The mortgage extends to the natural accessions, to the improvements, growing fruits, and the rents or income not yet received when the obligation becomes due, and to the amount of the indemnity granted or owing to the proprietor from the insurers of the property mortgaged, or in virtue of expropriation for public use, with the declarations, amplifications and limitations established by law, whether the estate remains in the possession of the mortgagor, or it passes into the hands of a third person. (1877)