humectant vs vaseline

humectant

noun
  • Any substance that promotes the retention of water, especially one used to keep a food product moist. 

vaseline

noun
  • Any particular kind of petroleum jelly or of any similar lubricant. 

  • Petroleum jelly. 

verb
  • To lubricate with vaseline. 

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