All the talk about the big Ohio State-Michigan game this weekend got me thinking about the ball, the "pigskin." According to the Oxford English Dictionary, the use of "pigskin" as slang for "football" goes back to 1894, when the University of Chicago Weekly noted that "Roby put the pigskin over the line." As far as I can tell, current NCAA and NFL footballs do not have any porcine content, although they don't specify where the leather comes from exactly. The Wilson Company makes over 700,000 footballs per year at its Ada, Ohio factory. You can watch an overly dramatic video about football production here. The exterior of a football is usually made of leather (cowhide, I assume), which surrounds an inflatable bladder, now made of rubber. Animal bladders were used until the mass production of vulcanized rubber. The Straight Dope notes that rubber bladders were being used in 1871, just two years after the beginning of college football. Props to the NBA, by the way, for going with an animal-free basketball, although apparently the players dislike it, arguing that it is harder to grip than the traditional leather basketball.