synthesize vs unify

synthesize

verb
  • To be combined producing a new, more complex product. 

  • To produce a substance by chemical synthesis. 

  • To combine two or more things to produce a new product. 

  • To be produced by chemical synthesis. 

unify

verb
  • Cause to become one; make into a unit; consolidate; merge; combine. 

  • Become one. 

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