Article 760. Every donation inter vivos, made by a person having no children or descendants, legitimate or legitimated by subsequent marriage, or illegitimate, may be revoked or reduced as provided in the next article, by the happening of any of these events:
(1) If the donor, after the donation, should have legitimate or legitimated or illegitimate children, even though they be posthumous;
(2) If the child of the donor, whom the latter believed to be dead when he made the donation, should turn out to be living;
(3) If the donor subsequently adopt a minor child. (644a)
Article 764. The donation shall be revoked at the instance of the donor, when the donee fails to comply with any of the conditions which the former imposed upon the latter.
In this case, the property donated shall be returned to the donor, the alienations made by the donee and the mortgages imposed thereon by him being void, with the limitations established, with regard to third persons, by the Mortgage Law and the Land Registration laws.
This action shall prescribe after four years from the noncompliance with the condition, may be transmitted to the heirs of the donor, and may be exercised against the donee's heirs. (647a)
Article 765. The donation may also be revoked at the instance of the donor, by reason of ingratitude in the following cases:
(1) If the donee should commit some offense against the person, the honor or the property of the donor, or of his wife or children under his parental authority;
(2) If the donee imputes to the donor any criminal offense, or any act involving moral turpitude, even though he should prove it, unless the crime or the act has been committed against the donee himself, his wife or children under his authority;
(3) If he unduly refuses him support when the donee is legally or morally bound to give support to the donor. (648a)