The research reported in the third volume of Analytical Calorimetry covers a wide variety of topics. The variety indicates the sophistication which thermal analysis is reaching and addition ally the ever widening applications that are being developed, Advances in instrumentation include: microcalorimeter design, development and refinement of titration calorimetry, definition of further theory of scanning calorimetry, studies of the temperature of resolution of thermistors, and a refinement of the effluent gas analysis technique and its application to agricultural chemicals as well as organic materials. A wide variety of applications is reported. These cover the fields of polymeric materials, dental materials, inorganic proteins, biochemical materials, gels, mixed crystals, and other specialized areas. Contributions also include applications of important related techniques such as thermomechanical and thermogravimetric analysis. The contributions to this Volume represent papers presented before the Division of Analytical Chemistry at the Third Symposium on Analytical Chemistry held at the 167th National Meeting of the American Chemical Society, March 30 - April 5, 1974.