denature vs preserve

denature

verb
  • To take away a natural characteristic or inherent property of (a thing or a person). 

  • To combine fissile material with nonfissile material in order to prevent its use in an atomic weapon. 

  • To alter its original form or state, especially of a protein, by heat, acidity etc. 

  • To add something to (alcohol) that makes it unsuitable for consumption but leaves it suitable for most other purposes. 

preserve

verb
  • To save from decay by the use of some preservative substance, such as sugar or salt; to season and prepare (fruits, meat, etc.) for storage. 

  • To maintain throughout; to keep intact. 

  • To protect; to keep from harm or injury. 

noun
  • An activity with restricted access. 

  • A sweet spread made of any of a variety of fruits. 

  • A reservation, a nature preserve. 

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