Provided always, that if the trial of any issue shall be brought on in the said jury court before the jury in any other issue shall have brought in their verdict or be discharged, it shall and may be lawful for the court to order twelve of the residue of the said parchments or papers, not containing the names of any of the jurors who shall not have so brought in their verdict, or be discharged, to be drawn in such manner as is aforesaid, for the trial of the issue which shall be so brought on to be tried.