Application of the ACTRON 4.2 calorimeter shows that several types of measurement can be made satisfactorily. After a short review of the automatic device for the range 15-180-degrees-C with a resolution of 0.05 mK, five types of experiments are described to demonstrate its versatility. The measurement of mixing enthalpy by step-wise injection of propanol pinpoints the position of a maximum at 5.67 mol% n-propanol in water. Titrations of solutions of ammonia and boric acid, respectively, yield results of good accuracy in the mmol/I range.