19. Period within which interest must vest.

Subject to certain exceptions1, at common law every future estate or interest in any kind of property the rights in which are governed by the law of England2 must be such that, at the time when the instrument creating it comes into operation3, it can be predicated that, if the estate or interest vests at all, it must necessarily vest not later than at the end of a certain period4.

This period is the life of a person or the survivor of any number of persons5 in being at the time of creation of the future estate or interest, and