Civil Code (Cap. 16), article 752

752. (1) It shall be lawful for any one of the spouses, the other ascendants, the uncle or aunt, brother or sister, to substitute a third party in the place of a minor in the event of the latter dying without issue, before attaining the age of eighteen years, but only wit h regard to the property in which such minor shall have been instituted heir or appointed legatee. (2) It shall also be lawful for any of the said persons to substitute a third party in the place of any person with a ment al disorder or other condition, which renders him incapable of managing his own affairs or insane person, in regard to such property only as they shall have devised to him, in the event o f his dying with the mental disorder or other condition, whilst still incapable of managing his own affairs, or in a state of insanit y, 192 [CAP. 16. CIVIL CODE without issue. (3) Any substitution referred to in this article, if made by any one of the parents or any other ascendant by whom a share of the reser ved portion is due to the heir-institute or legatee, may only inclu de such portion of the property as the minor, on attaining majority, or the insane person, or person with a mental disorder or other condition, if of sound mind at the time of his death, could dispose of. Substitution of several persons in the place of one, or vice versa.