A contract entered into because of mistake as to an essential element is void.1 While this general rule is substantially unquestioned, con-

1 England. Gordon v. Street (1899), 2 Q. B. 641 (really a case of fraud).

United States. Allen v. Hammond, 36 U. S. (11 Pet.) 63, 9 L. ed. 633. 377

Indiana. Alexander v. Swockhamer, 105 Ind. 81, 55 Am. Rep. 180, 4 N. E. 433, 5N. E. 908 (fraud).

Iowa. Eldorado Jewelry Co. v. Darsiderable difficulty is found in determining whether mistake applies to an essential feature of a contract or a collateral matter, such as a quality or characteristic of the subject-matter or of the parties.2 A detailed discussion of the forms of mistake in an essential feature of a contract is therefore necessary, including mistakes as to the identity of the adversary party, as to the identity or existence of the subject-matter and as to the terms and contents of the contract.