bole vs kaolin

bole

noun
  • The shade of reddish brown which resembles this clay. 

  • The trunk or stem of a tree. 

  • Any of several varieties of friable earthy clay, usually coloured red by iron oxide, and composed essentially of hydrous silicates of alumina, or more rarely of magnesia. 

  • An aperture with a shutter in the wall of a house, to admit air or light. 

  • A small closet. 

kaolin

noun
  • A fine clay, rich in kaolinite, used in ceramics, paper-making, etc. 

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