When, in the opinion of the court, it is proper for the jury to have a view of the property which is the subject of litigation, or of the place in which any material fact occurred, it may order them to be conducted, in a body, under the charge of an officer, to the place, which shall be shown to them by some person appointed by the court for that purpose. While the jury are thus absent, no person, other than the person so appointed, shall speak to them on any subject connected with the trial.