Revival of a will or codicil

No will or codicil, nor any part tihereof, which shall be in any manner revoked, shall be revived other- wise than by the re-execution thereof, or by a codicil executed in manner hereinbefore required, and ehowing an intention to revive the same ; and when any will or codioil, which shall bepartly revoked and afterwards wholly revoked, shall be revived, euoh revival shall not extend to so much thereof as shall have been revoked before the revocation of the whole thereof, unlegs an intention to the contrary shall be shown by the will or codicil.