First, they muſt have one and the ſame intereſt. One joint-tenant cannot be entitled to one period of duration or quantity of intereſt in lands, and the other to a different: one cannot be tenant for life, and the other for years: one cannot be tenant in fee, and the other in tail[1]. But, if land be limited to A and B for their lives, this makes them joint-tenants of the freehold; if to A and B and their heirs, it makes them joint-tenants of the inheritance[2]. If land be granted to A and B for their lives and to the heirs of A; here A and B are joint-tenants of the freehold during their reſpective lives, and A has the remainder of the fee in ſeveralty: or, if land be given to A and B, and the heirs of the body of A; here both have a joint eſtate for life, and A hath a ſeveral remainder in tail[3]. Secondly, joint-tenants muſt alſo have an unity of title: their eſtate muſt be created by one and the ſame act, whether legal or illegal; as by one and the ſame grant, or by one and the ſame diſſeiſin[4]. Joint-tenancy cannot ariſe by deſcent or act of law; but merely by purchaſe, or acquiſition by the act of the party: and, unleſs that act be one and the ſame, the two tenants would have different titles; and if they had different titles, one might prove good, and the other bad, which would abſolutely deſtroy the jointure. Thirdly, there muſt alſo be an unity of time: their eſtates muſt be veſted at one and the ſame period, as well as by one and the ſame title. As in caſe of a preſent eſtate made to A and B; or a remainder in fee to A and B after a particular eſtate; in either caſe A and B are joint-tenants of this preſent eſtate, or this veſted remainder. But if, after a leaſe for life, the remainder be limited to the heirs of A and B; and during the continuance of the particular eſtate A dies, which veſts the remainder of one moiety in his heir; and then B dies, whereby the other moiety becomes veſted in the heir of B: now A's heir and B's heir are not joint-tenants of this remainder, but tenants in common; for one moiety veſted at one time, and the other moiety veſted at another[5]. Yet, where
