celluloid vs silver screen

celluloid

noun
  • The genre of cinema; film. 

  • Any of a variety of thermoplastics created from nitrocellulose and camphor, once used as photographic film. 

silver screen

noun
  • By extension, movies, or that which is related to movies or cinema. 

  • A cinema screen onto which movies are projected. 

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