Ohio Rev. Code § 3375.391: Treasurer to credit earnings on investments.

The board of library trustees of any free public library district may adopt a resolution requiring the treasurer of the district to credit the earnings made on the investment of the principal of the moneys specified in the resolution to the fund from which the earnings arose or any other fund of the district as the board specifies in its resolution.

This section does not apply to the earnings made on the investment of any bond retirement fund or any sinking fund.