inhalant vs inhalation

inhalant

noun
  • something, especially a medication, that is inhaled 

adj
  • intended for inhaling 

inhalation

noun
  • The substance (medicament) which is inhaled. 

  • The act of inhaling; inbreathing. 

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