Calorimetric and thermometric techniques have been used sometimes to measure the electrochemical Peltier heat and sometimes to promote understanding of a reaction mechanism or of the nature of complexes from which metals are deposited. In what appears to be an entirely separate branch of study, the “Mylius method” is used to monitor corrosion or the working of inhibitors by thermometric measurements. A review of the above work and a brief description of the instrumentation used, which ranges from a simple mercury-in-glass thermometer to microwatt calorimeters and thermistor measurement circuits detecting changes of 10 -3 °C or less, are given in this paper.