Provided always, and be it enacted, That all Contracts of Excambion to be executed in virtue of the Powers of this Act shall be recorded in the Sheriff Court Books of each of the Shires or Stewartry in which the Lands or Heritages excambed are situated, and shall thereupon be effectual to all Intents and Purposes, without the Necessity of being recorded in the Register of Tailzies, as by the said first-recited Act required.