  Employing heuristic susceptibility equations in conjunction with the
well-known critical exponents, the magnetization and partition function for
two-dimensional nearest neighbour Ising models are formulated in terms of the
Gauss hypergeometric functions. The isomorphism existing between the
Bragg-Williams approximation and the exact solution of Onsager is pointed out.
The precise manner in which the critical exponents influence the partition
functions is pointed out.
