celluloid vs seventh art

celluloid

noun
  • The genre of cinema; film. 

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

seventh art

noun
  • Chiefly preceded by the: the art of making motion pictures; filmmaking. 

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