(a) The court or judge in vacation, or a Justice of the Supreme Court, may authorize either party to take the deposition of a material witness where there are reasonable grounds to apprehend that, before trial, the witness will die, will become mentally incapable of giving testimony or physically incapable of attending the trial, or will become a nonresident of the state. The materiality of the testimony and the reason for taking the deposition shall be shown by affidavit.
(b) The court or judge shall, by written order, prescribe the manner of taking the deposition whether by interrogatories or upon notice to the parties.
(c) Upon the death of the witness, or upon his becoming mentally incapable of testifying or a nonresident of the state and absent therefrom so that he could not be summoned, the deposition taken in pursuance of such order may be read as evidence, provided that the grounds of nonresidence and absence from the state shall not be sufficient unless the party wishing to use the deposition makes an affidavit that he has tried in good faith to procure the attendance of such witness and been unable to do so.