The d.c. and a.c. conductivity and the thermoelectric power of the compounds H3N+(CH2)nN+H3FeCl4, where n = 2, 3, 7 or 10, have been studied over a temperature range of 150–500 K. The conductivity results confirm the presence of more than one structural phase transition for each compound investigated. The thermoelectric power measurements show that electrons are the main charge carriers in all crystal phases. The conductivity results are explained on the basis of an electron-hopping mechanism over the whole temperature range.