Constructive actual seisin

Upon the issuing of the patent to John Craig, in November 1784, the possession then being vacant, he became, by operation of law, vested with a constructive actual seisin of the whole tract of land included in his patent. His whole title (such as it was) passed by his prior conveyance, in July 1784, to Michael Gratz, the ancestor of the lessor of the plaintiff, and the moment it became complete at law, by the issuing of the patent, the actual constructive seisin of Craig was transferred to Gratz.