In all claims, or money demands, of whatever kind, and howsoever due, where an agreement is made and accepted for a less amount than that demanded or claimed to be due, in satisfaction thereof, the payment of the less amount according to such agreement in compromise of the whole is a full and complete discharge of the same.  (1874-5, c. 178; Code, s. 574; Rev., s. 859; C.S., s. 895.)