When the proceedings aforesaid shall be concluded, a list of the twelve members of the Senate and a separate list of the twenty-five members of the House of Representatives so drawn shall be given to each of the parties, who shall immediately withdraw to some adjoining room, with a clerk or members appointed by the joint vote of members present, where they shall proceed to strike off alternately the names upon such list, until the number shall be reduced to four members of the Senate and nine of the House of Representatives, which shall constitute a select committee.
25 P.S. § 3318