The board of education shall have the power to remove from office any school officer who shall have been directly or indirectly interested in the furnishing of any supplies or materials, or in the doing of any work or labor, or in the sale or leasing of any real estate, or in any proposal, agreement or contract for any of these purposes, in any case in which the price or consideration is to be paid, in whole or in part, directly or indirectly, out of any school moneys, or who shall have received from any source whatever any commission or compensation in connection with any of the matters aforesaid; and any school officer who shall violate the preceding provisions of this section shall be deemed guilty of a misdemeanor, and shall also forfeit such office and be ineligible to any office or employment under the board of education or under the city or any agency. The provisions of this section shall not apply to authors of school books used in any of the public schools because of any interest they may have as authors in such books.