The jurors sworn to try an action may, in the discretion of the court, be permitted to separate or be kept in charge of a proper officer. Where the jurors are permitted to separate, the court shall properly admonish them. Where the jurors are kept in charge of a proper officer, the officer must be sworn to keep the jurors together until the next meeting of the court, to suffer no person to speak to them or communicate with them, nor to do so himself, on any subject connected with the trial, and to return them into court at the next meeting thereof.