A judgment of imprisonment to be served in a county jail must be executed by delivering the defendant into the custody of the sheriff or other officer in charge of the county jail. A copy of the judgment of conviction, duly certified by the judge or justice, is a sufficient warrant for the doing of every act necessary or proper in the due execution thereof. The officer shall, upon discharging the defendant, return such copy to the justice, with an account of the officer’s doings endorsed thereon, and must at the same time pay over to the justice all money which the officer may have received from the defendant in payment of the fine.