"I think the fact that the appellant had been convicted by justices under one act of Parliament for what amounted to an assault is a bar to a conviction under another act of Parliament for the same assault. The defence does not arise on a plea of autre fois convict, but on the well established rule at common law that, where a person has been convicted and punished for an offence by a court of competent jurisdiction, transit in rem judicatum, that is, the conviction shall be a bar to all further proceedings for the same offence, and he shall not be punished again for the same matter; otherwise, there might be two different punishments for the same offence. The only point raised is whether a defence in the nature of a plea of autre fois convict would extend to a conviction before two justices whose jurisdiction is created by statute. I think the fact that the jurisdiction of the justices is created by statute makes no difference. Where the conviction is by a court of competent jurisdiction, it matters not whether the conviction is by a summary proceeding before justices or by trial before a jury."