Where a full jury shall not appear before the said jury court or elsewhere, after challenge by either of the parties, and the jury is like to remain untaken for default of jurors, it shall be lawful for the said court, or the commissioner before whom any issue is to be tried, to direct the F1sheriff principal or other officer or officers who summoned the said jury, upon request made by either party, to add to the list of the said jury the name or names of such other person or persons of the county, city, town, or place where the issue is to be tried, who shall be inserted in some other list of the jurors, and who shall then be attending the court where such trial is to be had, to serve upon such jury, and not any others, if so many out of the said other list be present in court, or can there be found; and either of the parties, pursuer and defender, may have his challenge to the juror or jurors so named and added to the former original list, in such wise as if he or they had been originally included in the said list of jurors for the trial of such issue; and the said court or commissioner who sits to try such issue shall and may proceed to the trial thereof with those persons whose names were originally inserted in the said list of jurors, together with the person or persons whose names have been so added to the original list of jurors as aforesaid, in the same manner as the said court or commissioner might and ought to have done if all the said jurors whose names were inserted in the said original list had appeared to try such issue; and in case any person or persons so added to the said list of jurors as aforesaid, and who shall have been present at that time, shall be called and not appear, or after his or their appearance shall wilfully withdraw himself or themselves from the said service, then and in every such case the said jury court shall and may set a fine upon every such person making default or wilfully withdrawing himself, such fine not exceeding the sum of five pounds sterling, nor less than the sum of F2two pounds, as the said jury court shall think reasonable.