curtain off vs detach

curtain off

verb
  • To separate, isolate or block by means of a curtain or other barrier. 

  • To isolate. 

detach

verb
  • To separate for a special object or use. 

  • To take apart from; to take off. 

  • To come off something. 

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