In connection with the law of land there is frequent occasion for the application of the familiar principle that one who, by his words or actions, represents a certain state of facts to be true, and thereby induces another to act to his detriment, is precluded from thereafter denying the existence of such a state of facts. So it has frequently been decided that if one, having title to land, as he knows or has reason to know, disclaims any rights therein,64 or fails to assert his rights,65 and thereby causes one, excusably ignorant of the true state of the title, to purchase the land from a third person, he cannot thereafter assert any claim to the land. Likewise, the true owner of land who stands by and sees another, under the belief that he has the unincumbered title to the land, make expenditures for improvements thereon, may be under such a duty to inform the person in possession of the true state of the title as to be thereafter estopped from asserting any rights in the land.66 The mere failure to assert one's title, without any active misrepresentation in regard thereto, will not ordinarily have the effect of an estoppel, if his title appears of record, since one purchasing or improving the land is in such case charged with notice of the true state of the title.67 And the result appears to be

62. Lamprey v. Pike, 28 Fed. 30; Brown v. Barker, 35 Okla. 498, 130 Pac. 155. See also Wat-kins v. Wassell, 15 Ark. 73. Compare Leslie v. Harrison Nat. Bank, 97 Kan. 22, 154 Pac. 209.

63. In Pennsylvania a judgment creditor is so protected as against a mortgage made by the debtor before acquiring title. Calder v. Chapman, 52 Pa. 559, 91 Am. Dec. 163; Gallagher v. Stern, 250 Pa. 292, 95 At. 518. The latter case is criticized in an editorial note in 29 Harv. Law Rev. 457 on the ground that the judgment creditor was chargeable with notice.

64. Dickerson v. Colgrove. 100 U. S. 578, 25 L. Ed. 618; Burleson v. Mays, 189 Ala. 107, 66 So. 36; Coogler v. Rogers, 25 Fla. 853, 7 So. 391; Whalen v.

Schneider, 281 111. 557, 118 N. E. 41; Webb v. Hardaway - (Ky.)-, 121 S. W. 669; Blodgett v. Mc-murtry, 34 Neb. 782, 52 N. W. 706; Mayer v. Ramsey, 46 Tex. 371.

65. Bryan v. Ramirez, 8 Cal. 461, 68 Am. Dec. 340; Baillarge v. Clark, 145 Cal. 589, 79 Pac. 268; Coram v. Palmer, 63 Fla. 116, 58 So. 721; Loughran v. Gorman, 256 111. 46, 99 N. E. 886; Simpson v. Yocum, 172 Ky. 449, 189 S. W. 439; Hatch v. Kimball, 16 Me. 146; Brown v. Union Depot St. Ry. & Transfer Co., 65 Minn. 508, 68 N. W. 107; Pabst v. Berch, 126 Minn. 58, 147 N. W. 714; Guffey v. O'reilly, 88 Mo. 418, 57 Am. Rep. 424; Thompson v. Sanborn, 11 N. H. 201, 35 Am. Dec. 490; Wendell v. Van Rensselaer, 1 Johns. Ch. (N.

Y.) 344; Heckman v. Davis, 56 Okla. 483, 155 Pac. 1170; Gaddes v. Pawtucket Inst, for Savings, 33 R. I. 177, Ann. Cas. 1912B. 407, 80 Atl. 415; Marines v. Goblet, 31 S. C. 153, 17 Am. St. Rep. 22; Grigsby v. Verch, 34 S. D. 39, 146 N. W. 1075.

66. Kirk v. Hamilton, 102 U. S. 68, 26 L. Ed. 79; Hendrix v. Southern Ry. Co., 130 Ala. 205, 80 Am. St. Rep. 27, 30 So. 596; Gibson v. Herriott, 55 Ark. 85, 29 Am. St. Rep.. 17; Beardsley v. Clem, 137 Cal. 328, 70 Pac. 175; Holmes v. Brooks, 84 Conn. 512. 80 Atl. 773; Coram v. Palmer, 63 Fla. 116, 58 So. 721; Georgia Pac. Ry. Co. v. Strickland, 80 Ga. 776, 12 Am. St. Rep. 232, 6 S. E. 27; Crumley v. Laurens Banking Co., 141 Ga. 603, 81 3. S. 871; Holcomb v. Independent School Dist., 67 Minn. 321, 69 N. W. 1067; Thomas v. Puliis, 56 Mo. 211; Dellett v. Kemble 23 N. J Eq. 58; Marvin v. Tuscb. 86 Ohio St. 49, 98 N. E. 860; Prusha v

Board of Education of Oklahoma City 41 Okla. 595, 139 Pac. 298, L R. A. 1916C, 233; Mcbroom v. Thompson, 25 Ore. 559, 42 Am. St. Rep. 806, 37 Pac. 57; Wampol v. Kountz, 14 S. D. 331, S6 Am. St. Rep. 765. 85 N. W. 595; Danielson v. Gustafson, 33 S. D. 440, 146 N. W. 562; Clark v. Kirby, 18 Utah, 258, 55 Pac. 372. 67. Wiser v. Lawler, 189 U. S. 260, 271; Porter v. Wheeler, 105 Ala. 451, 47 L. Ed. 802; Waits v Moore, 89 Ark. 19, 115 S. W. 931; Neal v. Gregory, 19 Fla. 356; Bell v. Nye, 255 111. 283, 99 N. E. 610; Farm Land Mfg. & Debenture Co. v. Hopkins, 63 Kan. 678, 66 Pac. 1015; Mason v. Philbrook, 69 Me. 57; Oberheim v. Reeside, 116 Md. 265, 81 Atl. 590; Gray v. Bartlett, 20 Pick. 186; Boston & A. R. R. v. Rear-don, 226 Mass. 286, 115 N. E. 408; Staton v. Bryant, 55 Miss. 261: Blodgett v. Perry, 97 Mo. 203. 10 Am. St. Rep. 307, 10 S. W. 891; Clark v. Parsons, 69 N. H. 147, 76 the same when the true owner is in possession of the land.68

An estoppel of this character, since it is based on a representation that one has not title to land, and not that he has title, has obviously no effect upon a title afterwards acquired by the person making the representation.69

This class of estoppel, though frequently spoken if as "equitable" estoppel, is ordinarily recognized and enforced in courts of law as well as in equity. But though the principles governing in this class of cases were not clearly recognized and formulated under that name until well into the nineteenth century,70 before this there existed in equity a doctrine which was equivalent to the modern doctrine of estoppel by representation, to the effect that one who knowingly makes a false representation to one who acts on it is bound to make that representation good;71 and a similar principle was also involved in the equitable rule that the fraudulent failure of one to make known his title to a person about to purchase the land from another would have the effect of changing the ordinary rule of prioriam. St. Rep. 157, 39 Atl. 898; Chambers v. Bessent, 17 N. M. 487, 134 Pac. 237; Fisher v. Moss-man, 11 Ohio St. 42; Knouff v. Thompson, 16 Pa. 357; Sullivan v. Moore, 84 S. C. 426, 65 S. E. 108; Crabtree v. Winchester Bank, 108 Tenn. 483, 67 S. W. 797; Bigelow v. Tapliff, 25 Vt. 273; Kingman v. Graham, 51 Wis. 232, 8 N. W. 181. Contra, Farr v. Semmler, 24 S. D. 290, 123 N. W. 835.