keepsake vs reminiscing

keepsake

noun
  • Some object given by a person and retained in memory of something or someone; something kept for sentimental or nostalgic reasons. 

  • Specifically, a type of literary album popular in the nineteenth-century, containing scraps of poetry and prose, and engravings. 

reminiscing

noun
  • reminiscence 

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