aqua vs hydrogen oxide

aqua

noun
  • The compound water. 

  • A shade of colour, usually a mix of blue and green similar to the colour turquoise. 

adj
  • Of a greenish-blue colour. 

hydrogen oxide

noun
  • The simple systematic name for water, H₂O. 

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