fraud in the party defendant in which the party plaintiff has not participated; 18 Pet. 26; secondly, where there is con- structive fraud against public policy and the party plaintiff has not participated therein; see 4 Munf. 316; thirdly, where there is a fraud against public policy and the party plaintiff has participated therein, but public policy would be defeated by allowing it to stand; fourthly, where there is a constructive fraud by both parties,-that is, where both parties are in delicto, but prince, at the request of the parties, re- specting some matter in dispute between them, or to magistrates, in relation to some doubtful matter submitted to him. The rescript was differently denominated according to the character of those who sought it. They were called annotations or subnotations, when the answer was given at the request of private citizens; letters or epistles, when he answered the consultation of magistrates; pragmatic sanctions, when he answered a corpora- not in pari delicto; see 2 Story, Eq. Jur. §tion, the citizens of a province, or a mu- 694; 3 Jones, Eq. 494; 2 Mas. 378; 25 Ga. 89; 1 Pat. & H. 307; Bisph. Eq. § 81. The court will decree that a deed or other solemn instrument shall be delivered up and cancelled, not only when it is avoid- able on account of fraud, but also when it is absolutely void, unless its invalidity ap- pears upon the face of it, so that it may be defeated at any time by a defence at law; 2 Story, Eq. Jur., 18th ed. § 698; 6 Du. 597. To cancel an executed contract for alleged false representations, fraud must be made clearly to appear, and it must be shown that the complainant has been injured and deceived thereby; 124 U. S. 173. The ignorance or mistake which will authorizə relief in equity must be an igno- rance or mistake of material facts; 1 Stor. 178; 11 Conn. 134; 6 Wend. 77; 6 Harr. & J. 500; 10 Leigh 37; and the mistake must be mutual; 3 Green, Ch. 103; 2 Sumn. 387; 11 Pet. 63; 24 Me. 82; 10 Vt. 570; 6 Mo. 16; 153 Pa. 134; 89 Ga. 619. If the facts are known but the law is mistaken, the same rule applies in equity as at law, that a mere mistake or ignorance of law, where there is no fraud or trust, is imma- terial: ignorantia legis neminem excusat; Adams, Eq., 8th ed. 188. See 99 N. C. 30; IGNORANCE; MISTAKE. Instruments may also be rescinded and cancelled when they have been obtained from persons who were at the time under duress or incapacity: 2 Root 216; 8 Ohio 214; 3 Yerg. 537; 36 Miss. 685; or by per- sons who stood in a confidential relation and took advantage of that relation: 5 Sneed 583; 31 Ala. N. S. 292; 3 Cow. 537; 2 A. K. Marsh. 175; 9 Md. 248; 8 Jones, Eq. 152, 186; 30 Miss. 369; 8 Beav. 437; 151 Pa. 593; 115 Mo. 465; 96 Mich. 562. Gross inadequacy of consideration; 17 Vt. 9; 22 Ga. 637; 19 How. 303; 82 Va. 394; 119 U. S. 499; fraudulent misrepre- sentation and concealment; 3 Pet. 210; 2 Ala. N. S. 251; 10 Yerg. 206; 1 A. K. Marsh. 235; 2 Mo. 126; 34 Ala. N. 8. 596; 6 Wisc. 295; 74 la. 161; 85 Ky. 160; 116 Md. 367; hardship and unfairness; 17 Vt. 542; 2 Root 216; 2 Green, Ch. 357; 2 Harr. & J. 285: 3 Yerg. 537; 8 Ohio 214; 81 Vt. 101; undue influence; 2 Mas. 378; are among the causes for a rescission of contracts in equity. See, generally, 9 L. R. A. 607; ELECTION OF RIGHTS AND REMEDIES; PERFORMANCE,