Le Pelerinage de Lourdes §9

⁹ In many ways the nineteenth century was to become, after the turmoil of the Revolution, a century of Marian favors. To mention but a single instance, everyone is familiar today with the "miraculous medal." This medal, with its image of "Mary conceived without sin," was revealed to a humble daughter of Saint Vincent de Paul whom We had the joy of inscribing in the catalogue of Saints, and it has spread its spiritual and material wonders everywhere.