New York Consolidated Laws, Real Property Law - RPP § 243. Grant of fee or freehold

A grant in fee or of a freehold estate, must be subscribed by the person from whom the estate or interest conveyed is intended to pass, or by his lawful agent thereunto authorized in writing.  If not duly acknowledged before its delivery, according to the provisions of this chapter, its execution and delivery must be attested by at least one witness, or, if not so attested, it does not take effect as against a subsequent purchaser or incumbrancer until so acknowledged.