An action for use and occupation would not lie at Common Law, if the occupant was holding by a formal lease under seal.1 At Modern Law the same principle applies, where the occupant holds by a formal lease which is enforceable and contains an express covenant to pay rent. An occupant who enters under a formal lease, may be liable for use and occupation, if for any reason the lease itself proves unenforceable. Thus, where a tenant was partially evicted by his landlord, and his landlord had sued in debt and failed to recover because of such partial eviction,2 it was held that he might sue the tenant on a quantum meruit account in assumpsit for the beneficial use which the tenant had.3 If a lease under seal has been subsequently modified or varied in legal effect, in any other way whatever than by another instrument under seal, the resulting obligation is treated in law as a simple obligation, and not a specialty. Accordingly, an action in assumpsit can be brought upon such an obligation in a proper case, and the fact that the original lease was under seal does not prevent this form of action. Thus, where by statute the election of a city to take for public use part of any land under lease, discharges such lease as to the part taken, but leaves it valid as to the residue, and upon such election the city acquires legal title in the part taken, a tenant holding under a sealed lease is liable after such election in an action for the use and occupation of the residue.4 If A holds property under a perpetual lease from B, and A sells to X, subject to the annual rent reserved, and X recognizes B's rights in such property, the law implies a promise by X to B to pay the rent; and accordingly, assumpsit will lie.5 A statute allowing assumpsit on sealed contracts makes it possible to maintain assumpsit on a written lease under seal.6

1 Codman v. Jenkins, 14 Mass. 93;

2 Meredith Association v. Twist-Drill Co.. 66 N. H. 539; 30 Atl. 1119.

3 Meredith Association v. Twist- Drill Co.. 67 N. H. 450; 39 Atl. 330.

4McCardell v. Miller, 22 R. I. 96; 46 Atl. 184.

5 Derrick v. Luddy, 64 Vt. 462; 24 Atl. 1050.