dissertation vs treatment

dissertation

noun
  • A lengthy lecture on a subject; a treatise; a discourse; a sermon. 

  • A formal exposition of a subject, especially a research paper that students write in order to complete the requirements for a doctoral degree in the US and a non-doctoral degree in the UK; a thesis. 

treatment

noun
  • A treatise; a formal written description or characterization of a subject. 

  • Medical care for an illness or injury. 

  • A brief, third-person, present-tense summary of a proposed film. 

  • The use of a substance or process to preserve or give particular properties to something. 

  • The process or manner of treating someone or something. 

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