carbonated water vs caustic soda

carbonated water

noun
  • Water containing carbon dioxide dissolved in it under pressure. 

caustic soda

noun
  • sodium hydroxide (NaOH), a strong alkaline substance used in the manufacture of paint, soap and detergents, or as a drain cleaner. 

How often have the words carbonated water and caustic soda occurred in a corpus of books? (source: Google Ngram Viewer )