222. (1) Probate shall be granted only to an executor appointed by the will. (2) The appointment may be expressed or by necessary implication. Illustrations (i) A wills that C be his executor if B will not. B is appointed executor by implication. (ii) A gives a legacy to B and several legacies to other persons, among the rest to his daughter-in-law C, and adds "but should the within-named C be not living I do constitute and appoint B my whole and sole executrix". C is appointed executrix by implication. (iii) A appoints several persons executors of his will and codicils and his nephew residurary legatee, and in another codicil are these words, "I appoint my nephew my residuary legatee, to discharge all lawful demands against my will and codicils signed of different dates." The nephew is appointed an executor by implication.