The electron theory of solids has attracted great attention in recent years, mainly because of the numerous practical applications of semicon ductors. However, all the reviews and monographs on this subject deal only with crystalline conductors. At present, mainly in the Soviet Union, experi mental and theoretical investigations have been extended to liquid and solid amorphous conductors, and in particular to such semiconductors. However, all the work published so far in this field is in the form of separate papers scat tered throughout various journals, and there has as yet been no Soviet or...