Sexual discrimination; salary deductions; employment as clerk or librarian.

In assigning salaries to teachers, no discrimination shall be made between male and female teachers employed in the same grade of school and performing a like class of duties; nor shall it be lawful to pay, or authorize or require to be paid, from any of the salaries of such teachers any portion or percentage thereof for the purpose of adding to salaries of higher or lower grades; and no such teacher shall be employed as, or required to discharge the duties of, a clerk or librarian.