¶1The instruction given to the jury upon the request of the counsel for the defendant raised a question of estoppel in pais, and presented a distinct question from that of the alleged agreement by the plaintiff, upon a good consideration, to modify the terms of his lease to the defendant, and abate one half of the rent stipulated to be paid to him. If that instruction was wrong, the plaintiff is entitled to have the verdict set aside. That it was so, we think is manifest. It omits to state those elements which are essential to an estoppel in pais. It does not require the jury to find that the plaintiff wilfully intended that the silence and conduct on his part should lead to any action on the part of the defend mt in reference to the lease, *402or that the defendant did in fact act upon them, and in consequence thereof materially change his situation in reference to the matter of the lease, or assume any new liabilities by reason thereof. See Plumer v. Lord, 9 Allen, 455; Andrews v. Lyons, 11 Allen, 349.
¶2Independently of any objection to this instruction as to the alleged estoppel, arising from the want of definiteness as to the extent of the abatement of rent and the period of time to which it would apply, or the further objection urged as to its effect in controlling and essentially varying a sealed contract executed by the party setting up this estoppel, for the reasons heretofore stated the instruction was erroneous, and the verdict must be set aside. jExceptions sustained.