igneous vs vehement

igneous

adj
  • Pertaining to or having the nature of fire; containing fire; resembling fire. 

  • Resulting from, or produced by, great heat. With rocks, it could also mean formed from lava or magma. 

vehement

adj
  • Showing strong feelings; passionate; forceful or intense. 

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