The board of regents of the University of Idaho, and of the Idaho geological survey may prescribe a special course of instructions in practical prospecting, including a short course in practical mining including identification and classification of minerals at the University of Idaho, or in a mobile unit of the school of mines, which shall be open to special students desirous of studying such subjects, but who may be ineligible for admission to enter the University of Idaho on account of having deficient entrance credits.