The general rule of the common law is, that things affixed to the realty become part thereof, and belong to the owner of the soil. This is decisive of the right of the plaintiff to the building in question, unless the defendant can show that the facts in the present case bring it within a recognized exception to the rule. This he attempts to do, by endeavoring to maintain that his insolvent, Poole, stood in. the relation of lessee of the premises on which the building in question was erected, and had therefore a right to remove it as a tenant’s fixture. But this position is not tenable.

*241Although, in a certain sense, a person occupying land under a contract of purchase may be said to be a tenant of the owner, still the analogy does not hold good in all respects. In one essential particular, it fails. The occupier is not liable to pay rent to the owner. It would seem to follow, that he has no right to remove fixtures annexed by him to the freehold. The reason why a tenant is allowed to remove structures erected for purposes of trade or convenience, affixed by him to the realty during his tenancy, is because, having paid as rent a full equivalent for the use of the premises as demised, it would be inequitable to compel him to forfeit articles, at the end of his term, which he had procured for his own use and at his own expense. Wall v. Hinds, 4 Gray, 270, 271. That reason is wholly inapplicable to a case like the present. The occupant has paid no equivalent for the use and enjoyment of the premises; nor is he compelled to surrender the estate at a fixed period of time, as upon the expiration of a term demised. He can, by fulfilling his contract of purchase, become the owner of the estate, and enjoy the full benefit of all the erections and improvements which he has made thereon. There is therefore no reason for applying to a case of this sort the very liberal rule in regard to fixtures, which prevails where the relation of lessor and lessee subsists between the parties.

Besides, on referring to the contract proved in the case, it is plain that the erection of the building on the premises was intended to be in the nature of security to the plaintiff for the payment of one hundred dollars, which was originally agreed to be paid in cash by Poole, but the payment of which was postponed at his request, in consideration that he would erect the building on the land. It would be most inequitable now to deprive the plaintiff of this security. The parties stood, in relation to it, rather in the light of mortgagor and mortgagee. Nothing is more clear than the rule, that the former would have no right to remove fixtures erected by him on the mortgaged estate. The defendant, as assignee of Poole, can have no better title to the building than his insolvent. He fails to show therefore any right to remove it from the premises, and must be *242restrained accordingly. Milton v. Colby, 5 Met. 78. Butler v. Page, 7 Met. 40. Eastman v. Foster, 8 Met. 26. Cooper v Adams, 6 Cush. 87. Dakin v. Allen, 8 Cush. 33.

Injunction made perpetual.