What is the common law test on perpetuities?

Dealing firstly with the issue raised by the rule against perpetuities, it is common ground that there is no period stated in which the interest in favour of the plaintiff must vest. Prior to the coming into force in Alberta of the Perpetuities Act, this agreement would probably have failed, if in fact the agreement is to be interpreted as creating an option in favour of the plaintiff. However, s. 3 and 4 of the Perpetuities Act create a presumption in favour of validity until actual events establish that the interest is incapable of vesting during the perpetuity period. In this case it would be 21 years after July 24, 1976. The court in Sullivan v. Newsome found that the agreement in the case offended the common law rule after determining that the Perpetuities Act which was first enacted in 1972 did not apply to the agreement in that case because it was dated May 24th, 1967 and s. 25 provides that the statutory rules only apply to instruments taking effect after July 1, 1973.