Section 31. Agreement for contribution by employee void

No agreement by an
  employee to pay any portion of the premium paid by his employer  to  the
  state  insurance  fund  or to contribute to a benefit fund or department
  maintained by such employer or to the cost of mutual insurance or  other
  insurance,  maintained  for  or  carried  for  the  purpose of providing
  compensation as herein required, shall be valid, and  any  employer  who
  makes  a  deduction  for  such  purpose  from the wages or salary of any
  employee entitled to the benefits of this chapter shall be guilty  of  a
  misdemeanor.