leavings vs tailings

leavings

noun
  • A worthless and incidental residuum, such as scraps from a meal, or shavings or sawdust from wood. 

tailings

noun
  • The waste that remains after the minerals have been extracted from an ore by ore dressing. 

  • The feints, the last fraction of product obtained at the end of distillation. 

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