of it; to abrogate a law is to abolish it entirely.Dig. 50, 17, 102.