The Act of Union continues from (9)...:
"[II. Similarly, no persons to have power to make Justices of Eyre, Assie, Justices of the Peace or of Gaol Delivery except the King's Great Seal.]
[III. All original writs, judicial writs, indictments of treason, felony, and trespass to be made only in the King's name.]"
The system of courts and application of the laws, customs, and statutes were to be centralized with the central government, which in this case was the "Crown".