In some cases representations as to future conduct may be the basis of estoppel, if their purpose and effect involves the abandonment of an existing right and affects the conduct of another ; Union Mut. Life Ins. Co. v. Mow ry, 96 U. S. 544, 24 L. Ed. 674 ; Edison Elec tric Light Co. v. Electric Co., 59 Fed. 691, 699 ; Shields v. Smith, 37 Ark. 47 ; Stayton v. Graham, 139 Pa. 1, 21 Atl. 2 ; but in Eng land it is otherwise ; 5 H. L. Cas. 185, 214; 8 App. Cas. 467 ; [1902] A. C. 117, 130.
In the leading case on this subject (Pickard v. Sears, 6 Ad. & El. 469) a mortgagee of per sonalty was held to be estopped from assert ing his title under the mortgage because he had passively acquiesced in a purchase of the same by the defendant under an execu tion against the mortgagor. The rule of that case was that an estoppel arose from wilful ly causing another to believe in a certain state of facts, and to act on that belief ; in Gregg v. Wells, 9 A. & E. 97, Lord Denman stated the rule more broadly as subjecting to an estoppel one who negligently and cul pably stands by and allows another to con tract on the faith of a fact which he can contradict ; and in Freeman v. Cooke, 2 Exch. 654, it was said by Parke, B., that the rule of Pickard v. Sears must be considered as es tablished, but that by the term "wilfully" it must be understood, "if not that the party represents that to be true which he knows to be untrue, at least, that he means his rep resentations to be acted upon, and that it is acted upon accordingly." The establishment of the rule as thus limited was followed by Folger, J., in Continental Nat. Bank v. Bank, 50 N. Y. 575, where the principle was recog nized that doing an act and the omission to act are the same ; Howard v. Hudson, 2 El. & Bl. 1; Knights v. Wiffen, L. R. 5 Q. B. 660 ; Casco Bank v. Keene, 53 Me. 103. Cases of estoppel by silence are numerous ; Appeal of Thompson, 126 Pa. 367, 17 Atl. 643 ; Sillo way v. Ins. Co., 12 Gray (Mass.) 73 ; Blake v. Ins. Co., 12 Gray (Mass.) 265 ; 35 Can. Sup. Ct. 133 (criticised at length; 19 Harv. L. Rev. 113) ; but silence does not always amount to fraud ; Lawrence v. Luhr, 65 Pa. 241 ; and there is no estoppel by silence where a party has had no opportunity to speak ; National Newark Banking Co. v. Bank, 63 Pa. 417. See Carroll v. Tucker, 2 Misc. Rep. 397, 21 N. Y. Supp. 952.
The estoppel will be limited to the acts which were based upon the representations out of which the estoppel arose ; thus, where a sheriff had a writ against A, but took B into custody, upon B's representations that she was A, but detained her after he was informed that she was not A, B was estop ped to recover damages for the false arrest but not for the subsequent detention ; 2 C. B. N. S. 495. See Burney v. Collins, 50 Ga. 90 ; Tilton v. Nelson, 27 Barb. (N. Y.) 595 ; Bisph. Eq. § 292.
The acts alleged as an estoppel must be executed and not merely executory ; Rorer Iron Co. v. Trout, 83 Va. 397, 2 S. E. 713, 5 Am. St. Rep. 285 ; as when a statement is not accepted and acted upon, it does not con stitute au estoppel ; Nosier v. R. Co., 73 Ia. 268, 34 N. E. 850; Gilbert v. Vail, 60 Vt. 261, 14 Atl. 542.
The doctrine of estoppel in pais is applied at law as well as in equity ; Dickerson v. Col grove, 100 U. S. 578, 25 L. Ed. 618 (where the early cases are cited) ; Drexel v. Berney, 122
U. S. 241, 253, 7 Sup. Ct. 1200, 30 L. Ed. 1219 ; Wehrman v. Conklin, 155 U. S. 327, 15 Sup. Ct. 129, 39 L. Ed. 167 ; Tracy v. Roberts, 88 Me. 317, 34 Atl. 68, 51 Am. St. Rep. 394 ; Hagan v. Ellis, 39 Fla. 472, 22 South. 727, 63 Am. St. Rep. 167 ; Duke v. Griffith, 9 Utah 476, 35 Pac. 512; Marine Iron Works v. Wiess, 148 Fed. 145, 78 C. C. A. 279; Camp bell v. 1VB.n. Co., 141 Fed. 610, 73 C. C. A. 260 ; and therefore it is neither necessary nor per missible to resort to equity to obtain the ben efit of it ; Barnard v. German American Sem inary, 49 Mich. 444, 13 N. W. 811; Vermont Copper Min. Co. v. Ormsby, 47 Vt. 709, 713; Anglo-American Land, Mortgage & Agency Co. v. Lombard, 132 Fed. 721, 68 C. C. A. 89 ; to be available it must be specifically plead ed ; id. A title by estoppel has been held suf ficient to maintain, ejectment or defend against it ; George v. Tate, 102 U. S. 570, 26 L. Ed. 232 ; where the subject of acquiring title to land by estoppel is fully considered. See ADVERSE POSSESSION.
Whether "title by estoppel," so called, may be acquired to personal property is the sub ject of interesting discussion in the English courts in cases of registration of a forged transfer of stock. Such a transfer was held to work an estoppel in favor of subsequent transferees ; L. R. 3 Q. B. 584; but not in favor of the holder under the forged trans fer ; 49 L. J. Q. B. N. S. 392, where Brett, L. J., said that "an estoppel gives no title to that which is the subject-matter of it." He considered that the meaning of the phrase "legal title by estoppel," as used in the older cases, is simply an expression of the recog nition of the doctrine of estoppel by the courts of law as much as in those of equity, and while "the estoppel assumes that the reality is contrary to that which the person is estopped from denying, it has no effect whatever upon the reality of the circum stances." It is said that the contract of a person under disability cannot be made good by es toppel; Bisph. Eq. § 293. See Lowell v. Dan iels, 2 Gray (Mass.) 161, 61 Am. Dec. 448; Merriam v. R. Co., 117 Mass. 241; Glidden v. Strupler, 52 Pa. 400. It makes no differ ence that the person, if a married woman, falsely represented herself to be sole; 9 Ex. 422; Weathersbee v. Farrar, 97 N. C. 107, 1 S. E. 616. But estoppel may operate to pre vent such a person from enforcing a right. For instance, if a married woman were to induce A to buy property from B, knowing that the title was not in B, but in herself, she would be estopped from asserting her ti tle against A ; Connolly v. Branstler, 3 Bush (Ky.) 702, 96 Am. Dec. 278 ; Brinkerhoff v. Brinkerhoff, 23 N. J. Eq. 477; Drake v. Glo er, 30 Ala. 382. The same principle would extend to similar acts on the part of an in fant ; 3 Hare 503 ; Whittington v. Doe, 9 Ga. 23 ; but not unless the conduct was inten tional and fraudulent ; Harmon v. Smith, 38 Fed. 482 ; but infancy, being in law a shield and not a sword, cannot be pleaded to avoid liability for frauds, trespasses or torts ; 1 Lev. 169 ; International Land Co. v. Mar shall, 22 Okl. 693, 98 Pac. 951, 19 L. R. A. (N. S.) 1056, where the cases are discussed by C. J. See notes in 57 L. R. A. 684 ; 9 L. R. A. (N. S.) 1117; 16 L. R. A. 672.