The first amendment filed by the defendant was verified as to the facts therein set forth, but the affidavit did not conform to the other requirements of the act of 1897 (Acts 1897, p. 35). The second amendment was verified in strict conformity to the act above referred to. It does not appear from the record that the judge disallowed either of the amendments, but it would seem that he allowed the amendments, and then struck the plea as amended, as insufficient in law. The order, after reciting that the defendant had offered two amendments to his plea, and that the plaintiff insisted “upon his demurrers thereto,” proceeded to declare that the demurrers were sustained and that the plea and amendments “are all hereby stricken.” The only demurrer contained in the record is a demurrer filed to the original plea, which is broad enough in its terms to raise objections to the plea as amended. In addition to this, the original plea put the plaintiff upon notice that the defendant relied upon a mistake, but the plea was defective, in that it did not allege that the mistake was mutual, and in other *543respects. The first amendment merely amplified the plea, and cured some of the defects therein, and was therefore not an amendment which is required to be verified in the manner prescribed by the act of 1897. See Conant v. Jones, 120 Ga. 568(2). We will therefore deal with the case as the judge seems to have dealt with 'it, by determining whether the pleas were good in. substance.
The requirements of a plea of usury, where the purpose .of the plea is either to recover back usury paid or set off the same against the plaintiff's demand, are fixed by statute. Civil Code, §5090. The purpose of this statute is to require the defense of usury to be so pleaded that the amount that is sought to be recovered or set off may be determined accurately from the allegations in the plea, without aid from extraneous sources. Any defect, therefore, in such a plea which would prevent the determination of the amount would be a defect in substance, and can be taken advantage of by a general demurrer in writing, or an oral motion to strike. When this test is applied to that portion of the plea which is relied upon as a plea of usury, it is at once seen that the plea is defective, if for' no other reason, because there were in the plea blanks as to the date and maturity of some of the notes. Without these blanks being filled,.of course, the amount of usury could not be calculated. As to the effect of blanks in a plea of usury, see the remarks of Mr. Chief Justice Bleckley in Odom v. New England Mortgage Co., 91 Ga. 508(2). The plea of usury was therefore properly stricken.
2. As to the other plea, the facts alleged are sufficient to show that there Avas a mutual mistake between the parties as to the amount due at the time that the note sued on was given, and the plea was good in substance. Even if, as contended, the plea is contradictory as to the sum represented by the mistake, this would not make the plea bad, in the absence of a special demurrer raising that objection. If no amendment were made to such a plea, the defendant might be held to the least amount set forth.
Counsel for plaintiff in error in their brief state that the plea was really stricken upon the ground, that, being an equitable plea in its nature calling for affirmative relief, the city court had no jurisdiction to entertain it. There is nothing in the record to indicate that this point was made in the court below; nor does it appear that the judge struck the plea of mistake for this reason, mor does counsel for defendant in error seek to uphold the judg*544ment on this ground. Of course, if this is true, the court would have no jurisdiction, and the judgment would be affirmed without reference to the ground upon which the judge based it. But we think the city court has jurisdiction of such a plea. A city court has jurisdiction to entertain an equitable plea which is purely defensive in its nature, and which if sustained would result simply in a verdict finding generally, in favor of the defendant, or reducing the amount of plaintiff’s recovery, when such reduction is not brought about by the exercise of any of the extraordinary powers of a court of equity, such as' cancellation, reformation, equitable set off, and the like. See Hecht v. Snook & Austin Co., 114 Ga. 927; House v. Oliver, 123 Ga. 784.
Judgment reversed.
All the Justices concur.