This dissertation concerns a branch of physical chemistry that began in the era when chemistry was first emerging as a recognized branch of natural philosophy. Antoine Lavoisier, "the father of chemistry," conducted some of the first calorimetric experiments over 170 years ago when he determined the heats of combustion of hydrogen, phosphorus, candle wax, and olive oil and the heat of reaction of potassium nitrate with charcoal. Although experiments concerning heats of combustion and reaction are more properly termed thermochemistry, the related field of chemical thermodynamics evolved simultaneously as the laws of thermodynamics were discovered and consolidated. Despite their age, these fields continue to interest investigators--a fact made evident by the numerous current research publications dealing with problems in thermochemistry and chemical thermodynamics.