In the history of thermodynamics, "On the Equilibrium of Heterogeneous Substances" is a 300-page paper written by American chemical physicist Willard Gibbs. It is one of the founding papers in

thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed b ...

, along with German physicist

Hermann von Helmholtz Hermann Ludwig Ferdinand von Helmholtz (; ; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The ...

's 1882 paper "'' Thermodynamik chemischer Vorgänge''." Together they form the foundation of

chemical thermodynamics Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. Chemical thermodynamics involves not only laboratory measure ...

as well as a large part of

physical chemistry Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mech ...

. Gibbs's paper marked the beginning of chemical thermodynamics by integrating chemical, physical, electrical, and

electromagnetic In physics, electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interacti ...

phenomena into a coherent system. It introduced concepts such as

chemical potential In thermodynamics, the chemical potential of a Chemical specie, species is the energy that can be absorbed or released due to a change of the particle number of the given species, e.g. in a chemical reaction or phase transition. The chemical potent ...

, phase rule, and more, which form the basis for modern physical chemistry. American writer Bill Bryson describes Gibbs's paper as "the '' Principia'' of thermodynamics". "On the Equilibrium of Heterogeneous Substances", was originally published in a relatively obscure American journal, the '' Transactions of the Connecticut Academy of Arts and Sciences'', in several parts, during the years 1875 to 1878 (although most cite "1876" as the key year). It remained largely unknown until translated into German by Wilhelm Ostwald and into French by Henry Louis Le Châtelier.

Overview

Gibbs first contributed to mathematical physics with two papers published in 1873 in the ''Transactions of the Connecticut Academy of Arts and Sciences'' on "Graphical Methods in the Thermodynamics of Fluids," and "Method of Geometrical Representation of the Thermodynamic Properties of Substances by means of Surfaces." His subsequent and most important publication was "On the Equilibrium of Heterogeneous Substances" (in two parts, 1876 and 1878). In this monumental, densely woven, 300-page treatise, the

first law of thermodynamics The first law of thermodynamics is a formulation of the law of conservation of energy in the context of thermodynamic processes. For a thermodynamic process affecting a thermodynamic system without transfer of matter, the law distinguishes two ...

, the

second law of thermodynamics The second law of thermodynamics is a physical law based on Universal (metaphysics), universal empirical observation concerning heat and Energy transformation, energy interconversions. A simple statement of the law is that heat always flows spont ...

, the fundamental thermodynamic relation, are applied to the predication and quantification of thermodynamic reaction tendencies in any thermodynamic system in a visual, three-dimensional graphical language of

Lagrangian mechanics In physics, Lagrangian mechanics is a formulation of classical mechanics founded on the d'Alembert principle of virtual work. It was introduced by the Italian-French mathematician and astronomer Joseph-Louis Lagrange in his presentation to the ...

and

phase transition In physics, chemistry, and other related fields like biology, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic Sta ...

s, among others. As stated by Le Chatelier, it "founded a new department of chemical science that is becoming comparable in importance to that created by ntoineLavoisier." This work was translated into German by Ostwald (who styled its author the "founder of chemical energetics") in 1891 and into French by Le Châtelier in 1899. Gibbs's Equilibrium paper is considered one of the greatest achievements in physical science in the 19th century and one of the foundations of the science of physical chemistry. In these papers Gibbs applied thermodynamics to the interpretation of physicochemical phenomena and showed the explanation and interrelationship of what had been known only as isolated, inexplicable facts. Gibbs' papers on heterogeneous equilibria included: * Some

concepts * Some free energy concepts * A Gibbsian ensemble ideal (basis of the

statistical mechanics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. Sometimes called statistical physics or statistical thermodynamics, its applicati ...

field) * the phase rule

References

External links

{{Wikisource, Scientific Papers of Josiah Willard Gibbs, Volume 1/Chapter IIIa, On the Equilibrium of Heterogeneous Substances * At the Internet Archive
Part 1
an
Part 2
in various file formats. Thermodynamics literature 1870s in science 1876 in science Works originally published in American magazines 1876 non-fiction books Works originally published in science and technology magazines Physics papers