55 ILCS 100/5

In case any officer whose signature appears on said bonds or coupons attached thereto, shall cease to be such officer before the delivery of the bonds to the purchaser, such signature shall, nevertheless, be valid and sufficient for all purposes, to the same effect as if he had remained in office until the delivery of the bonds. Such bonds shall have all the qualities of negotiable paper under the law merchant and the negotiable instrument law.