Abstract
The progress in the development of the theory of liquids from early lattice or cell theories, which were fashionable until the 1960s, the formulation of perturbation theories that employ a hard sphere reference fluid, and a simple method of estimating the second-order term is reviewed. With the present availability of several useful simulation methods and theories, it may be difficult for modern scientists to realize that this work with John Barker during my stay in Melbourne in 1966–1967 was the first successful theory of the liquid state. Ironically, perturbation theory is similar to the van der Waals theory, which until recently was regarded, incorrectly, as only of pedagogical interest.
Acknowledgements
It is a pleasure to acknowledge that my visit to Australia was made possible by Sloan Foundation, Ian Potter Foundation, and CSIRO fellowships.