Whenever it shall appear to the judge of the circuit court that the jury box is so nearly exhausted as to require refilling, he shall notify the president of the jury commission, who in turn shall call together the other members of the commission and shall proceed to refill the box as provided in this chapter; provided, that the judge of the circuit court may, whenever in his discretion he deems it necessary or expedient, call the jury commission together and empty and refill the jury box of the particular county as provided in this chapter.