Derek Moran
...speaking of setting-up a TRUST:
"...the intention of the creator of the trust..."
Specific non-charitable trusts
16.(1)A trust for a specific non-charitable purpose that creates no enforceable equitable interest in a specific person shall be construed as a power to appoint the income or the capital, as the case may be, and, unless the trust is created for an illegal purpose or a purpose contrary to public policy, the trust is valid so long as and to the extent that it is exercised either by the original trustee or the trustee's successor, within a period of twenty-one years, despite the fact that the limitation creating the trust manifested an intention, either expressly or by implication, that the trust should or might continue for a period in excess of that period, but, in the case of such a trust that is expressed to be of perpetual duration, the court may declare the limitation to be void if the court is of opinion that by so doing the result would more closely approximate the intention of the creator of the trust than the period of validity provided by this section.
Idem
(2)To the extent that the income or capital of a trust for a specific non-charitable purpose is not fully expended within a period of twenty-one years, or within any annual or other recurring period within which the limitation creating the trust provided for the expenditure of all or a specified portion of the income or the capital, the person or persons, or the person or person's successors, who would have been entitled to the property comprised in the trust if the trust had been invalid from the time of its creation, are entitled to such unexpended income or capital.
http://www.e-laws.gov.on.ca/html/statutes/english/elaws_statutes_90p09_e.htm