They aren't banknotes. They are
stamped paper.
You can read online the only catalog of Spanish stamped paper in
http://www.filaposta.com/biblioteca/ (click Timbres españoles in left menu)
Your first stamped paper is in chapter 5, page 14, serie 1844, sello 4º. It's a Isabella II stamped paper of 1844 face value 40 maravedis.
The second is in chapter 5, page 4, serie 1812-clasico, oficio. It's a Ferdinand VII stamped paper of 1812 face value 4 maravedis.