CHAPTER 5 THERMODYNAMIC POTENTIALS
5.3 ENTHALPY, HELMHOLTZENERGY,ANDGIBBSENERGY 138
BIOGRAPHICAL SKETCH
Josiah Willard Gibbs (1839–1903)Willard Gibbs’s brilliant and rigorous formu-
lation of the theoretical basis of classical ther-
modynamics was essential for further develop-
ment of the subject.
Gibbs was born in New Haven, Connecti-
cut, and lived there all his life. His father was
a professor in the Yale Divinity School. Gibbs
was Professor of Mathematical Physics at Yale
College from 1871 until his death.
Gibbs never married. In demeanor he was
serene, kindly, reserved, and self-effacing. A
biographer wrote:a
Gibbs’ attitude toward his discoveries is also il-
luminating as to his character.... he made no ef-
fort to “sell” his discoveries (aside from the usual
distribution of reprints of his papers) or to pop-
ularize the results. He was so confident of their
rightness and ability to stand on their own feet
that he was entirely content to let their value and
importance be “discovered” by others. The fact
thathehad made a discovery was to him an ir-
relevant matter; the important thing was the truth
established.
In 1873, when he was 34, the first two of
Gibbs’s remarkable papers on theoretical ther-
modynamics appeared in an obscure journal,
Transactions of the Connecticut Academy.b,c
These papers explored relations among state
functions using two- and three-dimensional
geometrical constructions.
James Clerk Maxwell promoted Gibbs’s
ideas in England, and made a small plaster
model of the three-dimensionalS–V–Usur-face for H 2 O which he sent to Gibbs.
The two papers of 1873 were followed by a
monumental paper in the same journal—in two
parts (1876 and 1878) and over 300 pages in
length!—entitled simply “On the Equilibrium
of Heterogeneous Substances.”dThis third pa-
per used an analytical rather than geometri-
cal approach. From the first and second laws
of thermodynamics, it derived the conditions
needed for equilibrium in the general case of
a multiphase, multicomponent system. It in-
troduced the state functions now known as en-
thalpy, Helmholtz energy,eGibbs energy, and
chemical potential. Included in the paper was
the exposition of the Gibbs phase rule.
The only public comment Gibbs ever made
on his thermodynamic papers was in a letter of
1881 accepting membership in the American
Academy of Arts and Sciences:f
The leading idea which I followed in my paper
on the Equilibrium of Heterogeneous Substances
was to develop therolesˆ of energy and entropy in
the theory of thermo-dynamic equilibrium. By
means of these quantities the general condition
of equilibrium is easily expressed, and by apply-
ing this to various cases we are led at once to
the special conditions which characterize them.
We thus obtain the consequences resulting from
the fundamental principles of thermo-dynamics
(which are implied in the definitions of energy
and entropy) by a process which seems more
simple, and which lends itself more readily to the
solution of problems, than the usual method, in
which the several parts of a cyclic operation are
explicitly and separately considered. Although
my results were in a large measure such as had
previously been demonstrated by other methods,
yet, as I readily obtained those which were to me
before unknown, I was confirmed in my belief in
the suitableness of the method adopted.
Gibbs had a visit about 1898 from a young
Gilbert Lewis. He told Lewis that he was
rather lonely at Yale, where few others were
actively interested in his work.gaRef. [ 171 ], page 83. bRef. [ 62 ]. cRef. [ 63 ]. dRef. [ 64 ]. eHermann von Helmholtz, a German
physiologist and physicist, introduced the term “free energy” for this quantity in 1882. fRef. [ 171 ], page- gRef. [ 131 ].