Granted. The order granting a new trial is reversed, and the jury verdict is reinstated. The trial court did not grant a new trial because a peremptory ground therefor existed. See, C.C.P. Art. 1972. The trial judge granted a new trial because he concluded from an informal discussion with jurors after a verdict was returned that the jury had erroneously applied a rule of law to the evidence. This does not constitute “good ground” for a discretionary grant of a new trial under C.C.P. Art. 1973. Except for purposes of determining if certain types of irregularities have occurred, the law does not permit inquiry into the thought processes by which a jury reaches a verdict. Conner v. Florida Farm Bureau Casualty Insurance, 446 So.2d 383, 387 (La.App.3d Cir. 1984); cf. La.R.S. 15:470; Code of Jud.Cond.Canon 3(A)(4); State v. Graham, 422 So.2d 123 (La. 1982).