Thermoelectric analysis of the electrical conductivity in Ir(CO3) Br and K2Pt(CN)4Cl0.3·xH2O as a function of temperature and atmosphere gives additional insight into the transport processes involved. The temperature independence of the thermoelectric power measured for Ir(CO3) Br indicates that the observed temperature dependence of conductivity is due to the mobility of the carriers and is consistent with a hopping model for conductivity. Two quite different electronic states of K2Pt(CN)4Cl0.3·xH2O are defined as (i) a high‐conductivity hydrated state withx≈ 2.6, which exhibits a small positive thermoelectric power, and (ii) a lower‐conductivity dehydrated state withx≈ 0, which exhibits a larger negative thermoelectric power. Log conductivity in the former state varies as 1/T1/2, whereas in the latter state log conductivity varies as 1/T.