When the private seal of a person or corporation is required on an instrument or writing to make such instrument or writing legal and valid, such seal shall consist of an impression as provided in section 133 of this title or of a wafer, wax, or other adhesive substance affixed thereto or of a paper or other similar substance affixed thereto or the word "seal" or the letters "L.S." opposite the signature.
1 V.S.A. § 134