The description of the offence in the indictment *589is sufficiently precise and unequivocal. And the form is sustained in Commonwealth v. McDonald, 5 Cush. 365.

The statute allowed the defendant, at his election, to become a witness. St. 1866, c. 260. By availing himself of the privilege he assumed the character of a witness, and subjected himself to the liabilities incident to that position. The statute does not exempt him from cross-examination, and impeachment as a witness; and there is no reason why he should be exempt from it. Commonwealth v. Mullen, ante, 545. Gen. Sts. c. 131, § 13. Commonwealth v. Lannan, 13 Allen, 563.

Exceptions overruled.