asleep vs in the arms of Morpheus

asleep

adj
  • In a state of sleep; also, broadly, resting. 

  • Inattentive. 

  • Having a numb or prickling sensation accompanied by a degree of unresponsiveness. 

  • Dead. 

in the arms of Morpheus

prep
  • Asleep, sleeping. 

  • In a state of being completely forgotten, or of unawareness. 

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