natural science vs pomology

natural science

noun
  • Any science involved in studying phenomena or laws of the physical world: physics, chemistry, biology, astronomy, and so on. 

pomology

noun
  • A work or treatise written on this subject. 

  • The study of pome fruit and of the cultivation of such fruit. 

  • The study of fruit in general and of the cultivation of fruit. 

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