insubstantial vs vapory

insubstantial

adj
  • Lacking substance; not real or strong. 

vapory

adj
  • Resembling vapor; vaporous. 

  • Characterized by the presence of vapor; full of, or obscured by, vapor. 

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