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In regard to the making of a will and other such matters, undue influence is persuasion carried to the point of overpowering the will, or such a control over the person in question as prevents him from acting intelligently, understanding^’, and voluntarily, and in effect destroys his, and constrains him to do what he would not have done if such control had not been exercised. See Mitchell v. Mitchell, 43 Minn. 73, 44 N. W. SS5; Bennett v. Bennett, 50 N. J. Eq. 439, 20 Atl. 573: Francis v. Wilkinson, 147 111. 370, 35 N. E. 150; Conley v. Nailer, 118 U. S. 127, 0 Sup. Ct. 1001, 30 L. Ed. 112; Marx v. Mcglynn, 88 N. Y. 370; In re Hogan's Estate, 195 Pa. 2S2. 45 Atl. 729: Mooney v. Olsen, 22 Kan. 79; In re Black’s Estate, Myr. Prob. (Cal.) 31. Undue influence consists (1) in the use, by one in whom a confidence is reposed by another, or who holds a real or apparent authority over him, of such confidence or au- thority, for the purpose of obtaining an unfair advantage over him; (2) in taking an unfair advantage of another’s weakness of mind; or (3) in taking a grossly oppressive and unfair advantage of another’s necessities or distress. Civ. Code Dak.