87. Substitutionary clauses.

Where the limitation is first to a class of children or other issue absolutely, who are themselves ascertainable within a proper time, and a substitutionary clause is added giving the share of each one dying before distribution to a class of his or her issue not necessarily ascertainable within the perpetuity period, then, provided that the substitutionary clause is separated from the first absolute gift, the first absolute gift stands good, and the substitutionary clause only is invalid1; but, if there is no absolute gift in the first instance, the whole is void