patent medicine vs placebo

patent medicine

noun
  • A medicine that is protected by a patent. 

  • Any medicine with a proprietary formula which can be bought without a prescription, irrespective of whether it is protected by a patent. 

placebo

noun
  • A dummy medicine containing no active ingredients; an inert treatment. 

  • The vespers sung in the office for the dead. 

How often have the words patent medicine and placebo occurred in a corpus of books? (source: Google Ngram Viewer )