|A wall statue of American engineer Willard Gibbs (at Yale University), captioned as "discoverer and interpreter of the laws of chemical equilibrium", the central founder in the history of chemical thermodynamics.|
"The story of how chemical thermodynamics developed is a somewhat tangled one, since several investigators worked along different lines and quite independently of one another."
1. The establishment of the basic laws of thermodynamics (1842-1865).Jensen goes into more detail into each of these periods, in terms of the people and subjects involved. 
2. The application of these laws to the theory of chemical affinity and equilibrium (1873-1905).
3. The quantification of chemical thermodynamics via a fusion of theory with experimental data (1905-1923).
|While German physicist Rudolf Clausius (1865) laid out the foundation of thermodynamics, it was German physical chemist August Horstmann (1869) who was the first to apply the newly formed "entropy" concept to chemical problems.|
“[While it was] Clausius [who first] called attention to the general applicability of the theory of heat to chemical reactions … we have Horstmann to thank for the fundamental advance from this incidental observation to a fruitful thermodynamic treatment of chemical problems.”(add)
Massieu | Characteristic functions
“Massieu has shown how all the properties of a fluid ‘which are considered in thermodynamics’ may be deduced from a single function, which he calls a characteristic function of the fluid considered; he introduces two different functions of this kind, vis, a function of the temperature and volume, which he denotes by Ψ, and a function of the temperature and pressure, which he denotes by Ψ’; in both cases he considers a constant quantity (one kilogram) of the fluid, which is regarded as invariable in composition.”
|American engineer and mathematical physicist Willard Gibbs (1876) and German physicist Hermann Helmholtz (1882) laid the foundation of chemical thermodynamics.|
|Physical chemists American Gilbert Lewis (1923) and Englishman Edward Guggenheim (1933) are considered as the founders of "modern chemical thermodynamics" for their textbook truncations of the dense earlier foundational work of American engineer and mathematical physicist Willard Gibbs (1976).|
“Lewis, Randall and Guggenheim must be considered as the founders of modern chemical thermodynamics because of the major contributions of these two books in unifying the applications of thermodynamics to chemistry.”
“The mathematical formalism developed by Gibbs in several papers was utilized by Gilbert Lewis and Merle Randall in the United States and Edward Guggenheim in England for the evaluation of free energy and of a large number of chemical compounds. The book by Lewis and Randall Thermodynamics and the Free Energy of Chemical Substances of 1923 and that by Guggenheim, Modern Thermodynamics by the Methods of Willard Gibbs of 1933 are the fundamental classics of modern chemical-physics. Before the publication of these two textbooks, the most known text of thermodynamics, especially in Germany was the 1912 treatise Lehrbuch der Thermodhemie und Thermodynamik written by Otto Sackur, that, once translated into English in 1917 by the American naturalized Scotsman George Gibson, became the official textbook of thermodynamics in American universities until 1923, when it was replaced by that of Lewis and Randall.”
|German polymath Johann Goethe (1809), with his "affinity" based human chemical theory, and American electrochemical engineer Libb Thims (2007), with his "free energy" based equivalent, albeit modern human molecular formula based human chemical reaction theory, can be considered as the pioneers of the newly forming 21st century science of human chemical thermodynamics, an extension of modern chemical thermodynamics to social and economic phenomena.|
See main: History of human chemical thermodynamicsBuilding on the "modern chemical thermodynamics" Lewis-Guggenheim platform of, in 2007 the term "human chemical thermodynamics" was introduced by American electrochemical engineer Libb Thims as the subject of the chemical thermodynamic study of systems of reactive human molecules, and beginning in 2010 was lecturing on this subject to American engineering thermodynamics students, bioengineering thermodynamics students in 2010 to 2012, at University of Illinois at Chicago, and in 2013, to mechanical engineering thermodynamics students, at Northern Illinois University, specifically entitled "An Introduction to Human Chemical Thermodynamics" (see: 2013 lecture), explaining how German polymath Johann Goethe's 1809 human chemical theory of reactive "chemical affinities", symbol, A mediating human chemical reactions (see: theory), scales up through German physicist Hermann Helmholtz's 1882 thermodynamic theory of affinity proof that free energy is the true measure of "affinity", and through American physical chemist Gilbert Lewis' 1923 formulation of Gibbs free energy as the "driving force" for isothermal-isobaric chemical reactions (typical earth-bound reactions), in regards to prediction of reaction "spontaneity", through German-born American biochemist Fritz Lipmann’s 1941 theory of free energy coupling, as applied socially and economically (e.g. see: Robert Kenoun, 2006), in terms of human free energy theory, in respect to engineering applications (see: applied human thermodynamics) and basic principles.