swart vs tar baby

swart

noun
  • Black or dark dyestuff. 

verb
  • To make swart or tawny; blacken; tan. 

adj
  • Of a dark hue; moderately black; swarthy; tawny. 

  • Black. 

tar baby

noun
  • A black person. 

  • A difficult, abstract problem that worsens as one attempts to handle it; a "sticky" situation, especially one where attempts to make it better only make it worse. 

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