What is the test for repugnant to the nature of a gift?

The usual type of condition which is void as being repugnant to the nature of a gift is a gift of the capital of a fund to a person subject to a condition that the fund is not to be paid to the person until he attains some age greater than the age of majority. This application of the doctrine of repugnancy is usually referred to as the rule in Saunders v. Vautier. Though Saunders v. Vautier was, on its face, a case of postponing enjoyment beyond the age of majority, today the rule in Saunders v. Vautier is frequently spoken of as referring to all aspects of the doctrine of repugnancy. This is because Saunders v. Vautier lays down the general principle that restrictions on the enjoyment of gift contrary to the nature of that gift are void.