text: Grant McDonald Wilson (May 24, 1931 – September 10, 2012) was a notable American thermodynamicist.  He is widely known to the fields of chemical engineering and physical chemistry for having developed the Wilson equation, one of the first attempts of practical importance to model nonideal behavior in liquid mixtures as observed in practice with common polar compounds such as alcohols, amines, etc.  The equation has been in use in all commercial chemical process simulators to predict phase behavior and produce safe process designs of commercial and environmental protection importance to the chemical industry.  He founded the company Wilco (now Wiltec) in 1977 to research, measure, commercialize, and publish thermophysical property data for numerous chemical mixtures of interest to the industry.  The Journal of Chemical & Engineering Data published a posthumous issue in honor of Wilson in April 2014 in recognition of his extensive contributions to the field.