Such order can only be made on the motion of a party, upon affidavit showing the nature of the action or proceeding, the testimony expected from the witness and its materiality.

[(9-712) C.C.P. 1881, sec. 952; R.S., R.C., & C.L., sec. 6046; C.S., sec. 7992; I.C.A., sec. 16-712.]