A sampling device is described which enables the Picker flow heat capacity calorimeter to handle viscous liquids. The necessary constant liquid flow through the calorimetric cell is achieved by an overpressure on the entering liquids, and can be maintained by pressure control. In addition, the device permits automatic measurement of a number of samples. The approach is applied to densities and heat capacities of binary mixtures of dimethylformamide and the viscous liquidsN-ethylacetamide,N-n-propylacetamide, andN-n-butylacetamide. The results appear to be accurate enough to establish excess molar heat capacities as well as apparent molar heat capacities.