An adiabatic vacuum calorimeter and the precision measurement of specific heats of liquids. --.

Author's signature redacted from title page.This thesis represents a study of calorimetric methods with the object of developing a convenient, yet accurate, means for the measurement of specific heats of liquids. The method of mixtures was chosen as being the most generally convenient and readily applicable of calorimetric methods.[...] The greater portion of the time spent on this research was given to the development of the calorimeter. A large number of tests were made on the apparatus in its progressive stages of development and assembly in order to determine the characteristics of the calorimeter and the optimum conditions for its operation. In its present form, as described in this thesis, it is capable of a very high degree of accuracy. By the unique use of a vacuum in the design, most of the common sources of error in calorimetric investigations have been eliminated. Great interest has been shown in the isotopes of hydrogen, and their compounds, since their discovery in 1932. Hence, as an application of the calorimetric method developed in this thesis, the specific heats of deuterium oxide have been measured over the range 25°C to 90°C. The results are compared with the specific heats of water in the same temperature range and their theoretical significance is discussed. [...