Upon the return of said summons, or as soon thereafter as the business of court will permit, the said court shall proceed to the hearing of such petition and shall impanel a jury to ascertain the just compensation to be paid for the property taken or damaged, but if any defendant or party in interest shall demand, and the court shall deem it proper, separate juries may be impaneled as to the compensation or damages to be paid to any one or more of such defendants or parties in interest.