I bought an unction of a mountebank,
So mortal that, but dip a knife in it,
Where it draws blood so cataplasm so rare,
Collected from all simples that have virtue
Under the moon, can save the thing from death
That is but scratched withal. I'll touch my point
With this contagion, that, if I gall him slightly,
It may be death.
— William Shakespeare
Quackery