This column is about judgment, with my not apparently having any; and oh, yes, about the scientific literature being flawed.

“HOY POLLOI”
Arcane, not at all in common use, Kenneth Hoy’s system for matching polymers to solvents is a very useful system. His system was supposedly based on group contribution methodology (see the July/August 2009 C4 column), which doesn’t require any values of physical properties — just a molecular structure. Yet it was referenced in scientific literature as being derived from something called the “Haggenmacher Equation.” The derived equation is noted here; it requires values of physical properties for solution.

CURIOSITY KILLED THE COLUMNIST
I wanted to know more, so I invested some time. I wanted to cover Hoy’s solubility parameter system for my forthcoming book on cleaning with solvents and a subsequent book on cleaning with detergents. But I couldn’t make Hoy’s system work, so I couldn’t use it or write about it.

From Hoy’s original publication it wasn’t clear if this Haggenmacher Equation was used or not. After work with some chemicals for which I knew there were not physical properties available, I concluded that Hoy had only derived and noted this equation but not used it. Apparently no other author had recognized this.

Curiosity drove me. I wanted to make this equation work, learn what it could teach me. But the numerical answers I produced were worthless — just wrong.