P.R. Laws tit. 31, § 2480
The legacy shall have no effect:
(1) If the testator changes the thing bequeathed in such manner that it does not retain either the form or the denomination it previously had.
(2) If the testator alienates, for any consideration or reason whatsoever, the thing bequeathed or a part thereof, it being understood, in the latter case, that the bequest is without effect only with regard to the part alienated. If, after the alienation, the thing should revert to the ownership of the testator, even though it were by reason of the nullity of the contract, the bequest shall not be valid, after such fact, excepting the case in which the reacquisition takes place on account of an agreement of resale.
(3) If the thing bequeathed is entirely lost during the life of the testator or after his death, without the fault of the heir. Nevertheless, the person obliged to pay the legacy shall be liable for the eviction, if the thing bequeathed should not have been determined in kind in accordance with the provisions of § 2473 of this title.
History —Civil Code, 1930, § 791.