The Waring button yields a plot of the Waring function vs Temperature
The Waring Function is defined as RT2[d ln(p)/dT], where R is the gas constant, and T and p are temperature and pressure.
For nearly all organic materials, the Waring Function displays a minimum for 0.8 < T/Tc <0.9, where Tc is the critical temperature.
See: Waring, W. in Ind. Eng. Chem., 1954, 46, 762 and Steele, W. V. in J. Chem. Thermodyn., 1995, 27, 135.