detergent vs preservative

detergent

noun
  • Any non-soap cleaning agent, especially a synthetic surfactant. 

adj
  • Synonym of cleansing. 

preservative

noun
  • Any agent, natural or artificial that acts to preserve, especially when added to food. 

adj
  • Tending to preserve. 

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