Article 2474 of the French Civil Code
Mortgages are extinguished in particular: 1° By the extinction of the principal obligation subject to the case provided for in Article 2422; 2° By the creditor’s renunciation of the mortgage subject to the same reservation; 3° By purge; 4° By the termination permitted in the last paragraph of Article 2417 and to the extent provided for by that text.