demurrer vs protestation

demurrer

noun
  • A motion by a party to an action, for the immediate or summary judgment of the court on the question, whether, assuming the truth of the matter alleged by the opposite party, it is sufficient in law to sustain the action or defense, and hence whether the party resting is bound to answer or proceed further. 

  • Someone who demurs. 

protestation

noun
  • A declaration in common-law pleading, by which the party interposes an oblique allegation or denial of some fact, protesting that it does or does not exist, and at the same time avoiding a direct affirmation or denial. 

  • a formal solemn objection or other declaration 

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