Smallpox cultists, the half a billion neurons in your guts, androgen immunity, and the citric acid panic of 1976.
In 1897 a doctor from Sierra Leone infiltrated a Nigerian smallpox cult in order to expose their horrible secret.
Humans have more than half a billion neurons lining their gastrointestinal tract, nearly the same number as in a dog’s brain.
Some people are genetically immune to androgen.
A pseudoscientific pamphlet spread throughout Europe in the late 1970s and early 1980s; it claimed that citric acid and cellulose were “toxic.”
For more about the quirks, mysteries, and surprises of the human body, begin here:
The Generalist Academy 
