1. “Affidavits of illegality are, upon motion and leave oí court, amendable instanter by the insertion of new and independent grounds: Provided, the defendant will swear that he did not know of such grounds when the original affidavit was filed.” Civil Code (1910), § 5704. The defendant in execution will not be permitted to amend his affidavit of illegality by the addition of new and independent grounds, whether of fact or of law, for causes which existed and were known, or *767in the exercise of reasonable diligence might have been known, at the time of the filing of the original affidavit. Baker v. Smith, 91 Ga. 142 (2), 143 (16 S. E. 967). An amendment which does not add a new and independent ground of illegality, but which merely amplifies or amends a ground in the original affidavit, need not be sworn to.

2. Applying the foregoing principles, the amendment to the affidavit of illegality in this case added new and independent grounds; and such new and independent grounds not having been verified as required by the statute, the court erred in allowing the same over timely objection, and in refusing to strike the same upon demurrer. In so far as the amendment raised only questions of law, the defendant in execution was conclusively presumed to have had knowledge of these grounds at the time of the filing of his original affidavit, and the court did not err in refusing to allow the same.

Judgment reversed on the main hill of exceptions, and affirmed on the cross-hill.