1. On an affidavit of illegality on the ground of payment, the burden is upon the defendant to show that the execution is proceeding illegally by being paid off, and the court was right, the fi. fa. and affidavit having been read by the plaintiff injí. fa., and no evidence having been offered by him, in refusing to allow a verdict taken to sustain the illegality, though the plaintiff may have said that he assumed the burden of proof.

*1612. When parties agree m writing to settle a fi. fa. in a certain way therein described, the writing is the best evidence of how the fi. fa. was to be settled, and must be produced to show whether the articles received, or alleged to have been received, came up to the written agreement.