The latent heats of a number of the commoner metals have been measured by determining the total heat of liquid and solid from a series of initial high temperatures. The calorimetry was by the method of mixtures, introducing several refinements, of which the chief were the use of fairly large charges of metal (of the order of 2 kilograms), and a device by which the hot charge was not allowed in contact with the water of the calorimeter until the latter was completely closed; this eliminates error due to production and escape of steam, with a consequent loss of heat. The device referred to consisted in the provision of a sheet metal vessel suspended by threads from the main lid of the calorimeter. The aperture through which the charge was introduced was closed by a rotating lid, in the main lid, and the crucible being introduced, was submerged after the closing of this smaller lid by means of a wire passing through an eyelet in the base of the calorimeter, and out at the top. The results for the latent heat are given below: - Metal. Melting point, °C. Latent Heat. (Calories per gm.) Aluminium 657 92.4 Antimony 630 24.3 Bismuth 269 13.0 Lead 327 6.26 Magnesium 644 46.5 Tin 232 14.6 Zinc 420 26.6 The Paper also contains values for the specific heats up to the melting point, obtained by differentiation of the temperature-total heat curves.