case Perkins all versus walker all novembris in court Lord chancellor a  mortgage after a voluntary settlement with power of revocation and a will in  confirmation of it be a revocation pro tanto only one John walker have by a  voluntary settlement make himself tenant for life with a power to lease or  grant for a thousand year at any rend he by deed grant the whole term to  trustee in trust that he himself shall enjoy the same during his life and  afterward in trust by sale or otherwise to raise out of the premise several  sum of money for payment of his debt and to discharge a mortgage of and other  sum which he appoint to the plaintiff his nephew and niece which deed be with  a power of revocation after this the say John walker have occasion for money  he mortgage this estate three several time to sir William humble have before  that make his will and confirm his say first deed and thereby appoint other  legacy to be pay by his trustee the point insist on be that by these  subsequent mortgage to humble the say walker have revoke his will and the  former deed that be make with a power of revocation say non allocatur it may  be a revocation pro tanto but no otherwise and the Lord chancellor cite the  case of coke and bullock crook that Vernon chancery case er p a man have by  will devise a feesimple afterward by indenture make a lease for year of the  same land this lease if not make to the same person shall be a revocation pro  tanto only even at law and the principal case be much strong in equity which  will charge and subject a equity of redemption Reg lib b fol vide duppa v Mayo  sand Rep p n bridge v duke of chandos Ves jun earl temple v duke of chandos  Ves Baxter v dyer Ves and Harmood v Oglander Ves Ves S c in which the doctrine  of revocation of will be elaborate discuss and all the lead case cite Vawser v  Jeffere Ves swan in the case of Baxter v dyer it be determine that a devise be  not revoke by a mortgage in fee to the devisee so partition mere as such not a  revocation attorneygeneral v vigour Ves Qure if exchange be not ibidem nor be  seize ibidem