Mistake is divided into two classes; mistake of law and mistake of fact. Everybody is conclusively presumed to know the law and a mistake of law is therefore no defense either in a criminal prosecution or in a suit on a contract. There are three apparent exceptions to this rule; the following being considered as mistakes of fact rather than as mistakes of law: (1) Mistakes as to foreign law; (2) mistakes as to private statutes; (3) mistakes of fact which are in their turn occasioned by mistakes of law.6 Money paid under a mistake of law can not be recovered back;7 but money paid under a mistake of fact can be so recovered.8

3 Rovengo vs. Defferari, 40 Cal., 459; Duncan vs. N. Y. L. Ins. Co., 138 N. Y., 88, 33, N. E. 730, 20 L. R. A., 386.

4 Lane vs. Hogan, 5 Yerg., 448;

Jones vs. Hyde, 5 Taunt, 448; Markle vs. Hatfield, 2 Johns, 455; 3 Am. D., 446.

5 U. S. Bank vs. Bank of Georgia,

10 Wheaton, 333; Smith vs. Mercer, 6 Taunt, 76.

6 For a fuller treatment of this subject see subject of Equity Jurisprudence.

7 Manning vs. Poling, 114 la., 20, 86 N. W., 30; Heath & Milli-gan Mfg. Co. vs. Nat. Linseed Oil Co., 197 I11., 632, 64 N. E., 732.

8 Burr vs. Vieder, 3 Wend. 412; Dickins vs. Jones, 6 Yerg., 433, 27 Am. D. 448.