Section 5. The persons so trained in the work of first-aid and mine rescue as described in section one of this act shall, upon the completion of a course of training and instruction as may be prescribed by the Secretary of Mines, be granted a certificate of competency. Such certificate shall be issued by the Secretary of Mines upon written notice from the chief of crew that the applicant has completed in a satisfactory manner the course of training and instruction prescribed by the said Secretary of Mines.