imprecation vs rogation

imprecation

noun
  • The act of imprecating, or invoking evil upon someone; a prayer that a curse or calamity may befall someone. 

  • A curse. 

rogation

noun
  • A deeply serious and somber prayer or entreaty. 

  • The demand, by the consuls or tribunes, of a law to be passed by the people; a proposed law or decree. 

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