black tar vs mojo

black tar

noun
  • An illicit drug formed from the incomplete acetylation of morphine, containing a variable percentage of heroin. 

mojo

noun
  • Illegal drugs. 

  • A telecopier; a fax machine. 

  • Any of various sauces originating in the Canary Islands and made with olive oil, peppers, garlic, paprika, and other spices. 

  • A magic charm or spell. 

  • Sex appeal; sex drive. 

  • Personal magnetism; charm. 

  • Supernatural skill or luck. 

How often have the words black tar and mojo occurred in a corpus of books? (source: Google Ngram Viewer )