The atomic heat of bismuth at higher temperatures

The thermal capacity of metallic bismuth has been investigated by a number of experimenters. Though the true specific heat from absolute zero up to air temperatures is known from measurements made with the vacuum calorimeter by Keesom and Ende, and by Anderson, from air temperatures up to the melting point we have only mean specific heats, determined over considerable ranges of temperature, while of the true specific heat of the liquid and its variation with temperature nothing reliable is known. In order to use a vacuum calorimeter at temperatures much above room temperature it is necessary to evolve a design employing materials which have satisfactory electrical, mechanical and thermal properties at the temperatures in question. Such a calorimeter has been successfully developed, and the present paper describes its construction and gives the results of measurements made by means of it on bismuth, over a temperature range of 30° to 370°C.

I. On the specific heats of gases at constant volume. Part II. Carbon dioxide

In the former experiments on this gas, recorded in the first part of this research, the highest absolute density at which the specific heat was determined was 0·0378. In the present observations the determinations of specific heat have been carried to densities at which the substance was partly in the liquid state at the lower limit of temperature of the experiments. Observations dealing with true specific heat, uncomplicated by the presence of thermal effects due to the presence of liquid, are limited by the density 0·1444. At this density the mean specific heat over the range, 12° C. to 100° C., is 0·2035.