from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
ACCESSORY CONTRACT. One made for assuring the performance of a prior
contract, either by the same parties, or by others; such as suretyship,
mortgages, and pledges.
2. It is a general rule, that payment of the debt due, or the
performance of a thing required to be performed by the first or principal
contract, is a full discharge of such accessory obligation. Poth. Ob. part.
1, c. 1, s. 1, art. 2, n. 14. Id. n. 182, 186. See 8 Mass. 551; 15 Mass.
233; 17 Mass. 419; 4 Pick. 11; 8 Pick. 522.
3. An accessory agreement to guaranty an original contract, which is
void, has no binding effect. 6 Humph. 261.