In order to authorize the arrest of a debtor on execution, the judgment creditor, or some one in his behalf, must not only make affidavit to certain facts, but must prove them to the satisfaction of the magistrate before whom the affidavit is taken, and the affidavit, with a certificate of the magistrate that he is satisfied that there is reasonable cause to believe the truth of the charges therein contained or some one of them, must be annexed to the execution. Gen. Sts. c. 124, § 5. The magistrate, in determining whether the evidence laid before him is sufficient to satisfy him of such a state of facts as the statute requires, performs a judicial duty. The case stated shows that the master in chancery, who took the affidavit and made the certificate upon which the defendant was arrested, was at the same time the attorney of the plaintiff in this very matter. He was thereby disqualified from acting judicially therein; for no man can be at once the judge and an attorney for one of the parties. Bonham's case, 8 Co. 118 a. Richardson v. Welcome, 6 Cush. 332. The arrest of the defendant was therefore unlawful, and the recognizance given in order to obtain his discharge from imprisonment was void. Norton v. Danvers, 7 T. R. 375. Met. Con. 24, 25. Judgment for the defendants.