emendation vs recension

emendation

noun
  • Alteration by editorial criticism, as of a text so as to give a better reading; removal of errors or corruptions from a document. 

  • An intentional change in the spelling of a scientific name, which is usually not allowed. 

  • The act of altering for the better, or correcting what is erroneous or faulty; correction; improvement. 

recension

noun
  • A critical revision of a text. 

  • A family of manuscripts which share similar traits; the variety of a language which is used in such manuscripts. 

  • A census, an enumeration, a review, a survey. 

  • A text established by critical revision. 

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