Section 19. Accounts and loans by commissioners

Such railroad commissioners
  shall  present  to  the auditing board of the municipal corporation they
  represent, at each annual meeting of such board, a written statement  or
  report, showing all their receipts and expenditures, with vouchers. They
  shall  also  loan  on proper security or collaterals, or deposit in some
  solvent bank or banking institution, at the best rate of  interest  they
  can  obtain,  or  invest  in the bonds of the municipal corporation they
  represent, or in bonds of the state, or of any town,  village,  city  or
  county  therein,  issued  pursuant to law, or in the bonds of the United
  States, all moneys that shall come into their hands by virtue  of  their
  office,  and  not  needed  for  current  liabilities;  and all earnings,
  profits or interest accruing from such loans, deposits  or  investments,
  shall  be  credited  to  the  municipal  corporation they represent, and
  accounted for in  their  annual  settlement  with  the  governing  board
  thereof.