conserve vs insulate

conserve

verb
  • To save for later use, sometimes by the use of a preservative. 

  • To protect an environment, heritage, etc. 

  • To remain unchanged during a process 

noun
  • Wilderness where human development is prohibited. 

  • A jam or thick syrup made from fruit. 

insulate

verb
  • To separate, detach, or isolate. 

  • To separate a body or material from others, e.g. by non-conductors to prevent the transfer of electricity, heat, etc. 

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