Page:William Blackstone, Commentaries on the Laws of England (3rd ed, 1768, vol II).djvu/350

 334 various neceities of mankind induced alo the judges very oon to depart from the rigour and implicity of the rule's of the common law, and to allow a more minute and complex contruction upon conveyances to ues than upon others. Hence it was adjudged, that the ue need not always be executed the intant the conveyance is made: but, if it cannot take effect at that time, the operation of the tatute may wait till the ue hall arie upon ome future contingency, to happen within a reaonable period of time; and in the mean while the antient ue hall remain in the original grantor: as, when lands are conveyed to the ue of A and B, after a marriage hall be had between them, or to the ue of A and his heirs till B hall pay him a um of money, and then to the ue of B and his heirs. Which doctrine, when devies by will were again introduced, and conidered as equivalent in point of contruction to declarations of ues, was alo adopted in favour of executory devies. But herein thee, which are called contingent or pringing, ues differ from an executory devie; in that there mut be a peron eied to uch ues at the time when the contingency happens, ele they can never be executed by the tatute; and therefore, if the etate of the feoffee to uch ue be detroyed by alienation or otherwie, before the contingency aries, the ue is detroyed for ever : whereas by an executory devie the freehold itelf is transferred to the future deviee. And, in both thee caes, a fee may be limited to take effect after a fee, becaue, though that was forbidden by the common law in favour of the lord's echeat, yet, when the legal etate was not extended beyond one fee-imple, uch ubequent ues (after a ue in fee) were before the tatute permitted to be limited in equity; and then the tatute executed the legal etate in the ame manner as the ue before ubited. It was alo held that a ue, though executed, may change from one to another by circumtances ex pot facto ; as, if A makes a feoffment Rh