Published online by Cambridge University Press: 24 October 2008
A simple model of independent curled-up molecules is examined theoretically. The critical temperature is found to be of the right order of magnitude but does not increase sufficiently rapidly with the size of the molecule. The Onnes constant and the critical density show the discrepancies expected from the theoretical equation of state, and the former also has an incorrect dependence on molecular weight. In the critical region, therefore, the paraffins cannot be regarded as an assembly of independent molecules, curled up in the way expected at high temperatures and low densities.