adscititious vs insubstantial

adscititious

adj
  • Derived or acquired from something extrinsic; not part of the real, inherent, or essential nature of a thing. 

insubstantial

adj
  • Lacking substance; not real or strong. 

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