The object of this investigation was the determination, with the closest approach to accuracy, of the specific head of certain metals, and the changes therein caused by changes in temperature. The work, including the necessary preliminary standardisations, has occupied our attention during the last two years and we feel unable, in this abstract, to describe with any clearness the various precautions adopted, or the somewhat elaborate process of reducing the results. We, therefore, here content ourselves with a brief indication of the methods of experiment, a statement of the results, and a short discussion of certain suggestive features which they present.