The jurors sworn to try a criminal action, at any time before the cause is submitted to the jurors, in the discretion of the court, may be permitted to separate, or may be kept in charge of proper officers. The officers must be sworn to keep the jurors together until the next meeting of the court, to suffer no person to speak to nor communicate with them, nor to do so themselves, on any subject connected with the trial, and to return them into court at the next meeting thereof.