Abstract
An adiabatic calorimeter suitable for measurements of heats of solution in the vicinity of room temperature is described. The calorimeter vessel is hermetically sealed and suspended in a vacuum surrounded by a water jacket. The whole assembly is capable of rotation through 180° to initiate the solution process and to stir the contents. Temperatures are measured with a multijunction copper‐constantan thermocouple, temperature changes of 10−4°C being detectable. The performance of the calorimeter is illustrated by some results for sodium chloride in water at 25°C. These are in reasonable agreement with the data of other workers and appear to be more self‐consistent.