24. The aggregate of the amounts that a corporation may deduct under sections 22 and 23 in respect of the same taxation year shall not exceed one-half of the tax otherwise payable by the corporation for the year.
Furthermore, the aggregate of the amounts that a corporation may deduct under the said sections for the aggregate of its taxation years shall not exceed $500 000 for the aggregate of the allowable investments made during the period mentioned in the first paragraph of the said section 22.