Euler's formula and phase rule

Abstract

The striking similarity of Euler's equation for simple polyhedra and Gibbs' phase rule has been discussed by several authors. Arguments have been advanced both for and against this analogy. We propose that the correspondence of the relations must be viewed as being due to the similarity of phase equilibrium systems to a special class of planar graphs and not to simple polyhedra. The proposed correspondence is demonstrated by parallel derivations of the two relations for the respective cases.