No teacher in any of the schools of the state, and no county or municipal superintendent of schools, and no person officially connected with the government of or direction of any school shall, during the term of his office as said superintendent or during the time of his or her employment as teacher, act as agent or attorney for any textbook publishing company selling textbooks in this state. If, after election as county or municipal superintendent or employment as teacher, any person filling such position accepts the agency or attorneyship of any textbook publishing company, the acceptance of such agency or attorneyship shall work a forfeiture of the office or position as teacher held at the time of the acceptance of such agency or attorneyship.