caoutchouc vs pastille

caoutchouc

noun
  • latex; natural rubber 

pastille

noun
  • Any small, usually round and somewhat flat, granular piece of material; a tablet. 

  • An often round and somewhat flat flavoured candy or sweet. 

  • A medicinal pill, originally made of compressed herbs. 

  • A candy- or sweet-like lozenge, which, when sucked, releases substances that soothe a sore throat, and sometimes vapours to help unblock the nose or sinuses. 

  • A small pellet containing aromatic substances, burned to diffuse a fragrance or to disinfect or fumigate. 

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