Meat madness: eighteenth century mad-cow disease
While Shelley's association of meat with madness seems radical, it's a logical conclusion considering his period. Mad cow disease wasn't actually understood until the 1960s, but, in the eighteenth century, farmers were battling scrapie in their sheep. They didn't understand the science behind the madness at the time, but some drew the connection between the disease and mental deterioration. This disease was later linked with mad cow disease and its effect on humans when consumed.