dripstone vs intravenous

dripstone

noun
  • A water filter in which impurities are removed by running water through a porous stone. 

  • Stalactites and stalagmites collectively. 

  • A protective moulding over a door or window that allows rain to drip away from the structure. 

intravenous

noun
  • A dose of medicine administered from a drip, down through a hollow needle inserted into a patient's vein. 

adj
  • Inside the veins. 

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