first milk vs liquid gold

first milk

noun
  • colostrum; beestings 

liquid gold

noun
  • Colostrum. 

  • Water. 

  • Beer. 

  • Crude oil. 

  • Urine. 

  • Sandalwood oil 

  • A kind of liquid preparation used to decorate ceramic ware with gold or gold colour. 

  • Any liquid that is yellow in color, such as beer, olive oil or a liquid cheese. 

How often have the words first milk and liquid gold occurred in a corpus of books? (source: Google Ngram Viewer )