In thermodynamics, Hermann von Helmholtz (1821-1894) was a German physician, physicist, and thermodynamicist who, along with German physician and physicist Robert Mayer (1841) and English physicist James Joule (1843), is one of the founders of the first law of thermodynamics. [1] The version of the first law promoted by Helmholtz, in particular, was called the conservation of force. Along with the work of American mathematical physicist Willard Gibbs (1876), Helmholtz is also considered one of the founders of chemical thermodynamics, for his 1882 paper "The Thermodynamics of Chemical Processes". Helmholtz was one of the main proponents of the concept of the "heat death" of the universe.

In 1882, Helmholtz showed, through derivation, how the long-sought chemical "affinity" (the force of reaction) of chemistry was measured by the "free energy" of the system, i.e. that which could be converted into other forms of usable energy (such as mechanical work or electricity) not by the heat of the reaction. [2]

Helmholtz school

See main: Helmholtz school

Through his association with German physician and physiologist Ernst Brücke, Helmholtz was of great influence in the development of "psychodynamics", the thermodynamical aspects of mental life, via Sigmund Freud.

Human thermodynamics
In 1892, Helmholtz discussed his views on the thermodynamics of Goethe's Faust, in which he set forth preliminary views on cessation thermodynamics.

References
1. (a) Helmholtz, H. v. (1947). "The Conservation of Force: A Physical Memoir." In Selected Writings of Hermann von Helmholtz (1971), ed. R. Kahl, pgs. 3-55. Middletown, CT: Wesleyan University Press.
(b) 30+ Variations of the First Law of Thermodynamics - Institute of Human Thermodynamics
2. (a) Quote: "Given the unlimited validity of Clausius' law, it would then be the value of the free energy, not that of the total energy resulting from heat production, which determineds in which sense the chemical affinity can be active." (Source: Helmholtz, H. v. "Die Thermodynamic chemischer Vorgange," SB, pg. 23, pg. 22-29, in Wissenschaftlich Abhandlundgen von Hermann von Helmholtz. 3 vols. Leipzig: J.A. Barth, 1882-95.)
(b) Cahan, David (1993). Hermann von Helmholtz and the Foundations of Nineteenth-Century Science (Ch. 10: "Between Physics and Chemistry - Helmholtz's Route to a Theory of Chemical Thermodynamics" by Helge Kragh). University of California Press.
(c) Leicester, Henry M. (1956). The Historical Background of Chemistry, (pg. 206). New York: Dover (reprint).

Further reading
● McKendrick, John G. (1899). Hermann Ludwig Ferdinand von Helmholtz. London: T. Fisher Unwin.
● Koenigsberger, Leo. (1906). Hermann von Helmholtz. Clarendon Press.

External links
● Hermann von Helmholtz – Wikipedia.