by John Marshall Harlan

“ The doctrine of equitable estoppel is, as its name indicates, chiefly, if not wholly, derived from courts of equity, and as these courts apply it to any species of property, there would seem no reason why its application should be restricted in courts of law. Protection against fraud is equally necessary, whatever may be the nature of the interest at stake ”

“ But the common law has been enlarged and enriched under the principles and maxims of equity, which are constantly applied at the present day in this country, and even in England, for the relief of grantees, the protection of mortgagors, and the benefit of purchasers, by a wise adaptation of ancient forms to the more liberal spirit of modern times. ”

“ He forbore to raise any question whatever as to the validity of the sale, and by his conduct indicated his purpose not to make any issue in reference to the proceedings in the equity suit. Knowing that the defendants' claim to the premises rested upon that sale, he remained silent while the latter expended large sums in their improvement, and in effect, disclaimed title in himself. He was silent when good faith required him to put the purchaser on guard. ”

“ The evidence upon this point was properly admitted, and operated to defeat the action independently of the question whether the sale by Carrington, the trustee, and its confirmation by the court, was, itself, a valid, binding transfer of the title to the purchaser.
What has been said renders it unnecessary to consider the questions of law presented in the remaining bills of exceptions. ”

“ The defendants, further to maintain their defence, and to prove title in themselves, offered to introduce testimony tending to prove that, at the time of the purchase of the premises at the sale made by Carrington, trustee, in the suit of Moore & Co. v. Kirk, & c., the only improvement thereon was a two-story four-room brick house, and that, about the year 1868, the defendants erected an extensive building on the property, at a cost of some $4,000; that when they began such building, and for some time thereafter, the plaintiff Kirk resided on the adjoining premises ”