In Pulp Fiction, Jules — the character played by Samuel L. Jackson — explains to Vincent (John Travolta) why he doesn’t eat bacon: “Pigs are filthy animals.” It turns out that pigs are not really all that dirty, at least not physically. (They still eat anything, including feces.)  The reason why pigs find themselves at home, wallowing and slathered in mud, is not simply a preference of slovenly gluttony. Rather, pigs dive into mud baths in order to cool down.  It turns out that pigs’ sweat glands are ineffective at cooling their body temperatures, and therefore, the animals seek out the dirty water.  (Some researchers, however, think that it’s the other way around.) While this makes biological sense, it causes a linguistic problem.  If pigs don’t actually sweat, the idiomatic phrase “sweating like a pig” no longer makes any sense — until you find out that the phrase has nothing to do with pigs at all, but rather, the iron smelting process. Smelting is the process of producing a metal from its ore — in this case, iron ore. As part of the process to produce steel, iron ore is smelted into something called “pig iron.”  Pig iron is a brittle version … Continue reading Sweating Like a Pig