When any public free school in this state shall raise not less than ten dollars by subscription or otherwise for a library for such school, and shall furnish suitable bookcases with lock and key, the superintendent of education of the county where such subscription is raised may issue his certificate for a like amount not exceeding twenty-five dollars in favor of such school, to be paid out of the common school fund of that county. In no case shall the amount given by the county in any one year exceed two hundred and fifty dollars. No school shall receive a second donation from the school fund for library purposes so long as there are any new applications from schools that have not been supplied.