EN
The electrical conductivity σ and the thermal conductivity λ were investigated at varying temperature (40 < T < 120°C) for two sulphate compounds, anhydrous mercury(II) sulphate HgSO_{4} and cerous(III) sulphate Ce_{2}(SO_{4})_{3}·H_{2}O. It seems likely that each of the two sulphate salts undergoes structural phase transition around 90°C. The differential thermal analysis thermogram was carried out as an aid for confirming of the observed phase transitions. The mechanism of the heat transfer is mainly due to phonons. Interpretation of the obtained data was given on the basis of the reorientational motion of the SO_{4}‾ ‾ ions.