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