The thermoelectric powers, S, of the pure metals Mg, Ca, Sr, and Ba have been measured across their melting points. The values obtained for the liquids at the melting point are: Mg, 1.6 mu V degrees C^-1; Ca, 9.9 mu V degrees C^-1; Sr, -0.4 mu V degrees C^-1; Ba, -0.2 mu V degrees C^-1. S shows little change with melting for Ca, Sr, and Ba; for Mg, S changes sign upon melting. The measured liquid thermopowers, in light of recent resistivity data for these liquids, indicate a progressively increasing energy dependence of the pseudopotentials with increasing atomic number (Mg to Ba). The temperature dependence of the thermopower, dS/dT, for these liquids is discussed in terms of a simple theory.