Benjamin Robbins Curtis

“ Jackson, 4 Pet. 86, 88, that a mere recital of a fact in a deed is as effectual an estoppel as a covenant. There is no necessary connection, therefore, between the personal liability of the debtor on his covenant, and the estoppel which arises therefrom; and it is not an incongruity for the legislature to preserve the latter while they discharge the former.
Estoppels which run with the land and work thereon are not mere conclusions; they pass estates, and constitute titles; they are muniments of title, assuring it to the purchaser. ”

“ The purpose of the legislature to-afford complete and effectual protection to mortgage titles, against any thing which was to be done under the act, and the broad and strong terms in which this purpose is expressed, require us to say, that the debtor cannot derive from the act an enabling power to do or assert any thing which will impair a mortgage otherwise valid. Nor is there any incongruity with established principles, in holding that the personal discharge of the debtor does not free him from the estoppel. ”

“ We think there is sufficient reason why this proviso should be so construed as completely to save the effect and operation of all estoppels running with the land and operating at law to pass the legal title, or in equity to conclude the grantor from asserting the existence of a title inconsistent with what he undertook to sell and convey. ”