Determinations of the initial thermoelectric power were carried out at 1000 K in the whole composition range of the molten systems AgI-Ag2XO4 (X = Mo, W). For the composition XAgI= 0.8 the investigation was extended to the variation of the thermal emf at the “melting point” of the electrochemically noteworthy glass-like phases, obtained through rapid quenching of the melt. The hypothesis that these glass-like materials could keep the melt configuration at room temperature is contradicted by the results on the molten systems; more complex interpretations, based on the behaviour of the thermal emf at the “m.p.” are proposed.