If the ulterior bequest be not valid the original bequest is not affected by it.
Illustrations:
(i) An estate is bequeathed to A for his life with condition super-added that, if he shall not on a given day walk 100 miles in an hour, the estate shall go to B. The condition being void, A retains his estate as if no condition had been inserted in the will.
(ii) An estate is bequeathed to A for her life and, if she do not desert her husband, to B. A is entitled to the estate during her life as if no condition had been inserted in the will.
(iii) An estate is bequeathed to A for life, and, if he marries, to the eldest son of B for life. B, at the date of the testator's death, had not had a son. The bequest over is void under section 105, and A is entitled to the estate during his life.
Legal Commentary & Landmark Judgments: Section 133
Section 133 codifies the Rule in Lassence v. Tierney, establishing that where an original bequest is followed by an invalid second bequest, the original bequest remains absolute and unaffected.
If a will gives an estate to 'A' and then purports to create a gift over to 'A's unborn great-grandchildren' (which violates Section 114 perpetuity rules), invoke Section 133; the invalidity of the gift over confirms 'A' as the sole absolute owner.