The court are of opinion, that the conviction of the witness before a justice of the peace, for felony, rendered the witness incompetent. The conviction in the court of com mon pleas was not for felony. The case of larceny before the justice was a simple larceny, for stealing property of less value than five dollars, and therefore was a case in which the magistrate had jurisdiction to hear, decide, and award sentence. Rev. Sts. c. 143, § 5.

It was objected to this conviction, that it was erroneous, because the complainant set forth, by a positive averment, that his property had been stolen, and that he suspected the party charged, without a positive averment; and this is supposed to be erroneous, on the authority of Commonwealth v. Phillips, 16 Pick. 211. It is true that this might be a ground on which the court might have arrested the judgment, or on which the convict himself might have had error to reverse it. But, having submitted to it, and suffered the punishment, a different rule prevails. It is not a nullity, as a judgment of a tribunal having no jurisdiction, but simply an erroneous or irregular judgment, *533to stand good till reversed. Commonwealth v. Loud, 3 Met. 328. When the party himself who has submitted, and suffered the punishment, takes no measure to reverse the judgment, a third party cannot question its validity, in a collateral proceeding. And there is good reason for this; for any other course would produce a confusion of jurisdiction. A judgment given by one having no jurisdiction of the subject would be merelv void, and might be shown to be so, whenever offered.

New trial granted.