Evidence (Scotland) Act 1840 (c. 59)

IV Examination of Witnesses by the Parties against whom they are produced.

And be it declared and enacted, That in any Action, Cause, Prosecution, or other Judicial Proceeding, Civil or Criminal, where Proof shall be taken, whether by the Judge or a Person acting as Commissioner, it shall be competent for the Party against whom a Witness is produced and sworn in causâ to examine such Witness, not in cross only, but in causâ.