The board of directors of any railroad corporation may annually or oftener, as may be deemed expedient, set apart and appropriate a sum of money not exceeding fifty percent (50%) of its net earnings as resources for any one (1) year, after paying the current expenses of their road and the interest on its outstanding indebtedness, in order to sink, redeem, pay off, cancel, or discharge the indebtedness of such corporation; and the said sums so set apart shall be annually applied to the payment and discharge of such debts of such corporation as shall be due, and to the purchase and redemption of the outstanding evidences of indebtedness of such corporation, as the board of directors thereof shall deem most for the interest of such corporation, and for no other purpose.

R.L. 1910, § 1393.