I.A power releasable according to RSA 566:1, or under common law, may be released, wholly or partially, by the delivery of a written release executed by the donee of the power for consideration or under seal to any person who could be adversely affected by the exercise of the power, or to any person who alone or with another or others holds in trust property subject to the power, or, in the case of a power created by will, by the filing of such release in the registry of probate in the county in which such will was proved or allowed.II.No release of a power of appointment shall be valid as to land in this state subject to such power, except as against the releasor and persons having actual notice of the release, unless (a) in case of a power created by will or other written instrument, the release is acknowledged in the manner required in the case of deeds of land to entitle them to be recorded and is recorded in the registry of deeds for the county in which the land lies, or (b) in case of a power created by will, the release is filed in the registry of probate in the county in which such will was proved or allowed. 1947, 248:1, par. 2. RL 364-A:2.