Junk Science

Chimney Sweep Van Dyke From Mary PoppinsWhile I was doing some research last night, I came across this nugget from Wikipedia:

The first cause of cancer was identified by British surgeon Percivall Pott, who discovered in 1775 that cancer of the scrotum was a common disease among chimney sweeps.

This sparks so many questions that I don’t have the time right now to discover the answer to, foremost of which is “why”?

Is there some naughty secret to chimney sweeping that I’m not privy to?